1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 
  22 /*
  23  * Copyright 2010 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  *
  26  * Portions Copyright 2007 Ramprakash Jelari
  27  */
  28 
  29 #include <libintl.h>
  30 #include <libuutil.h>
  31 #include <stddef.h>
  32 #include <stdlib.h>
  33 #include <string.h>
  34 #include <unistd.h>
  35 #include <zone.h>
  36 
  37 #include <libzfs.h>
  38 
  39 #include "libzfs_impl.h"
  40 
  41 /*
  42  * Structure to keep track of dataset state.  Before changing the 'sharenfs' or
  43  * 'mountpoint' property, we record whether the filesystem was previously
  44  * mounted/shared.  This prior state dictates whether we remount/reshare the
  45  * dataset after the property has been changed.
  46  *
  47  * The interface consists of the following sequence of functions:
  48  *
  49  *      changelist_gather()
  50  *      changelist_prefix()
  51  *      < change property >
  52  *      changelist_postfix()
  53  *      changelist_free()
  54  *
  55  * Other interfaces:
  56  *
  57  * changelist_remove() - remove a node from a gathered list
  58  * changelist_rename() - renames all datasets appropriately when doing a rename
  59  * changelist_unshare() - unshares all the nodes in a given changelist
  60  * changelist_haszonedchild() - check if there is any child exported to
  61  *                              a local zone
  62  */
  63 typedef struct prop_changenode {
  64         zfs_handle_t            *cn_handle;
  65         int                     cn_shared;
  66         int                     cn_mounted;
  67         int                     cn_zoned;
  68         boolean_t               cn_needpost;    /* is postfix() needed? */
  69         uu_list_node_t          cn_listnode;
  70 } prop_changenode_t;
  71 
  72 struct prop_changelist {
  73         zfs_prop_t              cl_prop;
  74         zfs_prop_t              cl_realprop;
  75         zfs_prop_t              cl_shareprop;  /* used with sharenfs/sharesmb */
  76         uu_list_pool_t          *cl_pool;
  77         uu_list_t               *cl_list;
  78         boolean_t               cl_waslegacy;
  79         boolean_t               cl_allchildren;
  80         boolean_t               cl_alldependents;
  81         int                     cl_mflags;      /* Mount flags */
  82         int                     cl_gflags;      /* Gather request flags */
  83         boolean_t               cl_haszonedchild;
  84         boolean_t               cl_sorted;
  85 };
  86 
  87 /*
  88  * If the property is 'mountpoint', go through and unmount filesystems as
  89  * necessary.  We don't do the same for 'sharenfs', because we can just re-share
  90  * with different options without interrupting service. We do handle 'sharesmb'
  91  * since there may be old resource names that need to be removed.
  92  */
  93 int
  94 changelist_prefix(prop_changelist_t *clp)
  95 {
  96         prop_changenode_t *cn;
  97         int ret = 0;
  98 
  99         if (clp->cl_prop != ZFS_PROP_MOUNTPOINT &&
 100             clp->cl_prop != ZFS_PROP_SHARESMB)
 101                 return (0);
 102 
 103         for (cn = uu_list_first(clp->cl_list); cn != NULL;
 104             cn = uu_list_next(clp->cl_list, cn)) {
 105 
 106                 /* if a previous loop failed, set the remaining to false */
 107                 if (ret == -1) {
 108                         cn->cn_needpost = B_FALSE;
 109                         continue;
 110                 }
 111 
 112                 /*
 113                  * If we are in the global zone, but this dataset is exported
 114                  * to a local zone, do nothing.
 115                  */
 116                 if (getzoneid() == GLOBAL_ZONEID && cn->cn_zoned)
 117                         continue;
 118 
 119                 if (!ZFS_IS_VOLUME(cn->cn_handle)) {
 120                         /*
 121                          * Do the property specific processing.
 122                          */
 123                         switch (clp->cl_prop) {
 124                         case ZFS_PROP_MOUNTPOINT:
 125                                 if (zfs_unmount(cn->cn_handle, NULL,
 126                                     clp->cl_mflags) != 0) {
 127                                         ret = -1;
 128                                         cn->cn_needpost = B_FALSE;
 129                                 }
 130                                 break;
 131                         case ZFS_PROP_SHARESMB:
 132                                 (void) zfs_unshare_smb(cn->cn_handle, NULL);
 133                                 break;
 134                         }
 135                 }
 136         }
 137 
 138         if (ret == -1)
 139                 (void) changelist_postfix(clp);
 140 
 141         return (ret);
 142 }
 143 
 144 /*
 145  * If the property is 'mountpoint' or 'sharenfs', go through and remount and/or
 146  * reshare the filesystems as necessary.  In changelist_gather() we recorded
 147  * whether the filesystem was previously shared or mounted.  The action we take
 148  * depends on the previous state, and whether the value was previously 'legacy'.
 149  * For non-legacy properties, we only remount/reshare the filesystem if it was
 150  * previously mounted/shared.  Otherwise, we always remount/reshare the
 151  * filesystem.
 152  */
 153 int
 154 changelist_postfix(prop_changelist_t *clp)
 155 {
 156         prop_changenode_t *cn;
 157         char shareopts[ZFS_MAXPROPLEN];
 158         int errors = 0;
 159         libzfs_handle_t *hdl;
 160 
 161         /*
 162          * If we're changing the mountpoint, attempt to destroy the underlying
 163          * mountpoint.  All other datasets will have inherited from this dataset
 164          * (in which case their mountpoints exist in the filesystem in the new
 165          * location), or have explicit mountpoints set (in which case they won't
 166          * be in the changelist).
 167          */
 168         if ((cn = uu_list_last(clp->cl_list)) == NULL)
 169                 return (0);
 170 
 171         if (clp->cl_prop == ZFS_PROP_MOUNTPOINT)
 172                 remove_mountpoint(cn->cn_handle);
 173 
 174         /*
 175          * It is possible that the changelist_prefix() used libshare
 176          * to unshare some entries. Since libshare caches data, an
 177          * attempt to reshare during postfix can fail unless libshare
 178          * is uninitialized here so that it will reinitialize later.
 179          */
 180         if (cn->cn_handle != NULL) {
 181                 hdl = cn->cn_handle->zfs_hdl;
 182                 assert(hdl != NULL);
 183                 zfs_uninit_libshare(hdl);
 184         }
 185 
 186         /*
 187          * We walk the datasets in reverse, because we want to mount any parent
 188          * datasets before mounting the children.  We walk all datasets even if
 189          * there are errors.
 190          */
 191         for (cn = uu_list_last(clp->cl_list); cn != NULL;
 192             cn = uu_list_prev(clp->cl_list, cn)) {
 193 
 194                 boolean_t sharenfs;
 195                 boolean_t sharesmb;
 196                 boolean_t mounted;
 197 
 198                 /*
 199                  * If we are in the global zone, but this dataset is exported
 200                  * to a local zone, do nothing.
 201                  */
 202                 if (getzoneid() == GLOBAL_ZONEID && cn->cn_zoned)
 203                         continue;
 204 
 205                 /* Only do post-processing if it's required */
 206                 if (!cn->cn_needpost)
 207                         continue;
 208                 cn->cn_needpost = B_FALSE;
 209 
 210                 zfs_refresh_properties(cn->cn_handle);
 211 
 212                 if (ZFS_IS_VOLUME(cn->cn_handle))
 213                         continue;
 214 
 215                 /*
 216                  * Remount if previously mounted or mountpoint was legacy,
 217                  * or sharenfs or sharesmb  property is set.
 218                  */
 219                 sharenfs = ((zfs_prop_get(cn->cn_handle, ZFS_PROP_SHARENFS,
 220                     shareopts, sizeof (shareopts), NULL, NULL, 0,
 221                     B_FALSE) == 0) && (strcmp(shareopts, "off") != 0));
 222 
 223                 sharesmb = ((zfs_prop_get(cn->cn_handle, ZFS_PROP_SHARESMB,
 224                     shareopts, sizeof (shareopts), NULL, NULL, 0,
 225                     B_FALSE) == 0) && (strcmp(shareopts, "off") != 0));
 226 
 227                 mounted = zfs_is_mounted(cn->cn_handle, NULL);
 228 
 229                 if (!mounted && (cn->cn_mounted ||
 230                     ((sharenfs || sharesmb || clp->cl_waslegacy) &&
 231                     (zfs_prop_get_int(cn->cn_handle,
 232                     ZFS_PROP_CANMOUNT) == ZFS_CANMOUNT_ON)))) {
 233 
 234                         if (zfs_mount(cn->cn_handle, NULL, 0) != 0)
 235                                 errors++;
 236                         else
 237                                 mounted = TRUE;
 238                 }
 239 
 240                 /*
 241                  * If the file system is mounted we always re-share even
 242                  * if the filesystem is currently shared, so that we can
 243                  * adopt any new options.
 244                  */
 245                 if (sharenfs && mounted)
 246                         errors += zfs_share_nfs(cn->cn_handle);
 247                 else if (cn->cn_shared || clp->cl_waslegacy)
 248                         errors += zfs_unshare_nfs(cn->cn_handle, NULL);
 249                 if (sharesmb && mounted)
 250                         errors += zfs_share_smb(cn->cn_handle);
 251                 else if (cn->cn_shared || clp->cl_waslegacy)
 252                         errors += zfs_unshare_smb(cn->cn_handle, NULL);
 253         }
 254 
 255         return (errors ? -1 : 0);
 256 }
 257 
 258 /*
 259  * Is this "dataset" a child of "parent"?
 260  */
 261 boolean_t
 262 isa_child_of(const char *dataset, const char *parent)
 263 {
 264         int len;
 265 
 266         len = strlen(parent);
 267 
 268         if (strncmp(dataset, parent, len) == 0 &&
 269             (dataset[len] == '@' || dataset[len] == '/' ||
 270             dataset[len] == '\0'))
 271                 return (B_TRUE);
 272         else
 273                 return (B_FALSE);
 274 
 275 }
 276 
 277 /*
 278  * If we rename a filesystem, child filesystem handles are no longer valid
 279  * since we identify each dataset by its name in the ZFS namespace.  As a
 280  * result, we have to go through and fix up all the names appropriately.  We
 281  * could do this automatically if libzfs kept track of all open handles, but
 282  * this is a lot less work.
 283  */
 284 void
 285 changelist_rename(prop_changelist_t *clp, const char *src, const char *dst)
 286 {
 287         prop_changenode_t *cn;
 288         char newname[ZFS_MAXNAMELEN];
 289 
 290         for (cn = uu_list_first(clp->cl_list); cn != NULL;
 291             cn = uu_list_next(clp->cl_list, cn)) {
 292                 /*
 293                  * Do not rename a clone that's not in the source hierarchy.
 294                  */
 295                 if (!isa_child_of(cn->cn_handle->zfs_name, src))
 296                         continue;
 297 
 298                 /*
 299                  * Destroy the previous mountpoint if needed.
 300                  */
 301                 remove_mountpoint(cn->cn_handle);
 302 
 303                 (void) strlcpy(newname, dst, sizeof (newname));
 304                 (void) strcat(newname, cn->cn_handle->zfs_name + strlen(src));
 305 
 306                 (void) strlcpy(cn->cn_handle->zfs_name, newname,
 307                     sizeof (cn->cn_handle->zfs_name));
 308         }
 309 }
 310 
 311 /*
 312  * Given a gathered changelist for the 'sharenfs' or 'sharesmb' property,
 313  * unshare all the datasets in the list.
 314  */
 315 int
 316 changelist_unshare(prop_changelist_t *clp, zfs_share_proto_t *proto)
 317 {
 318         prop_changenode_t *cn;
 319         int ret = 0;
 320 
 321         if (clp->cl_prop != ZFS_PROP_SHARENFS &&
 322             clp->cl_prop != ZFS_PROP_SHARESMB)
 323                 return (0);
 324 
 325         for (cn = uu_list_first(clp->cl_list); cn != NULL;
 326             cn = uu_list_next(clp->cl_list, cn)) {
 327                 if (zfs_unshare_proto(cn->cn_handle, NULL, proto) != 0)
 328                         ret = -1;
 329         }
 330 
 331         return (ret);
 332 }
 333 
 334 /*
 335  * Check if there is any child exported to a local zone in a given changelist.
 336  * This information has already been recorded while gathering the changelist
 337  * via changelist_gather().
 338  */
 339 int
 340 changelist_haszonedchild(prop_changelist_t *clp)
 341 {
 342         return (clp->cl_haszonedchild);
 343 }
 344 
 345 /*
 346  * Remove a node from a gathered list.
 347  */
 348 void
 349 changelist_remove(prop_changelist_t *clp, const char *name)
 350 {
 351         prop_changenode_t *cn;
 352 
 353         for (cn = uu_list_first(clp->cl_list); cn != NULL;
 354             cn = uu_list_next(clp->cl_list, cn)) {
 355 
 356                 if (strcmp(cn->cn_handle->zfs_name, name) == 0) {
 357                         uu_list_remove(clp->cl_list, cn);
 358                         zfs_close(cn->cn_handle);
 359                         free(cn);
 360                         return;
 361                 }
 362         }
 363 }
 364 
 365 /*
 366  * Release any memory associated with a changelist.
 367  */
 368 void
 369 changelist_free(prop_changelist_t *clp)
 370 {
 371         prop_changenode_t *cn;
 372         void *cookie;
 373 
 374         if (clp->cl_list) {
 375                 cookie = NULL;
 376                 while ((cn = uu_list_teardown(clp->cl_list, &cookie)) != NULL) {
 377                         zfs_close(cn->cn_handle);
 378                         free(cn);
 379                 }
 380 
 381                 uu_list_destroy(clp->cl_list);
 382         }
 383         if (clp->cl_pool)
 384                 uu_list_pool_destroy(clp->cl_pool);
 385 
 386         free(clp);
 387 }
 388 
 389 static int
 390 change_one(zfs_handle_t *zhp, void *data)
 391 {
 392         prop_changelist_t *clp = data;
 393         char property[ZFS_MAXPROPLEN];
 394         char where[64];
 395         prop_changenode_t *cn;
 396         zprop_source_t sourcetype;
 397         zprop_source_t share_sourcetype;
 398 
 399         /*
 400          * We only want to unmount/unshare those filesystems that may inherit
 401          * from the target filesystem.  If we find any filesystem with a
 402          * locally set mountpoint, we ignore any children since changing the
 403          * property will not affect them.  If this is a rename, we iterate
 404          * over all children regardless, since we need them unmounted in
 405          * order to do the rename.  Also, if this is a volume and we're doing
 406          * a rename, then always add it to the changelist.
 407          */
 408 
 409         if (!(ZFS_IS_VOLUME(zhp) && clp->cl_realprop == ZFS_PROP_NAME) &&
 410             zfs_prop_get(zhp, clp->cl_prop, property,
 411             sizeof (property), &sourcetype, where, sizeof (where),
 412             B_FALSE) != 0) {
 413                 zfs_close(zhp);
 414                 return (0);
 415         }
 416 
 417         /*
 418          * If we are "watching" sharenfs or sharesmb
 419          * then check out the companion property which is tracked
 420          * in cl_shareprop
 421          */
 422         if (clp->cl_shareprop != ZPROP_INVAL &&
 423             zfs_prop_get(zhp, clp->cl_shareprop, property,
 424             sizeof (property), &share_sourcetype, where, sizeof (where),
 425             B_FALSE) != 0) {
 426                 zfs_close(zhp);
 427                 return (0);
 428         }
 429 
 430         if (clp->cl_alldependents || clp->cl_allchildren ||
 431             sourcetype == ZPROP_SRC_DEFAULT ||
 432             sourcetype == ZPROP_SRC_INHERITED ||
 433             (clp->cl_shareprop != ZPROP_INVAL &&
 434             (share_sourcetype == ZPROP_SRC_DEFAULT ||
 435             share_sourcetype == ZPROP_SRC_INHERITED))) {
 436                 if ((cn = zfs_alloc(zfs_get_handle(zhp),
 437                     sizeof (prop_changenode_t))) == NULL) {
 438                         zfs_close(zhp);
 439                         return (-1);
 440                 }
 441 
 442                 cn->cn_handle = zhp;
 443                 cn->cn_mounted = (clp->cl_gflags & CL_GATHER_MOUNT_ALWAYS) ||
 444                     zfs_is_mounted(zhp, NULL);
 445                 cn->cn_shared = zfs_is_shared(zhp);
 446                 cn->cn_zoned = zfs_prop_get_int(zhp, ZFS_PROP_ZONED);
 447                 cn->cn_needpost = B_TRUE;
 448 
 449                 /* Indicate if any child is exported to a local zone. */
 450                 if (getzoneid() == GLOBAL_ZONEID && cn->cn_zoned)
 451                         clp->cl_haszonedchild = B_TRUE;
 452 
 453                 uu_list_node_init(cn, &cn->cn_listnode, clp->cl_pool);
 454 
 455                 if (clp->cl_sorted) {
 456                         uu_list_index_t idx;
 457 
 458                         (void) uu_list_find(clp->cl_list, cn, NULL,
 459                             &idx);
 460                         uu_list_insert(clp->cl_list, cn, idx);
 461                 } else {
 462                         /*
 463                          * Add this child to beginning of the list. Children
 464                          * below this one in the hierarchy will get added above
 465                          * this one in the list. This produces a list in
 466                          * reverse dataset name order.
 467                          * This is necessary when the original mountpoint
 468                          * is legacy or none.
 469                          */
 470                         ASSERT(!clp->cl_alldependents);
 471                         verify(uu_list_insert_before(clp->cl_list,
 472                             uu_list_first(clp->cl_list), cn) == 0);
 473                 }
 474 
 475                 if (!clp->cl_alldependents)
 476                         return (zfs_iter_children(zhp, change_one, data));
 477         } else {
 478                 zfs_close(zhp);
 479         }
 480 
 481         return (0);
 482 }
 483 
 484 /*ARGSUSED*/
 485 static int
 486 compare_mountpoints(const void *a, const void *b, void *unused)
 487 {
 488         const prop_changenode_t *ca = a;
 489         const prop_changenode_t *cb = b;
 490 
 491         char mounta[MAXPATHLEN];
 492         char mountb[MAXPATHLEN];
 493 
 494         boolean_t hasmounta, hasmountb;
 495 
 496         /*
 497          * When unsharing or unmounting filesystems, we need to do it in
 498          * mountpoint order.  This allows the user to have a mountpoint
 499          * hierarchy that is different from the dataset hierarchy, and still
 500          * allow it to be changed.  However, if either dataset doesn't have a
 501          * mountpoint (because it is a volume or a snapshot), we place it at the
 502          * end of the list, because it doesn't affect our change at all.
 503          */
 504         hasmounta = (zfs_prop_get(ca->cn_handle, ZFS_PROP_MOUNTPOINT, mounta,
 505             sizeof (mounta), NULL, NULL, 0, B_FALSE) == 0);
 506         hasmountb = (zfs_prop_get(cb->cn_handle, ZFS_PROP_MOUNTPOINT, mountb,
 507             sizeof (mountb), NULL, NULL, 0, B_FALSE) == 0);
 508 
 509         if (!hasmounta && hasmountb)
 510                 return (-1);
 511         else if (hasmounta && !hasmountb)
 512                 return (1);
 513         else if (!hasmounta && !hasmountb)
 514                 return (0);
 515         else
 516                 return (strcmp(mountb, mounta));
 517 }
 518 
 519 /*
 520  * Given a ZFS handle and a property, construct a complete list of datasets
 521  * that need to be modified as part of this process.  For anything but the
 522  * 'mountpoint' and 'sharenfs' properties, this just returns an empty list.
 523  * Otherwise, we iterate over all children and look for any datasets that
 524  * inherit the property.  For each such dataset, we add it to the list and
 525  * mark whether it was shared beforehand.
 526  */
 527 prop_changelist_t *
 528 changelist_gather(zfs_handle_t *zhp, zfs_prop_t prop, int gather_flags,
 529     int mnt_flags)
 530 {
 531         prop_changelist_t *clp;
 532         prop_changenode_t *cn;
 533         zfs_handle_t *temp;
 534         char property[ZFS_MAXPROPLEN];
 535         uu_compare_fn_t *compare = NULL;
 536         boolean_t legacy = B_FALSE;
 537 
 538         if ((clp = zfs_alloc(zhp->zfs_hdl, sizeof (prop_changelist_t))) == NULL)
 539                 return (NULL);
 540 
 541         /*
 542          * For mountpoint-related tasks, we want to sort everything by
 543          * mountpoint, so that we mount and unmount them in the appropriate
 544          * order, regardless of their position in the hierarchy.
 545          */
 546         if (prop == ZFS_PROP_NAME || prop == ZFS_PROP_ZONED ||
 547             prop == ZFS_PROP_MOUNTPOINT || prop == ZFS_PROP_SHARENFS ||
 548             prop == ZFS_PROP_SHARESMB) {
 549 
 550                 if (zfs_prop_get(zhp, ZFS_PROP_MOUNTPOINT,
 551                     property, sizeof (property),
 552                     NULL, NULL, 0, B_FALSE) == 0 &&
 553                     (strcmp(property, "legacy") == 0 ||
 554                     strcmp(property, "none") == 0)) {
 555 
 556                         legacy = B_TRUE;
 557                 }
 558                 if (!legacy) {
 559                         compare = compare_mountpoints;
 560                         clp->cl_sorted = B_TRUE;
 561                 }
 562         }
 563 
 564         clp->cl_pool = uu_list_pool_create("changelist_pool",
 565             sizeof (prop_changenode_t),
 566             offsetof(prop_changenode_t, cn_listnode),
 567             compare, 0);
 568         if (clp->cl_pool == NULL) {
 569                 assert(uu_error() == UU_ERROR_NO_MEMORY);
 570                 (void) zfs_error(zhp->zfs_hdl, EZFS_NOMEM, "internal error");
 571                 changelist_free(clp);
 572                 return (NULL);
 573         }
 574 
 575         clp->cl_list = uu_list_create(clp->cl_pool, NULL,
 576             clp->cl_sorted ? UU_LIST_SORTED : 0);
 577         clp->cl_gflags = gather_flags;
 578         clp->cl_mflags = mnt_flags;
 579 
 580         if (clp->cl_list == NULL) {
 581                 assert(uu_error() == UU_ERROR_NO_MEMORY);
 582                 (void) zfs_error(zhp->zfs_hdl, EZFS_NOMEM, "internal error");
 583                 changelist_free(clp);
 584                 return (NULL);
 585         }
 586 
 587         /*
 588          * If this is a rename or the 'zoned' property, we pretend we're
 589          * changing the mountpoint and flag it so we can catch all children in
 590          * change_one().
 591          *
 592          * Flag cl_alldependents to catch all children plus the dependents
 593          * (clones) that are not in the hierarchy.
 594          */
 595         if (prop == ZFS_PROP_NAME) {
 596                 clp->cl_prop = ZFS_PROP_MOUNTPOINT;
 597                 clp->cl_alldependents = B_TRUE;
 598         } else if (prop == ZFS_PROP_ZONED) {
 599                 clp->cl_prop = ZFS_PROP_MOUNTPOINT;
 600                 clp->cl_allchildren = B_TRUE;
 601         } else if (prop == ZFS_PROP_CANMOUNT) {
 602                 clp->cl_prop = ZFS_PROP_MOUNTPOINT;
 603         } else if (prop == ZFS_PROP_VOLSIZE) {
 604                 clp->cl_prop = ZFS_PROP_MOUNTPOINT;
 605         } else {
 606                 clp->cl_prop = prop;
 607         }
 608         clp->cl_realprop = prop;
 609 
 610         if (clp->cl_prop != ZFS_PROP_MOUNTPOINT &&
 611             clp->cl_prop != ZFS_PROP_SHARENFS &&
 612             clp->cl_prop != ZFS_PROP_SHARESMB)
 613                 return (clp);
 614 
 615         /*
 616          * If watching SHARENFS or SHARESMB then
 617          * also watch its companion property.
 618          */
 619         if (clp->cl_prop == ZFS_PROP_SHARENFS)
 620                 clp->cl_shareprop = ZFS_PROP_SHARESMB;
 621         else if (clp->cl_prop == ZFS_PROP_SHARESMB)
 622                 clp->cl_shareprop = ZFS_PROP_SHARENFS;
 623 
 624         if (clp->cl_alldependents) {
 625                 if (zfs_iter_dependents(zhp, B_TRUE, change_one, clp) != 0) {
 626                         changelist_free(clp);
 627                         return (NULL);
 628                 }
 629         } else if (zfs_iter_children(zhp, change_one, clp) != 0) {
 630                 changelist_free(clp);
 631                 return (NULL);
 632         }
 633 
 634         /*
 635          * We have to re-open ourselves because we auto-close all the handles
 636          * and can't tell the difference.
 637          */
 638         if ((temp = zfs_open(zhp->zfs_hdl, zfs_get_name(zhp),
 639             ZFS_TYPE_DATASET)) == NULL) {
 640                 changelist_free(clp);
 641                 return (NULL);
 642         }
 643 
 644         /*
 645          * Always add ourself to the list.  We add ourselves to the end so that
 646          * we're the last to be unmounted.
 647          */
 648         if ((cn = zfs_alloc(zhp->zfs_hdl,
 649             sizeof (prop_changenode_t))) == NULL) {
 650                 zfs_close(temp);
 651                 changelist_free(clp);
 652                 return (NULL);
 653         }
 654 
 655         cn->cn_handle = temp;
 656         cn->cn_mounted = (clp->cl_gflags & CL_GATHER_MOUNT_ALWAYS) ||
 657             zfs_is_mounted(temp, NULL);
 658         cn->cn_shared = zfs_is_shared(temp);
 659         cn->cn_zoned = zfs_prop_get_int(zhp, ZFS_PROP_ZONED);
 660         cn->cn_needpost = B_TRUE;
 661 
 662         uu_list_node_init(cn, &cn->cn_listnode, clp->cl_pool);
 663         if (clp->cl_sorted) {
 664                 uu_list_index_t idx;
 665                 (void) uu_list_find(clp->cl_list, cn, NULL, &idx);
 666                 uu_list_insert(clp->cl_list, cn, idx);
 667         } else {
 668                 /*
 669                  * Add the target dataset to the end of the list.
 670                  * The list is not really unsorted. The list will be
 671                  * in reverse dataset name order. This is necessary
 672                  * when the original mountpoint is legacy or none.
 673                  */
 674                 verify(uu_list_insert_after(clp->cl_list,
 675                     uu_list_last(clp->cl_list), cn) == 0);
 676         }
 677 
 678         /*
 679          * If the mountpoint property was previously 'legacy', or 'none',
 680          * record it as the behavior of changelist_postfix() will be different.
 681          */
 682         if ((clp->cl_prop == ZFS_PROP_MOUNTPOINT) && legacy) {
 683                 /*
 684                  * do not automatically mount ex-legacy datasets if
 685                  * we specifically set canmount to noauto
 686                  */
 687                 if (zfs_prop_get_int(zhp, ZFS_PROP_CANMOUNT) !=
 688                     ZFS_CANMOUNT_NOAUTO)
 689                         clp->cl_waslegacy = B_TRUE;
 690         }
 691 
 692         return (clp);
 693 }