ReadVNode(): We need to create the VNode object before sending the request

to userland, since typically the file cache for the node is created there
and our FileCacheCreate() method requires and existing VNode object.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@29554 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/add-ons/kernel/file_systems/userlandfs/kernel_add_on/Volume.cpp

@@ -51,13 +51,15 @@ struct Volume::VNode : HashTableLink<VNode> {
 	void*	clientNode;
 	void*	fileCache;
 	int32	useCount;
+	bool	valid;
 
 	VNode(ino_t id, void* clientNode)
 		:
 		id(id),
 		clientNode(clientNode),
 		fileCache(NULL),
-		useCount(0)
+		useCount(0),
+		valid(true)
 	{
 	}
 
@@ -955,27 +957,36 @@ Volume::ReadVNode(ino_t vnid, bool reenter, void** _node, int* type,
 	request->vnid = vnid;
 	request->reenter = reenter;
 
+	// add the uninitialized node to our map
+	VNode* vnode = new(std::nothrow) VNode(vnid, NULL);
+	if (vnode == NULL)
+		RETURN_ERROR(B_NO_MEMORY);
+	vnode->valid = false;
+
+	MutexLocker locker(fLock);
+	fVNodes->Insert(vnode);
+	locker.Unlock();
+
 	// send the request
 	KernelRequestHandler handler(this, READ_VNODE_REPLY);
 	ReadVNodeReply* reply;
 	error = _SendRequest(port, &allocator, &handler, (Request**)&reply);
-	if (error != B_OK)
+	if (error != B_OK) {
+		_RemoveInvalidVNode(vnid);
 		return error;
+	}
 	RequestReleaser requestReleaser(port, reply);
 
 	// process the reply
-	if (reply->error != B_OK)
+	if (reply->error != B_OK) {
+		_RemoveInvalidVNode(vnid);
 		return reply->error;
-
-	// everything went fine so far -- add the node to our map
-	VNode* vnode = new(std::nothrow) VNode(vnid, reply->node);
-	if (vnode == NULL) {
-		WriteVNode(reply->node, reenter);
-		RETURN_ERROR(B_NO_MEMORY);
 	}
 
-	MutexLocker lock(fLock);
-	fVNodes->Insert(vnode);
+	// everything went fine -- mark the node valid
+	locker.Lock();
+	vnode->clientNode = reply->node;
+	vnode->valid = true;
 
 	*_node = vnode;
 	*type = reply->type;
@@ -4227,6 +4238,7 @@ Volume::_IncrementVNodeCount(ino_t vnid)
 //PRINT(("_IncrementVNodeCount(%Ld): count: %ld, fVNodeCountMap size: %ld\n", vnid, *count, fVNodeCountMap->Size()));
 }
 
+
 // _DecrementVNodeCount
 void
 Volume::_DecrementVNodeCount(ino_t vnid)
@@ -4247,6 +4259,31 @@ Volume::_DecrementVNodeCount(ino_t vnid)
 //PRINT(("_DecrementVNodeCount(%Ld): count: %ld, fVNodeCountMap size: %ld\n", vnid, tmpCount, fVNodeCountMap->Size()));
 }
 
+
+// _RemoveInvalidVNode
+void
+Volume::_RemoveInvalidVNode(ino_t vnid)
+{
+	MutexLocker locker(fLock);
+
+	VNode* vnode = fVNodes->Lookup(vnid);
+	if (vnode == NULL) {
+		ERROR(("Volume::_RemoveInvalidVNode(): Node with ID %lld not known!\n",
+			vnid));
+		return;
+	}
+
+	fVNodes->Remove(vnode);
+	locker.Unlock();
+
+	// release all references acquired so far
+	for (; vnode->useCount > 0; vnode->useCount--)
+		put_vnode(fFSVolume, vnid);
+
+	delete vnode;
+}
+
+
 // _InternalIOCtl
 status_t
 Volume::_InternalIOCtl(userlandfs_ioctl* buffer, int32 bufferSize)

src/add-ons/kernel/file_systems/userlandfs/kernel_add_on/Volume.h

@@ -257,6 +257,7 @@ private:
 
 			void				_IncrementVNodeCount(ino_t vnid);
 			void				_DecrementVNodeCount(ino_t vnid);
+			void				_RemoveInvalidVNode(ino_t vnid);
 
 			status_t			_InternalIOCtl(userlandfs_ioctl* buffer,
 									int32 bufferSize);