Kernel/ProcFS: Provide a way to write to ProcFS inodes

ProcFSGlobalInode now calls `write_bytes()`, `truncate()` and
`set_mtime()` on its associated component. This allows us to write 0 or
1 to a ProcFSSystemBoolean component to toggle a boolean value.

2 files changed, 12 insertions, 6 deletions

diff --git a/Kernel/FileSystem/ProcFS.cpp b/Kernel/FileSystem/ProcFS.cpp
index e6a034e8a6..fd88f671a4 100644
--- a/Kernel/FileSystem/ProcFS.cpp
+++ b/Kernel/FileSystem/ProcFS.cpp
@@ -99,11 +99,6 @@ KResult ProcFSInode::chown(UserID, GroupID)
     return EPERM;
 }
 
-KResult ProcFSInode::truncate(u64)
-{
-    return EPERM;
-}
-
 KResultOr<NonnullRefPtr<ProcFSGlobalInode>> ProcFSGlobalInode::try_create(const ProcFS& fs, const ProcFSExposedComponent& component)
 {
     return adopt_nonnull_ref_or_enomem(new (nothrow) ProcFSGlobalInode(fs, component));
@@ -151,6 +146,16 @@ KResultOr<NonnullRefPtr<Inode>> ProcFSGlobalInode::lookup(StringView)
     VERIFY_NOT_REACHED();
 }
 
+KResult ProcFSGlobalInode::truncate(u64 size)
+{
+    return m_associated_component->truncate(size);
+}
+
+KResult ProcFSGlobalInode::set_mtime(time_t time)
+{
+    return m_associated_component->set_mtime(time);
+}
+
 InodeMetadata ProcFSGlobalInode::metadata() const
 {
     MutexLocker locker(m_inode_lock);
diff --git a/Kernel/FileSystem/ProcFS.h b/Kernel/FileSystem/ProcFS.h
index 1be5b2f1c6..966cfd55a4 100644
--- a/Kernel/FileSystem/ProcFS.h
+++ b/Kernel/FileSystem/ProcFS.h
@@ -62,7 +62,6 @@ protected:
     virtual KResult remove_child(const StringView& name) override final;
     virtual KResult chmod(mode_t) override final;
     virtual KResult chown(UserID, GroupID) override final;
-    virtual KResult truncate(u64) override final;
 };
 
 class ProcFSGlobalInode : public ProcFSInode {
@@ -84,6 +83,8 @@ protected:
     virtual InodeMetadata metadata() const override;
     virtual KResult traverse_as_directory(Function<bool(FileSystem::DirectoryEntryView const&)>) const override;
     virtual KResultOr<NonnullRefPtr<Inode>> lookup(StringView) override;
+    virtual KResult truncate(u64) override final;
+    virtual KResult set_mtime(time_t) override final;
 
     NonnullRefPtr<ProcFSExposedComponent> m_associated_component;
 };