From c34752b7ccc945a70a2d9b1e505aa4a4de43163b Mon Sep 17 00:00:00 2001
From: John Hodge <tpg@mutabah.net>
Date: Thu, 16 May 2013 13:46:16 +0800
Subject: [PATCH] Kernel - Implimented VFS_Reopen

---
 KernelLand/Kernel/include/vfs_ext.h |  5 +++++
 KernelLand/Kernel/include/vfs_int.h | 12 ++++++++++++
 KernelLand/Kernel/syscalls.c        |  5 +++++
 KernelLand/Kernel/vfs/handle.c      | 14 --------------
 KernelLand/Kernel/vfs/open.c        | 26 ++++++++++++++++++++++++++
 5 files changed, 48 insertions(+), 14 deletions(-)

diff --git a/KernelLand/Kernel/include/vfs_ext.h b/KernelLand/Kernel/include/vfs_ext.h
index a3a85642..d18009d4 100644
--- a/KernelLand/Kernel/include/vfs_ext.h
+++ b/KernelLand/Kernel/include/vfs_ext.h
@@ -222,6 +222,11 @@ extern int	VFS_OpenChild(int FD, const char *Name, Uint Mode);
  */
 extern int	VFS_OpenInode(Uint32 Mount, Uint64 Inode, int Mode);
 
+/**
+ * \brief Open a file reusing an old FD
+ */
+extern int	VFS_Reopen(int FD, const char *Path, int Flags);
+
 /**
  * \brief Close a currently open file
  * \param FD	Handle returned by ::VFS_Open
diff --git a/KernelLand/Kernel/include/vfs_int.h b/KernelLand/Kernel/include/vfs_int.h
index 06ad8dab..c2dacd34 100644
--- a/KernelLand/Kernel/include/vfs_int.h
+++ b/KernelLand/Kernel/include/vfs_int.h
@@ -73,6 +73,18 @@ static inline void _CloseNode(tVFS_Node *Node)
 	if(Node && Node->Type && Node->Type->Close)
 		Node->Type->Close( Node );
 }
+static inline void _ReferenceNode(tVFS_Node *Node)
+{
+	if( !MM_GetPhysAddr(Node->Type) ) {
+		Log_Error("VFS", "Node %p's type is invalid (%p bad pointer) - %P corrupted",
+			Node, Node->Type, MM_GetPhysAddr(&Node->Type));
+		return ;
+	}
+	if( Node->Type && Node->Type->Reference )
+		Node->Type->Reference( Node );
+	else
+		Node->ReferenceCount ++;
+}
 
 
 #endif
diff --git a/KernelLand/Kernel/syscalls.c b/KernelLand/Kernel/syscalls.c
index 340a5ccc..34a35c5f 100644
--- a/KernelLand/Kernel/syscalls.c
+++ b/KernelLand/Kernel/syscalls.c
@@ -208,6 +208,11 @@ void SyscallHandler(tSyscallRegs *Regs)
 		LOG("VFS_Open(\"%s\", 0x%x)", (char*)Regs->Arg1, Regs->Arg2 | VFS_OPENFLAG_USER);
 		ret = VFS_Open((char*)Regs->Arg1, Regs->Arg2 | VFS_OPENFLAG_USER);
 		break;
+	case SYS_REOPEN:
+		CHECK_STR_NONULL( (char*)Regs->Arg2 );
+		LOG("VFS_Reopen(%i, \"%s\", 0x%x)", Regs->Arg1, (char*)Regs->Arg2, Regs->Arg3 | VFS_OPENFLAG_USER);
+		ret = VFS_Reopen(Regs->Arg1, (char*)Regs->Arg2, Regs->Arg3 | VFS_OPENFLAG_USER);
+		break;
 	
 	case SYS_CLOSE:
 		LOG("VFS_Close(%i)", Regs->Arg1);
diff --git a/KernelLand/Kernel/vfs/handle.c b/KernelLand/Kernel/vfs/handle.c
index 35aa00c8..6173c29a 100644
--- a/KernelLand/Kernel/vfs/handle.c
+++ b/KernelLand/Kernel/vfs/handle.c
@@ -16,26 +16,12 @@
 #define MAX_KERNEL_FILES	128
 
 // === PROTOTYPES ===
-inline void	_ReferenceNode(tVFS_Node *Node);
 
 // === GLOBALS ===
 tVFS_Handle	*gaUserHandles = (void*)MM_PPD_HANDLES;
 tVFS_Handle	*gaKernelHandles = (void*)MM_KERNEL_VFS;
 
 // === CODE ===
-inline void _ReferenceNode(tVFS_Node *Node)
-{
-	if( !MM_GetPhysAddr(Node->Type) ) {
-		Log_Error("VFS", "Node %p's type is invalid (%p bad pointer) - %P corrupted",
-			Node, Node->Type, MM_GetPhysAddr(&Node->Type));
-		return ;
-	}
-	if( Node->Type && Node->Type->Reference )
-		Node->Type->Reference( Node );
-	else
-		Node->ReferenceCount ++;
-}
-
 /**
  * \fn tVFS_Handle *VFS_GetHandle(int FD)
  * \brief Gets a pointer to the handle information structure
diff --git a/KernelLand/Kernel/vfs/open.c b/KernelLand/Kernel/vfs/open.c
index 2bfb2612..748d0f7e 100644
--- a/KernelLand/Kernel/vfs/open.c
+++ b/KernelLand/Kernel/vfs/open.c
@@ -722,6 +722,30 @@ int VFS_OpenInode(Uint32 Mount, Uint64 Inode, int Mode)
 	LEAVE_RET('x', VFS_int_CreateHandle(node, mnt, Mode));
 }
 
+int VFS_Reopen(int FD, const char *Path, int Flags)
+{
+	tVFS_Handle	*h = VFS_GetHandle(FD);
+	if(!h) {
+		errno = EBADF;
+		return -1;
+	}
+
+	int newf = VFS_Open(Path, Flags);
+	if( newf == -1 ) {
+		return -1;
+	}
+	
+	_CloseNode(h->Node);
+	_DereferenceMount(h->Mount, "Reopen");
+	memcpy(h, VFS_GetHandle(newf), sizeof(*h));
+	_ReferenceNode(h->Node);
+	_ReferenceMount(h->Mount, "Reopen");
+	
+	VFS_Close(newf);	
+
+	return FD;
+}
+
 /**
  * \fn void VFS_Close(int FD)
  * \brief Closes an open file handle
@@ -774,6 +798,8 @@ int VFS_DuplicateFD(int SrcFD, int DstFD)
 			return -1;
 		VFS_SetHandle(DstFD, src->Node, src->Mode);
 	}
+	_ReferenceMount(src->Mount, "DuplicateFD");
+	_ReferenceNode(src->Node);
 	memcpy(VFS_GetHandle(DstFD), src, sizeof(tVFS_Handle));
 	return DstFD;
 }
-- 
2.20.1