On 07.08.24 17:49, Steven Rostedt wrote:
> [...]
>
> So I could use destroy_inode() for the removing of the link list, and then
> free_inode to free it. Something like:
>
> diff --git a/fs/tracefs/inode.c b/fs/tracefs/inode.c
> index 1028ab6d9a74..ae2cb2221acd 100644
> --- a/fs/tracefs/inode.c
> +++ b/fs/tracefs/inode.c
> @@ -53,15 +53,14 @@ static struct inode *tracefs_alloc_inode(struct
> super_block *sb)
> return &ti->vfs_inode;
> }
>
> -static void tracefs_free_inode_rcu(struct rcu_head *rcu)
> +static void tracefs_free_inode(struct inode *inode)
> {
> - struct tracefs_inode *ti;
> + struct tracefs_inode *ti = get_tracefs(inode);
>
> - ti = container_of(rcu, struct tracefs_inode, rcu);
> kmem_cache_free(tracefs_inode_cachep, ti);
> }
>
> -static void tracefs_free_inode(struct inode *inode)
> +static void tracefs_destroy_inode(struct inode *inode)
> {
> struct tracefs_inode *ti = get_tracefs(inode);
> unsigned long flags;
> @@ -69,8 +68,6 @@ static void tracefs_free_inode(struct inode *inode)
> spin_lock_irqsave(&tracefs_inode_lock, flags);
> list_del_rcu(&ti->list);
> spin_unlock_irqrestore(&tracefs_inode_lock, flags);
> -
> - call_rcu(&ti->rcu, tracefs_free_inode_rcu);
> }
>
> static ssize_t default_read_file(struct file *file, char __user *buf,
> @@ -437,6 +434,7 @@ static int tracefs_drop_inode(struct inode *inode)
> static const struct super_operations tracefs_super_operations = {
> .alloc_inode = tracefs_alloc_inode,
> .free_inode = tracefs_free_inode,
> + .destroy_inode = tracefs_destroy_inode,
> .drop_inode = tracefs_drop_inode,
> .statfs = simple_statfs,
> .show_options = tracefs_show_options,
> diff --git a/fs/tracefs/internal.h b/fs/tracefs/internal.h
> index f704d8348357..d83c2a25f288 100644
> --- a/fs/tracefs/internal.h
> +++ b/fs/tracefs/internal.h
> @@ -10,10 +10,7 @@ enum {
> };
>
> struct tracefs_inode {
> - union {
> - struct inode vfs_inode;
> - struct rcu_head rcu;
> - };
> + struct inode vfs_inode;
> /* The below gets initialized with memset_after(ti, 0, vfs_inode) */
> struct list_head list;
> unsigned long flags;
>
>
> I'll run this under some more tests and see if it doesn't crash.
>
> I'll apply the first patch of this series too, and then probably use this
> one.
LGTM, will give it some testing here too.
Thanks,
Mathias
