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		728c3fbd14
		
	
	
	
	
		
			
			By protecting all the RefPtr<Custody> objects that may be accessed from multiple threads at the same time (with spinlocks), we remove the need for using LockRefPtr<Custody> (which is basically a RefPtr with a built-in spinlock.)
		
			
				
	
	
		
			89 lines
		
	
	
	
		
			2.7 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			89 lines
		
	
	
	
		
			2.7 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
| /*
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|  * Copyright (c) 2018-2022, 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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| 
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| #include <AK/RefPtr.h>
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| #include <AK/Singleton.h>
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| #include <AK/StringBuilder.h>
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| #include <AK/StringView.h>
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| #include <AK/Vector.h>
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| #include <Kernel/FileSystem/Custody.h>
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| #include <Kernel/FileSystem/Inode.h>
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| 
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| namespace Kernel {
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| 
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| static Singleton<SpinlockProtected<Custody::AllCustodiesList>> s_all_instances;
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| 
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| SpinlockProtected<Custody::AllCustodiesList>& Custody::all_instances()
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| {
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|     return s_all_instances;
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| }
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| 
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| ErrorOr<NonnullRefPtr<Custody>> Custody::try_create(Custody* parent, StringView name, Inode& inode, int mount_flags)
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| {
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|     return all_instances().with([&](auto& all_custodies) -> ErrorOr<NonnullRefPtr<Custody>> {
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|         for (Custody& custody : all_custodies) {
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|             if (custody.parent() == parent
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|                 && custody.name() == name
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|                 && &custody.inode() == &inode
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|                 && custody.mount_flags() == mount_flags) {
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|                 return NonnullRefPtr { custody };
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|             }
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|         }
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| 
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|         auto name_kstring = TRY(KString::try_create(name));
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|         auto custody = TRY(adopt_nonnull_ref_or_enomem(new (nothrow) Custody(parent, move(name_kstring), inode, mount_flags)));
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|         all_custodies.prepend(*custody);
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|         return custody;
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|     });
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| }
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| 
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| Custody::Custody(Custody* parent, NonnullOwnPtr<KString> name, Inode& inode, int mount_flags)
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|     : m_parent(parent)
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|     , m_name(move(name))
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|     , m_inode(inode)
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|     , m_mount_flags(mount_flags)
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| {
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| }
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| 
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| Custody::~Custody() = default;
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| 
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| ErrorOr<NonnullOwnPtr<KString>> Custody::try_serialize_absolute_path() const
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| {
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|     if (!parent())
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|         return KString::try_create("/"sv);
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| 
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|     Vector<Custody const*, 32> custody_chain;
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|     size_t path_length = 0;
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|     for (auto const* custody = this; custody; custody = custody->parent()) {
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|         TRY(custody_chain.try_append(custody));
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|         path_length += custody->m_name->length() + 1;
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|     }
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|     VERIFY(path_length > 0);
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| 
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|     char* buffer;
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|     auto string = TRY(KString::try_create_uninitialized(path_length - 1, buffer));
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|     size_t string_index = 0;
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|     for (size_t custody_index = custody_chain.size() - 1; custody_index > 0; --custody_index) {
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|         buffer[string_index] = '/';
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|         ++string_index;
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|         auto const& custody_name = *custody_chain[custody_index - 1]->m_name;
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|         __builtin_memcpy(buffer + string_index, custody_name.characters(), custody_name.length());
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|         string_index += custody_name.length();
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|     }
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|     VERIFY(string->length() == string_index);
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|     buffer[string_index] = 0;
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|     return string;
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| }
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| 
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| bool Custody::is_readonly() const
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| {
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|     if (m_mount_flags & MS_RDONLY)
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|         return true;
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| 
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|     return m_inode->fs().is_readonly();
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| }
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| 
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| }
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