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Kernel/FATFS: Implement remove_child

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Undefine 2024-01-18 21:07:06 +01:00 committed by Tim Schumacher
parent 3b39a2f71b
commit 511b298a1d
2 changed files with 59 additions and 2 deletions
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59
Kernel/FileSystem/FATFS/Inode.cpp
View file

@ -604,9 +604,64 @@ ErrorOr<void> FATInode::add_child(Inode& inode, StringView name, mode_t mode)
return {};
}
ErrorOr<void> FATInode::remove_child(StringView)
ErrorOr<void> FATInode::remove_child(StringView name)
{
return EROFS;
MutexLocker locker(m_inode_lock);
dbgln_if(FAT_DEBUG, "FATInode[{}]::remove_child(): removing inode \"{}\"", identifier(), name);
VERIFY(has_flag(m_entry.attributes, FATAttributes::Directory));
Vector<FATLongFileNameEntry> lfn_entries;
TRY(lfn_entries.try_ensure_capacity(ceil_div(max_filename_length, characters_per_lfn_entry)));
Vector<FATEntryLocation> lfn_entry_locations;
TRY(lfn_entry_locations.try_ensure_capacity(ceil_div(max_filename_length, characters_per_lfn_entry)));
auto block_list = TRY(get_block_list());
auto block_buffer = TRY(read_block_list());
for (u32 i = 0; i < block_buffer->size() / sizeof(FATEntry); i++) {
auto* entry = bit_cast<FATEntry*>(block_buffer->data() + i * sizeof(FATEntry));
auto entry_number_bytes = i * sizeof(FATEntry);
auto block = block_list[entry_number_bytes / fs().logical_block_size()];
auto entries_per_sector = fs().logical_block_size() / sizeof(FATEntry);
u32 block_entry = i % entries_per_sector;
if (entry->filename[0] == end_entry_byte) {
dbgln_if(FAT_DEBUG, "FATInode[{}]::remove_child(): Found end entry", identifier());
return ENOENT;
} else if (static_cast<u8>(entry->filename[0]) == unused_entry_byte) {
dbgln_if(FAT_DEBUG, "FATInode[{}]::remove_child(): Found unused entry", identifier());
lfn_entries.clear_with_capacity();
lfn_entry_locations.clear_with_capacity();
} else if (entry->attributes == FATAttributes::LongFileName) {
dbgln_if(FAT_DEBUG, "FATInode[{}]::remove_child(): Found LFN entry", identifier());
lfn_entries.unchecked_append(*bit_cast<FATLongFileNameEntry*>(entry));
lfn_entry_locations.unchecked_append({ block, block_entry });
} else {
dbgln_if(FAT_DEBUG, "FATInode[{}]::remove_child(): Found 8.3 entry at block {}, entry {}", identifier(), block, block_entry);
lfn_entries.reverse();
auto filename = TRY(compute_filename(*entry, lfn_entries));
if (filename->view() == name) {
// FIXME: If it's the last entry move the end entry instead of unused entries
FATEntry unused_entry {};
unused_entry.filename[0] = unused_entry_byte;
TRY(fs().write_block(block, UserOrKernelBuffer::for_kernel_buffer(bit_cast<u8*>(&unused_entry)), sizeof(FATEntry), block_entry * sizeof(FATEntry)));
for (auto const& lfn_entry_location : lfn_entry_locations)
TRY(fs().write_block(lfn_entry_location.block, UserOrKernelBuffer::for_kernel_buffer(bit_cast<u8*>(&unused_entry)), sizeof(FATEntry), lfn_entry_location.entry * sizeof(FATEntry)));
return {};
}
lfn_entries.clear_with_capacity();
lfn_entry_locations.clear_with_capacity();
}
}
return EINVAL;
}
ErrorOr<void> FATInode::chmod(mode_t)

2
Kernel/FileSystem/FATFS/Inode.h
View file

@ -51,6 +51,8 @@ private:
static constexpr size_t characters_per_lfn_entry = lfn_entry_characters_part_1_length + lfn_entry_characters_part_2_length + lfn_entry_characters_part_3_length;
static constexpr u8 last_lfn_entry_mask = 0x40;
static constexpr size_t max_filename_length = 255;
static ErrorOr<NonnullOwnPtr<KString>> compute_filename(FATEntry&, Vector<FATLongFileNameEntry> const& = {});
static StringView byte_terminated_string(StringView, u8);
static u8 lfn_entry_checksum(FATEntry const& entry);