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	 30861daa93
			
		
	
	
		30861daa93
		
	
	
	
	
		
			
			Before this change, we had File::mmap() which did all the work of setting up a VMObject, and then creating a Region in the current process's address space. This patch simplifies the interface by removing the region part. Files now only have to return a suitable VMObject from vmobject_for_mmap(), and then sys$mmap() itself will take care of actually mapping it into the address space. This fixes an issue where we'd try to block on I/O (for inode metadata lookup) while holding the address space spinlock. It also reduces time spent holding the address space lock.
		
			
				
	
	
		
			53 lines
		
	
	
	
		
			1.1 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			53 lines
		
	
	
	
		
			1.1 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
| /*
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|  * Copyright (c) 2018-2020, 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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| 
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| #include <AK/StringView.h>
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| #include <AK/Userspace.h>
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| #include <Kernel/FileSystem/File.h>
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| #include <Kernel/FileSystem/OpenFileDescription.h>
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| #include <Kernel/Process.h>
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| 
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| namespace Kernel {
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| 
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| File::File() = default;
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| File::~File() = default;
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| 
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| ErrorOr<NonnullLockRefPtr<OpenFileDescription>> File::open(int options)
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| {
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|     auto description = OpenFileDescription::try_create(*this);
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|     if (!description.is_error()) {
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|         description.value()->set_rw_mode(options);
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|         description.value()->set_file_flags(options);
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|     }
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|     return description;
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| }
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| 
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| ErrorOr<void> File::close()
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| {
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|     return {};
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| }
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| 
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| ErrorOr<void> File::ioctl(OpenFileDescription&, unsigned, Userspace<void*>)
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| {
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|     return ENOTTY;
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| }
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| 
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| ErrorOr<NonnullLockRefPtr<Memory::VMObject>> File::vmobject_for_mmap(Process&, Memory::VirtualRange const&, u64&, bool)
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| {
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|     return ENODEV;
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| }
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| 
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| ErrorOr<void> File::attach(OpenFileDescription&)
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| {
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|     m_attach_count++;
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|     return {};
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| }
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| 
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| void File::detach(OpenFileDescription&)
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| {
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|     m_attach_count--;
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| }
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| }
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