From 531dbaf5617a6fd6f2868bcce5b799917df5077b Mon Sep 17 00:00:00 2001
From: Michal Lenc <michallenc@seznam.cz>
Date: Mon, 7 Oct 2024 10:55:43 +0200
Subject: [PATCH] fs_close: provide inotify call for close

Close operation on file should lead to IN_CLOSE_WRITE or
IN_CLOSE_NOWRITE notifications. This commits adds the notification
support. Notifying on close is a little bit trickier as a lower layer
may not have the full file path after successful close and inode release.
Calling notification before close is not a solution since close might
not end successfully.

The solution is to obtain and buffer the path before calling close
and then pass the buffered path to the notify_close. This required the
change in notify_close function arguments: filep is no longer
required, path and oflags are passed instead.

Signed-off-by: Michal Lenc <michallenc@seznam.cz>
---
 fs/notify/inotify.c |  8 ++++----
 fs/notify/notify.h  |  2 +-
 fs/vfs/fs_close.c   | 46 +++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 51 insertions(+), 5 deletions(-)

diff --git a/fs/notify/inotify.c b/fs/notify/inotify.c
index f7e34bd34e..5b47bc54e8 100644
--- a/fs/notify/inotify.c
+++ b/fs/notify/inotify.c
@@ -1342,15 +1342,15 @@ void notify_open(FAR const char *path, int oflags)
  *
  ****************************************************************************/
 
-void notify_close(FAR struct file *filep)
+void notify_close(FAR const char *path, int oflags)
 {
-  if (filep->f_oflags & O_WROK)
+  if (oflags & O_WROK)
     {
-      notify_queue_filep_event(filep, IN_CLOSE_WRITE);
+      notify_queue_path_event(path, IN_CLOSE_WRITE);
     }
   else
     {
-      notify_queue_filep_event(filep, IN_CLOSE_NOWRITE);
+      notify_queue_path_event(path, IN_CLOSE_NOWRITE);
     }
 }
 
diff --git a/fs/notify/notify.h b/fs/notify/notify.h
index 4a0fc11b02..dad750513f 100644
--- a/fs/notify/notify.h
+++ b/fs/notify/notify.h
@@ -42,7 +42,7 @@
 /* These are internal OS interface and are not available to applications */
 
 void notify_open(FAR const char *path, int oflags);
-void notify_close(FAR struct file *filep);
+void notify_close(FAR const char *path, int oflags);
 void notify_close2(FAR struct inode *inode);
 void notify_read(FAR struct file *filep);
 void notify_write(FAR struct file *filep);
diff --git a/fs/vfs/fs_close.c b/fs/vfs/fs_close.c
index 52924030df..514a8bf71a 100644
--- a/fs/vfs/fs_close.c
+++ b/fs/vfs/fs_close.c
@@ -36,6 +36,33 @@
 #include "inode/inode.h"
 #include "vfs/lock.h"
 
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+#ifdef CONFIG_FS_NOTIFY
+static FAR char *file_get_path(FAR struct file *filep)
+{
+  FAR char *pathbuffer;
+  int ret;
+
+  pathbuffer = lib_get_pathbuffer();
+  if (pathbuffer == NULL)
+    {
+      return NULL;
+    }
+
+  ret = file_fcntl(filep, F_GETPATH, pathbuffer);
+  if (ret < 0)
+    {
+      lib_put_pathbuffer(pathbuffer);
+      return NULL;
+    }
+
+  return pathbuffer;
+}
+#endif
+
 /****************************************************************************
  * Public Functions
  ****************************************************************************/
@@ -60,11 +87,22 @@
 int file_close_without_clear(FAR struct file *filep)
 {
   struct inode *inode;
+#ifdef CONFIG_FS_NOTIFY
+  FAR char *path;
+#endif
   int ret = OK;
 
   DEBUGASSERT(filep != NULL);
   inode = filep->f_inode;
 
+#ifdef CONFIG_FS_NOTIFY
+  /* We lose the path and inode during close and release, so obtain it
+   * in advance. Then we pass it to notify_close function.
+   */
+
+  path = file_get_path(filep);
+#endif
+
   /* Check if the struct file is open (i.e., assigned an inode) */
 
   if (inode)
@@ -84,6 +122,14 @@ int file_close_without_clear(FAR struct file *filep)
 
       if (ret >= 0)
         {
+#ifdef CONFIG_FS_NOTIFY
+          if (path != NULL)
+            {
+              notify_close(path, filep->f_oflags);
+              lib_put_pathbuffer(path);
+            }
+#endif
+
           inode_release(inode);
         }
     }