--- zzzz-none-000/linux-5.4.213/fs/fhandle.c	2022-09-15 10:04:56.000000000 +0000
+++ alder-5690pro-762/linux-5.4.213/fs/fhandle.c	2024-08-14 09:02:08.000000000 +0000
@@ -16,7 +16,7 @@
 
 static long do_sys_name_to_handle(struct path *path,
 				  struct file_handle __user *ufh,
-				  int __user *mnt_id)
+				  int __user *mnt_id, int fh_flags)
 {
 	long retval;
 	struct file_handle f_handle;
@@ -24,11 +24,10 @@
 	struct file_handle *handle = NULL;
 
 	/*
-	 * We need to make sure whether the file system
-	 * support decoding of the file handle
+	 * We need to make sure whether the file system support decoding of
+	 * the file handle if decodeable file handle was requested.
 	 */
-	if (!path->dentry->d_sb->s_export_op ||
-	    !path->dentry->d_sb->s_export_op->fh_to_dentry)
+	if (!exportfs_can_encode_fh(path->dentry->d_sb->s_export_op, fh_flags))
 		return -EOPNOTSUPP;
 
 	if (copy_from_user(&f_handle, ufh, sizeof(struct file_handle)))
@@ -45,10 +44,10 @@
 	/* convert handle size to multiple of sizeof(u32) */
 	handle_dwords = f_handle.handle_bytes >> 2;
 
-	/* we ask for a non connected handle */
+	/* we ask for a non connectable maybe decodeable file handle */
 	retval = exportfs_encode_fh(path->dentry,
 				    (struct fid *)handle->f_handle,
-				    &handle_dwords,  0);
+				    &handle_dwords, fh_flags);
 	handle->handle_type = retval;
 	/* convert handle size to bytes */
 	handle_bytes = handle_dwords * sizeof(u32);
@@ -84,6 +83,7 @@
  * @handle: resulting file handle
  * @mnt_id: mount id of the file system containing the file
  * @flag: flag value to indicate whether to follow symlink or not
+ *        and whether a decodable file handle is required.
  *
  * @handle->handle_size indicate the space available to store the
  * variable part of the file handle in bytes. If there is not
@@ -96,17 +96,19 @@
 {
 	struct path path;
 	int lookup_flags;
+	int fh_flags;
 	int err;
 
-	if ((flag & ~(AT_SYMLINK_FOLLOW | AT_EMPTY_PATH)) != 0)
+	if (flag & ~(AT_SYMLINK_FOLLOW | AT_EMPTY_PATH | AT_HANDLE_FID))
 		return -EINVAL;
 
 	lookup_flags = (flag & AT_SYMLINK_FOLLOW) ? LOOKUP_FOLLOW : 0;
+	fh_flags = (flag & AT_HANDLE_FID) ? EXPORT_FH_FID : 0;
 	if (flag & AT_EMPTY_PATH)
 		lookup_flags |= LOOKUP_EMPTY;
 	err = user_path_at(dfd, name, lookup_flags, &path);
 	if (!err) {
-		err = do_sys_name_to_handle(&path, handle, mnt_id);
+		err = do_sys_name_to_handle(&path, handle, mnt_id, fh_flags);
 		path_put(&path);
 	}
 	return err;