| Message ID | 1534501324-13693-1-git-send-email-javier@cnexlabs.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | lightnvm: pblk: fix race condition on metadata I/O | expand |
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.
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))
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(-)