fs/file_table.c:fput(): add comment

A missed update to "fput: task_work_add() can fail if the caller has passed exit_task_work()". Cc: "Eric W. Biederman" <[email protected]> Cc: Al Viro <[email protected]> Cc: Andrey Vagin <[email protected]> Cc: David Howells <[email protected]> Cc: Oleg Nesterov <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Al Viro <[email protected]>
patjak · Jul 13, 2013 · 6437250 · 6437250
1 parent bb458c6
commit 6437250
Showing 1 changed file with 6 additions and 0 deletions.
diff --git a/fs/file_table.c b/fs/file_table.c
@@ -313,6 +313,12 @@ void fput(struct file *file)
 			init_task_work(&file->f_u.fu_rcuhead, ____fput);
 			if (!task_work_add(task, &file->f_u.fu_rcuhead, true))
 				return;
+			/*
+			 * After this task has run exit_task_work(),
+			 * task_work_add() will fail.  free_ipc_ns()->
+			 * shm_destroy() can do this.  Fall through to delayed
+			 * fput to avoid leaking *file.
+			 */
 		}
 		spin_lock_irqsave(&delayed_fput_lock, flags);
 		list_add(&file->f_u.fu_list, &delayed_fput_list);