Messages in this thread |  | | Subject | Re: [PATCH -next 1/4] blk-iocost: track whether iocg is still online | From | Yu Kuai <> | Date | Mon, 26 Dec 2022 09:10:41 +0800 |
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Hi, Christoph
在 2022/12/21 18:33, Christoph Hellwig 写道: > On Sat, Dec 17, 2022 at 11:05:24AM +0800, Yu Kuai wrote: >> @@ -459,6 +459,8 @@ struct ioc_gq { >> struct blkg_policy_data pd; >> struct ioc *ioc; >> >> + bool online; > > Nit: maybe tab align this field like the fields above it. > >> +static void ioc_pd_offline(struct blkg_policy_data *pd) >> +{ >> + struct ioc_gq *iocg = pd_to_iocg(pd); >> + struct ioc *ioc = iocg->ioc; >> + unsigned long flags; >> + >> + if (ioc) { > > How could ioc be NULL here? >
As I explained in another thread.. pd_offline_fn() can be called without pd_init_fn(), which is a bug from upper layer...
blkcg_activate_policy spin_lock_irq(&q->queue_lock); list_for_each_entry_reverse(blkg, &q->blkg_list pd_alloc_fn(GFP_NOWAIT | __GFP_NOWARN,...) -> failed
spin_unlock_irq(&q->queue_lock); // release queue_lock here is problematic, this will cause pd_offline_fn called without pd_init_fn. pd_alloc_fn(__GFP_NOWARN,...)
Thanks, Kuai > . >
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