nvme: fix a crash in nvme_mpath_add_disk

[ 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@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Christoph Hellwig 2020-06-29 16:30:19 +02:00 committed by Greg Kroah-Hartman
parent c64141c68f
commit cd62eeb315
1 changed files with 4 additions and 3 deletions

View File

@ -673,10 +673,11 @@ 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;
}
}