On Wed, Aug 07, 2024 at 09:35:45AM -0400, Steven Rostedt wrote:
> Perhaps:
>
> diff --git a/fs/tracefs/internal.h b/fs/tracefs/internal.h
> index f704d8348357..ab6d6c3d835d 100644
> --- a/fs/tracefs/internal.h
> +++ b/fs/tracefs/internal.h
> @@ -10,12 +10,12 @@ enum {
> };
>
> struct tracefs_inode {
> + struct inode vfs_inode;
> + /* The below gets initialized with memset_after(ti, 0, vfs_inode) */
> union {
> - struct inode vfs_inode;
> + struct list_head list;
> struct rcu_head rcu;
> };
> - /* The below gets initialized with memset_after(ti, 0, vfs_inode) */
> - struct list_head list;
> unsigned long flags;
> void *private;
> };
Your current variant gives you an RCU-delayed call of
tracefs_free_inode(), which schedules an RCU-delayed call of
tracefs_free_inode_rcu().
Do you really need that double RCU delay to start with?
Because if you do not, just do that list_del_rcu() in ->destroy_inode()
(which is called without an RCU delay) and have kmem_cache_free()
in ->free_inode() (which is called *with* RCU delay started after
the call of ->destroy_inode()).
