nfs4: Add unlink() and remove_dir() hooks

src/add-ons/kernel/file_systems/nfs4/Inode.cpp

@@ -210,6 +210,47 @@ Inode::LookUp(const char* name, ino_t* id)
 }
 
 
+// May cause problem similar to Rename (described below). When node's is has
+// more than one hard link and we delete the name it stores for filehandle
+// restoration node will inocorectly become unavailable.
+status_t
+Inode::Remove(const char* name)
+{
+	do {
+		RPC::Server* serv = fFilesystem->Server();
+		Request request(serv);
+		RequestBuilder& req = request.Builder();
+
+		req.PutFH(fHandle);
+		req.Remove(name);
+
+		status_t result = request.Send();
+		if (result != B_OK)
+			return result;
+
+		ReplyInterpreter& reply = request.Reply();
+
+		// filehandle has expired
+		if (reply.NFS4Error() == NFS4ERR_FHEXPIRED) {
+			_LookUpFilehandle();
+			continue;
+		}
+
+		// filesystem has been moved
+		if (reply.NFS4Error() == NFS4ERR_MOVED) {
+			fFilesystem->Migrate(fHandle, serv);
+			continue;
+		}
+
+		result = reply.PutFH();
+		if (result != B_OK)
+			return result;
+
+		return reply.Remove();
+	} while (true);
+}
+
+
 // Rename may cause some problems if filehandles are volatile and local Inode
 // object exists for renamed node. It's stored filename will become invalid
 // and, consequnetly, filehandle restoration will fail. Probably, it will

src/add-ons/kernel/file_systems/nfs4/Inode.h

@@ -32,6 +32,7 @@ public:
 
 					status_t	LookUp(const char* name, ino_t* id);
 					status_t	ReadLink(void* buffer, size_t* length);
+					status_t	Remove(const char* name);
 	static			status_t	Rename(Inode* from, Inode* to,
 									const char* fromName, const char* toName);
 					status_t	Access(int mode);

src/add-ons/kernel/file_systems/nfs4/NFS4Defs.h

@@ -34,6 +34,7 @@ enum Opcode {
 	OpRead					= 25,
 	OpReadDir				= 26,
 	OpReadLink				= 27,
+	OpRemove				= 28,
 	OpRename				= 29,
 	OpRenew					= 30,
 	OpSaveFH				= 32,

src/add-ons/kernel/file_systems/nfs4/ReplyInterpreter.cpp

@@ -290,6 +290,21 @@ ReplyInterpreter::ReadLink(void* buffer, uint32* size, uint32 maxSize)
 }
 
 
+status_t
+ReplyInterpreter::Remove()
+{
+	status_t res = _OperationError(OpRemove);
+	if (res != B_OK)
+		return res;
+
+	fReply->Stream().GetBoolean();
+	fReply->Stream().GetUHyper();
+	fReply->Stream().GetUHyper();
+
+	return fReply->Stream().IsEOF() ? B_BAD_VALUE : B_OK;
+}
+
+
 status_t
 ReplyInterpreter::Rename()
 {

src/add-ons/kernel/file_systems/nfs4/ReplyInterpreter.h

@@ -78,6 +78,7 @@ public:
 			status_t	ReadDir(uint64* cookie, uint64* cookieVerf,
 							DirEntry** dirents, uint32* count, bool* eof);
 			status_t	ReadLink(void* buffer, uint32* size, uint32 maxSize);
+			status_t	Remove();
 			status_t	Rename();
 	inline	status_t	Renew();
 	inline	status_t	SaveFH();

src/add-ons/kernel/file_systems/nfs4/RequestBuilder.cpp

@@ -308,6 +308,23 @@ RequestBuilder::ReadLink()
 }
 
 
+status_t
+RequestBuilder::Remove(const char* file)
+{
+	if (fProcedure != ProcCompound)
+		return B_BAD_VALUE;
+	if (fRequest == NULL)
+		return B_NO_MEMORY;
+
+	fRequest->Stream().AddUInt(OpRemove);
+	fRequest->Stream().AddString(file);
+
+	fOpCount++;
+
+	return B_OK;
+}
+
+
 status_t
 RequestBuilder::Rename(const char* from, const char* to)
 {

src/add-ons/kernel/file_systems/nfs4/RequestBuilder.h

@@ -44,6 +44,7 @@ public:
 										uint64 cookieVerf, Attribute* attrs,
 										uint32 attrCount);
 			status_t				ReadLink();
+			status_t				Remove(const char* file);
 			status_t				Rename(const char* from, const char* to);
 			status_t				Renew(uint64 clientId);
 			status_t				SaveFH();

src/add-ons/kernel/file_systems/nfs4/kernel_interface.cpp

@@ -212,6 +212,14 @@ nfs4_read_symlink(fs_volume* volume, fs_vnode* link, char* buffer,
 }
 
 
+static status_t
+nfs4_unlink(fs_volume* volume, fs_vnode* dir, const char* name)
+{
+	Inode* inode = reinterpret_cast<Inode*>(dir->private_node);
+	return inode->Remove(name);
+}
+
+
 static status_t
 nfs4_rename(fs_volume* volume, fs_vnode* fromDir, const char* fromName,
 	fs_vnode* toDir, const char* toName)
@@ -309,6 +317,14 @@ nfs4_read(fs_volume* volume, fs_vnode* vnode, void* _cookie, off_t pos,
 }
 
 
+static status_t
+nfs4_remove_dir(fs_volume* volume, fs_vnode* parent, const char* name)
+{
+	Inode* inode = reinterpret_cast<Inode*>(parent->private_node);
+	return inode->Remove(name);
+}
+
+
 static status_t
 nfs4_open_dir(fs_volume* volume, fs_vnode* vnode, void** _cookie)
 {
@@ -434,7 +450,7 @@ fs_vnode_ops gNFSv4VnodeOps = {
 	NULL,	// create_symlink()
 
 	NULL,	// link()
-	NULL,	// unlink()
+	nfs4_unlink,
 	nfs4_rename,
 
 	nfs4_access,
@@ -452,7 +468,7 @@ fs_vnode_ops gNFSv4VnodeOps = {
 
 	/* directory operations */
 	NULL,	// create_dir()
-	NULL,	// remove_dir()
+	nfs4_remove_dir,
 	nfs4_open_dir,
 	nfs4_close_dir,
 	nfs4_free_dir_cookie,