From: Christoph Hellwig <hch@lst.de>
Date: Mon, 29 Jun 2020 16:30:19 +0200
Subject: nvme: fix a crash in nvme_mpath_add_disk
Patch-mainline: v5.8-rc4
Git-commit: 72d447113bb751ded97b2e2c38f886e4a4139082
References: git-fixes, bsc#1159058
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>
Acked-by: Martin Wilck <mwilck@suse.com>
---
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 18d084ed497e..66509472fe06 100644
--- a/drivers/nvme/host/multipath.c
+++ b/drivers/nvme/host/multipath.c
@@ -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;
}
}
--
2.28.0