--- a/usr/src/lib/libzfs/common/libzfs.h	Sun May 20 02:46:39 2012 -0500
+++ b/usr/src/lib/libzfs/common/libzfs.h	Mon May 21 12:11:39 2012 -0700
@@ -291,6 +291,15 @@
 	ZPOOL_STATUS_BAD_LOG,		/* cannot read log chain(s) */
 
 	/*
+	 * If the pool has unsupported features but can still be opened in
+	 * read-only mode, its status is ZPOOL_STATUS_UNSUP_FEAT_WRITE. If the
+	 * pool has unsupported features but cannot be opened at all, its
+	 * status is ZPOOL_STATUS_UNSUP_FEAT_READ.
+	 */
+	ZPOOL_STATUS_UNSUP_FEAT_READ,	/* unsupported features for read */
+	ZPOOL_STATUS_UNSUP_FEAT_WRITE,	/* unsupported features for write */
+
+	/*
 	 * These faults have no corresponding message ID.  At the time we are
 	 * checking the status, the original reason for the FMA fault (I/O or
 	 * checksum errors) has been lost.
@@ -322,6 +331,7 @@
  * Statistics and configuration functions.
  */
 extern nvlist_t *zpool_get_config(zpool_handle_t *, nvlist_t **);
+extern nvlist_t *zpool_get_features(zpool_handle_t *);
 extern int zpool_refresh_stats(zpool_handle_t *, boolean_t *);
 extern int zpool_get_errlog(zpool_handle_t *, nvlist_t **);
 
@@ -334,6 +344,7 @@
     char *altroot);
 extern int zpool_import_props(libzfs_handle_t *, nvlist_t *, const char *,
     nvlist_t *, int);
+extern void zpool_print_unsup_feat(nvlist_t *config);
 
 /*
  * Search for pools to import
@@ -423,6 +434,8 @@
     uint64_t *propvalue);
 extern int zfs_prop_get_written(zfs_handle_t *zhp, const char *propname,
     char *propbuf, int proplen, boolean_t literal);
+extern int zfs_prop_get_feature(zfs_handle_t *zhp, const char *propname,
+    char *buf, size_t len);
 extern int zfs_get_snapused_int(zfs_handle_t *firstsnap, zfs_handle_t *lastsnap,
     uint64_t *usedp);
 extern uint64_t zfs_prop_get_int(zfs_handle_t *, zfs_prop_t);
@@ -450,10 +463,19 @@
 #define	ZFS_MOUNTPOINT_NONE	"none"
 #define	ZFS_MOUNTPOINT_LEGACY	"legacy"
 
+#define	ZFS_FEATURE_DISABLED	"disabled"
+#define	ZFS_FEATURE_ENABLED	"enabled"
+#define	ZFS_FEATURE_ACTIVE	"active"
+
+#define	ZFS_UNSUPPORTED_INACTIVE	"inactive"
+#define	ZFS_UNSUPPORTED_READONLY	"readonly"
+
 /*
  * zpool property management
  */
 extern int zpool_expand_proplist(zpool_handle_t *, zprop_list_t **);
+extern int zpool_prop_get_feature(zpool_handle_t *, const char *, char *,
+    size_t);
 extern const char *zpool_prop_default_string(zpool_prop_t);
 extern uint64_t zpool_prop_default_numeric(zpool_prop_t);
 extern const char *zpool_prop_column_name(zpool_prop_t);