nvme: Notify namespace changes better

When we get a namespace notification, we have to reconstrut the
namespace to get the new identification data from the namespace. For
each namespace in the AEN, we will reconstrict it before we call the
notification. We also flag it as changed for the duration of the change
callback (prior versions of the patch needed to keep track, but we no
longer do, so this bit may be removed). Note when we've seen the
namespace so we can notify when it goes away.

Approved by:	re (cperciva)
Co-authored-by: imp
Differential Revision: https://reviews.freebsd.org/D33032

(cherry picked from commit 20e94950c54e398049396647da36b9e2c3b639c1)
(cherry picked from commit fe6ee00d174e0d7f4c7a38db9af7b94c56579054)

3 files changed, 22 insertions, 6 deletions

diff --git a/sys/dev/nvme/nvme.h b/sys/dev/nvme/nvme.h
index 17c5cdb4db87..8e69c0ffe339 100644
--- a/sys/dev/nvme/nvme.h
+++ b/sys/dev/nvme/nvme.h
@@ -1930,8 +1930,11 @@ typedef void (*nvme_cons_async_fn_t)(void *, const struct nvme_completion *,
 typedef void (*nvme_cons_fail_fn_t)(void *);
 
 enum nvme_namespace_flags {
-	NVME_NS_DEALLOCATE_SUPPORTED	= 0x1,
-	NVME_NS_FLUSH_SUPPORTED		= 0x2,
+	NVME_NS_DEALLOCATE_SUPPORTED	= 0x01,
+	NVME_NS_FLUSH_SUPPORTED		= 0x02,
+	NVME_NS_ADDED			= 0x04,
+	NVME_NS_CHANGED			= 0x08,
+	NVME_NS_GONE			= 0x10,
 };
 
 int	nvme_ctrlr_passthrough_cmd(struct nvme_controller *ctrlr,
diff --git a/sys/dev/nvme/nvme_ctrlr.c b/sys/dev/nvme/nvme_ctrlr.c
index 07c1bcdfbf08..63b8643d97d7 100644
--- a/sys/dev/nvme/nvme_ctrlr.c
+++ b/sys/dev/nvme/nvme_ctrlr.c
@@ -1216,10 +1216,20 @@ nvme_ctrlr_aer_task(void *arg, int pending)
 	} else if (aer->log_page_id == NVME_LOG_CHANGED_NAMESPACE) {
 		struct nvme_ns_list *nsl =
 		    (struct nvme_ns_list *)aer->log_page_buffer;
+		struct nvme_controller *ctrlr = aer->ctrlr;
+
 		for (int i = 0; i < nitems(nsl->ns) && nsl->ns[i] != 0; i++) {
+			struct nvme_namespace *ns;
+			uint32_t id = nsl->ns[i];
+
 			if (nsl->ns[i] > NVME_MAX_NAMESPACES)
 				break;
-			nvme_notify_ns(aer->ctrlr, nsl->ns[i]);
+
+			ns = &ctrlr->ns[id - 1];
+			ns->flags |= NVME_NS_CHANGED;
+			nvme_ns_construct(ns, id, ctrlr);
+			nvme_notify_ns(ctrlr, id);
+			ns->flags &= ~NVME_NS_CHANGED;
 		}
 	}
 
diff --git a/sys/dev/nvme/nvme_ns.c b/sys/dev/nvme/nvme_ns.c
index e84d2066930e..21d7965bf7a6 100644
--- a/sys/dev/nvme/nvme_ns.c
+++ b/sys/dev/nvme/nvme_ns.c
@@ -78,7 +78,7 @@ nvme_ns_ioctl(struct cdev *cdev, u_long cmd, caddr_t arg, int flag,
 		break;
 	case NVME_PASSTHROUGH_CMD:
 		pt = (struct nvme_pt_command *)arg;
-		return (nvme_ctrlr_passthrough_cmd(ctrlr, pt, ns->id, 
+		return (nvme_ctrlr_passthrough_cmd(ctrlr, pt, ns->id,
 		    1 /* is_user_buffer */, 0 /* is_admin_cmd */));
 	case NVME_GET_NSID:
 	{
@@ -557,8 +557,10 @@ nvme_ns_construct(struct nvme_namespace *ns, uint32_t id,
 	 * 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);
+	if (ns->data.nsze == 0) {
+		ns->flags |= NVME_NS_GONE;
+		return ((ns->flags & NVME_NS_ADDED) ? 0 : ENXIO);
+	}
 
 	flbas_fmt = NVMEV(NVME_NS_DATA_FLBAS_FORMAT, ns->data.flbas);
 
@@ -622,6 +624,7 @@ nvme_ns_construct(struct nvme_namespace *ns, uint32_t id,
 	ns->cdev->si_drv2 = make_dev_alias(ns->cdev, "%sns%d",
 	    device_get_nameunit(ctrlr->dev), ns->id);
 	ns->cdev->si_flags |= SI_UNMAPPED;
+	ns->flags |= NVME_NS_ADDED;
 
 	return (0);
 }