[PATCH 3/3] nvme: check that EUI/GUID/UUID are globally unique

[Christoph Hellwig <hch@lst.de>]

Add a check to verify that the unique identifiers are unique globally
in addition to the existing check that verifies that they are unique
inside a single subsystem.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/nvme/host/core.c | 32 ++++++++++++++++++++++++++++++--
 1 file changed, 30 insertions(+), 2 deletions(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index ac4749f257439..4f9623d9f7ed9 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -3783,7 +3783,7 @@ static struct nvme_ns_head *nvme_alloc_ns_head(struct nvme_ctrl *ctrl,
 	ret = nvme_subsys_check_duplicate_ids(ctrl->subsys, &head->ids);
 	if (ret) {
 		dev_err(ctrl->device,
-			"duplicate IDs for nsid %d\n", nsid);
+			"duplicate IDs in subsystem for nsid %d\n", nsid);
 		goto out_cleanup_srcu;
 	}
 
@@ -3815,12 +3815,40 @@ static struct nvme_ns_head *nvme_alloc_ns_head(struct nvme_ctrl *ctrl,
 	return ERR_PTR(ret);
 }
 
+static int nvme_global_check_ids(struct nvme_subsystem *this,
+		struct nvme_ns_ids *ids)
+{
+	struct nvme_subsystem *s;
+	int ret = 0;
+
+	mutex_lock(&nvme_subsystems_lock);
+	list_for_each_entry(s, &nvme_subsystems, entry) {
+		if (s == this)
+			continue;
+		mutex_lock(&s->lock);
+		ret = nvme_subsys_check_duplicate_ids(s, ids);
+		mutex_unlock(&s->lock);
+		if (ret)
+			break;
+	}
+	mutex_unlock(&nvme_subsystems_lock);
+
+	return ret;
+}
+
 static int nvme_init_ns_head(struct nvme_ns *ns, unsigned nsid,
 		struct nvme_ns_ids *ids, bool is_shared)
 {
 	struct nvme_ctrl *ctrl = ns->ctrl;
 	struct nvme_ns_head *head = NULL;
-	int ret = 0;
+	int ret;
+
+	ret = nvme_global_check_ids(ctrl->subsys, ids);
+	if (ret) {
+		dev_err(ctrl->device,
+			"globally duplicate IDs for nsid %d\n", nsid);
+		return ret;
+	}
 
 	mutex_lock(&ctrl->subsys->lock);
 	head = nvme_find_ns_head(ctrl->subsys, nsid);
-- 
2.30.2