From 34db8f5360992b1eb64640a92fb4dde3347a2b52 Mon Sep 17 00:00:00 2001
From: Christian Helmuth <christian.helmuth@genode-labs.com>
Date: Mon, 20 Mar 2023 09:13:19 +0100
Subject: [PATCH] Fix single-client handling in some block providers

---
 repos/os/src/drivers/nvme/main.cc              | 5 ++++-
 repos/os/src/drivers/usb_block/main.cc         | 2 --
 repos/os/src/server/vfs_block/component.cc     | 3 +++
 repos/os/src/test/block_request_stream/main.cc | 5 ++++-
 4 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/repos/os/src/drivers/nvme/main.cc b/repos/os/src/drivers/nvme/main.cc
index 526aaaea7e..6f7416645b 100644
--- a/repos/os/src/drivers/nvme/main.cc
+++ b/repos/os/src/drivers/nvme/main.cc
@@ -2239,7 +2239,10 @@ struct Nvme::Main : Rpc_object<Typed_root<Block::Session>>
 	Capability<Session> session(Root::Session_args const &args,
 	                            Affinity const &) override
 	{
-		log("new block session: ", args.string());
+		if (_block_session.constructed()) {
+			error("device is already in use");
+			throw Service_denied();
+		}
 
 		Session_label  const label  { label_from_args(args.string()) };
 		Session_policy const policy { label, _config_rom.xml() };
diff --git a/repos/os/src/drivers/usb_block/main.cc b/repos/os/src/drivers/usb_block/main.cc
index bf7f4c3423..1b7c5f8020 100644
--- a/repos/os/src/drivers/usb_block/main.cc
+++ b/repos/os/src/drivers/usb_block/main.cc
@@ -1034,8 +1034,6 @@ struct Usb::Main : Rpc_object<Typed_root<Block::Session>>
 	Genode::Session_capability session(Root::Session_args const &args,
 	                                   Affinity const &) override
 	{
-		log("new block session: ", args.string());
-
 		if (block_session.constructed()) {
 			error("device is already in use");
 			throw Service_denied();
diff --git a/repos/os/src/server/vfs_block/component.cc b/repos/os/src/server/vfs_block/component.cc
index 47e598c75a..0bf5508bed 100644
--- a/repos/os/src/server/vfs_block/component.cc
+++ b/repos/os/src/server/vfs_block/component.cc
@@ -383,6 +383,9 @@ struct Main : Rpc_object<Typed_root<Block::Session>>,
 
 	void close(Capability<Session> cap) override
 	{
+		if (!_block_session.constructed())
+			return;
+
 		if (cap == _block_session->cap()) {
 			_block_session.destruct();
 			_block_file.destruct();
diff --git a/repos/os/src/test/block_request_stream/main.cc b/repos/os/src/test/block_request_stream/main.cc
index fac20dc594..8233ae500b 100644
--- a/repos/os/src/test/block_request_stream/main.cc
+++ b/repos/os/src/test/block_request_stream/main.cc
@@ -212,7 +212,10 @@ struct Test::Main : Rpc_object<Typed_root<Block::Session> >
 	Capability<Session> session(Root::Session_args const &args,
 	                            Affinity const &) override
 	{
-		log("new block session: ", args.string());
+		if (_block_session.constructed()) {
+			error("already in use");
+			throw Service_denied();
+		}
 
 		size_t const ds_size =
 			Arg_string::find_arg(args.string(), "tx_buf_size").ulong_value(0);