Commit 72d44711 authored Jun 29, 2020 by Christoph Hellwig

nvme: fix a crash in nvme_mpath_add_disk



For private namespaces ns->head_disk is NULL, so add a NULL check
before updating the BDI capabilities.

Fixes: b2ce4d90 ("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>

parent ea43d970

drivers/nvme/host/multipath.c

+4 −3

Original line number	Diff line number	Diff line
		@@ -672,10 +672,11 @@ 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;
		}
		}

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