4171 clean up spa_feature_*() interfaces
4172 implement extensible_dataset feature for use by other zpool features
Reviewed by: Max Grossman <max.grossman@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>

*** 20,30 ****
   */
  
  /*
   * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
   * Copyright 2011 Nexenta Systems, Inc. All rights reserved.
!  * Copyright (c) 2012 by Delphix. All rights reserved.
   * Copyright (c) 2013, Joyent, Inc. All rights reserved.
   */
  
  #include <ctype.h>
  #include <errno.h>
--- 20,30 ----
   */
  
  /*
   * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
   * Copyright 2011 Nexenta Systems, Inc. All rights reserved.
!  * Copyright (c) 2013 by Delphix. All rights reserved.
   * Copyright (c) 2013, Joyent, Inc. All rights reserved.
   */
  
  #include <ctype.h>
  #include <errno.h>
*** 411,424 ****
                  const char *propname = nvpair_name(elem);
  
                  prop = zpool_name_to_prop(propname);
                  if (prop == ZPROP_INVAL && zpool_prop_feature(propname)) {
                          int err;
-                         zfeature_info_t *feature;
                          char *fname = strchr(propname, '@') + 1;
  
!                         err = zfeature_lookup_name(fname, &feature);
                          if (err != 0) {
                                  ASSERT3U(err, ==, ENOENT);
                                  zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                                      "invalid feature '%s'"), fname);
                                  (void) zfs_error(hdl, EZFS_BADPROP, errbuf);
--- 411,423 ----
                  const char *propname = nvpair_name(elem);
  
                  prop = zpool_name_to_prop(propname);
                  if (prop == ZPROP_INVAL && zpool_prop_feature(propname)) {
                          int err;
                          char *fname = strchr(propname, '@') + 1;
  
!                         err = zfeature_lookup_name(fname, NULL);
                          if (err != 0) {
                                  ASSERT3U(err, ==, ENOENT);
                                  zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                                      "invalid feature '%s'"), fname);
                                  (void) zfs_error(hdl, EZFS_BADPROP, errbuf);
*** 805,822 ****
           * unecessary for unsupported@... properties because they already
           * use guids.
           */
          if (supported) {
                  int ret;
!                 zfeature_info_t *fi;
  
!                 ret = zfeature_lookup_name(feature, &fi);
                  if (ret != 0) {
                          (void) strlcpy(buf, "-", len);
                          return (ENOTSUP);
                  }
!                 feature = fi->fi_guid;
          }
  
          if (nvlist_lookup_uint64(features, feature, &refcount) == 0)
                  found = B_TRUE;
  
--- 804,821 ----
           * unecessary for unsupported@... properties because they already
           * use guids.
           */
          if (supported) {
                  int ret;
!                 spa_feature_t fid;
  
!                 ret = zfeature_lookup_name(feature, &fid);
                  if (ret != 0) {
                          (void) strlcpy(buf, "-", len);
                          return (ENOTSUP);
                  }
!                 feature = spa_feature_table[fid].fi_guid;
          }
  
          if (nvlist_lookup_uint64(features, feature, &refcount) == 0)
                  found = B_TRUE;