On 11/12/2018 13.32, santosh.shilimkar@xxxxxxxxxx wrote:
>>> --- a/net/rds/message.c
>>> +++ b/net/rds/message.c
>>> @@ -313,11 +313,14 @@ struct scatterlist *rds_message_alloc_sgs(struct rds_message *rm, int nents)
>>> struct scatterlist *sg_first = (struct scatterlist *) &rm[1];
>>> struct scatterlist *sg_ret;
>>> - WARN_ON(rm->m_used_sgs + nents > rm->m_total_sgs);
>>> - WARN_ON(!nents);
>>> -
>>> - if (rm->m_used_sgs + nents > rm->m_total_sgs)
>>> + if (rm->m_used_sgs + nents > rm->m_total_sgs) {
>>> + pr_warn("rds: alloc sgs failed! total %d used %d nents %d\n",
>>> + rm->m_total_sgs, rm->m_used_sgs, nents);
>>> return NULL;
>>> + }
>>> +
>>> + if (!nents)
>>> + pr_warn("rds: alloc sgs failed! nents 0\n");
> I believe your are taking about above pr_warn, for nents==0 case.
> Its ok to drop the pr_warn but if the behavior leads to
> corruption, then lets fail the nents==0 case to instead of
> silently proceeding.
>
Correct.
IMHO a BUG_ON(!nents) beats memory corruption any day.
Just my 2ç,
Gerd
