JSON: Fix class values for mirrored special vdevs

This fixes things so mirrored special vdevs report themselves as
"class=special" rather than "class=normal".

This happens due to the way the vdev nvlists are constructed:

mirrored special devices - The 'mirror' vdev has allocation bias as
"special" and it's leaf vdevs are "normal"

single or RAID0 special devices - Leaf vdevs have allocation bias as
"special".

This commit adds in code to check if a leaf's parent is a "special"
vdev to see if it should also report "special".

Reviewed-by: Ameer Hamza <ahamza@ixsystems.com>
Reviewed-by: Umer Saleem <usaleem@ixsystems.com>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes #16217

cmd/zpool/zpool_main.c

@@ -1154,11 +1154,16 @@ fill_vdev_info(nvlist_t *list, zpool_handle_t *zhp, char *name,
 	vdev_stat_t *vs;
 	uint_t c;
 	nvlist_t *nvdev;
+	nvlist_t *nvdev_parent = NULL;
+	char *_name;
 
 	if (strcmp(name, zpool_get_name(zhp)) != 0)
-		nvdev = zpool_find_vdev(zhp, name, NULL, &l2c, NULL);
+		_name = name;
 	else
-		nvdev = zpool_find_vdev(zhp, "root-0", NULL, &l2c, NULL);
+		_name = (char *)"root-0";
+
+	nvdev = zpool_find_vdev(zhp, _name, NULL, &l2c, NULL);
+
 	fnvlist_add_string(list, "name", name);
 	if (addtype)
 		fnvlist_add_string(list, "type", "VDEV");
@@ -1201,10 +1206,34 @@ fill_vdev_info(nvlist_t *list, zpool_handle_t *zhp, char *name,
 		else {
 			(void) nvlist_lookup_string(nvdev,
 			    ZPOOL_CONFIG_ALLOCATION_BIAS, &bias);
+			if (bias != NULL)
+				fnvlist_add_string(list, "class", bias);
+			else {
+				nvdev_parent = NULL;
+				nvdev_parent = zpool_find_parent_vdev(zhp,
+				    _name, NULL, NULL, NULL);
+
+				/*
+				 * With a mirrored special device, the parent
+				 * "mirror" vdev will have
+				 * ZPOOL_CONFIG_ALLOCATION_BIAS set to "special"
+				 * not the leaf vdevs.  If we're a leaf vdev
+				 * in that case we need to look at our parent
+				 * to see if they're "special" to know if we
+				 * are "special" too.
+				 */
+				if (nvdev_parent) {
+					(void) nvlist_lookup_string(
+					    nvdev_parent,
+					    ZPOOL_CONFIG_ALLOCATION_BIAS,
+					    &bias);
+				}
 				if (bias != NULL)
 					fnvlist_add_string(list, "class", bias);
 				else
-				fnvlist_add_string(list, "class", "normal");
+					fnvlist_add_string(list, "class",
+					    "normal");
+			}
 		}
 		if (nvlist_lookup_uint64_array(nvdev, ZPOOL_CONFIG_VDEV_STATS,
 		    (uint64_t **)&vs, &c) == 0) {

include/libzfs.h

@@ -327,6 +327,8 @@ _LIBZFS_H int zpool_vdev_clear(zpool_handle_t *, uint64_t);
 
 _LIBZFS_H nvlist_t *zpool_find_vdev(zpool_handle_t *, const char *, boolean_t *,
     boolean_t *, boolean_t *);
+_LIBZFS_H nvlist_t *zpool_find_parent_vdev(zpool_handle_t *, const char *,
+    boolean_t *, boolean_t *, boolean_t *);
 _LIBZFS_H nvlist_t *zpool_find_vdev_by_physpath(zpool_handle_t *, const char *,
     boolean_t *, boolean_t *, boolean_t *);
 _LIBZFS_H int zpool_label_disk(libzfs_handle_t *, zpool_handle_t *,

lib/libzfs/libzfs.abi

@@ -486,6 +486,7 @@
     <elf-symbol name='zpool_feature_init' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='zpool_find_config' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='zpool_find_vdev' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
+    <elf-symbol name='zpool_find_parent_vdev' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='zpool_find_vdev_by_physpath' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='zpool_free_handles' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='zpool_get_all_vdev_props' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
@@ -6540,6 +6541,14 @@
       <parameter type-id='37e3bd22' name='log'/>
       <return type-id='5ce45b60'/>
     </function-decl>
+    <function-decl name='zpool_find_parent_vdev' mangled-name='zpool_find_parent_vdev' visibility='default' binding='global' size-in-bits='64' elf-symbol-id='zpool_find_parent_vdev'>
+      <parameter type-id='4c81de99' name='zhp'/>
+      <parameter type-id='80f4b756' name='path'/>
+      <parameter type-id='37e3bd22' name='avail_spare'/>
+      <parameter type-id='37e3bd22' name='l2cache'/>
+      <parameter type-id='37e3bd22' name='log'/>
+      <return type-id='5ce45b60'/>
+    </function-decl>
     <function-decl name='zpool_vdev_path_to_guid' mangled-name='zpool_vdev_path_to_guid' visibility='default' binding='global' size-in-bits='64' elf-symbol-id='zpool_vdev_path_to_guid'>
       <parameter type-id='4c81de99' name='zhp'/>
       <parameter type-id='80f4b756' name='path'/>

lib/libzfs/libzfs_pool.c

@@ -2863,10 +2863,13 @@ zpool_scan(zpool_handle_t *zhp, pool_scan_func_t func, pool_scrub_cmd_t cmd)
  * the nvpair name to determine how we should look for the device.
  * 'avail_spare' is set to TRUE if the provided guid refers to an AVAIL
  * spare; but FALSE if its an INUSE spare.
+ *
+ * If 'return_parent' is set, then return the *parent* of the vdev you're
+ * searching for rather than the vdev itself.
  */
 static nvlist_t *
 vdev_to_nvlist_iter(nvlist_t *nv, nvlist_t *search, boolean_t *avail_spare,
-    boolean_t *l2cache, boolean_t *log)
+    boolean_t *l2cache, boolean_t *log, boolean_t return_parent)
 {
 	uint_t c, children;
 	nvlist_t **child;
@@ -2874,6 +2877,8 @@ vdev_to_nvlist_iter(nvlist_t *nv, nvlist_t *search, boolean_t *avail_spare,
 	uint64_t is_log;
 	const char *srchkey;
 	nvpair_t *pair = nvlist_next_nvpair(search, NULL);
+	const char *tmp = NULL;
+	boolean_t is_root;
 
 	/* Nothing to look for */
 	if (search == NULL || pair == NULL)
@@ -2882,6 +2887,12 @@ vdev_to_nvlist_iter(nvlist_t *nv, nvlist_t *search, boolean_t *avail_spare,
 	/* Obtain the key we will use to search */
 	srchkey = nvpair_name(pair);
 
+	nvlist_lookup_string(nv, ZPOOL_CONFIG_TYPE, &tmp);
+	if (strcmp(tmp, "root") == 0)
+		is_root = B_TRUE;
+	else
+		is_root = B_FALSE;
+
 	switch (nvpair_type(pair)) {
 	case DATA_TYPE_UINT64:
 		if (strcmp(srchkey, ZPOOL_CONFIG_GUID) == 0) {
@@ -3012,7 +3023,7 @@ vdev_to_nvlist_iter(nvlist_t *nv, nvlist_t *search, boolean_t *avail_spare,
 
 	for (c = 0; c < children; c++) {
 		if ((ret = vdev_to_nvlist_iter(child[c], search,
-		    avail_spare, l2cache, NULL)) != NULL) {
+		    avail_spare, l2cache, NULL, return_parent)) != NULL) {
 			/*
 			 * The 'is_log' value is only set for the toplevel
 			 * vdev, not the leaf vdevs.  So we always lookup the
@@ -3025,7 +3036,7 @@ vdev_to_nvlist_iter(nvlist_t *nv, nvlist_t *search, boolean_t *avail_spare,
 			    is_log) {
 				*log = B_TRUE;
 			}
-			return (ret);
+			return (ret && return_parent && !is_root ? nv : ret);
 		}
 	}
 
@@ -3033,9 +3044,11 @@ vdev_to_nvlist_iter(nvlist_t *nv, nvlist_t *search, boolean_t *avail_spare,
 	    &child, &children) == 0) {
 		for (c = 0; c < children; c++) {
 			if ((ret = vdev_to_nvlist_iter(child[c], search,
-			    avail_spare, l2cache, NULL)) != NULL) {
+			    avail_spare, l2cache, NULL, return_parent))
+			    != NULL) {
 				*avail_spare = B_TRUE;
-				return (ret);
+				return (ret && return_parent &&
+				    !is_root ? nv : ret);
 			}
 		}
 	}
@@ -3044,9 +3057,11 @@ vdev_to_nvlist_iter(nvlist_t *nv, nvlist_t *search, boolean_t *avail_spare,
 	    &child, &children) == 0) {
 		for (c = 0; c < children; c++) {
 			if ((ret = vdev_to_nvlist_iter(child[c], search,
-			    avail_spare, l2cache, NULL)) != NULL) {
+			    avail_spare, l2cache, NULL, return_parent))
+			    != NULL) {
 				*l2cache = B_TRUE;
-				return (ret);
+				return (ret && return_parent &&
+				    !is_root ? nv : ret);
 			}
 		}
 	}
@@ -3081,7 +3096,8 @@ zpool_find_vdev_by_physpath(zpool_handle_t *zhp, const char *ppath,
 	*l2cache = B_FALSE;
 	if (log != NULL)
 		*log = B_FALSE;
-	ret = vdev_to_nvlist_iter(nvroot, search, avail_spare, l2cache, log);
+	ret = vdev_to_nvlist_iter(nvroot, search, avail_spare, l2cache, log,
+	    B_FALSE);
 	fnvlist_free(search);
 
 	return (ret);
@@ -3109,11 +3125,12 @@ zpool_vdev_is_interior(const char *name)
 }
 
 /*
- * Lookup the nvlist for a given vdev.
+ * Lookup the nvlist for a given vdev or vdev's parent (depending on
+ * if 'return_parent' is set).
  */
-nvlist_t *
+static nvlist_t *
-zpool_find_vdev(zpool_handle_t *zhp, const char *path, boolean_t *avail_spare,
+__zpool_find_vdev(zpool_handle_t *zhp, const char *path, boolean_t *avail_spare,
-    boolean_t *l2cache, boolean_t *log)
+    boolean_t *l2cache, boolean_t *log, boolean_t return_parent)
 {
 	char *end;
 	nvlist_t *nvroot, *search, *ret;
@@ -3150,12 +3167,30 @@ zpool_find_vdev(zpool_handle_t *zhp, const char *path, boolean_t *avail_spare,
 	*l2cache = B_FALSE;
 	if (log != NULL)
 		*log = B_FALSE;
-	ret = vdev_to_nvlist_iter(nvroot, search, avail_spare, l2cache, log);
+	ret = vdev_to_nvlist_iter(nvroot, search, avail_spare, l2cache, log,
+	    return_parent);
 	fnvlist_free(search);
 
 	return (ret);
 }
 
+nvlist_t *
+zpool_find_vdev(zpool_handle_t *zhp, const char *path, boolean_t *avail_spare,
+    boolean_t *l2cache, boolean_t *log)
+{
+	return (__zpool_find_vdev(zhp, path, avail_spare, l2cache, log,
+	    B_FALSE));
+}
+
+/* Given a vdev path, return its parent's nvlist */
+nvlist_t *
+zpool_find_parent_vdev(zpool_handle_t *zhp, const char *path,
+    boolean_t *avail_spare, boolean_t *l2cache, boolean_t *log)
+{
+	return (__zpool_find_vdev(zhp, path, avail_spare, l2cache, log,
+	    B_TRUE));
+}
+
 /*
  * Convert a vdev path to a GUID.  Returns GUID or 0 on error.
  *