Re: [PATCH 05/14] tracefs: replace call_rcu by kfree_rcu for simple kmem_cache_free callback

Steven Rostedt
2024-06-10T15:22:26Z

On Sun, 9 Jun 2024 10:27:17 +0200
Julia Lawall <Julia.Lawall@inria.fr> wrote:

> diff --git a/fs/tracefs/inode.c b/fs/tracefs/inode.c
> index 7c29f4afc23d..338c52168e61 100644
> --- a/fs/tracefs/inode.c
> +++ b/fs/tracefs/inode.c
> @@ -53,14 +53,6 @@ static struct inode *tracefs_alloc_inode(struct super_block *sb)
> return &ti->vfs_inode;
> }
>
> -static void tracefs_free_inode_rcu(struct rcu_head *rcu)
> -{
> - struct tracefs_inode *ti;
> -
> - ti = container_of(rcu, struct tracefs_inode, rcu);
> - kmem_cache_free(tracefs_inode_cachep, ti);

Does this work?

tracefs needs to be freed via the tracefs_inode_cachep. Does
kfree_rcu() handle specific frees for objects that were not allocated
via kmalloc()?

-- Steve

> -}
> -
> static void tracefs_free_inode(struct inode *inode)
> {
> struct tracefs_inode *ti = get_tracefs(inode);
> @@ -70,7 +62,7 @@ static void tracefs_free_inode(struct inode *inode)
> list_del_rcu(&ti->list);
> spin_unlock_irqrestore(&tracefs_inode_lock, flags);
>
> - call_rcu(&ti->rcu, tracefs_free_inode_rcu);
> + kfree_rcu(ti, rcu);
> }
>
> static ssize_t default_read_file(struct file *file, char __user *buf,