Messages in this thread | | | Subject | Re: [PATCH] lightnvm: pblk: fix race condition on metadata I/O | From | Matias Bjørling <> | Date | Fri, 17 Aug 2018 12:37:02 +0200 |
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On 08/17/2018 12:22 PM, Javier González wrote: > In pblk, when a new line is allocated, metadata for the previously > written line is scheduled. This is done through a fixed memory region > that is shared through time and contexts across different lines and > therefore protected by a lock. Unfortunately, this lock is not properly > covering all the metadata used for sharing this memory regions, > resulting on a race condition. > > This patch fixes this race condition by protecting this metadata > properly. > > Fixes: dd2a43437337 ("lightnvm: pblk: sched. metadata on write thread") > > Signed-off-by: Javier González <javier@cnexlabs.com> > --- > drivers/lightnvm/pblk-write.c | 14 +++++++------- > 1 file changed, 7 insertions(+), 7 deletions(-) > > diff --git a/drivers/lightnvm/pblk-write.c b/drivers/lightnvm/pblk-write.c > index 508c63701eda..df99c45778d4 100644 > --- a/drivers/lightnvm/pblk-write.c > +++ b/drivers/lightnvm/pblk-write.c > @@ -417,12 +417,11 @@ int pblk_submit_meta_io(struct pblk *pblk, struct pblk_line *meta_line) > rqd->ppa_list[i] = addr_to_gen_ppa(pblk, paddr, id); > } > > + spin_lock(&l_mg->close_lock); > emeta->mem += rq_len; > - if (emeta->mem >= lm->emeta_len[0]) { > - spin_lock(&l_mg->close_lock); > + if (emeta->mem >= lm->emeta_len[0]) > list_del(&meta_line->list); > - spin_unlock(&l_mg->close_lock); > - } > + spin_unlock(&l_mg->close_lock); > > pblk_down_page(pblk, rqd->ppa_list, rqd->nr_ppas); > > @@ -491,14 +490,15 @@ static struct pblk_line *pblk_should_submit_meta_io(struct pblk *pblk, > struct pblk_line *meta_line; > > spin_lock(&l_mg->close_lock); > -retry: > if (list_empty(&l_mg->emeta_list)) { > spin_unlock(&l_mg->close_lock); > return NULL; > } > meta_line = list_first_entry(&l_mg->emeta_list, struct pblk_line, list); > - if (meta_line->emeta->mem >= lm->emeta_len[0]) > - goto retry; > + if (meta_line->emeta->mem >= lm->emeta_len[0]) { > + spin_unlock(&l_mg->close_lock); > + return NULL; > + } > spin_unlock(&l_mg->close_lock); > > if (!pblk_valid_meta_ppa(pblk, meta_line, data_rqd)) >
Thanks. Applied for 4.20.
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