mirror of
https://github.com/SerenityOS/serenity
synced 2026-05-11 01:22:12 +02:00
6a4ceb6bf2
Previously, you'd occasionally see this sort of construct (simplified):
```
return FooDevice::all_instances().with([&](auto& list) {
for (auto& device : list) {
if (/* search condition */)
continue;
return do_something_that_reacquires(device.index());
}
return ENOENT;
});
```
This would only work if the relevant `all_instances()` used a recursive
spinlock, since reacquiring the device would lock that again.
To get around this, a new helper has been added in `Device` through
which devices can be accessed whilst locking the device list, removing
the need to loop through the device type's `all_instances()`.
89 lines
2.7 KiB
C++
89 lines
2.7 KiB
C++
/*
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* Copyright (c) 2024, Liav A. <liavalb@hotmail.co.il>
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*
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* SPDX-License-Identifier: BSD-2-Clause
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*/
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#include <Kernel/API/DeviceFileTypes.h>
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#include <Kernel/API/MajorNumberAllocation.h>
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#include <Kernel/Devices/Device.h>
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#include <Kernel/Devices/Loop/LoopDevice.h>
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#include <Kernel/FileSystem/DevLoopFS/FileSystem.h>
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#include <Kernel/FileSystem/DevLoopFS/Inode.h>
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#include <Kernel/FileSystem/RAMBackedFileType.h>
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#include <Kernel/Time/TimeManagement.h>
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namespace Kernel {
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ErrorOr<NonnullRefPtr<FileSystem>> DevLoopFS::try_create(FileSystemSpecificOptions const&)
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{
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return TRY(adopt_nonnull_ref_or_enomem(new (nothrow) DevLoopFS));
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}
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DevLoopFS::DevLoopFS() = default;
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DevLoopFS::~DevLoopFS() = default;
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u8 DevLoopFS::internal_file_type_to_directory_entry_type(DirectoryEntryView const& entry) const
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{
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return ram_backed_file_type_to_directory_entry_type(entry);
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}
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ErrorOr<void> DevLoopFS::initialize()
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{
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m_root_inode = TRY(adopt_nonnull_ref_or_enomem(new (nothrow) DevLoopFSInode(*this)));
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m_root_inode->m_metadata.inode = { fsid(), 1 };
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m_root_inode->m_metadata.mode = S_IFDIR
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| S_IROTH | S_IRGRP | S_IRUSR
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| S_IXUSR | S_IXGRP | S_IXOTH;
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m_root_inode->m_metadata.uid = 0;
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m_root_inode->m_metadata.gid = 0;
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m_root_inode->m_metadata.size = 0;
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m_root_inode->m_metadata.mtime = TimeManagement::boot_time();
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return {};
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}
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static unsigned inode_index_to_loop_index(InodeIndex inode_index)
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{
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VERIFY(inode_index > 1);
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return inode_index.value() - 2;
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}
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Inode& DevLoopFS::root_inode()
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{
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return *m_root_inode;
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}
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ErrorOr<void> DevLoopFS::rename(Inode&, StringView, Inode&, StringView)
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{
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return EROFS;
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}
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ErrorOr<NonnullRefPtr<Inode>> DevLoopFS::get_inode(InodeIdentifier inode_id) const
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{
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if (inode_id.index() == 1)
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return *m_root_inode;
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unsigned loop_index = inode_index_to_loop_index(inode_id.index());
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LockRefPtr<LoopDevice> device;
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Device::run_by_type_and_major_minor_numbers(DeviceNodeType::Block, to_underlying(MajorAllocation::BlockDeviceFamily::Loop), loop_index, [&](RefPtr<Device> found_device) {
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if (!found_device)
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return;
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device = static_cast<LoopDevice&>(*found_device);
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});
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if (!device)
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return ENOENT;
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auto inode = TRY(adopt_nonnull_ref_or_enomem(new (nothrow) DevLoopFSInode(const_cast<DevLoopFS&>(*this), inode_id.index(), device)));
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inode->m_metadata.inode = inode_id;
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inode->m_metadata.size = 0;
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inode->m_metadata.uid = 0;
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inode->m_metadata.gid = 0;
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inode->m_metadata.mode = S_IFBLK | S_IRUSR | S_IWUSR;
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inode->m_metadata.major_device = to_underlying(MajorAllocation::BlockDeviceFamily::Loop);
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inode->m_metadata.minor_device = loop_index;
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inode->m_metadata.mtime = TimeManagement::boot_time();
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return inode;
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}
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}
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