| Date | Wed, 28 Nov 2012 16:17:59 -0800 | From | Zach Brown <> | Subject | Re: [PATCH 12/25] aio: Refcounting cleanup |
| |
> struct kioctx { > atomic_t users; > - int dead; > + atomic_t dead;
Do we want to be paranoid and atomic_set() that to 0 when the ioctx is allocated?
> + while (!list_empty(&ctx->active_reqs)) { > + struct list_head *pos = ctx->active_reqs.next; > + struct kiocb *iocb = list_kiocb(pos);
I'd use list_first_entry() and ignore the list_kiocb() wrapper, I think.
> + if (!atomic_xchg(&ctx->dead, 1)) { > + hlist_del_rcu(&ctx->list); > + synchronize_rcu();
> + hlist_for_each_entry_rcu(ctx, n, &mm->ioctx_list, list) > + if (ctx->user_id == ctx_id){ > + BUG_ON(atomic_read(&ctx->dead));
Hmm. Won't it be possible to race lookup and io_destroy() to hit this BUG?
- z
|