Implement shadow mirrors

cmd/zpool/zpool_main.c

@@ -1558,7 +1558,7 @@ zpool_do_add(int argc, char **argv)
 
 	/* pass off to make_root_vdev for processing */
 	nvroot = make_root_vdev(zhp, props, !check_inuse,
-	    check_replication, B_FALSE, dryrun, argc, argv);
+	    check_replication, B_FALSE, dryrun, B_FALSE, argc, argv);
 	if (nvroot == NULL) {
 		zpool_close(zhp);
 		return (1);
@@ -2159,7 +2159,7 @@ zpool_do_create(int argc, char **argv)
 
 	/* pass off to make_root_vdev for bulk processing */
 	nvroot = make_root_vdev(NULL, props, force, !force, B_FALSE, dryrun,
-	    argc - 1, argv + 1);
+	    B_FALSE, argc - 1, argv + 1);
 	if (nvroot == NULL)
 		goto errout;
 
@@ -7628,6 +7628,7 @@ zpool_do_attach_or_replace(int argc, char **argv, int replacing)
 	boolean_t force = B_FALSE;
 	boolean_t rebuild = B_FALSE;
 	boolean_t wait = B_FALSE;
+	boolean_t shadow = B_FALSE;
 	int c;
 	nvlist_t *nvroot;
 	char *poolname, *old_disk, *new_disk;
@@ -7637,7 +7638,7 @@ zpool_do_attach_or_replace(int argc, char **argv, int replacing)
 	int ret;
 
 	/* check options */
-	while ((c = getopt(argc, argv, "fo:sw")) != -1) {
+	while ((c = getopt(argc, argv, "fo:sSw")) != -1) {
 		switch (c) {
 		case 'f':
 			force = B_TRUE;
@@ -7658,6 +7659,9 @@ zpool_do_attach_or_replace(int argc, char **argv, int replacing)
 		case 's':
 			rebuild = B_TRUE;
 			break;
+		case 'S':
+			shadow = B_TRUE;
+			break;
 		case 'w':
 			wait = B_TRUE;
 			break;
@@ -7735,7 +7739,7 @@ zpool_do_attach_or_replace(int argc, char **argv, int replacing)
 	}
 
 	nvroot = make_root_vdev(zhp, props, force, B_FALSE, replacing, B_FALSE,
-	    argc, argv);
+	    shadow, argc, argv);
 	if (nvroot == NULL) {
 		zpool_close(zhp);
 		nvlist_free(props);

cmd/zpool/zpool_util.h

@@ -56,8 +56,8 @@ char *zpool_get_cmd_search_path(void);
  */
 
 nvlist_t *make_root_vdev(zpool_handle_t *zhp, nvlist_t *props, int force,
-    int check_rep, boolean_t replacing, boolean_t dryrun, int argc,
-    char **argv);
+    int check_rep, boolean_t replacing, boolean_t dryrun, boolean_t shadow,
+    int argc, char **argv);
 nvlist_t *split_mirror_vdev(zpool_handle_t *zhp, char *newname,
     nvlist_t *props, splitflags_t flags, int argc, char **argv);
 

cmd/zpool/zpool_vdev.c

@@ -1549,7 +1549,7 @@ draid_config_by_type(nvlist_t *nv, const char *type, uint64_t width,
  * because the program is just going to exit anyway.
  */
 static nvlist_t *
-construct_spec(nvlist_t *props, int argc, char **argv)
+construct_spec(nvlist_t *props, boolean_t shadow, int argc, char **argv)
 {
 	nvlist_t *nvroot, *nv, **top, **spares, **l2cache;
 	int t, toplevels, mindev, maxdev, nspares, nlogs, nl2cache;
@@ -1895,6 +1895,10 @@ construct_spec(nvlist_t *props, int argc, char **argv)
 
 			verify(nvlist_add_uint64(nv,
 			    ZPOOL_CONFIG_IS_LOG, is_log) == 0);
+			if (shadow) {
+				fnvlist_add_boolean(nv,
+				    ZPOOL_VDEV_CONFIG_SHADOW);
+			}
 			if (is_log) {
 				verify(nvlist_add_string(nv,
 				    ZPOOL_CONFIG_ALLOCATION_BIAS,
@@ -1974,7 +1978,8 @@ split_mirror_vdev(zpool_handle_t *zhp, char *newname, nvlist_t *props,
 	uint_t c, children;
 
 	if (argc > 0) {
-		if ((newroot = construct_spec(props, argc, argv)) == NULL) {
+		if ((newroot = construct_spec(props, B_FALSE, argc, argv)) ==
+		    NULL) {
 			(void) fprintf(stderr, gettext("Unable to build a "
 			    "pool from the specified devices\n"));
 			return (NULL);
@@ -2048,7 +2053,8 @@ num_normal_vdevs(nvlist_t *nvroot)
  */
 nvlist_t *
 make_root_vdev(zpool_handle_t *zhp, nvlist_t *props, int force, int check_rep,
-    boolean_t replacing, boolean_t dryrun, int argc, char **argv)
+    boolean_t replacing, boolean_t dryrun, boolean_t shadow, int argc,
+    char **argv)
 {
 	nvlist_t *newroot;
 	nvlist_t *poolconfig = NULL;
@@ -2059,7 +2065,7 @@ make_root_vdev(zpool_handle_t *zhp, nvlist_t *props, int force, int check_rep,
 	 * that we have a valid specification, and that all devices can be
 	 * opened.
 	 */
-	if ((newroot = construct_spec(props, argc, argv)) == NULL)
+	if ((newroot = construct_spec(props, shadow, argc, argv)) == NULL)
 		return (NULL);
 
 	if (zhp && ((poolconfig = zpool_get_config(zhp, NULL)) == NULL)) {

include/sys/fs/zfs.h

@@ -486,6 +486,7 @@ typedef enum {
 	VDEV_PROP_FGROUP,
 	VDEV_PROP_ALLOC_BIAS,
 	VDEV_PROP_ROTATIONAL,
+	VDEV_PROP_SHADOW,
 	VDEV_NUM_PROPS
 } vdev_prop_t;
 
@@ -879,6 +880,7 @@ typedef struct zpool_load_policy {
 #define	ZPOOL_CONFIG_VDEV_STATS		"vdev_stats"	/* not stored on disk */
 #define	ZPOOL_CONFIG_CONDENSE_STATS	"com.klarasystems:condense_stats"
 #define	ZPOOL_CONFIG_INDIRECT_SIZE	"indirect_size"	/* not stored on disk */
+#define	ZPOOL_VDEV_CONFIG_SHADOW	"com.klarasystems:shadow_vdev"
 
 /* container nvlist of extended stats */
 #define	ZPOOL_CONFIG_VDEV_STATS_EX	"vdev_stats_ex"

include/sys/vdev_impl.h

@@ -420,6 +420,8 @@ struct vdev {
 	boolean_t	vdev_kobj_flag; /* kobj event record */
 	boolean_t	vdev_attaching; /* vdev attach ashift handling */
 	boolean_t	vdev_is_blkdev; /* vdev is backed by block device */
+	/* vdev is shadow drive or has shadow children */
+	boolean_t	vdev_shadow;
 	vdev_queue_t	vdev_queue;	/* I/O deadline schedule queue	*/
 	spa_aux_vdev_t	*vdev_aux;	/* for l2cache and spares vdevs	*/
 	zio_t		*vdev_probe_zio; /* root of current probe	*/

include/zfeature_common.h

@@ -91,6 +91,7 @@ typedef enum spa_feature {
 	SPA_FEATURE_BLOCK_CLONING_ENDIAN,
 	SPA_FEATURE_PHYSICAL_REWRITE,
 	SPA_FEATURE_DRAID_FAIL_DOMAINS,
+	SPA_FEATURE_SHADOW_MIRROR,
 	SPA_FEATURES
 } spa_feature_t;