From 310713d203cc69c8ac84ec91b947e247b6487624 Mon Sep 17 00:00:00 2001
From: Bananymous <bananymousosq@gmail.com>
Date: Fri, 24 Mar 2023 01:17:39 +0200
Subject: [PATCH] Kernel: Lock process functions instead of the ata controller

Process has to use locks at least on some functions so multithreaded
disk io is safe. This seemed to fix corrupted reads from disk
---
 kernel/include/kernel/Process.h               |  3 +++
 kernel/include/kernel/Storage/ATAController.h |  2 --
 kernel/kernel/Process.cpp                     | 15 ++++++++++++++-
 kernel/kernel/Storage/ATAController.cpp       |  7 +------
 4 files changed, 18 insertions(+), 9 deletions(-)

diff --git a/kernel/include/kernel/Process.h b/kernel/include/kernel/Process.h
index 5c580fbe..0a74a380 100644
--- a/kernel/include/kernel/Process.h
+++ b/kernel/include/kernel/Process.h
@@ -4,6 +4,7 @@
 #include <BAN/StringView.h>
 #include <BAN/Vector.h>
 #include <kernel/FS/Inode.h>
+#include <kernel/SpinLock.h>
 #include <kernel/Thread.h>
 
 namespace Kernel
@@ -60,6 +61,8 @@ namespace Kernel
 
 		BAN::Vector<OpenFileDescription> m_open_files;
 
+		mutable SpinLock m_lock;
+
 		pid_t m_pid = 0;
 		BAN::String m_working_directory;
 		BAN::Vector<BAN::RefPtr<Thread>> m_threads;
diff --git a/kernel/include/kernel/Storage/ATAController.h b/kernel/include/kernel/Storage/ATAController.h
index fc6c8e9c..6fc05499 100644
--- a/kernel/include/kernel/Storage/ATAController.h
+++ b/kernel/include/kernel/Storage/ATAController.h
@@ -1,7 +1,6 @@
 #pragma once
 
 #include <BAN/Errors.h>
-#include <kernel/SpinLock.h>
 #include <kernel/Storage/StorageController.h>
 
 namespace Kernel
@@ -68,7 +67,6 @@ namespace Kernel
 		BAN::ErrorOr<void> write(ATADevice*, uint64_t, uint8_t, const uint8_t*);
 
 	private:
-		SpinLock m_lock;
 		ATABus m_buses[2];
 		const PCIDevice& m_pci_device;
 
diff --git a/kernel/kernel/Process.cpp b/kernel/kernel/Process.cpp
index 7e1a7e00..8b3e6fc7 100644
--- a/kernel/kernel/Process.cpp
+++ b/kernel/kernel/Process.cpp
@@ -1,7 +1,8 @@
 #include <BAN/StringView.h>
+#include <kernel/FS/VirtualFileSystem.h>
+#include <kernel/LockGuard.h>
 #include <kernel/Process.h>
 #include <kernel/Scheduler.h>
-#include <kernel/FS/VirtualFileSystem.h>
 
 #include <fcntl.h>
 
@@ -37,6 +38,8 @@ namespace Kernel
 
 	BAN::ErrorOr<int> Process::open(BAN::StringView path, int flags)
 	{
+		LockGuard _(m_lock);
+
 		if (flags != O_RDONLY)
 			return BAN::Error::from_errno(ENOTSUP);
 
@@ -56,6 +59,8 @@ namespace Kernel
 
 	BAN::ErrorOr<void> Process::close(int fd)
 	{
+		LockGuard _(m_lock);
+
 		TRY(validate_fd(fd));
 		auto& open_file_description = this->open_file_description(fd);
 		open_file_description.inode = nullptr;
@@ -64,6 +69,8 @@ namespace Kernel
 
 	BAN::ErrorOr<size_t> Process::read(int fd, void* buffer, size_t count)
 	{
+		LockGuard _(m_lock);
+
 		TRY(validate_fd(fd));
 		auto& open_file_description = this->open_file_description(fd);
 		if (open_file_description.offset >= open_file_description.inode->size())
@@ -74,6 +81,8 @@ namespace Kernel
 
 	BAN::ErrorOr<void> Process::creat(BAN::StringView path, mode_t mode)
 	{
+		LockGuard _(m_lock);
+
 		auto absolute_path = TRY(absolute_path_of(path));
 		while (absolute_path.sv().back() != '/')
 			absolute_path.pop_back();
@@ -86,12 +95,16 @@ namespace Kernel
 
 	Inode& Process::inode_for_fd(int fd)
 	{
+		LockGuard _(m_lock);
+
 		MUST(validate_fd(fd));
 		return *open_file_description(fd).inode;
 	}
 
 	BAN::ErrorOr<void> Process::set_working_directory(BAN::StringView path)
 	{
+		LockGuard _(m_lock);
+
 		BAN::String absolute_path = TRY(absolute_path_of(path));
 
 		auto file = TRY(VirtualFileSystem::get().file_from_absolute_path(absolute_path));
diff --git a/kernel/kernel/Storage/ATAController.cpp b/kernel/kernel/Storage/ATAController.cpp
index 06023e2f..492fafef 100644
--- a/kernel/kernel/Storage/ATAController.cpp
+++ b/kernel/kernel/Storage/ATAController.cpp
@@ -1,5 +1,4 @@
 #include <kernel/IO.h>
-#include <kernel/LockGuard.h>
 #include <kernel/Storage/ATAController.h>
 
 #define ATA_PRIMARY  	0
@@ -191,8 +190,6 @@ namespace Kernel
 		if (lba + sector_count > device->lba_count)
 			return BAN::Error::from_c_string("Attempted to read outside of the device boundaries");
 
-		LockGuard _(m_lock);
-
 		if (lba < (1 << 28))
 		{
 			// LBA28
@@ -223,8 +220,6 @@ namespace Kernel
 		if (lba + sector_count > device->lba_count)
 			return BAN::Error::from_c_string("Attempted to read outside of the device boundaries");
 
-		LockGuard _(m_lock);
-
 		if (lba < (1 << 28))
 		{
 			// LBA28
@@ -247,8 +242,8 @@ namespace Kernel
 			ASSERT(false);
 		}
 
-		device->bus->write(ATA_PORT_COMMAND, ATA_COMMAND_CACHE_FLUSH);
 		TRY(device->bus->wait(false));
+		device->bus->write(ATA_PORT_COMMAND, ATA_COMMAND_CACHE_FLUSH);
 
 		return {};
 	}