From: Herbert Xu <herb...@gondor.apana.org.au> Date: Wed, 29 May 2019 13:40:26 +0800
> The smp_store_release call in fqdir_exit cannot protect the setting > of fqdir->dead as claimed because its memory barrier is only > guaranteed to be one-way and the barrier precedes the setting of > fqdir->dead. > > IOW it doesn't provide any barriers between fq->dir and the following > hash table destruction. > > In fact, the code is safe anyway because call_rcu does provide both > the memory barrier as well as a guarantee that when the destruction > work starts executing all RCU readers will see the updated value for > fqdir->dead. > > Therefore this patch removes the unnecessary smp_store_release call > as well as the corresponding READ_ONCE on the read-side in order to > not confuse future readers of this code. Comments have been added > in their places. > > Signed-off-by: Herbert Xu <herb...@gondor.apana.org.au> Applied.
