fergalmoran/ladybird
1
0
Fork 0
mirror of https://github.com/fergalmoran/ladybird.git synced 2026-01-05 08:06:09 +00:00
Code Issues Packages Projects Releases Wiki Activity

Kernel/FATFS: Cache the cluster list and don't cache the InodeMetadata

Browse Source 
Caching the cluster list allows us to fill the two fields in the
InodeMetadata. While at it, don't cache the metadata as when we
have write support having to keep both InodeMetadata and FATEntry
correct is going to get very annoying.
This commit is contained in:
Undefine
2024-01-16 21:24:45 +01:00
committed by Tim Schumacher
parent d4badfac72
commit 33f00a7efb
4 changed files with 55 additions and 54 deletions
Download Patch File Download Diff File Expand all files Collapse all files

79
Kernel/FileSystem/FATFS/Inode.cpp
View File

@@ -14,7 +14,13 @@ namespace Kernel {
ErrorOr<NonnullRefPtr<FATInode>> FATInode::create(FATFS& fs, FATEntry entry, FATEntryLocation inode_metadata_location, Vector<FATLongFileNameEntry> const& lfn_entries)
{
auto filename = TRY(compute_filename(entry, lfn_entries));
return adopt_nonnull_ref_or_enomem(new (nothrow) FATInode(fs, entry, inode_metadata_location, move(filename)));
u32 entry_first_cluster = entry.first_cluster_low;
if (fs.m_fat_version == FATVersion::FAT32)
entry_first_cluster |= (static_cast<u32>(entry.first_cluster_high) << 16);
auto inode = TRY(adopt_nonnull_ref_or_enomem(new (nothrow) FATInode(fs, entry, inode_metadata_location, move(filename))));
MutexLocker locker(inode->m_inode_lock);
inode->m_cluster_list = TRY(inode->compute_cluster_list(fs, entry_first_cluster));
return inode;
}
FATInode::FATInode(FATFS& fs, FATEntry entry, FATEntryLocation inode_metadata_location, NonnullOwnPtr<KString> filename)
@@ -24,37 +30,20 @@ FATInode::FATInode(FATFS& fs, FATEntry entry, FATEntryLocation inode_metadata_lo
, m_filename(move(filename))
{
dbgln_if(FAT_DEBUG, "FATFS: Creating inode {} with filename \"{}\"", index(), m_filename);
m_metadata = {
.inode = identifier(),
.size = m_entry.file_size,
.mode = static_cast<mode_t>((has_flag(m_entry.attributes, FATAttributes::Directory) ? S_IFDIR : S_IFREG) | 0777),
.uid = 0,
.gid = 0,
.link_count = 0,
.atime = time_from_packed_dos(m_entry.last_accessed_date, { 0 }),
.ctime = time_from_packed_dos(m_entry.creation_date, m_entry.creation_time),
.mtime = time_from_packed_dos(m_entry.modification_date, m_entry.modification_time),
.dtime = {},
.block_count = 0,
.block_size = 0,
.major_device = 0,
.minor_device = 0,
};
}
ErrorOr<Vector<u32>> FATInode::compute_cluster_list()
ErrorOr<Vector<u32>> FATInode::compute_cluster_list(FATFS& fs, u32 first_cluster)
{
VERIFY(m_inode_lock.is_locked());
dbgln_if(FAT_DEBUG, "FATFS: computing cluster list for inode {}", index());
dbgln_if(FAT_DEBUG, "FATFS: computing block list starting with cluster {}", first_cluster);
u32 cluster = first_cluster();
u32 cluster = first_cluster;
Vector<u32> cluster_list;
while (cluster < end_of_chain_marker()) {
dbgln_if(FAT_DEBUG, "FATFS: Appending cluster {} to inode {}'s cluster chain", cluster, index());
while (cluster < fs.end_of_chain_marker()) {
dbgln_if(FAT_DEBUG, "FATFS: Appending cluster {} to cluster chain starting with {}", cluster, first_cluster);
TRY(cluster_list.try_append(cluster));
@@ -75,7 +64,7 @@ ErrorOr<Vector<u32>> FATInode::compute_cluster_list()
}
// Look up the next cluster to read, or read End of Chain marker from table.
cluster = TRY(fs().fat_read(cluster));
cluster = TRY(fs.fat_read(cluster));
}
return cluster_list;
@@ -89,9 +78,6 @@ ErrorOr<Vector<BlockBasedFileSystem::BlockIndex>> FATInode::get_block_list()
Vector<BlockBasedFileSystem::BlockIndex> block_list;
if (m_cluster_list.is_empty())
m_cluster_list = TRY(compute_cluster_list());
for (auto cluster : m_cluster_list) {
auto span = fs().first_block_of_cluster(cluster);
for (size_t i = 0; i < span.number_of_sectors; i++) {
@@ -103,23 +89,6 @@ ErrorOr<Vector<BlockBasedFileSystem::BlockIndex>> FATInode::get_block_list()
return block_list;
}
u32 FATInode::end_of_chain_marker() const
{
// Returns the end of chain entry for the given file system.
// Any FAT entry of this value or greater signifies the end
// of the chain has been reached for a given entry.
switch (fs().m_fat_version) {
case FATVersion::FAT12:
return 0xFF8;
case FATVersion::FAT16:
return 0xFFF8;
case FATVersion::FAT32:
return 0x0FFFFFF8;
default:
VERIFY_NOT_REACHED();
}
}
ErrorOr<NonnullOwnPtr<KBuffer>> FATInode::read_block_list()
{
VERIFY(m_inode_lock.is_locked());
@@ -275,7 +244,7 @@ ErrorOr<size_t> FATInode::read_bytes_locked(off_t offset, size_t size, UserOrKer
{
dbgln_if(FAT_DEBUG, "FATFS: Reading inode {}: size: {} offset: {}", identifier().index(), size, offset);
VERIFY(offset >= 0);
if (offset >= m_metadata.size)
if (offset >= m_entry.file_size)
return 0;
// FIXME: Read only the needed blocks instead of the whole file
@@ -286,7 +255,7 @@ ErrorOr<size_t> FATInode::read_bytes_locked(off_t offset, size_t size, UserOrKer
// 2. The file size.
// 3. The number of blocks returned for reading.
size_t read_size = min(
min(size, m_metadata.size - offset),
min(size, m_entry.file_size - offset),
(m_cluster_list.size() * fs().m_device_block_size * fs().m_parameter_block->common_bpb()->sectors_per_cluster) - offset);
TRY(buffer.write(blocks->data() + offset, read_size));
@@ -295,7 +264,23 @@ ErrorOr<size_t> FATInode::read_bytes_locked(off_t offset, size_t size, UserOrKer
InodeMetadata FATInode::metadata() const
{
return m_metadata;
return {
.inode = identifier(),
.size = m_entry.file_size,
// FIXME: Linux also removes the write permission if the file has the read only attribute set.
.mode = static_cast<mode_t>((has_flag(m_entry.attributes, FATAttributes::Directory) ? S_IFDIR : S_IFREG) | 0777),
.uid = 0,
.gid = 0,
.link_count = 0,
.atime = time_from_packed_dos(m_entry.last_accessed_date, { 0 }),
.ctime = time_from_packed_dos(m_entry.creation_date, m_entry.creation_time),
.mtime = time_from_packed_dos(m_entry.modification_date, m_entry.modification_time),
.dtime = {},
.block_count = m_cluster_list.size() * fs().m_parameter_block->common_bpb()->sectors_per_cluster,
.block_size = fs().m_device_block_size,
.major_device = 0,
.minor_device = 0,
};
}
ErrorOr<void> FATInode::traverse_as_directory(Function<ErrorOr<void>(FileSystem::DirectoryEntryView const&)> callback) const