banan-os/kernel/kernel/FS/TmpFS/Inode.cpp

375 lines
10 KiB
C++

#include <kernel/FS/TmpFS/FileSystem.h>
#include <kernel/FS/TmpFS/Inode.h>
#include <kernel/Timer/Timer.h>
namespace Kernel
{
static TmpInodeInfo create_inode_info(mode_t mode, uid_t uid, gid_t gid)
{
auto current_time = SystemTimer::get().real_time();
TmpInodeInfo info;
info.uid = uid;
info.gid = gid;
info.mode = mode;
info.atime = current_time;
info.mtime = current_time;
info.ctime = current_time;
return info;
}
static uint8_t inode_mode_to_dt_type(Inode::Mode mode)
{
if (mode.ifreg())
return DT_REG;
if (mode.ifdir())
return DT_DIR;
if (mode.ifchr())
return DT_CHR;
if (mode.ifblk())
return DT_BLK;
if (mode.ififo())
return DT_FIFO;
if (mode.ifsock())
return DT_SOCK;
if (mode.iflnk())
return DT_LNK;
ASSERT_NOT_REACHED();
}
/* GENERAL INODE */
BAN::ErrorOr<BAN::RefPtr<TmpInode>> TmpInode::create_from_existing(TmpFileSystem& fs, ino_t ino, const TmpInodeInfo& info)
{
TmpInode* inode_ptr = nullptr;
switch (info.mode & Mode::TYPE_MASK)
{
case Mode::IFDIR:
inode_ptr = new TmpDirectoryInode(fs, ino, info);
break;
case Mode::IFREG:
inode_ptr = new TmpFileInode(fs, ino, info);
break;
default:
ASSERT_NOT_REACHED();
}
if (inode_ptr == nullptr)
return BAN::Error::from_errno(ENOMEM);
return BAN::RefPtr<TmpInode>::adopt(inode_ptr);
}
TmpInode::TmpInode(TmpFileSystem& fs, ino_t ino, const TmpInodeInfo& info)
: m_fs(fs)
, m_inode_info(info)
, m_ino(ino)
{
// FIXME: this should be able to fail
MUST(fs.add_to_cache(this));
}
void TmpInode::sync()
{
m_fs.write_inode(m_ino, m_inode_info);
}
void TmpInode::free_all_blocks()
{
for (auto block : m_inode_info.block)
ASSERT(block == 0);
}
BAN::Optional<size_t> TmpInode::block_index(size_t data_block_index)
{
ASSERT(data_block_index < TmpInodeInfo::direct_block_count);
if (m_inode_info.block[data_block_index])
return m_inode_info.block[data_block_index];
return {};
}
BAN::ErrorOr<size_t> TmpInode::block_index_with_allocation(size_t data_block_index)
{
if (data_block_index >= TmpInodeInfo::direct_block_count)
{
dprintln("only {} blocks supported :D", TmpInodeInfo::direct_block_count);
return BAN::Error::from_errno(ENOSPC);
}
if (m_inode_info.block[data_block_index] == 0)
{
m_inode_info.block[data_block_index] = TRY(m_fs.allocate_block());
m_inode_info.blocks++;
}
return m_inode_info.block[data_block_index];
}
/* FILE INODE */
BAN::ErrorOr<BAN::RefPtr<TmpFileInode>> TmpFileInode::create_new(TmpFileSystem& fs, mode_t mode, uid_t uid, gid_t gid)
{
auto info = create_inode_info(Mode::IFREG | mode, uid, gid);
ino_t ino = TRY(fs.allocate_inode(info));
auto* inode_ptr = new TmpFileInode(fs, ino, info);
if (inode_ptr == nullptr)
return BAN::Error::from_errno(ENOMEM);
return BAN::RefPtr<TmpFileInode>::adopt(inode_ptr);
}
TmpFileInode::TmpFileInode(TmpFileSystem& fs, ino_t ino, const TmpInodeInfo& info)
: TmpInode(fs, ino, info)
{
ASSERT(mode().ifreg());
}
TmpFileInode::~TmpFileInode()
{
if (nlink() > 0)
{
sync();
return;
}
free_all_blocks();
m_fs.delete_inode(ino());
}
BAN::ErrorOr<size_t> TmpFileInode::read_impl(off_t offset, BAN::ByteSpan out_buffer)
{
if (offset >= size() || out_buffer.size() == 0)
return 0;
const size_t bytes_to_read = BAN::Math::min<size_t>(size() - offset, out_buffer.size());
size_t read_done = 0;
while (read_done < bytes_to_read)
{
const size_t data_block_index = (read_done + offset) / blksize();
const size_t block_offset = (read_done + offset) % blksize();
const auto block_index = this->block_index(data_block_index);
const size_t bytes = BAN::Math::min<size_t>(bytes_to_read - read_done, blksize() - block_offset);
if (block_index.has_value())
m_fs.with_block_buffer(block_index.value(), [&](BAN::ByteSpan block_buffer) {
memcpy(out_buffer.data() + read_done, block_buffer.data() + block_offset, bytes);
});
else
memset(out_buffer.data() + read_done, 0x00, bytes);
read_done += bytes;
}
return read_done;
}
BAN::ErrorOr<size_t> TmpFileInode::write_impl(off_t offset, BAN::ConstByteSpan in_buffer)
{
// FIXME: handle overflow
if (offset + in_buffer.size() > (size_t)size())
TRY(truncate_impl(offset + in_buffer.size()));
const size_t bytes_to_write = in_buffer.size();
size_t write_done = 0;
while (write_done < bytes_to_write)
{
const size_t data_block_index = (write_done + offset) / blksize();
const size_t block_offset = (write_done + offset) % blksize();
const size_t block_index = TRY(block_index_with_allocation(data_block_index));
const size_t bytes = BAN::Math::min<size_t>(bytes_to_write - write_done, blksize() - block_offset);
m_fs.with_block_buffer(block_index, [&](BAN::ByteSpan block_buffer) {
memcpy(block_buffer.data() + block_offset, in_buffer.data() + write_done, bytes);
});
write_done += bytes;
}
return write_done;
}
BAN::ErrorOr<void> TmpFileInode::truncate_impl(size_t new_size)
{
m_inode_info.size = new_size;
return {};
}
/* DIRECTORY INODE */
BAN::ErrorOr<BAN::RefPtr<TmpDirectoryInode>> TmpDirectoryInode::create_root(TmpFileSystem& fs, mode_t mode, uid_t uid, gid_t gid)
{
auto info = create_inode_info(Mode::IFDIR | mode, uid, gid);
ino_t ino = TRY(fs.allocate_inode(info));
auto* inode_ptr = new TmpDirectoryInode(fs, ino, info);
if (inode_ptr == nullptr)
return BAN::Error::from_errno(ENOMEM);
auto inode = BAN::RefPtr<TmpDirectoryInode>::adopt(inode_ptr);
TRY(inode->link_inode(*inode, "."sv));
TRY(inode->link_inode(*inode, ".."sv));
return inode;
}
BAN::ErrorOr<BAN::RefPtr<TmpDirectoryInode>> TmpDirectoryInode::create_new(TmpFileSystem& fs, mode_t mode, uid_t uid, gid_t gid, TmpInode& parent)
{
auto info = create_inode_info(Mode::IFDIR | mode, uid, gid);
ino_t ino = TRY(fs.allocate_inode(info));
auto* inode_ptr = new TmpDirectoryInode(fs, ino, info);
if (inode_ptr == nullptr)
return BAN::Error::from_errno(ENOMEM);
auto inode = BAN::RefPtr<TmpDirectoryInode>::adopt(inode_ptr);
TRY(inode->link_inode(*inode, "."sv));
TRY(inode->link_inode(parent, ".."sv));
return inode;
}
TmpDirectoryInode::TmpDirectoryInode(TmpFileSystem& fs, ino_t ino, const TmpInodeInfo& info)
: TmpInode(fs, ino, info)
{
ASSERT(mode().ifdir());
}
TmpDirectoryInode::~TmpDirectoryInode()
{
if (nlink() >= 2)
{
sync();
return;
}
free_all_blocks();
m_fs.delete_inode(ino());
}
BAN::ErrorOr<BAN::RefPtr<Inode>> TmpDirectoryInode::find_inode_impl(BAN::StringView name)
{
ino_t result = 0;
for_each_entry([&](const TmpDirectoryEntry& entry) {
if (entry.type == DT_UNKNOWN)
return BAN::Iteration::Continue;
if (entry.name_sv() != name)
return BAN::Iteration::Continue;
result = entry.ino;
return BAN::Iteration::Break;
});
if (result == 0)
return BAN::Error::from_errno(ENOENT);
auto inode = TRY(m_fs.open_inode(result));
return BAN::RefPtr<Inode>(inode);
}
BAN::ErrorOr<void> TmpDirectoryInode::list_next_inodes_impl(off_t, DirectoryEntryList*, size_t)
{
return BAN::Error::from_errno(ENOTSUP);
}
BAN::ErrorOr<void> TmpDirectoryInode::create_file_impl(BAN::StringView name, mode_t mode, uid_t uid, gid_t gid)
{
auto new_inode = TRY(TmpFileInode::create_new(m_fs, mode, uid, gid));
TRY(link_inode(*new_inode, name));
return {};
}
BAN::ErrorOr<void> TmpDirectoryInode::create_directory_impl(BAN::StringView name, mode_t mode, uid_t uid, gid_t gid)
{
auto new_inode = TRY(TmpDirectoryInode::create_new(m_fs, mode, uid, gid, *this));
TRY(link_inode(*new_inode, name));
return {};
}
BAN::ErrorOr<void> TmpDirectoryInode::unlink_impl(BAN::StringView)
{
return BAN::Error::from_errno(ENOTSUP);
}
BAN::ErrorOr<void> TmpDirectoryInode::link_inode(TmpInode& inode, BAN::StringView name)
{
static constexpr size_t directory_entry_alignment = 16;
size_t new_entry_size = sizeof(TmpDirectoryEntry) + name.size();
if (auto rem = new_entry_size % directory_entry_alignment)
new_entry_size += directory_entry_alignment - rem;
ASSERT(new_entry_size < (size_t)blksize());
size_t new_entry_offset = size() % blksize();
// Target is the last block, or if it doesn't fit the new entry, the next one.
size_t target_data_block = size() / blksize();
if (blksize() - new_entry_offset < new_entry_size)
{
// insert an empty entry at the end of current block
m_fs.with_block_buffer(block_index(target_data_block).value(), [&](BAN::ByteSpan bytespan) {
auto& empty_entry = bytespan.slice(new_entry_offset).as<TmpDirectoryEntry>();
empty_entry.type = DT_UNKNOWN;
empty_entry.ino = 0;
empty_entry.rec_len = blksize() - new_entry_offset;
});
m_inode_info.size += blksize() - new_entry_offset;
target_data_block++;
new_entry_offset = 0;
}
size_t block_index = TRY(block_index_with_allocation(target_data_block));
m_fs.with_block_buffer(block_index, [&](BAN::ByteSpan bytespan) {
auto& new_entry = bytespan.slice(new_entry_offset).as<TmpDirectoryEntry>();
ASSERT(new_entry.type == DT_UNKNOWN);
new_entry.type = inode_mode_to_dt_type(inode.mode());
new_entry.ino = inode.ino();
new_entry.name_len = name.size();
new_entry.rec_len = new_entry_size;
memcpy(new_entry.name, name.data(), name.size());
});
// increase current size
m_inode_info.size += new_entry_size;
// add link to linked inode
inode.m_inode_info.nlink++;
return {};
}
template<TmpFuncs::for_each_entry_callback F>
void TmpDirectoryInode::for_each_entry(F callback)
{
for (size_t data_block_index = 0; data_block_index * blksize() < (size_t)size(); data_block_index++)
{
const size_t block_index = this->block_index(data_block_index).value();
const size_t byte_count = BAN::Math::min<size_t>(size() - data_block_index * blksize(), blksize());
m_fs.with_block_buffer(block_index, [&](BAN::ByteSpan bytespan) {
bytespan = bytespan.slice(0, byte_count);
while (bytespan.size() > 0)
{
const auto& entry = bytespan.as<TmpDirectoryEntry>();
switch (callback(entry))
{
case BAN::Iteration::Continue:
break;
case BAN::Iteration::Break:
return;
default:
ASSERT_NOT_REACHED();
}
bytespan = bytespan.slice(entry.rec_len);
}
});
}
}
}