ladybird/Kernel/Memory/InodeVMObject.cpp
creator1creeper1 d1f265e851 Kernel: Make VMOBject construction OOM-aware
This commit moves the allocation of the resources required for VMObject
from its constructors to the constructors of its child classes.

We're making this change to give the child classes the chance to expose
the fallibility of the allocation.
2022-01-15 22:16:00 +02:00

92 lines
2.1 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <Kernel/FileSystem/Inode.h>
#include <Kernel/Memory/InodeVMObject.h>
namespace Kernel::Memory {
InodeVMObject::InodeVMObject(Inode& inode, size_t size)
: VMObject(VMObject::must_create_physical_pages_but_fixme_should_propagate_errors(size))
, m_inode(inode)
, m_dirty_pages(page_count(), false)
{
}
InodeVMObject::InodeVMObject(InodeVMObject const& other)
: VMObject(other.must_clone_physical_pages_but_fixme_should_propagate_errors())
, m_inode(other.m_inode)
, m_dirty_pages(page_count(), false)
{
for (size_t i = 0; i < page_count(); ++i)
m_dirty_pages.set(i, other.m_dirty_pages.get(i));
}
InodeVMObject::~InodeVMObject()
{
}
size_t InodeVMObject::amount_clean() const
{
size_t count = 0;
VERIFY(page_count() == m_dirty_pages.size());
for (size_t i = 0; i < page_count(); ++i) {
if (!m_dirty_pages.get(i) && m_physical_pages[i])
++count;
}
return count * PAGE_SIZE;
}
size_t InodeVMObject::amount_dirty() const
{
size_t count = 0;
for (size_t i = 0; i < m_dirty_pages.size(); ++i) {
if (m_dirty_pages.get(i))
++count;
}
return count * PAGE_SIZE;
}
int InodeVMObject::release_all_clean_pages()
{
SpinlockLocker locker(m_lock);
int count = 0;
for (size_t i = 0; i < page_count(); ++i) {
if (!m_dirty_pages.get(i) && m_physical_pages[i]) {
m_physical_pages[i] = nullptr;
++count;
}
}
if (count) {
for_each_region([](auto& region) {
region.remap();
});
}
return count;
}
u32 InodeVMObject::writable_mappings() const
{
u32 count = 0;
const_cast<InodeVMObject&>(*this).for_each_region([&](auto& region) {
if (region.is_writable())
++count;
});
return count;
}
u32 InodeVMObject::executable_mappings() const
{
u32 count = 0;
const_cast<InodeVMObject&>(*this).for_each_region([&](auto& region) {
if (region.is_executable())
++count;
});
return count;
}
}