Re: [PATCH net 3/3] net/smc: Resolve the race between SMC-R link access and clear

Wen Gu
2022-01-11T15:49:12Z

Thanks for your review.

On 2022/1/11 4:40 pm, Karsten Graul wrote:
> On 10/01/2022 10:26, Wen Gu wrote:
>> @@ -1226,15 +1245,23 @@ void smcr_link_clear(struct smc_link *lnk, bool log)
>> smc_wr_free_link(lnk);
>> smc_ib_destroy_queue_pair(lnk);
>> smc_ib_dealloc_protection_domain(lnk);
>> - smc_wr_free_link_mem(lnk);
>> - smc_lgr_put(lnk->lgr); /* lgr_hold in smcr_link_init() */
>> smc_ibdev_cnt_dec(lnk);
>> put_device(&lnk->smcibdev->ibdev->dev);
>> smcibdev = lnk->smcibdev;
>> - memset(lnk, 0, sizeof(struct smc_link));
>> - lnk->state = SMC_LNK_UNUSED;
>> if (!atomic_dec_return(&smcibdev->lnk_cnt))
>> wake_up(&smcibdev->lnks_deleted);
>
> Same here, waiter should not be woken up until the link memory is actually freed.
>

OK, I will correct this as well.

And similarly I want to move smc_ibdev_cnt_dec() and put_device() to
__smcr_link_clear() as well to ensure that put link related resources
only when link is actually cleared. What do you think?

Thanks,
Wen Gu