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Kernel: Ext2Inode now supports indirect blocks through for_each_block()

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This commit is contained in:
Bananymous
2023-02-20 10:25:15 +02:00
parent 80006ea137
commit efaca469ee
4 changed files with 186 additions and 61 deletions
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9
kernel/include/kernel/FS/Ext2.h
View File

@@ -131,9 +131,12 @@ namespace Kernel
virtual BAN::StringView name() const override { return m_name; }
virtual BAN::ErrorOr<BAN::Vector<uint8_t>> read_all() const override;
virtual BAN::ErrorOr<BAN::Vector<BAN::RefCounted<Inode>>> directory_inodes() const override;
virtual BAN::ErrorOr<BAN::RefCounted<Inode>> directory_find(BAN::StringView) const override;
virtual BAN::ErrorOr<BAN::Vector<uint8_t>> read_all() override;
virtual BAN::ErrorOr<BAN::Vector<BAN::RefCounted<Inode>>> directory_inodes() override;
virtual BAN::ErrorOr<BAN::RefCounted<Inode>> directory_find(BAN::StringView) override;
private:
BAN::ErrorOr<void> for_each_block(BAN::Function<BAN::ErrorOr<bool>(const BAN::Vector<uint8_t>&)>&);
private:
Ext2Inode() {}

6
kernel/include/kernel/FS/Inode.h
View File

@@ -20,9 +20,9 @@ namespace Kernel
virtual BAN::StringView name() const = 0;
virtual BAN::ErrorOr<BAN::Vector<uint8_t>> read_all() const = 0;
virtual BAN::ErrorOr<BAN::Vector<BAN::RefCounted<Inode>>> directory_inodes() const = 0;
virtual BAN::ErrorOr<BAN::RefCounted<Inode>> directory_find(BAN::StringView) const = 0;
virtual BAN::ErrorOr<BAN::Vector<uint8_t>> read_all() = 0;
virtual BAN::ErrorOr<BAN::Vector<BAN::RefCounted<Inode>>> directory_inodes() = 0;
virtual BAN::ErrorOr<BAN::RefCounted<Inode>> directory_find(BAN::StringView) = 0;
};
}

176
kernel/kernel/FS/Ext2.cpp
View File

@@ -148,72 +148,168 @@ namespace Kernel
return m_inode.mode & Ext2::Enum::IFREG;
}
BAN::ErrorOr<BAN::Vector<uint8_t>> Ext2Inode::read_all() const
BAN::ErrorOr<void> Ext2Inode::for_each_block(BAN::Function<BAN::ErrorOr<bool>(const BAN::Vector<uint8_t>&)>& func)
{
return BAN::Error::from_string("not implemented");
uint32_t data_blocks_left = m_inode.blocks / (2 << m_fs->superblock().log_block_size);
uint32_t block_array_block_count = (1024 << m_fs->superblock().log_block_size) / sizeof(uint32_t);
// Direct blocks
for (uint32_t i = 0; i < 12; i++)
{
if (m_inode.block[i] == 0)
continue;
auto block_data = TRY(m_fs->read_block(m_inode.block[i]));
if (!TRY(func(block_data)))
return {};
if (--data_blocks_left == 0)
return {};
}
BAN::ErrorOr<BAN::RefCounted<Inode>> Ext2Inode::directory_find(BAN::StringView name) const
// Singly indirect block
if (m_inode.block[12])
{
auto block_array = TRY(m_fs->read_block(m_inode.block[12]));
for (uint32_t i = 0; i < block_array_block_count; i++)
{
uint32_t block = ((uint32_t*)block_array.data())[i];
if (block == 0)
continue;
auto block_data = TRY(m_fs->read_block(block));
if (!TRY(func(block_data)))
return {};
if (--data_blocks_left == 0)
return {};
}
}
// Doubly indirect blocks
if (m_inode.block[13])
{
auto singly_indirect_array = TRY(m_fs->read_block(m_inode.block[13]));
for (uint32_t i = 0; i < block_array_block_count; i++)
{
uint32_t singly_indirect_block = ((uint32_t*)singly_indirect_array.data())[i];
auto block_array = TRY(m_fs->read_block(singly_indirect_block));
for (uint32_t j = 0; j < block_array_block_count; j++)
{
uint32_t block = ((uint32_t*)block_array.data())[j];
if (block == 0)
continue;
auto block_data = TRY(m_fs->read_block(block));
if (!TRY(func(block_data)))
return {};
if (--data_blocks_left == 0)
return {};
}
}
}
// Triply indirect blocks
if (m_inode.block[14])
{
auto doubly_indirect_array = TRY(m_fs->read_block(m_inode.block[14]));
for (uint32_t i = 0; i < block_array_block_count; i++)
{
uint32_t doubly_indirect_block = ((uint32_t*)doubly_indirect_array.data())[i];
auto singly_indirect_array = TRY(m_fs->read_block(doubly_indirect_block));
for (uint32_t j = 0; j < block_array_block_count; j++)
{
uint32_t singly_indirect_block = ((uint32_t*)singly_indirect_array.data())[j];
auto block_array = TRY(m_fs->read_block(singly_indirect_block));
for (uint32_t k = 0; k < block_array_block_count; k++)
{
uint32_t block = ((uint32_t*)block_array.data())[k];
if (block == 0)
continue;
auto block_data = TRY(m_fs->read_block(block));
if (!TRY(func(block_data)))
return {};
if (--data_blocks_left == 0)
return {};
}
}
}
}
return BAN::Error::from_string("Inode did not contain enough blocks");
}
BAN::ErrorOr<BAN::Vector<uint8_t>> Ext2Inode::read_all()
{
if (is_directory())
return BAN::Error::from_string("Inode is a directory");
BAN::Vector<uint8_t> data_buffer;
TRY(data_buffer.resize(m_inode.size));
uint32_t bytes_done = 0;
uint32_t bytes_left = m_inode.size;
BAN::Function<BAN::ErrorOr<bool>(const BAN::Vector<uint8_t>&)> read_func(
[&](const BAN::Vector<uint8_t>& block_data)
{
uint32_t to_copy = BAN::Math::min<uint32_t>(block_data.size(), bytes_left);
memcpy(data_buffer.data() + bytes_done, block_data.data(), to_copy);
bytes_done += to_copy;
bytes_left -= to_copy;
return bytes_left > 0;
}
);
TRY(for_each_block(read_func));
ASSERT(bytes_left == 0);
return data_buffer;
}
BAN::ErrorOr<BAN::RefCounted<Inode>> Ext2Inode::directory_find(BAN::StringView file_name)
{
if (!is_directory())
return BAN::Error::from_string("Inode is not a directory");
uint32_t data_block_count = m_inode.blocks / (2 << m_fs->superblock().log_block_size);
uint32_t data_blocks_found = 0;
for (uint32_t data_block = 0; data_block < 12 && data_blocks_found < data_block_count; data_block++)
BAN::RefCounted<Inode> result;
BAN::Function<BAN::ErrorOr<bool>(const BAN::Vector<uint8_t>&)> function(
[&](const BAN::Vector<uint8_t>& block_data) -> BAN::ErrorOr<bool>
{
if (m_inode.block[0] == 0)
continue;
data_blocks_found++;
auto inode_data = TRY(m_fs->read_block(m_inode.block[data_block]));
uintptr_t inode_data_end = (uintptr_t)inode_data.data() + inode_data.size();
uintptr_t entry_addr = (uintptr_t)inode_data.data();
while (entry_addr < inode_data_end)
uintptr_t block_data_end = (uintptr_t)block_data.data() + block_data.size();
uintptr_t entry_addr = (uintptr_t)block_data.data();
while (entry_addr < block_data_end)
{
Ext2::LinkedDirectoryEntry* entry = (Ext2::LinkedDirectoryEntry*)entry_addr;
BAN::StringView entry_name = BAN::StringView(entry->name, entry->name_len);
if (entry->inode && name == entry_name)
if (entry->inode && file_name == entry_name)
{
Ext2::Inode asked_inode = TRY(m_fs->read_inode(entry->inode));
return BAN::RefCounted<Inode>(new Ext2Inode(m_fs, BAN::move(asked_inode), entry_name));
result = BAN::RefCounted<Inode>(new Ext2Inode(m_fs, BAN::move(asked_inode), entry_name));
return false;
}
entry_addr += entry->rec_len;
}
return true;
}
);
TRY(for_each_block(function));
if (result)
return result;
return BAN::Error::from_string("Could not find the asked inode");
}
BAN::ErrorOr<BAN::Vector<BAN::RefCounted<Inode>>> Ext2Inode::directory_inodes() const
BAN::ErrorOr<BAN::Vector<BAN::RefCounted<Inode>>> Ext2Inode::directory_inodes()
{
if (!is_directory())
return BAN::Error::from_string("Inode is not a directory");
uint32_t data_block_count = m_inode.blocks / (2 << m_fs->superblock().log_block_size);
uint32_t data_blocks_found = 0;
BAN::Vector<BAN::RefCounted<Inode>> inodes;
// FIXME: implement indirect pointers
for (uint32_t data_block = 0; data_block < 12 && data_blocks_found < data_block_count; data_block++)
BAN::Function<BAN::ErrorOr<bool>(const BAN::Vector<uint8_t>&)> function(
[&](const BAN::Vector<uint8_t>& block_data) -> BAN::ErrorOr<bool>
{
if (m_inode.block[0] == 0)
continue;
data_blocks_found++;
auto inode_data = TRY(m_fs->read_block(m_inode.block[data_block]));
uintptr_t inode_data_end = (uintptr_t)inode_data.data() + inode_data.size();
uintptr_t entry_addr = (uintptr_t)inode_data.data();
while (entry_addr < inode_data_end)
uintptr_t block_data_end = (uintptr_t)block_data.data() + block_data.size();
uintptr_t entry_addr = (uintptr_t)block_data.data();
while (entry_addr < block_data_end)
{
Ext2::LinkedDirectoryEntry* entry = (Ext2::LinkedDirectoryEntry*)entry_addr;
if (entry->inode)
{
BAN::StringView entry_name = BAN::StringView(entry->name, entry->name_len);
@@ -221,13 +317,13 @@ namespace Kernel
auto ref_counted_inode = BAN::RefCounted<Inode>(new Ext2Inode(m_fs, BAN::move(current_inode), entry_name));
TRY(inodes.push_back(BAN::move(ref_counted_inode)));
}
entry_addr += entry->rec_len;
}
return true;
}
);
// FIXME: for now we can just assert that we found everything in direct pointers
ASSERT(data_blocks_found == data_block_count);
TRY(for_each_block(function));
return inodes;
}

26
kernel/kernel/Shell.cpp
View File

@@ -300,6 +300,32 @@ argument_done:
if (!inode->is_directory())
TTY_PRINTLN(" {7} {}", inode->size(), inode->name());
}
else if (arguments.front() == "cat")
{
if (!VirtualFileSystem::is_initialized())
return TTY_PRINTLN("VFS not initialized :(");
if (arguments.size() > 2)
return TTY_PRINTLN("usage: 'cat path'");
auto file = VirtualFileSystem::get().root_inode();
auto path_parts = MUST(arguments[1].sv().split('/'));
for (auto part : path_parts)
{
auto inode_or_error = file->directory_find(part);
if (inode_or_error.is_error())
return TTY_PRINTLN("{}", inode_or_error.get_error().get_message());
file = inode_or_error.value();
}
auto data_or_error = file->read_all();
if (data_or_error.is_error())
return TTY_PRINTLN("{}", data_or_error.get_error().get_message());
auto& data = data_or_error.value();
TTY_PRINTLN("{}", BAN::StringView((const char*)data.data(), data.size()));
}
else
{
TTY_PRINTLN("unrecognized command '{}'", arguments.front());