From a8a18dd5901e33c520ab5a53d02fb0196c9bcbaa Mon Sep 17 00:00:00 2001
From: Warner Losh <imp@FreeBSD.org>
Date: Tue, 7 Mar 2017 21:47:54 +0000
Subject: [PATCH] Make multi-namespace nvme drives more robust.

Fix assumptions about name spaces in NVME driver. First, it assumes
cdata.nn is the number of configured devices. However, it is the
number of supported name spaces. Second, it assumes that there will
never be more than 16 name spaces supported, but a certain drive I'm
testing reports 1024. It assumes that name spaces are a tightly packed
namespace, but the standard seems to indicate otherwise. Finally, it
assumes that an error would be generated when quearying an
unconfigured namespace. Instead, it succeeds but the identify data is
all zeros.

Fix these by limiting the number of name spaces we probe to 16. Remove
aborting when we find one in error. When the size of the name space is
zero, ignore it.

This is admittedly a bandaide. The long term fix will be to
participate in the enumeration and name space change protocols
definfed in the NVNe standard.

Sponsored by: Netflix
---
 sys/dev/nvme/nvme.c       |  4 +++-
 sys/dev/nvme/nvme_ctrlr.c |  8 +++-----
 sys/dev/nvme/nvme_ns.c    | 11 ++++++++++-
 3 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/sys/dev/nvme/nvme.c b/sys/dev/nvme/nvme.c
index 9db2b14d13d..8196ff78c85 100644
--- a/sys/dev/nvme/nvme.c
+++ b/sys/dev/nvme/nvme.c
@@ -327,8 +327,10 @@ nvme_notify(struct nvme_consumer *cons,
 		 */
 		return;
 	}
-	for (ns_idx = 0; ns_idx < ctrlr->cdata.nn; ns_idx++) {
+	for (ns_idx = 0; ns_idx < min(ctrlr->cdata.nn, NVME_MAX_NAMESPACES); ns_idx++) {
 		ns = &ctrlr->ns[ns_idx];
+		if (ns->data.nsze == 0)
+			continue;
 		if (cons->ns_fn != NULL)
 			ns->cons_cookie[cons->id] =
 			    (*cons->ns_fn)(ns, ctrlr_cookie);
diff --git a/sys/dev/nvme/nvme_ctrlr.c b/sys/dev/nvme/nvme_ctrlr.c
index fd836f99109..c3a818f3d63 100644
--- a/sys/dev/nvme/nvme_ctrlr.c
+++ b/sys/dev/nvme/nvme_ctrlr.c
@@ -458,13 +458,11 @@ static int
 nvme_ctrlr_construct_namespaces(struct nvme_controller *ctrlr)
 {
 	struct nvme_namespace	*ns;
-	int			i, status;
+	int			i;
 
-	for (i = 0; i < ctrlr->cdata.nn; i++) {
+	for (i = 0; i < min(ctrlr->cdata.nn, NVME_MAX_NAMESPACES); i++) {
 		ns = &ctrlr->ns[i];
-		status = nvme_ns_construct(ns, i+1, ctrlr);
-		if (status != 0)
-			return (status);
+		nvme_ns_construct(ns, i+1, ctrlr);
 	}
 
 	return (0);
diff --git a/sys/dev/nvme/nvme_ns.c b/sys/dev/nvme/nvme_ns.c
index 754d074c493..80364b4a079 100644
--- a/sys/dev/nvme/nvme_ns.c
+++ b/sys/dev/nvme/nvme_ns.c
@@ -511,6 +511,15 @@ nvme_ns_construct(struct nvme_namespace *ns, uint16_t id,
 		return (ENXIO);
 	}
 
+	/*
+	 * If the size of is zero, chances are this isn't a valid
+	 * namespace (eg one that's not been configured yet). The
+	 * standard says the entire id will be zeros, so this is a
+	 * cheap way to test for that.
+	 */
+	if (ns->data.nsze == 0)
+		return (ENXIO);
+
 	/*
 	 * Note: format is a 0-based value, so > is appropriate here,
 	 *  not >=.
@@ -518,7 +527,7 @@ nvme_ns_construct(struct nvme_namespace *ns, uint16_t id,
 	if (ns->data.flbas.format > ns->data.nlbaf) {
 		printf("lba format %d exceeds number supported (%d)\n",
 		    ns->data.flbas.format, ns->data.nlbaf+1);
-		return (1);
+		return (ENXIO);
 	}
 
 	if (ctrlr->cdata.oncs.dsm)