From: Christoph Hellwig <hch@xxxxxx> [ Upstream commit 72d447113bb751ded97b2e2c38f886e4a4139082 ] For private namespaces ns->head_disk is NULL, so add a NULL check before updating the BDI capabilities. Fixes: b2ce4d90690b ("nvme-multipath: set bdi capabilities once") Reported-by: Avinash M N <Avinash.M.N@xxxxxxx> Signed-off-by: Christoph Hellwig <hch@xxxxxx> Reviewed-by: Sagi Grimberg <sagi@xxxxxxxxxxx> Reviewed-by: Max Gurtovoy <maxg@xxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/nvme/host/multipath.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c index 3ad6183c5e6b4..2e63c1106030b 100644 --- a/drivers/nvme/host/multipath.c +++ b/drivers/nvme/host/multipath.c @@ -532,10 +532,11 @@ void nvme_mpath_add_disk(struct nvme_ns *ns, struct nvme_id_ns *id) } if (bdi_cap_stable_pages_required(ns->queue->backing_dev_info)) { - struct backing_dev_info *info = - ns->head->disk->queue->backing_dev_info; + struct gendisk *disk = ns->head->disk; - info->capabilities |= BDI_CAP_STABLE_WRITES; + if (disk) + disk->queue->backing_dev_info->capabilities |= + BDI_CAP_STABLE_WRITES; } } -- 2.25.1