From: Israel Rukshin israelr@mellanox.com
Commit b837b28394fb76993c28bb242db7061ee0417da6 upstream.
There is a problem when another module (e.g. nvmet) takes a reference on the nvme block device and the physical nvme drive is removed. In that case nvme_free_ctrl() will not be called and the controller state will be "deleting" or "dead" unless nvmet module releases the block device. Later on, the same nvme drive probes back and nvme_init_subsystem() will be called and fail due to duplicate subnqn (if the nvme device doesn't support subsystem with multiple controllers). This will cause a probe failure. This commit changes the check of multiple controllers support at nvme_init_subsystem() by not counting all the controllers at "dead" or "deleting" state (this is safe because controllers at this state will never be active again).
Fixes: ab9e00cc72fa ("nvme: track subsystems") Reviewed-by: Max Gurtovoy maxg@mellanox.com Signed-off-by: Israel Rukshin israelr@mellanox.com Signed-off-by: Christoph Hellwig hch@lst.de Signed-off-by: Keith Busch keith.busch@intel.com --- drivers/nvme/host/core.c | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-)
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c index 3551fbd6fe41..935593032123 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -2052,6 +2052,22 @@ static const struct attribute_group *nvme_subsys_attrs_groups[] = { NULL, };
+static int nvme_active_ctrls(struct nvme_subsystem *subsys) +{ + int count = 0; + struct nvme_ctrl *ctrl; + + mutex_lock(&subsys->lock); + list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry) { + if (ctrl->state != NVME_CTRL_DELETING && + ctrl->state != NVME_CTRL_DEAD) + count++; + } + mutex_unlock(&subsys->lock); + + return count; +} + static int nvme_init_subsystem(struct nvme_ctrl *ctrl, struct nvme_id_ctrl *id) { struct nvme_subsystem *subsys, *found; @@ -2090,7 +2106,7 @@ static int nvme_init_subsystem(struct nvme_ctrl *ctrl, struct nvme_id_ctrl *id) * Verify that the subsystem actually supports multiple * controllers, else bail out. */ - if (!(id->cmic & (1 << 1))) { + if (nvme_active_ctrls(found) && !(id->cmic & (1 << 1))) { dev_err(ctrl->device, "ignoring ctrl due to duplicate subnqn (%s).\n", found->subnqn);