On 22/06/2020 18:25, Keith Busch wrote:
[...]

+static void *nvme_zns_alloc_report_buffer(struct nvme_ns *ns,
+					  unsigned int nr_zones, size_t *buflen)
+{
+	struct request_queue *q = ns->disk->queue;
+	size_t bufsize;
+	void *buf;
+
+	const size_t min_bufsize = sizeof(struct nvme_zone_report) +
+				   sizeof(struct nvme_zone_descriptor);
+
+	nr_zones = min_t(unsigned int, nr_zones,
+			 get_capacity(ns->disk) >> ilog2(ns->zsze));
+
+	bufsize = sizeof(struct nvme_zone_report) +
+		nr_zones * sizeof(struct nvme_zone_descriptor);
+	bufsize = min_t(size_t, bufsize,
+			queue_max_hw_sectors(q) << SECTOR_SHIFT);
+	bufsize = min_t(size_t, bufsize, queue_max_segments(q) << PAGE_SHIFT);
+
+	while (bufsize >= min_bufsize) {
+		buf = __vmalloc(bufsize,
+				GFP_KERNEL | __GFP_ZERO | __GFP_NORETRY);

Nit: The __GFP_ZERO flag isn't needed as nvme_ns_report_zones() 
calls memset() on the report buffer before submitting it.

[...]

Accidental line break.

Otherwise:
Reviewed-by: Johannes Thumshirn <redacted>