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authorSteve Wise <swise@opengridcomputing.com>2016-09-02 09:01:54 -0700
committerSagi Grimberg <sagi@grimberg.me>2016-09-12 22:29:41 +0300
commite87a911fed07e368c6f97e75152e6297a7dfba48 (patch)
tree993be810cc0bd7019f3e1c5faf2d2a02b33202a4 /drivers
parente89ca58f9c901c8c4cfb09f96d879b186bb01492 (diff)
nvme-rdma: use ib_client API to detect device removal
Change nvme-rdma to use the IB Client API to detect device removal. This has the wonderful benefit of being able to blow away all the ib/rdma_cm resources for the device being removed. No craziness about not destroying the cm_id handling the event. No deadlocks due to broken iw_cm/rdma_cm/iwarp dependencies. And no need to have a bound cm_id around during controller recovery/reconnect to catch device removal events. We don't use the device_add aspect of the ib_client service since we only want to create resources for an IB device if we have a target utilizing that device. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Steve Wise <swise@opengridcomputing.com> Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/nvme/host/rdma.c108
1 files changed, 40 insertions, 68 deletions
diff --git a/drivers/nvme/host/rdma.c b/drivers/nvme/host/rdma.c
index eeb08b658640..d6bdf55a969e 100644
--- a/drivers/nvme/host/rdma.c
+++ b/drivers/nvme/host/rdma.c
@@ -1320,64 +1320,6 @@ out_destroy_queue_ib:
return ret;
}
-/**
- * nvme_rdma_device_unplug() - Handle RDMA device unplug
- * @queue: Queue that owns the cm_id that caught the event
- *
- * DEVICE_REMOVAL event notifies us that the RDMA device is about
- * to unplug so we should take care of destroying our RDMA resources.
- * This event will be generated for each allocated cm_id.
- *
- * In our case, the RDMA resources are managed per controller and not
- * only per queue. So the way we handle this is we trigger an implicit
- * controller deletion upon the first DEVICE_REMOVAL event we see, and
- * hold the event inflight until the controller deletion is completed.
- *
- * One exception that we need to handle is the destruction of the cm_id
- * that caught the event. Since we hold the callout until the controller
- * deletion is completed, we'll deadlock if the controller deletion will
- * call rdma_destroy_id on this queue's cm_id. Thus, we claim ownership
- * of destroying this queue before-hand, destroy the queue resources,
- * then queue the controller deletion which won't destroy this queue and
- * we destroy the cm_id implicitely by returning a non-zero rc to the callout.
- */
-static int nvme_rdma_device_unplug(struct nvme_rdma_queue *queue)
-{
- struct nvme_rdma_ctrl *ctrl = queue->ctrl;
- int ret = 0;
-
- /* Own the controller deletion */
- if (!nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_DELETING))
- return 0;
-
- dev_warn(ctrl->ctrl.device,
- "Got rdma device removal event, deleting ctrl\n");
-
- /* Get rid of reconnect work if its running */
- cancel_delayed_work_sync(&ctrl->reconnect_work);
-
- /* Disable the queue so ctrl delete won't free it */
- if (!test_and_set_bit(NVME_RDMA_Q_DELETING, &queue->flags)) {
- /* Free this queue ourselves */
- nvme_rdma_stop_queue(queue);
- nvme_rdma_destroy_queue_ib(queue);
-
- /* Return non-zero so the cm_id will destroy implicitly */
- ret = 1;
- }
-
- /*
- * Queue controller deletion. Keep a reference until all
- * work is flushed since delete_work will free the ctrl mem
- */
- kref_get(&ctrl->ctrl.kref);
- queue_work(nvme_rdma_wq, &ctrl->delete_work);
- flush_work(&ctrl->delete_work);
- nvme_put_ctrl(&ctrl->ctrl);
-
- return ret;
-}
-
static int nvme_rdma_cm_handler(struct rdma_cm_id *cm_id,
struct rdma_cm_event *ev)
{
@@ -1419,8 +1361,8 @@ static int nvme_rdma_cm_handler(struct rdma_cm_id *cm_id,
nvme_rdma_error_recovery(queue->ctrl);
break;
case RDMA_CM_EVENT_DEVICE_REMOVAL:
- /* return 1 means impliciy CM ID destroy */
- return nvme_rdma_device_unplug(queue);
+ /* device removal is handled via the ib_client API */
+ break;
default:
dev_err(queue->ctrl->ctrl.device,
"Unexpected RDMA CM event (%d)\n", ev->event);
@@ -2030,27 +1972,57 @@ static struct nvmf_transport_ops nvme_rdma_transport = {
.create_ctrl = nvme_rdma_create_ctrl,
};
+static void nvme_rdma_add_one(struct ib_device *ib_device)
+{
+}
+
+static void nvme_rdma_remove_one(struct ib_device *ib_device, void *client_data)
+{
+ struct nvme_rdma_ctrl *ctrl;
+
+ /* Delete all controllers using this device */
+ mutex_lock(&nvme_rdma_ctrl_mutex);
+ list_for_each_entry(ctrl, &nvme_rdma_ctrl_list, list) {
+ if (ctrl->device->dev != ib_device)
+ continue;
+ dev_info(ctrl->ctrl.device,
+ "Removing ctrl: NQN \"%s\", addr %pISp\n",
+ ctrl->ctrl.opts->subsysnqn, &ctrl->addr);
+ __nvme_rdma_del_ctrl(ctrl);
+ }
+ mutex_unlock(&nvme_rdma_ctrl_mutex);
+
+ flush_workqueue(nvme_rdma_wq);
+}
+
+static struct ib_client nvme_rdma_ib_client = {
+ .name = "nvme_rdma",
+ .add = nvme_rdma_add_one,
+ .remove = nvme_rdma_remove_one
+};
+
static int __init nvme_rdma_init_module(void)
{
+ int ret;
+
nvme_rdma_wq = create_workqueue("nvme_rdma_wq");
if (!nvme_rdma_wq)
return -ENOMEM;
+ ret = ib_register_client(&nvme_rdma_ib_client);
+ if (ret) {
+ destroy_workqueue(nvme_rdma_wq);
+ return ret;
+ }
+
nvmf_register_transport(&nvme_rdma_transport);
return 0;
}
static void __exit nvme_rdma_cleanup_module(void)
{
- struct nvme_rdma_ctrl *ctrl;
-
nvmf_unregister_transport(&nvme_rdma_transport);
-
- mutex_lock(&nvme_rdma_ctrl_mutex);
- list_for_each_entry(ctrl, &nvme_rdma_ctrl_list, list)
- __nvme_rdma_del_ctrl(ctrl);
- mutex_unlock(&nvme_rdma_ctrl_mutex);
-
+ ib_unregister_client(&nvme_rdma_ib_client);
destroy_workqueue(nvme_rdma_wq);
}