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Kernel/Ext2FS: Add full support for large inodes

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128-byte inodes are more-or-less deprecated since they store timestamps
as unsigned 32-bit integer offsets from the UNIX epoch. Large inodes, on
the other hand, contain records that may specify a different epoch, and
are thus less susceptible to overflows. These very same records also
have the capability to store timestamps with nanosecond precision, which
this commit adds full support for as well.
This commit is contained in:
implicitfield
2024-11-23 00:43:31 +02:00
committed by Nico Weber
parent 2a205768b6
commit 0e368bb71a
5 changed files with 111 additions and 25 deletions
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49
Kernel/FileSystem/Ext2FS/FileSystem.cpp
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@@ -210,18 +210,28 @@ u64 Ext2FS::inode_size() const
{
return EXT2_INODE_SIZE(&super_block());
}
u64 Ext2FS::blocks_per_group() const
{
return EXT2_BLOCKS_PER_GROUP(&super_block());
}
ErrorOr<void> Ext2FS::write_ext2_inode(InodeIndex inode, ext2_inode const& e2inode)
ErrorOr<void> Ext2FS::write_ext2_inode(InodeIndex inode, ext2_inode_large const& e2inode)
{
BlockIndex block_index;
unsigned offset;
if (!find_block_containing_inode(inode, block_index, offset))
return EINVAL;
auto buffer = UserOrKernelBuffer::for_kernel_buffer(const_cast<u8*>((u8 const*)&e2inode));
Vector<u8> inode_storage;
TRY(inode_storage.try_resize(inode_size()));
size_t used_inode_size = inode_size() > EXT2_GOOD_OLD_INODE_SIZE ? EXT2_GOOD_OLD_INODE_SIZE + e2inode.i_extra_isize : inode_size();
VERIFY(used_inode_size >= EXT2_GOOD_OLD_INODE_SIZE && used_inode_size <= inode_size());
memcpy(inode_storage.data(), &e2inode, min(used_inode_size, sizeof(ext2_inode_large)));
auto buffer = UserOrKernelBuffer::for_kernel_buffer(inode_storage.data());
return write_block(block_index, buffer, inode_size(), offset);
}
@@ -493,20 +503,31 @@ ErrorOr<NonnullRefPtr<Inode>> Ext2FS::create_inode(Ext2FSInode& parent_inode, St
if (parent_inode.m_raw_inode.i_links_count == 0)
return ENOENT;
ext2_inode e2inode {};
auto now = kgettimeofday().truncated_seconds_since_epoch();
ext2_inode_large e2inode {};
auto now = kgettimeofday().to_timespec();
u32 extra = Ext2FSInode::encode_time_to_extra(now.tv_sec, now.tv_nsec);
e2inode.i_mode = mode;
e2inode.i_uid = static_cast<u16>(uid.value());
ext2fs_set_i_uid_high(e2inode, uid.value() >> 16);
e2inode.i_gid = static_cast<u16>(gid.value());
ext2fs_set_i_gid_high(e2inode, gid.value() >> 16);
e2inode.i_size = 0;
e2inode.i_atime = now;
e2inode.i_ctime = now;
e2inode.i_mtime = now;
e2inode.i_atime = now.tv_sec;
e2inode.i_ctime = now.tv_sec;
e2inode.i_mtime = now.tv_sec;
e2inode.i_crtime = now.tv_sec;
e2inode.i_atime_extra = extra;
e2inode.i_ctime_extra = extra;
e2inode.i_mtime_extra = extra;
e2inode.i_crtime_extra = extra;
e2inode.i_dtime = 0;
e2inode.i_flags = 0;
if (inode_size() > EXT2_GOOD_OLD_INODE_SIZE)
e2inode.i_extra_isize = min(inode_size(), sizeof(ext2_inode_large)) - EXT2_GOOD_OLD_INODE_SIZE;
// For directories, add +1 link count for the "." entry in self.
e2inode.i_links_count = is_directory(mode);
@@ -606,7 +627,7 @@ ErrorOr<void> Ext2FS::free_inode(Ext2FSInode& inode)
}
// NOTE: After this point, the inode metadata is wiped.
memset(&inode.m_raw_inode, 0, sizeof(ext2_inode));
memset(&inode.m_raw_inode, 0, sizeof(ext2_inode_large));
inode.m_raw_inode.i_dtime = kgettimeofday().truncated_seconds_since_epoch();
TRY(write_ext2_inode(inode.index(), inode.m_raw_inode));
@@ -707,7 +728,11 @@ ErrorOr<NonnullRefPtr<Ext2FSInode>> Ext2FS::build_root_inode() const
auto inode = TRY(adopt_nonnull_ref_or_enomem(new (nothrow) Ext2FSInode(const_cast<Ext2FS&>(*this), EXT2_ROOT_INO)));
auto buffer = UserOrKernelBuffer::for_kernel_buffer(reinterpret_cast<u8*>(&inode->m_raw_inode));
TRY(read_block(block_index, &buffer, sizeof(ext2_inode), offset));
size_t size = min(inode_size(), sizeof(ext2_inode_large));
VERIFY(size >= EXT2_GOOD_OLD_INODE_SIZE);
TRY(read_block(block_index, &buffer, size, offset));
return inode;
}
@@ -744,7 +769,11 @@ ErrorOr<NonnullRefPtr<Inode>> Ext2FS::get_inode(InodeIdentifier inode) const
auto new_inode = TRY(adopt_nonnull_ref_or_enomem(new (nothrow) Ext2FSInode(const_cast<Ext2FS&>(*this), inode.index())));
auto buffer = UserOrKernelBuffer::for_kernel_buffer(reinterpret_cast<u8*>(&new_inode->m_raw_inode));
TRY(read_block(block_index, &buffer, sizeof(ext2_inode), offset));
size_t size = min(inode_size(), sizeof(ext2_inode_large));
VERIFY(size >= EXT2_GOOD_OLD_INODE_SIZE);
TRY(read_block(block_index, &buffer, size, offset));
TRY(m_inode_cache.try_set(inode.index(), new_inode));
return new_inode;