Illumos #1693: persistent 'comment' field for a zpool

Reviewed by: George Wilson <gwilson@zfsmail.com>
Reviewed by: Eric Schrock <eric.schrock@delphix.com>
Approved by: Richard Lowe <richlowe@richlowe.net>

References:
  https://www.illumos.org/issues/1693

Ported by: Martin Matuska <martin@matuska.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #678

module/zcommon/zpool_prop.c

@@ -20,6 +20,8 @@
  */
 /*
  * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright 2011 Nexenta Systems, Inc. All rights reserved.
+ * Copyright (c) 2011 by Delphix. All rights reserved.
  */
 
 #include <sys/zio.h>
@@ -69,6 +71,8 @@ zpool_prop_init(void)
 	    ZFS_TYPE_POOL, "<filesystem>", "BOOTFS");
 	zprop_register_string(ZPOOL_PROP_CACHEFILE, "cachefile", NULL,
 	    PROP_DEFAULT, ZFS_TYPE_POOL, "<file> | none", "CACHEFILE");
+	zprop_register_string(ZPOOL_PROP_COMMENT, "comment", NULL,
+	    PROP_DEFAULT, ZFS_TYPE_POOL, "<comment-string>", "COMMENT");
 
 	/* readonly number properties */
 	zprop_register_number(ZPOOL_PROP_SIZE, "size", 0, PROP_READONLY,

module/zfs/spa.c

@@ -206,6 +206,11 @@ spa_prop_get_config(spa_t *spa, nvlist_t **nvp)
 
 	spa_prop_add_list(*nvp, ZPOOL_PROP_GUID, NULL, spa_guid(spa), src);
 
+	if (spa->spa_comment != NULL) {
+		spa_prop_add_list(*nvp, ZPOOL_PROP_COMMENT, spa->spa_comment,
+		    0, ZPROP_SRC_LOCAL);
+	}
+
 	if (spa->spa_root != NULL)
 		spa_prop_add_list(*nvp, ZPOOL_PROP_ALTROOT, spa->spa_root,
 		    0, ZPROP_SRC_LOCAL);
@@ -347,7 +352,7 @@ spa_prop_validate(spa_t *spa, nvlist_t *props)
 		char *propname, *strval;
 		uint64_t intval;
 		objset_t *os;
-		char *slash;
+		char *slash, *check;
 
 		propname = nvpair_name(elem);
 
@@ -467,6 +472,20 @@ spa_prop_validate(spa_t *spa, nvlist_t *props)
 				error = EINVAL;
 			break;
 
+		case ZPOOL_PROP_COMMENT:
+			if ((error = nvpair_value_string(elem, &strval)) != 0)
+				break;
+			for (check = strval; *check != '\0'; check++) {
+				if (!isprint(*check)) {
+					error = EINVAL;
+					break;
+				}
+				check++;
+			}
+			if (strlen(strval) > ZPROP_MAX_COMMENT)
+				error = E2BIG;
+			break;
+
 		case ZPOOL_PROP_DEDUPDITTO:
 			if (spa_version(spa) < SPA_VERSION_DEDUP)
 				error = ENOTSUP;
@@ -1060,6 +1079,11 @@ spa_unload(spa_t *spa)
 
 	spa->spa_async_suspended = 0;
 
+	if (spa->spa_comment != NULL) {
+		spa_strfree(spa->spa_comment);
+		spa->spa_comment = NULL;
+	}
+
 	spa_config_exit(spa, SCL_ALL, FTAG);
 }
 
@@ -1787,6 +1811,7 @@ spa_load(spa_t *spa, spa_load_state_t state, spa_import_type_t type,
 {
 	nvlist_t *config = spa->spa_config;
 	char *ereport = FM_EREPORT_ZFS_POOL;
+	char *comment;
 	int error;
 	uint64_t pool_guid;
 	nvlist_t *nvl;
@@ -1794,6 +1819,10 @@ spa_load(spa_t *spa, spa_load_state_t state, spa_import_type_t type,
 	if (nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_GUID, &pool_guid))
 		return (EINVAL);
 
+	ASSERT(spa->spa_comment == NULL);
+	if (nvlist_lookup_string(config, ZPOOL_CONFIG_COMMENT, &comment) == 0)
+		spa->spa_comment = spa_strdup(comment);
+
 	/*
 	 * Versioning wasn't explicitly added to the label until later, so if
 	 * it's not present treat it as the initial version.
@@ -5401,6 +5430,20 @@ spa_sync_props(void *arg1, void *arg2, dmu_tx_t *tx)
 			 * properties.
 			 */
 			break;
+		case ZPOOL_PROP_COMMENT:
+			VERIFY(nvpair_value_string(elem, &strval) == 0);
+			if (spa->spa_comment != NULL)
+				spa_strfree(spa->spa_comment);
+			spa->spa_comment = spa_strdup(strval);
+			/*
+			 * We need to dirty the configuration on all the vdevs
+			 * so that their labels get updated.  It's unnecessary
+			 * to do this for pool creation since the vdev's
+			 * configuratoin has already been dirtied.
+			 */
+			if (tx->tx_txg != TXG_INITIAL)
+				vdev_config_dirty(spa->spa_root_vdev);
+			break;
 		default:
 			/*
 			 * Set pool property values in the poolprops mos object.

module/zfs/spa_config.c

@@ -21,6 +21,8 @@
 
 /*
  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright 2011 Nexenta Systems, Inc. All rights reserved.
+ * Copyright (c) 2011 by Delphix. All rights reserved.
  */
 
 #include <sys/spa.h>
@@ -344,6 +346,10 @@ spa_config_generate(spa_t *spa, vdev_t *vd, uint64_t txg, int getstats)
 	    txg) == 0);
 	VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_GUID,
 	    spa_guid(spa)) == 0);
+	VERIFY(spa->spa_comment == NULL || nvlist_add_string(config,
+	    ZPOOL_CONFIG_COMMENT, spa->spa_comment) == 0);
+
+
 #ifdef	_KERNEL
 	hostid = zone_get_hostid(NULL);
 #else	/* _KERNEL */