Kernel: Make FileSystem::initialize() return KResult

This forced me to also come up with error codes for a bunch of
situations where we'd previously just panic the kernel.

Kernel/FileSystem/BlockBasedFileSystem.cpp

@@ -114,26 +114,26 @@ BlockBasedFileSystem::~BlockBasedFileSystem()
 {
 }
 
-bool BlockBasedFileSystem::initialize()
+KResult BlockBasedFileSystem::initialize()
 {
     VERIFY(block_size() != 0);
     auto cached_block_data = KBuffer::try_create_with_size(DiskCache::EntryCount * block_size());
     if (!cached_block_data)
-        return false;
+        return ENOMEM;
 
     auto entries_data = KBuffer::try_create_with_size(DiskCache::EntryCount * sizeof(CacheEntry));
     if (!entries_data)
-        return false;
+        return ENOMEM;
 
     auto disk_cache = adopt_own_if_nonnull(new (nothrow) DiskCache(*this, cached_block_data.release_nonnull(), entries_data.release_nonnull()));
     if (!disk_cache)
-        return false;
+        return ENOMEM;
 
     m_cache.with_exclusive([&](auto& cache) {
         cache = move(disk_cache);
     });
 
-    return true;
+    return KSuccess;
 }
 
 KResult BlockBasedFileSystem::write_block(BlockIndex index, const UserOrKernelBuffer& data, size_t count, size_t offset, bool allow_cache)

Kernel/FileSystem/BlockBasedFileSystem.h

@@ -16,7 +16,7 @@ public:
     TYPEDEF_DISTINCT_ORDERED_ID(u64, BlockIndex);
 
     virtual ~BlockBasedFileSystem() override;
-    virtual bool initialize() override;
+    virtual KResult initialize() override;
 
     u64 logical_block_size() const { return m_logical_block_size; };
 

Kernel/FileSystem/DevFS.cpp

@@ -56,9 +56,9 @@ DevFS::~DevFS()
 {
 }
 
-bool DevFS::initialize()
+KResult DevFS::initialize()
 {
-    return true;
+    return KSuccess;
 }
 
 Inode& DevFS::root_inode()

Kernel/FileSystem/DevFS.h

@@ -22,7 +22,7 @@ public:
     virtual ~DevFS() override;
     static NonnullRefPtr<DevFS> create();
 
-    virtual bool initialize() override;
+    virtual KResult initialize() override;
     virtual StringView class_name() const override { return "DevFS"sv; }
 
     void notify_new_device(Device&);

Kernel/FileSystem/DevPtsFS.cpp

@@ -27,17 +27,19 @@ DevPtsFS::~DevPtsFS()
 
 static Singleton<HashTable<unsigned>> s_ptys;
 
-bool DevPtsFS::initialize()
+KResult DevPtsFS::initialize()
 {
-    m_root_inode = adopt_ref(*new DevPtsFSInode(*this, 1, nullptr));
+    m_root_inode = adopt_ref_if_nonnull(new (nothrow) DevPtsFSInode(*this, 1, nullptr));
+    if (!m_root_inode)
+        return ENOMEM;
+
     m_root_inode->m_metadata.inode = { fsid(), 1 };
     m_root_inode->m_metadata.mode = 0040555;
     m_root_inode->m_metadata.uid = 0;
     m_root_inode->m_metadata.gid = 0;
     m_root_inode->m_metadata.size = 0;
     m_root_inode->m_metadata.mtime = mepoch;
-
-    return true;
+    return KSuccess;
 }
 
 static unsigned inode_index_to_pty_index(InodeIndex inode_index)

Kernel/FileSystem/DevPtsFS.h

@@ -22,7 +22,7 @@ public:
     virtual ~DevPtsFS() override;
     static NonnullRefPtr<DevPtsFS> create();
 
-    virtual bool initialize() override;
+    virtual KResult initialize() override;
     virtual StringView class_name() const override { return "DevPtsFS"sv; }
 
     virtual Inode& root_inode() override;

Kernel/FileSystem/Ext2FileSystem.cpp

@@ -86,7 +86,7 @@ const ext2_group_desc& Ext2FS::group_descriptor(GroupIndex group_index) const
     return block_group_descriptors()[group_index.value() - 1];
 }
 
-bool Ext2FS::initialize()
+KResult Ext2FS::initialize()
 {
     MutexLocker locker(m_lock);
 
@@ -99,8 +99,10 @@ bool Ext2FS::initialize()
     if constexpr (EXT2_DEBUG) {
         dmesgln("Ext2FS: super block magic: {:04x} (super block size: {})", super_block.s_magic, sizeof(ext2_super_block));
     }
-    if (super_block.s_magic != EXT2_SUPER_MAGIC)
-        return false;
+    if (super_block.s_magic != EXT2_SUPER_MAGIC) {
+        dmesgln("Ext2FS: Bad super block magic");
+        return EINVAL;
+    }
 
     if constexpr (EXT2_DEBUG) {
         dmesgln("Ext2FS: {} inodes, {} blocks", super_block.s_inodes_count, super_block.s_blocks_count);
@@ -117,9 +119,8 @@ bool Ext2FS::initialize()
     set_fragment_size(EXT2_FRAG_SIZE(&super_block));
 
     // Note: This depends on the block size being available.
-    auto baseclass_result = BlockBasedFileSystem::initialize();
-    if (!baseclass_result)
-        return baseclass_result;
+    if (auto result = BlockBasedFileSystem::initialize(); result.is_error())
+        return result;
 
     VERIFY(block_size() <= (int)max_block_size);
 
@@ -127,7 +128,7 @@ bool Ext2FS::initialize()
 
     if (m_block_group_count == 0) {
         dmesgln("Ext2FS: no block groups :(");
-        return false;
+        return EINVAL;
     }
 
     auto blocks_to_read = ceil_div(m_block_group_count * sizeof(ext2_group_desc), block_size());
@@ -135,13 +136,12 @@ bool Ext2FS::initialize()
     m_cached_group_descriptor_table = KBuffer::try_create_with_size(block_size() * blocks_to_read, Memory::Region::Access::ReadWrite, "Ext2FS: Block group descriptors");
     if (!m_cached_group_descriptor_table) {
         dbgln("Ext2FS: Failed to allocate memory for group descriptor table");
-        return false;
+        return ENOMEM;
     }
     auto buffer = UserOrKernelBuffer::for_kernel_buffer(m_cached_group_descriptor_table->data());
     if (auto result = read_blocks(first_block_of_bgdt, blocks_to_read, buffer); result.is_error()) {
-        // FIXME: Propagate the error
         dbgln("Ext2FS: initialize had error: {}", result.error());
-        return false;
+        return result;
     }
 
     if constexpr (EXT2_DEBUG) {
@@ -154,10 +154,10 @@ bool Ext2FS::initialize()
     m_root_inode = static_ptr_cast<Ext2FSInode>(get_inode({ fsid(), EXT2_ROOT_INO }));
     if (!m_root_inode) {
         dbgln("Ext2FS: failed to acquire root inode");
-        return false;
+        return EINVAL;
     }
 
-    return true;
+    return KSuccess;
 }
 
 Ext2FSInode& Ext2FS::root_inode()

Kernel/FileSystem/Ext2FileSystem.h

@@ -92,7 +92,7 @@ public:
     static NonnullRefPtr<Ext2FS> create(FileDescription&);
 
     virtual ~Ext2FS() override;
-    virtual bool initialize() override;
+    virtual KResult initialize() override;
 
     virtual unsigned total_block_count() const override;
     virtual unsigned free_block_count() const override;

Kernel/FileSystem/FileSystem.h

@@ -31,7 +31,7 @@ public:
     static void sync();
     static void lock_all();
 
-    virtual bool initialize() = 0;
+    virtual KResult initialize() = 0;
     virtual StringView class_name() const = 0;
     virtual Inode& root_inode() = 0;
     virtual bool supports_watchers() const { return false; }

Kernel/FileSystem/ISO9660FileSystem.cpp

@@ -202,18 +202,15 @@ ISO9660FS::~ISO9660FS()
 {
 }
 
-bool ISO9660FS::initialize()
-{
-    if (!BlockBasedFileSystem::initialize())
-        return false;
-
-    // FIXME: Fix the FileSystem::initialize contract to be able to return a
-    //        KResult.
-    if (parse_volume_set().is_error())
-        return false;
-    if (create_root_inode().is_error())
-        return false;
-    return true;
+KResult ISO9660FS::initialize()
+{
+    if (auto result = BlockBasedFileSystem::initialize(); result.is_error())
+        return result;
+    if (auto result = parse_volume_set(); result.is_error())
+        return result;
+    if (auto result = create_root_inode(); result.is_error())
+        return result;
+    return KSuccess;
 }
 
 Inode& ISO9660FS::root_inode()

Kernel/FileSystem/ISO9660FileSystem.h

@@ -312,7 +312,7 @@ public:
     static KResultOr<NonnullRefPtr<ISO9660FS>> try_create(FileDescription&);
 
     virtual ~ISO9660FS() override;
-    virtual bool initialize() override;
+    virtual KResult initialize() override;
     virtual StringView class_name() const override { return "ISO9660FS"; }
     virtual Inode& root_inode() override;
 

Kernel/FileSystem/Plan9FileSystem.cpp

@@ -195,7 +195,7 @@ private:
     bool m_have_been_built { false };
 };
 
-bool Plan9FS::initialize()
+KResult Plan9FS::initialize()
 {
     ensure_thread();
 
@@ -204,7 +204,7 @@ bool Plan9FS::initialize()
 
     auto result = post_message_and_wait_for_a_reply(version_message);
     if (result.is_error())
-        return false;
+        return result;
 
     u32 msize;
     StringView remote_protocol_version;
@@ -227,11 +227,13 @@ bool Plan9FS::initialize()
     result = post_message_and_wait_for_a_reply(attach_message);
     if (result.is_error()) {
         dbgln("Attaching failed");
-        return false;
+        return result;
     }
 
     m_root_inode = Plan9FSInode::create(*this, root_fid);
-    return true;
+    if (!m_root_inode)
+        return ENOMEM;
+    return KSuccess;
 }
 
 Plan9FS::ProtocolVersion Plan9FS::parse_protocol_version(const StringView& s) const

Kernel/FileSystem/Plan9FileSystem.h

@@ -22,7 +22,7 @@ public:
     virtual ~Plan9FS() override;
     static NonnullRefPtr<Plan9FS> create(FileDescription&);
 
-    virtual bool initialize() override;
+    virtual KResult initialize() override;
 
     virtual bool supports_watchers() const override { return false; }
 

Kernel/FileSystem/ProcFS.cpp

@@ -51,9 +51,9 @@ ProcFS::~ProcFS()
 {
 }
 
-bool ProcFS::initialize()
+KResult ProcFS::initialize()
 {
-    return true;
+    return KSuccess;
 }
 
 Inode& ProcFS::root_inode()

Kernel/FileSystem/ProcFS.h

@@ -30,7 +30,7 @@ public:
     virtual ~ProcFS() override;
     static RefPtr<ProcFS> create();
 
-    virtual bool initialize() override;
+    virtual KResult initialize() override;
     virtual StringView class_name() const override { return "ProcFS"sv; }
 
     virtual Inode& root_inode() override;

Kernel/FileSystem/SysFS.cpp

@@ -75,9 +75,9 @@ SysFS::~SysFS()
 {
 }
 
-bool SysFS::initialize()
+KResult SysFS::initialize()
 {
-    return true;
+    return KSuccess;
 }
 
 Inode& SysFS::root_inode()

Kernel/FileSystem/SysFS.h

@@ -62,7 +62,7 @@ public:
     virtual ~SysFS() override;
     static NonnullRefPtr<SysFS> create();
 
-    virtual bool initialize() override;
+    virtual KResult initialize() override;
     virtual StringView class_name() const override { return "SysFS"sv; }
 
     virtual Inode& root_inode() override;

Kernel/FileSystem/TmpFS.cpp

@@ -23,10 +23,12 @@ TmpFS::~TmpFS()
 {
 }
 
-bool TmpFS::initialize()
+KResult TmpFS::initialize()
 {
     m_root_inode = TmpFSInode::create_root(*this);
-    return !m_root_inode.is_null();
+    if (!m_root_inode)
+        return ENOMEM;
+    return KSuccess;
 }
 
 Inode& TmpFS::root_inode()

Kernel/FileSystem/TmpFS.h

@@ -20,7 +20,7 @@ class TmpFS final : public FileSystem {
 public:
     virtual ~TmpFS() override;
     static RefPtr<TmpFS> create();
-    virtual bool initialize() override;
+    virtual KResult initialize() override;
 
     virtual StringView class_name() const override { return "TmpFS"sv; }
 

Kernel/Storage/StorageManagement.cpp

@@ -183,8 +183,8 @@ NonnullRefPtr<FileSystem> StorageManagement::root_filesystem() const
         PANIC("StorageManagement: Couldn't find a suitable device to boot from");
     }
     auto e2fs = Ext2FS::create(FileDescription::create(boot_device_description.release_nonnull()).value());
-    if (!e2fs->initialize()) {
-        PANIC("StorageManagement: Couldn't open root filesystem");
+    if (auto result = e2fs->initialize(); result.is_error()) {
+        PANIC("StorageManagement: Couldn't open root filesystem: {}", result);
     }
     return e2fs;
 }

Kernel/Syscalls/mount.cpp

@@ -121,9 +121,9 @@ KResultOr<FlatPtr> Process::sys$mount(Userspace<const Syscall::SC_mount_params*>
     if (!fs)
         return ENOMEM;
 
-    if (!fs->initialize()) {
+    if (auto result = fs->initialize(); result.is_error()) {
         dbgln("mount: failed to initialize {} filesystem, fd={}", fs_type, source_fd);
-        return ENODEV;
+        return result;
     }
 
     auto result = VirtualFileSystem::the().mount(fs.release_nonnull(), target_custody, params.flags);