mirror of
https://github.com/SerenityOS/serenity
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e8d9734a9c
This makes it not as easy to forgot to handle OOMs in the kernel. This commit replaces most usages of this function with `try_append(...).release_value_but_fixme_should_propagate_errors()`. But in some cases, using the `TRY` macro or `unchecked_append()` is already possible. In places where allocations should not fail or an OOM would be fatal anyways, `MUST(try_append(...))` should be used explicitly.
101 lines
3.9 KiB
C++
101 lines
3.9 KiB
C++
/*
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* Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
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*
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* SPDX-License-Identifier: BSD-2-Clause
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*/
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#include <Kernel/FileSystem/Inode.h>
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#include <Kernel/Locking/Spinlock.h>
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#include <Kernel/Memory/SharedInodeVMObject.h>
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namespace Kernel::Memory {
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ErrorOr<NonnullLockRefPtr<SharedInodeVMObject>> SharedInodeVMObject::try_create_with_inode(Inode& inode)
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{
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if (inode.size() == 0)
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return EINVAL;
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return try_create_with_inode_and_range(inode, 0, inode.size());
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}
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ErrorOr<NonnullLockRefPtr<SharedInodeVMObject>> SharedInodeVMObject::try_create_with_inode_and_range(Inode& inode, u64 offset, size_t range_size)
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{
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// Note: To ensure further allocation of a Region with this VMObject will not complain
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// on "smaller" VMObject than the requested Region, we simply take the max size between both values.
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auto size = max(inode.size(), (offset + range_size));
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VERIFY(size > 0);
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if (auto shared_vmobject = inode.shared_vmobject())
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return shared_vmobject.release_nonnull();
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auto new_physical_pages = TRY(VMObject::try_create_physical_pages(size));
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auto dirty_pages = TRY(Bitmap::create(new_physical_pages.size(), false));
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auto vmobject = TRY(adopt_nonnull_lock_ref_or_enomem(new (nothrow) SharedInodeVMObject(inode, move(new_physical_pages), move(dirty_pages))));
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TRY(vmobject->inode().set_shared_vmobject(*vmobject));
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return vmobject;
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}
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ErrorOr<NonnullLockRefPtr<VMObject>> SharedInodeVMObject::try_clone()
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{
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auto new_physical_pages = TRY(this->try_clone_physical_pages());
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auto dirty_pages = TRY(Bitmap::create(new_physical_pages.size(), false));
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return adopt_nonnull_lock_ref_or_enomem<VMObject>(new (nothrow) SharedInodeVMObject(*this, move(new_physical_pages), move(dirty_pages)));
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}
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SharedInodeVMObject::SharedInodeVMObject(Inode& inode, FixedArray<RefPtr<PhysicalRAMPage>>&& new_physical_pages, Bitmap dirty_pages)
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: InodeVMObject(inode, move(new_physical_pages), move(dirty_pages))
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{
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}
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SharedInodeVMObject::SharedInodeVMObject(SharedInodeVMObject const& other, FixedArray<RefPtr<PhysicalRAMPage>>&& new_physical_pages, Bitmap dirty_pages)
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: InodeVMObject(other, move(new_physical_pages), move(dirty_pages))
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{
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}
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ErrorOr<void> SharedInodeVMObject::sync(off_t offset_in_pages, size_t pages)
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{
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return TRY(sync_impl(offset_in_pages, pages, true));
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}
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ErrorOr<void> SharedInodeVMObject::sync_before_destroying()
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{
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return TRY(sync_impl(0, page_count(), false));
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}
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ErrorOr<void> SharedInodeVMObject::sync_impl(off_t offset_in_pages, size_t pages, bool should_remap)
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{
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SpinlockLocker locker(m_lock);
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size_t highest_page_to_flush = min(page_count(), offset_in_pages + pages);
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AK::Vector<size_t> pages_to_flush = {};
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TRY(pages_to_flush.try_ensure_capacity(highest_page_to_flush - offset_in_pages));
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for (size_t page_index = offset_in_pages; page_index < highest_page_to_flush; ++page_index) {
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auto& physical_page = m_physical_pages[page_index];
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if (physical_page && is_page_dirty(page_index))
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TRY(pages_to_flush.try_append(page_index));
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}
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if (pages_to_flush.size() == 0)
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return {};
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// Mark pages as clean and remap regions before writing the pages to disk.
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// This makes the pages read-only while we are flushing them to disk. Any writes will page-fault and block until we release the lock.
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if (should_remap) {
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for (auto it = pages_to_flush.begin(); it != pages_to_flush.end(); ++it)
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set_page_dirty(*it, false);
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remap_regions_locked();
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}
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for (auto it = pages_to_flush.begin(); it != pages_to_flush.end(); ++it) {
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size_t page_index = *it;
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auto& physical_page = m_physical_pages[page_index];
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u8 page_buffer[PAGE_SIZE];
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MM.copy_physical_page(*physical_page, page_buffer);
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TRY(m_inode->write_bytes(page_index * PAGE_SIZE, PAGE_SIZE, UserOrKernelBuffer::for_kernel_buffer(page_buffer), nullptr));
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}
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return {};
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}
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}
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