[PATCH 02/13] nvme-multipath: add error handling support for add_disk()
From: Luis Chamberlain <mcgrof@kernel.org>
Date: 2021-10-15 23:53:03
Also in:
linux-nvme, linuxppc-dev, lkml, nvdimm
Subsystem:
nvm express driver, the rest · Maintainers:
Keith Busch, Jens Axboe, Christoph Hellwig, Sagi Grimberg, Linus Torvalds
We never checked for errors on add_disk() as this function returned void. Now that this is fixed, use the shiny new error handling. Since we now can tell for sure when a disk was added, move setting the bit NVME_NSHEAD_DISK_LIVE only when we did add the disk successfully. Nothing to do here as the cleanup is done elsewhere. We take care and use test_and_set_bit() because it is protects against two nvme paths simultaneously calling device_add_disk() on the same namespace head. Signed-off-by: Luis Chamberlain <mcgrof@kernel.org> --- drivers/nvme/host/multipath.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-)
diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c
index e8ccdd398f78..022837f7be41 100644
--- a/drivers/nvme/host/multipath.c
+++ b/drivers/nvme/host/multipath.c@@ -496,13 +496,23 @@ int nvme_mpath_alloc_disk(struct nvme_ctrl *ctrl, struct nvme_ns_head *head) static void nvme_mpath_set_live(struct nvme_ns *ns) { struct nvme_ns_head *head = ns->head; + int rc; if (!head->disk) return; + /* + * test_and_set_bit() is used because it is protecting against two nvme + * paths simultaneously calling device_add_disk() on the same namespace + * head. + */ if (!test_and_set_bit(NVME_NSHEAD_DISK_LIVE, &head->flags)) { - device_add_disk(&head->subsys->dev, head->disk, - nvme_ns_id_attr_groups); + rc = device_add_disk(&head->subsys->dev, head->disk, + nvme_ns_id_attr_groups); + if (rc) { + clear_bit(NVME_NSHEAD_DISK_LIVE, &ns->flags); + return; + } nvme_add_ns_head_cdev(head); }
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2.30.2