Re: [PATCH] blktrace: Protect q->blk_trace with RCU

On 2/6/20 11:46 AM, Chaitanya Kulkarni wrote:

Hi Jan,

What do you think about following patch on the top of yours ?

The new helper that I've added on the top of your patch will also future uses of the rcu_dereference_protected(). e.g. blktrace extension [1] support that I'm working on.

P.S. it is compile only if your okay I'll send a separate patch.

+/* Dereference q->blk_trace with q->blk_trace_mutex check only. */ +static inline struct blk_trace *blk_trace_rcu_deref(struct request_queue *q) +{

•   return rcu_dereference_protected(q->blk_trace,
  

lockdep_is_held(&q->blk_trace_mutex)); +}

Let's please not do that, it serves no real purpose and it just obfuscates what's really going on.