Pass info to zpool cmd whether devices are solid state, or rotational.

Info is passed in ZPOOL_CONFIG_VDEV_STATS_EX -> ZPOOL_CONFIG_VDEV_KIND.

include/sys/fs/zfs.h

@@ -595,6 +595,9 @@ typedef struct zpool_rewind_policy {
 /* vdev enclosure sysfs path */
 #define	ZPOOL_CONFIG_VDEV_ENC_SYSFS_PATH	"vdev_enc_sysfs_path"
 
+/* Kind (ssd, file, mix, hdd) (part of vdev_stat_ex_t) */
+#define	ZPOOL_CONFIG_VDEV_KIND		"kind"
+
 #define	ZPOOL_CONFIG_WHOLE_DISK		"whole_disk"
 #define	ZPOOL_CONFIG_ERRCOUNT		"error_count"
 #define	ZPOOL_CONFIG_NOT_PRESENT	"not_present"
@@ -730,6 +733,14 @@ typedef enum vdev_aux {
 	VDEV_AUX_SPLIT_POOL	/* vdev was split off into another pool	*/
 } vdev_aux_t;
 
+typedef enum vdev_kind_info {
+	VDEV_KIND_UNKNOWN = 0,	/* not set yet			*/
+	VDEV_KIND_SSD,		/* device is solid state	*/
+	VDEV_KIND_FILE,		/* device is file backed	*/
+	VDEV_KIND_MIXED,	/* device has both kinds	*/
+	VDEV_KIND_HDD		/* device is not solid state	*/
+} vdev_kind_info_t;
+
 /*
  * pool state.  The following states are written to disk as part of the normal
  * SPA lifecycle: ACTIVE, EXPORTED, DESTROYED, SPARE, L2CACHE.  The remaining
@@ -887,6 +898,8 @@ typedef struct vdev_stat_ex {
 	uint64_t vsx_agg_histo[ZIO_PRIORITY_NUM_QUEUEABLE]
 	    [VDEV_RQ_HISTO_BUCKETS];
 
+	/* Kind of vdev (ssd, file, mixed, hdd).  Exported as one value. */
+	uint64_t vsx_kind;
 } vdev_stat_ex_t;
 
 /*

module/zfs/vdev.c

@@ -2906,6 +2906,17 @@ vdev_get_stats_ex_impl(vdev_t *vd, vdev_stat_t *vs, vdev_stat_ex_t *vsx)
 			    &vd->vdev_queue.vq_class[t].vqc_queued_tree);
 		}
 	}
+	if (vsx) {
+		if (vd->vdev_nonrot) {
+			if (vd->vdev_ops == &vdev_file_ops)
+				vsx->vsx_kind = VDEV_KIND_FILE;
+			else
+				vsx->vsx_kind = VDEV_KIND_SSD;
+		} else if (vd->vdev_nonrot_mix)
+			vsx->vsx_kind = VDEV_KIND_MIXED;
+		else
+			vsx->vsx_kind = VDEV_KIND_HDD;
+	}
 }
 
 void

module/zfs/vdev_label.c

@@ -344,6 +344,8 @@ vdev_config_generate_stats(vdev_t *vd, nvlist_t *nv)
 	    vsx->vsx_agg_histo[ZIO_PRIORITY_SCRUB],
 	    ARRAY_SIZE(vsx->vsx_agg_histo[ZIO_PRIORITY_SCRUB]));
 
+	fnvlist_add_uint64(nvx, ZPOOL_CONFIG_VDEV_KIND, vsx->vsx_kind);
+
 	/* Add extended stats nvlist to main nvlist */
 	fnvlist_add_nvlist(nv, ZPOOL_CONFIG_VDEV_STATS_EX, nvx);