diff options
| author | Javier González <javier@javigon.com> | 2018-10-09 13:11:35 +0200 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2018-10-09 08:25:06 -0600 |
| commit | d8adaa3b86324c6186d0adf74bc256bdacfffdb6 (patch) | |
| tree | 57dc2d2307041907fd8b116876e668565f400b25 /drivers/lightnvm/pblk-write.c | |
| parent | 656e33ca3d405196f94133babc4e38454a49cb73 (diff) | |
lightnvm: pblk: fix race condition on metadata I/O
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>
Diffstat (limited to 'drivers/lightnvm/pblk-write.c')
| -rw-r--r-- | drivers/lightnvm/pblk-write.c | 14 |
1 files 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)) |