On 2018-11-05 7:26 a.m., Hans Holmberg wrote:
> From: Hans Holmberg <hans.holmberg@xxxxxxxxxxxx>
>
> Make sure we only look up valid lba addresses on the resubmission path.
>
> If an lba is invalidated in the write buffer, that sector will be
> submitted to disk(as it is already mapped to a ppa), and that write
submitted to disk(as it is already mapped to a ppa), and that write
^
add a space
> might fail, resulting in a crash when trying to look up the lba in the
> mapping table (as the lba is marked as invalid).
>
> Signed-off-by: Hans Holmberg <hans.holmberg@xxxxxxxxxxxx>
> ---
> drivers/lightnvm/pblk-write.c | 8 +++++---
> 1 file changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/lightnvm/pblk-write.c b/drivers/lightnvm/pblk-write.c
> index fa8726493b39..3ddd16f47106 100644
> --- a/drivers/lightnvm/pblk-write.c
> +++ b/drivers/lightnvm/pblk-write.c
> @@ -148,9 +148,11 @@ static void pblk_prepare_resubmit(struct pblk *pblk, unsigned int sentry,
> w_ctx = &entry->w_ctx;
>
> /* Check if the lba has been overwritten */
> - ppa_l2p = pblk_trans_map_get(pblk, w_ctx->lba);
> - if (!pblk_ppa_comp(ppa_l2p, entry->cacheline))
> - w_ctx->lba = ADDR_EMPTY;
> + if (w_ctx->lba != ADDR_EMPTY) {
> + ppa_l2p = pblk_trans_map_get(pblk, w_ctx->lba);
> + if (!pblk_ppa_comp(ppa_l2p, entry->cacheline))
> + w_ctx->lba = ADDR_EMPTY;
> + }
Was w_ctx->lba set to ADDR_EMPTY in the same kernel I/O thread ?
I wonder if w_ctx->lba could become ADDR_EMPTY after
if (w_ctx->lba != ADDR_EMPTY) {
but before
ppa_l2p = pblk_trans_map_get(pblk, w_ctx->lba);
>
> /* Mark up the entry as submittable again */
> flags = READ_ONCE(w_ctx->flags);
>
