Re: [RFC v2 2/5] blktrace: fix debugfs use after free

[Bart Van Assche]

On 2020-04-09 14:45, Luis Chamberlain wrote:
> +void blk_q_debugfs_register(struct request_queue *q)
> +{
> +	q->debugfs_dir = debugfs_create_dir(kobject_name(q->kobj.parent),
> +					    blk_debugfs_root);
> +}
> +
> +void blk_q_debugfs_unregister(struct request_queue *q)
> +{
> +	debugfs_remove_recursive(q->debugfs_dir);
> +	q->debugfs_dir = NULL;
> +}

There are no other functions in the block layer that start with the
prefix blk_q_. How about changing that prefix into blk_?

> -#ifdef CONFIG_BLK_DEBUG_FS
> +#ifdef CONFIG_DEBUG_FS
>  	struct dentry		*debugfs_dir;
> +#endif

Please add a comment above 'debugfs_dir' that it is used not only by the
code in block/blk-*debugfs.c but also by the code in
kernel/trace/blktrace.c. Otherwise this patch looks good to me.

Thanks,

Bart.