From 6f69d5204fecf151ca0c4a1c0ca904c13ae8d095 Mon Sep 17 00:00:00 2001
From: Andreas Kling <kling@serenityos.org>
Date: Thu, 21 Oct 2021 17:01:52 +0200
Subject: [PATCH] Kernel: Make Inode::flush_metadata() return a KResult

Even if this goes nowhere yet, we have to start building an error
propagation path somewhere.
---
 Kernel/FileSystem/DevPtsFS.cpp          | 3 ++-
 Kernel/FileSystem/DevPtsFS.h            | 2 +-
 Kernel/FileSystem/DevTmpFS.cpp          | 3 ++-
 Kernel/FileSystem/DevTmpFS.h            | 2 +-
 Kernel/FileSystem/Ext2FileSystem.cpp    | 3 ++-
 Kernel/FileSystem/Ext2FileSystem.h      | 2 +-
 Kernel/FileSystem/ISO9660FileSystem.cpp | 3 ++-
 Kernel/FileSystem/ISO9660FileSystem.h   | 2 +-
 Kernel/FileSystem/Inode.cpp             | 6 +++---
 Kernel/FileSystem/Inode.h               | 2 +-
 Kernel/FileSystem/Plan9FileSystem.cpp   | 3 ++-
 Kernel/FileSystem/Plan9FileSystem.h     | 2 +-
 Kernel/FileSystem/ProcFS.cpp            | 3 ++-
 Kernel/FileSystem/ProcFS.h              | 2 +-
 Kernel/FileSystem/SysFS.cpp             | 3 ++-
 Kernel/FileSystem/SysFS.h               | 2 +-
 Kernel/FileSystem/TmpFS.cpp             | 3 ++-
 Kernel/FileSystem/TmpFS.h               | 2 +-
 18 files changed, 28 insertions(+), 20 deletions(-)

diff --git a/Kernel/FileSystem/DevPtsFS.cpp b/Kernel/FileSystem/DevPtsFS.cpp
index 4c64ef1958a..b96cb5bf13d 100644
--- a/Kernel/FileSystem/DevPtsFS.cpp
+++ b/Kernel/FileSystem/DevPtsFS.cpp
@@ -145,8 +145,9 @@ KResultOr<NonnullRefPtr<Inode>> DevPtsFSInode::lookup(StringView name)
     });
 }
 
-void DevPtsFSInode::flush_metadata()
+KResult DevPtsFSInode::flush_metadata()
 {
+    return KSuccess;
 }
 
 KResult DevPtsFSInode::add_child(Inode&, const StringView&, mode_t)
diff --git a/Kernel/FileSystem/DevPtsFS.h b/Kernel/FileSystem/DevPtsFS.h
index 11a336039ba..e907a521777 100644
--- a/Kernel/FileSystem/DevPtsFS.h
+++ b/Kernel/FileSystem/DevPtsFS.h
@@ -51,7 +51,7 @@ private:
     virtual InodeMetadata metadata() const override;
     virtual KResult traverse_as_directory(Function<bool(FileSystem::DirectoryEntryView const&)>) const override;
     virtual KResultOr<NonnullRefPtr<Inode>> lookup(StringView name) override;
-    virtual void flush_metadata() override;
+    virtual KResult flush_metadata() override;
     virtual KResultOr<size_t> write_bytes(off_t, size_t, const UserOrKernelBuffer& buffer, OpenFileDescription*) override;
     virtual KResultOr<NonnullRefPtr<Inode>> create_child(StringView name, mode_t, dev_t, UserID, GroupID) override;
     virtual KResult add_child(Inode&, const StringView& name, mode_t) override;
diff --git a/Kernel/FileSystem/DevTmpFS.cpp b/Kernel/FileSystem/DevTmpFS.cpp
index 93df86d516c..8552bb2eaa3 100644
--- a/Kernel/FileSystem/DevTmpFS.cpp
+++ b/Kernel/FileSystem/DevTmpFS.cpp
@@ -70,8 +70,9 @@ KResultOr<NonnullRefPtr<Inode>> DevTmpFSInode::lookup(StringView)
     VERIFY_NOT_REACHED();
 }
 
-void DevTmpFSInode::flush_metadata()
+KResult DevTmpFSInode::flush_metadata()
 {
+    return KSuccess;
 }
 
 KResultOr<size_t> DevTmpFSInode::write_bytes(off_t, size_t, const UserOrKernelBuffer&, OpenFileDescription*)
diff --git a/Kernel/FileSystem/DevTmpFS.h b/Kernel/FileSystem/DevTmpFS.h
index d2545599ead..418252d6afa 100644
--- a/Kernel/FileSystem/DevTmpFS.h
+++ b/Kernel/FileSystem/DevTmpFS.h
@@ -51,7 +51,7 @@ protected:
     virtual KResultOr<size_t> read_bytes(off_t, size_t, UserOrKernelBuffer& buffer, OpenFileDescription*) const override;
     virtual KResult traverse_as_directory(Function<bool(FileSystem::DirectoryEntryView const&)>) const override;
     virtual KResultOr<NonnullRefPtr<Inode>> lookup(StringView name) override;
-    virtual void flush_metadata() override;
+    virtual KResult flush_metadata() override;
     virtual InodeMetadata metadata() const override final;
     virtual KResultOr<size_t> write_bytes(off_t, size_t, const UserOrKernelBuffer& buffer, OpenFileDescription*) override;
     virtual KResultOr<NonnullRefPtr<Inode>> create_child(StringView name, mode_t, dev_t, UserID, GroupID) override;
diff --git a/Kernel/FileSystem/Ext2FileSystem.cpp b/Kernel/FileSystem/Ext2FileSystem.cpp
index f50ba218499..98a9979dc0c 100644
--- a/Kernel/FileSystem/Ext2FileSystem.cpp
+++ b/Kernel/FileSystem/Ext2FileSystem.cpp
@@ -773,7 +773,7 @@ InodeMetadata Ext2FSInode::metadata() const
     return metadata;
 }
 
-void Ext2FSInode::flush_metadata()
+KResult Ext2FSInode::flush_metadata()
 {
     MutexLocker locker(m_inode_lock);
     dbgln_if(EXT2_DEBUG, "Ext2FSInode[{}]::flush_metadata(): Flushing inode", identifier());
@@ -786,6 +786,7 @@ void Ext2FSInode::flush_metadata()
         }
     }
     set_metadata_dirty(false);
+    return KSuccess;
 }
 
 KResultOr<NonnullRefPtr<Inode>> Ext2FS::get_inode(InodeIdentifier inode) const
diff --git a/Kernel/FileSystem/Ext2FileSystem.h b/Kernel/FileSystem/Ext2FileSystem.h
index 1da3ccf9aa3..078152daf1f 100644
--- a/Kernel/FileSystem/Ext2FileSystem.h
+++ b/Kernel/FileSystem/Ext2FileSystem.h
@@ -42,7 +42,7 @@ private:
     virtual InodeMetadata metadata() const override;
     virtual KResult traverse_as_directory(Function<bool(FileSystem::DirectoryEntryView const&)>) const override;
     virtual KResultOr<NonnullRefPtr<Inode>> lookup(StringView name) override;
-    virtual void flush_metadata() override;
+    virtual KResult flush_metadata() override;
     virtual KResultOr<size_t> write_bytes(off_t, size_t, const UserOrKernelBuffer& data, OpenFileDescription*) override;
     virtual KResultOr<NonnullRefPtr<Inode>> create_child(StringView name, mode_t, dev_t, UserID, GroupID) override;
     virtual KResult add_child(Inode& child, const StringView& name, mode_t) override;
diff --git a/Kernel/FileSystem/ISO9660FileSystem.cpp b/Kernel/FileSystem/ISO9660FileSystem.cpp
index a964f1945fc..492433f3d73 100644
--- a/Kernel/FileSystem/ISO9660FileSystem.cpp
+++ b/Kernel/FileSystem/ISO9660FileSystem.cpp
@@ -499,8 +499,9 @@ KResultOr<NonnullRefPtr<Inode>> ISO9660Inode::lookup(StringView name)
     return inode.release_nonnull();
 }
 
-void ISO9660Inode::flush_metadata()
+KResult ISO9660Inode::flush_metadata()
 {
+    return KSuccess;
 }
 
 KResultOr<size_t> ISO9660Inode::write_bytes(off_t, size_t, const UserOrKernelBuffer&, OpenFileDescription*)
diff --git a/Kernel/FileSystem/ISO9660FileSystem.h b/Kernel/FileSystem/ISO9660FileSystem.h
index f0bb51832dd..5db938cdd8b 100644
--- a/Kernel/FileSystem/ISO9660FileSystem.h
+++ b/Kernel/FileSystem/ISO9660FileSystem.h
@@ -351,7 +351,7 @@ public:
     virtual InodeMetadata metadata() const override;
     virtual KResult traverse_as_directory(Function<bool(FileSystem::DirectoryEntryView const&)>) const override;
     virtual KResultOr<NonnullRefPtr<Inode>> lookup(StringView name) override;
-    virtual void flush_metadata() override;
+    virtual KResult flush_metadata() override;
     virtual KResultOr<size_t> write_bytes(off_t, size_t, const UserOrKernelBuffer& buffer, OpenFileDescription*) override;
     virtual KResultOr<NonnullRefPtr<Inode>> create_child(StringView name, mode_t, dev_t, UserID, GroupID) override;
     virtual KResult add_child(Inode&, const StringView& name, mode_t) override;
diff --git a/Kernel/FileSystem/Inode.cpp b/Kernel/FileSystem/Inode.cpp
index 799e6cbb7a6..dd53e593d9f 100644
--- a/Kernel/FileSystem/Inode.cpp
+++ b/Kernel/FileSystem/Inode.cpp
@@ -41,14 +41,14 @@ void Inode::sync_all()
 
     for (auto& inode : inodes) {
         VERIFY(inode.is_metadata_dirty());
-        inode.flush_metadata();
+        (void)inode.flush_metadata();
     }
 }
 
 void Inode::sync()
 {
     if (is_metadata_dirty())
-        flush_metadata();
+        (void)flush_metadata();
     fs().flush_writes();
 }
 
@@ -103,7 +103,7 @@ void Inode::will_be_destroyed()
 {
     MutexLocker locker(m_inode_lock);
     if (m_metadata_dirty)
-        flush_metadata();
+        (void)flush_metadata();
 }
 
 KResult Inode::set_atime(time_t)
diff --git a/Kernel/FileSystem/Inode.h b/Kernel/FileSystem/Inode.h
index 4356915a82a..eddb3030c1b 100644
--- a/Kernel/FileSystem/Inode.h
+++ b/Kernel/FileSystem/Inode.h
@@ -81,7 +81,7 @@ public:
     virtual KResult increment_link_count();
     virtual KResult decrement_link_count();
 
-    virtual void flush_metadata() = 0;
+    virtual KResult flush_metadata() = 0;
 
     void will_be_destroyed();
 
diff --git a/Kernel/FileSystem/Plan9FileSystem.cpp b/Kernel/FileSystem/Plan9FileSystem.cpp
index d239f4a7411..3ad1158577e 100644
--- a/Kernel/FileSystem/Plan9FileSystem.cpp
+++ b/Kernel/FileSystem/Plan9FileSystem.cpp
@@ -822,9 +822,10 @@ InodeMetadata Plan9FSInode::metadata() const
     return metadata;
 }
 
-void Plan9FSInode::flush_metadata()
+KResult Plan9FSInode::flush_metadata()
 {
     // Do nothing.
+    return KSuccess;
 }
 
 KResult Plan9FSInode::traverse_as_directory(Function<bool(FileSystem::DirectoryEntryView const&)> callback) const
diff --git a/Kernel/FileSystem/Plan9FileSystem.h b/Kernel/FileSystem/Plan9FileSystem.h
index 1dfe4f7e55d..835432b44e2 100644
--- a/Kernel/FileSystem/Plan9FileSystem.h
+++ b/Kernel/FileSystem/Plan9FileSystem.h
@@ -155,7 +155,7 @@ public:
 
     // ^Inode
     virtual InodeMetadata metadata() const override;
-    virtual void flush_metadata() override;
+    virtual KResult flush_metadata() override;
     virtual KResultOr<size_t> read_bytes(off_t, size_t, UserOrKernelBuffer& buffer, OpenFileDescription*) const override;
     virtual KResultOr<size_t> write_bytes(off_t, size_t, const UserOrKernelBuffer& data, OpenFileDescription*) override;
     virtual KResult traverse_as_directory(Function<bool(FileSystem::DirectoryEntryView const&)>) const override;
diff --git a/Kernel/FileSystem/ProcFS.cpp b/Kernel/FileSystem/ProcFS.cpp
index fd88f671a42..de36b0513f0 100644
--- a/Kernel/FileSystem/ProcFS.cpp
+++ b/Kernel/FileSystem/ProcFS.cpp
@@ -70,8 +70,9 @@ ProcFSInode::~ProcFSInode()
 {
 }
 
-void ProcFSInode::flush_metadata()
+KResult ProcFSInode::flush_metadata()
 {
+    return KSuccess;
 }
 
 KResult ProcFSInode::add_child(Inode&, const StringView&, mode_t)
diff --git a/Kernel/FileSystem/ProcFS.h b/Kernel/FileSystem/ProcFS.h
index 966cfd55a41..abd525ea5b2 100644
--- a/Kernel/FileSystem/ProcFS.h
+++ b/Kernel/FileSystem/ProcFS.h
@@ -56,7 +56,7 @@ protected:
     // ^Inode
     virtual KResult attach(OpenFileDescription& description) = 0;
     virtual void did_seek(OpenFileDescription&, off_t) = 0;
-    virtual void flush_metadata() override final;
+    virtual KResult flush_metadata() override final;
     virtual KResultOr<NonnullRefPtr<Inode>> create_child(StringView name, mode_t, dev_t, UserID, GroupID) override final;
     virtual KResult add_child(Inode&, const StringView& name, mode_t) override final;
     virtual KResult remove_child(const StringView& name) override final;
diff --git a/Kernel/FileSystem/SysFS.cpp b/Kernel/FileSystem/SysFS.cpp
index cc26614663c..e45da8a7337 100644
--- a/Kernel/FileSystem/SysFS.cpp
+++ b/Kernel/FileSystem/SysFS.cpp
@@ -148,8 +148,9 @@ InodeMetadata SysFSInode::metadata() const
     return metadata;
 }
 
-void SysFSInode::flush_metadata()
+KResult SysFSInode::flush_metadata()
 {
+    return KSuccess;
 }
 
 KResultOr<size_t> SysFSInode::write_bytes(off_t offset, size_t count, UserOrKernelBuffer const& buffer, OpenFileDescription* fd)
diff --git a/Kernel/FileSystem/SysFS.h b/Kernel/FileSystem/SysFS.h
index 4b8bf05c946..d62781f48c4 100644
--- a/Kernel/FileSystem/SysFS.h
+++ b/Kernel/FileSystem/SysFS.h
@@ -137,7 +137,7 @@ protected:
     virtual KResultOr<size_t> read_bytes(off_t, size_t, UserOrKernelBuffer& buffer, OpenFileDescription*) const override;
     virtual KResult traverse_as_directory(Function<bool(FileSystem::DirectoryEntryView const&)>) const override;
     virtual KResultOr<NonnullRefPtr<Inode>> lookup(StringView name) override;
-    virtual void flush_metadata() override;
+    virtual KResult flush_metadata() override;
     virtual InodeMetadata metadata() const override;
     virtual KResultOr<size_t> write_bytes(off_t, size_t, UserOrKernelBuffer const&, OpenFileDescription*) override;
     virtual KResultOr<NonnullRefPtr<Inode>> create_child(StringView name, mode_t, dev_t, UserID, GroupID) override;
diff --git a/Kernel/FileSystem/TmpFS.cpp b/Kernel/FileSystem/TmpFS.cpp
index f1e43397e28..17115a093a9 100644
--- a/Kernel/FileSystem/TmpFS.cpp
+++ b/Kernel/FileSystem/TmpFS.cpp
@@ -216,7 +216,7 @@ void TmpFSInode::notify_watchers()
     set_metadata_dirty(false);
 }
 
-void TmpFSInode::flush_metadata()
+KResult TmpFSInode::flush_metadata()
 {
     // We don't really have any metadata that could become dirty.
     // The only reason we even call set_metadata_dirty() is
@@ -224,6 +224,7 @@ void TmpFSInode::flush_metadata()
     // switched to a different mechanism, we can stop ever marking
     // our metadata as dirty at all.
     set_metadata_dirty(false);
+    return KSuccess;
 }
 
 KResult TmpFSInode::chmod(mode_t mode)
diff --git a/Kernel/FileSystem/TmpFS.h b/Kernel/FileSystem/TmpFS.h
index 87441885b66..c13cc908f27 100644
--- a/Kernel/FileSystem/TmpFS.h
+++ b/Kernel/FileSystem/TmpFS.h
@@ -56,7 +56,7 @@ public:
     virtual InodeMetadata metadata() const override;
     virtual KResult traverse_as_directory(Function<bool(FileSystem::DirectoryEntryView const&)>) const override;
     virtual KResultOr<NonnullRefPtr<Inode>> lookup(StringView name) override;
-    virtual void flush_metadata() override;
+    virtual KResult flush_metadata() override;
     virtual KResultOr<size_t> write_bytes(off_t, size_t, const UserOrKernelBuffer& buffer, OpenFileDescription*) override;
     virtual KResultOr<NonnullRefPtr<Inode>> create_child(StringView name, mode_t, dev_t, UserID, GroupID) override;
     virtual KResult add_child(Inode&, const StringView& name, mode_t) override;