Kernel: Move InodeWatcher::Event into Kernel/API/InodeWatcherEvent

This allows userspace code to parse these events.

Kernel/API/InodeWatcherEvent.h

@@ -0,0 +1,42 @@
+/*
+ * Copyright (c) 2020, the SerenityOS developers.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+
+#include <AK/Types.h>
+
+struct [[gnu::packed]] InodeWatcherEvent
+{
+    enum class Type {
+        Invalid = 0,
+        Modified,
+        ChildAdded,
+        ChildRemoved,
+    };
+
+    Type type { Type::Invalid };
+    unsigned inode_index { 0 };
+};

Kernel/FileSystem/Inode.cpp

@@ -28,6 +28,7 @@
 #include <AK/Singleton.h>
 #include <AK/StringBuilder.h>
 #include <AK/StringView.h>
+#include <Kernel/API/InodeWatcherEvent.h>
 #include <Kernel/FileSystem/Custody.h>
 #include <Kernel/FileSystem/Inode.h>
 #include <Kernel/FileSystem/InodeWatcher.h>
@@ -229,7 +230,7 @@ void Inode::set_metadata_dirty(bool metadata_dirty)
         //        We don't always end up on this particular code path, for instance when writing to an ext2fs file.
         LOCKER(m_lock);
         for (auto& watcher : m_watchers) {
-            watcher->notify_inode_event({}, InodeWatcher::Event::Type::Modified);
+            watcher->notify_inode_event({}, InodeWatcherEvent::Type::Modified);
         }
     }
 }

Kernel/FileSystem/InodeWatcher.cpp

@@ -67,7 +67,7 @@ KResultOr<size_t> InodeWatcher::read(FileDescription&, size_t, UserOrKernelBuffe
 
     auto event = m_queue.dequeue();
 
-    if (buffer_size < sizeof(Event))
+    if (buffer_size < sizeof(InodeWatcherEvent))
         return buffer_size;
 
     size_t bytes_to_write = min(buffer_size, sizeof(event));
@@ -94,7 +94,7 @@ String InodeWatcher::absolute_path(const FileDescription&) const
     return "InodeWatcher:(gone)";
 }
 
-void InodeWatcher::notify_inode_event(Badge<Inode>, Event::Type event_type)
+void InodeWatcher::notify_inode_event(Badge<Inode>, InodeWatcherEvent::Type event_type)
 {
     LOCKER(m_lock);
     m_queue.enqueue({ event_type });
@@ -104,14 +104,14 @@ void InodeWatcher::notify_inode_event(Badge<Inode>, Event::Type event_type)
 void InodeWatcher::notify_child_added(Badge<Inode>, const InodeIdentifier& child_id)
 {
     LOCKER(m_lock);
-    m_queue.enqueue({ Event::Type::ChildAdded, child_id.index() });
+    m_queue.enqueue({ InodeWatcherEvent::Type::ChildAdded, child_id.index() });
     evaluate_block_conditions();
 }
 
 void InodeWatcher::notify_child_removed(Badge<Inode>, const InodeIdentifier& child_id)
 {
     LOCKER(m_lock);
-    m_queue.enqueue({ Event::Type::ChildRemoved, child_id.index() });
+    m_queue.enqueue({ InodeWatcherEvent::Type::ChildRemoved, child_id.index() });
     evaluate_block_conditions();
 }
 

Kernel/FileSystem/InodeWatcher.h

@@ -29,6 +29,7 @@
 #include <AK/Badge.h>
 #include <AK/CircularQueue.h>
 #include <AK/WeakPtr.h>
+#include <Kernel/API/InodeWatcherEvent.h>
 #include <Kernel/FileSystem/File.h>
 #include <Kernel/Lock.h>
 
@@ -41,18 +42,6 @@ public:
     static NonnullRefPtr<InodeWatcher> create(Inode&);
     virtual ~InodeWatcher() override;
 
-    struct Event {
-        enum class Type {
-            Invalid = 0,
-            Modified,
-            ChildAdded,
-            ChildRemoved,
-        };
-
-        Type type { Type::Invalid };
-        unsigned inode_index { 0 };
-    };
-
     virtual bool can_read(const FileDescription&, size_t) const override;
     virtual bool can_write(const FileDescription&, size_t) const override;
     virtual KResultOr<size_t> read(FileDescription&, size_t, UserOrKernelBuffer&, size_t) override;
@@ -60,7 +49,7 @@ public:
     virtual String absolute_path(const FileDescription&) const override;
     virtual const char* class_name() const override { return "InodeWatcher"; };
 
-    void notify_inode_event(Badge<Inode>, Event::Type);
+    void notify_inode_event(Badge<Inode>, InodeWatcherEvent::Type);
     void notify_child_added(Badge<Inode>, const InodeIdentifier& child_id);
     void notify_child_removed(Badge<Inode>, const InodeIdentifier& child_id);
 
@@ -69,7 +58,7 @@ private:
 
     Lock m_lock;
     WeakPtr<Inode> m_inode;
-    CircularQueue<Event, 32> m_queue;
+    CircularQueue<InodeWatcherEvent, 32> m_queue;
 };
 
 }