nvmet: Make cntlid globally unique

We usually log the cntlid which is confusing in case
we have multiple subsystems each with it's own cntlid ida.
Instead make cntlid ida globally unique and log the initial
association.
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

drivers/nvme/target/core.c

@@ -17,6 +17,7 @@
 #include "nvmet.h"
 
 static struct nvmet_fabrics_ops *nvmet_transports[NVMF_TRTYPE_MAX];
+static DEFINE_IDA(cntlid_ida);
 
 /*
  * This read/write semaphore is used to synchronize access to configuration
@@ -749,7 +750,7 @@ u16 nvmet_alloc_ctrl(const char *subsysnqn, const char *hostnqn,
 	if (!ctrl->sqs)
 		goto out_free_cqs;
 
-	ret = ida_simple_get(&subsys->cntlid_ida,
+	ret = ida_simple_get(&cntlid_ida,
 			     NVME_CNTLID_MIN, NVME_CNTLID_MAX,
 			     GFP_KERNEL);
 	if (ret < 0) {
@@ -819,7 +820,7 @@ static void nvmet_ctrl_free(struct kref *ref)
 	flush_work(&ctrl->async_event_work);
 	cancel_work_sync(&ctrl->fatal_err_work);
 
-	ida_simple_remove(&subsys->cntlid_ida, ctrl->cntlid);
+	ida_simple_remove(&cntlid_ida, ctrl->cntlid);
 	nvmet_subsys_put(subsys);
 
 	kfree(ctrl->sqs);
@@ -918,9 +919,6 @@ struct nvmet_subsys *nvmet_subsys_alloc(const char *subsysnqn,
 	mutex_init(&subsys->lock);
 	INIT_LIST_HEAD(&subsys->namespaces);
 	INIT_LIST_HEAD(&subsys->ctrls);
-
-	ida_init(&subsys->cntlid_ida);
-
 	INIT_LIST_HEAD(&subsys->hosts);
 
 	return subsys;
@@ -933,7 +931,6 @@ static void nvmet_subsys_free(struct kref *ref)
 
 	WARN_ON_ONCE(!list_empty(&subsys->namespaces));
 
-	ida_destroy(&subsys->cntlid_ida);
 	kfree(subsys->subsysnqn);
 	kfree(subsys);
 }
@@ -976,6 +973,7 @@ static void __exit nvmet_exit(void)
 {
 	nvmet_exit_configfs();
 	nvmet_exit_discovery();
+	ida_destroy(&cntlid_ida);
 
 	BUILD_BUG_ON(sizeof(struct nvmf_disc_rsp_page_entry) != 1024);
 	BUILD_BUG_ON(sizeof(struct nvmf_disc_rsp_page_hdr) != 1024);

drivers/nvme/target/fabrics-cmd.c

@@ -153,8 +153,8 @@ static void nvmet_execute_admin_connect(struct nvmet_req *req)
 		goto out;
 	}
 
-	pr_info("creating controller %d for NQN %s.\n",
-			ctrl->cntlid, ctrl->hostnqn);
+	pr_info("creating controller %d for subsystem %s for NQN %s.\n",
+		ctrl->cntlid, ctrl->subsys->subsysnqn, ctrl->hostnqn);
 	req->rsp->result.u16 = cpu_to_le16(ctrl->cntlid);
 
 out:

drivers/nvme/target/nvmet.h

@@ -142,7 +142,6 @@ struct nvmet_subsys {
 	unsigned int		max_nsid;
 
 	struct list_head	ctrls;
-	struct ida		cntlid_ida;
 
 	struct list_head	hosts;
 	bool			allow_any_host;