4.19-stable review patch. If anyone has any objections, please let me know.
------------------
From: Javier González javier@cnexlabs.com
[ Upstream commit d8adaa3b86324c6186d0adf74bc256bdacfffdb6 ]
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 in 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 Signed-off-by: Matias Bjørling mb@lightnvm.io Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/lightnvm/pblk-write.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-)
--- a/drivers/lightnvm/pblk-write.c +++ b/drivers/lightnvm/pblk-write.c @@ -417,12 +417,11 @@ int pblk_submit_meta_io(struct pblk *pbl 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_sub 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))