Vendor import of openzfs master @ 184df27eef0abdc7ab2105b21257f753834b936bvendor/openzfs/2.0-rc0-g184df27

Sponsored by:	iX Systems, Inc.

1 files changed, 1581 insertions, 0 deletions

diff --git a/cmd/zpool/zpool_vdev.c b/cmd/zpool/zpool_vdev.c
new file mode 100644
index 000000000000..9aa09b18c4ae
--- /dev/null
+++ b/cmd/zpool/zpool_vdev.c
@@ -0,0 +1,1581 @@
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or http://www.opensolaris.org/os/licensing.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+
+/*
+ * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2013, 2018 by Delphix. All rights reserved.
+ * Copyright (c) 2016, 2017 Intel Corporation.
+ * Copyright 2016 Igor Kozhukhov <ikozhukhov@gmail.com>.
+ */
+
+/*
+ * Functions to convert between a list of vdevs and an nvlist representing the
+ * configuration.  Each entry in the list can be one of:
+ *
+ * 	Device vdevs
+ * 		disk=(path=..., devid=...)
+ * 		file=(path=...)
+ *
+ * 	Group vdevs
+ * 		raidz[1|2]=(...)
+ * 		mirror=(...)
+ *
+ * 	Hot spares
+ *
+ * While the underlying implementation supports it, group vdevs cannot contain
+ * other group vdevs.  All userland verification of devices is contained within
+ * this file.  If successful, the nvlist returned can be passed directly to the
+ * kernel; we've done as much verification as possible in userland.
+ *
+ * Hot spares are a special case, and passed down as an array of disk vdevs, at
+ * the same level as the root of the vdev tree.
+ *
+ * The only function exported by this file is 'make_root_vdev'.  The
+ * function performs several passes:
+ *
+ * 	1. Construct the vdev specification.  Performs syntax validation and
+ *         makes sure each device is valid.
+ * 	2. Check for devices in use.  Using libblkid to make sure that no
+ *         devices are also in use.  Some can be overridden using the 'force'
+ *         flag, others cannot.
+ * 	3. Check for replication errors if the 'force' flag is not specified.
+ *         validates that the replication level is consistent across the
+ *         entire pool.
+ * 	4. Call libzfs to label any whole disks with an EFI label.
+ */
+
+#include <assert.h>
+#include <ctype.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <libintl.h>
+#include <libnvpair.h>
+#include <libzutil.h>
+#include <limits.h>
+#include <sys/spa.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include "zpool_util.h"
+#include <sys/zfs_context.h>
+#include <sys/stat.h>
+
+/*
+ * For any given vdev specification, we can have multiple errors.  The
+ * vdev_error() function keeps track of whether we have seen an error yet, and
+ * prints out a header if its the first error we've seen.
+ */
+boolean_t error_seen;
+boolean_t is_force;
+
+
+
+
+/*PRINTFLIKE1*/
+void
+vdev_error(const char *fmt, ...)
+{
+	va_list ap;
+
+	if (!error_seen) {
+		(void) fprintf(stderr, gettext("invalid vdev specification\n"));
+		if (!is_force)
+			(void) fprintf(stderr, gettext("use '-f' to override "
+			    "the following errors:\n"));
+		else
+			(void) fprintf(stderr, gettext("the following errors "
+			    "must be manually repaired:\n"));
+		error_seen = B_TRUE;
+	}
+
+	va_start(ap, fmt);
+	(void) vfprintf(stderr, fmt, ap);
+	va_end(ap);
+}
+
+/*
+ * Check that a file is valid.  All we can do in this case is check that it's
+ * not in use by another pool, and not in use by swap.
+ */
+int
+check_file(const char *file, boolean_t force, boolean_t isspare)
+{
+	char  *name;
+	int fd;
+	int ret = 0;
+	pool_state_t state;
+	boolean_t inuse;
+
+	if ((fd = open(file, O_RDONLY)) < 0)
+		return (0);
+
+	if (zpool_in_use(g_zfs, fd, &state, &name, &inuse) == 0 && inuse) {
+		const char *desc;
+
+		switch (state) {
+		case POOL_STATE_ACTIVE:
+			desc = gettext("active");
+			break;
+
+		case POOL_STATE_EXPORTED:
+			desc = gettext("exported");
+			break;
+
+		case POOL_STATE_POTENTIALLY_ACTIVE:
+			desc = gettext("potentially active");
+			break;
+
+		default:
+			desc = gettext("unknown");
+			break;
+		}
+
+		/*
+		 * Allow hot spares to be shared between pools.
+		 */
+		if (state == POOL_STATE_SPARE && isspare) {
+			free(name);
+			(void) close(fd);
+			return (0);
+		}
+
+		if (state == POOL_STATE_ACTIVE ||
+		    state == POOL_STATE_SPARE || !force) {
+			switch (state) {
+			case POOL_STATE_SPARE:
+				vdev_error(gettext("%s is reserved as a hot "
+				    "spare for pool %s\n"), file, name);
+				break;
+			default:
+				vdev_error(gettext("%s is part of %s pool "
+				    "'%s'\n"), file, desc, name);
+				break;
+			}
+			ret = -1;
+		}
+
+		free(name);
+	}
+
+	(void) close(fd);
+	return (ret);
+}
+
+/*
+ * This may be a shorthand device path or it could be total gibberish.
+ * Check to see if it is a known device available in zfs_vdev_paths.
+ * As part of this check, see if we've been given an entire disk
+ * (minus the slice number).
+ */
+static int
+is_shorthand_path(const char *arg, char *path, size_t path_size,
+    struct stat64 *statbuf, boolean_t *wholedisk)
+{
+	int error;
+
+	error = zfs_resolve_shortname(arg, path, path_size);
+	if (error == 0) {
+		*wholedisk = zfs_dev_is_whole_disk(path);
+		if (*wholedisk || (stat64(path, statbuf) == 0))
+			return (0);
+	}
+
+	strlcpy(path, arg, path_size);
+	memset(statbuf, 0, sizeof (*statbuf));
+	*wholedisk = B_FALSE;
+
+	return (error);
+}
+
+/*
+ * Determine if the given path is a hot spare within the given configuration.
+ * If no configuration is given we rely solely on the label.
+ */
+static boolean_t
+is_spare(nvlist_t *config, const char *path)
+{
+	int fd;
+	pool_state_t state;
+	char *name = NULL;
+	nvlist_t *label;
+	uint64_t guid, spareguid;
+	nvlist_t *nvroot;
+	nvlist_t **spares;
+	uint_t i, nspares;
+	boolean_t inuse;
+
+	if ((fd = open(path, O_RDONLY|O_DIRECT)) < 0)
+		return (B_FALSE);
+
+	if (zpool_in_use(g_zfs, fd, &state, &name, &inuse) != 0 ||
+	    !inuse ||
+	    state != POOL_STATE_SPARE ||
+	    zpool_read_label(fd, &label, NULL) != 0) {
+		free(name);
+		(void) close(fd);
+		return (B_FALSE);
+	}
+	free(name);
+	(void) close(fd);
+
+	if (config == NULL) {
+		nvlist_free(label);
+		return (B_TRUE);
+	}
+
+	verify(nvlist_lookup_uint64(label, ZPOOL_CONFIG_GUID, &guid) == 0);
+	nvlist_free(label);
+
+	verify(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE,
+	    &nvroot) == 0);
+	if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES,
+	    &spares, &nspares) == 0) {
+		for (i = 0; i < nspares; i++) {
+			verify(nvlist_lookup_uint64(spares[i],
+			    ZPOOL_CONFIG_GUID, &spareguid) == 0);
+			if (spareguid == guid)
+				return (B_TRUE);
+		}
+	}
+
+	return (B_FALSE);
+}
+
+/*
+ * Create a leaf vdev.  Determine if this is a file or a device.  If it's a
+ * device, fill in the device id to make a complete nvlist.  Valid forms for a
+ * leaf vdev are:
+ *
+ *	/dev/xxx	Complete disk path
+ *	/xxx		Full path to file
+ *	xxx		Shorthand for <zfs_vdev_paths>/xxx
+ */
+static nvlist_t *
+make_leaf_vdev(nvlist_t *props, const char *arg, uint64_t is_log)
+{
+	char path[MAXPATHLEN];
+	struct stat64 statbuf;
+	nvlist_t *vdev = NULL;
+	char *type = NULL;
+	boolean_t wholedisk = B_FALSE;
+	uint64_t ashift = 0;
+	int err;
+
+	/*
+	 * Determine what type of vdev this is, and put the full path into
+	 * 'path'.  We detect whether this is a device of file afterwards by
+	 * checking the st_mode of the file.
+	 */
+	if (arg[0] == '/') {
+		/*
+		 * Complete device or file path.  Exact type is determined by
+		 * examining the file descriptor afterwards.  Symbolic links
+		 * are resolved to their real paths to determine whole disk
+		 * and S_ISBLK/S_ISREG type checks.  However, we are careful
+		 * to store the given path as ZPOOL_CONFIG_PATH to ensure we
+		 * can leverage udev's persistent device labels.
+		 */
+		if (realpath(arg, path) == NULL) {
+			(void) fprintf(stderr,
+			    gettext("cannot resolve path '%s'\n"), arg);
+			return (NULL);
+		}
+
+		wholedisk = zfs_dev_is_whole_disk(path);
+		if (!wholedisk && (stat64(path, &statbuf) != 0)) {
+			(void) fprintf(stderr,
+			    gettext("cannot open '%s': %s\n"),
+			    path, strerror(errno));
+			return (NULL);
+		}
+
+		/* After whole disk check restore original passed path */
+		strlcpy(path, arg, sizeof (path));
+	} else {
+		err = is_shorthand_path(arg, path, sizeof (path),
+		    &statbuf, &wholedisk);
+		if (err != 0) {
+			/*
+			 * If we got ENOENT, then the user gave us
+			 * gibberish, so try to direct them with a
+			 * reasonable error message.  Otherwise,
+			 * regurgitate strerror() since it's the best we
+			 * can do.
+			 */
+			if (err == ENOENT) {
+				(void) fprintf(stderr,
+				    gettext("cannot open '%s': no such "
+				    "device in %s\n"), arg, DISK_ROOT);
+				(void) fprintf(stderr,
+				    gettext("must be a full path or "
+				    "shorthand device name\n"));
+				return (NULL);
+			} else {
+				(void) fprintf(stderr,
+				    gettext("cannot open '%s': %s\n"),
+				    path, strerror(errno));
+				return (NULL);
+			}
+		}
+	}
+
+	/*
+	 * Determine whether this is a device or a file.
+	 */
+	if (wholedisk || S_ISBLK(statbuf.st_mode)) {
+		type = VDEV_TYPE_DISK;
+	} else if (S_ISREG(statbuf.st_mode)) {
+		type = VDEV_TYPE_FILE;
+	} else {
+		(void) fprintf(stderr, gettext("cannot use '%s': must be a "
+		    "block device or regular file\n"), path);
+		return (NULL);
+	}
+
+	/*
+	 * Finally, we have the complete device or file, and we know that it is
+	 * acceptable to use.  Construct the nvlist to describe this vdev.  All
+	 * vdevs have a 'path' element, and devices also have a 'devid' element.
+	 */
+	verify(nvlist_alloc(&vdev, NV_UNIQUE_NAME, 0) == 0);
+	verify(nvlist_add_string(vdev, ZPOOL_CONFIG_PATH, path) == 0);
+	verify(nvlist_add_string(vdev, ZPOOL_CONFIG_TYPE, type) == 0);
+	verify(nvlist_add_uint64(vdev, ZPOOL_CONFIG_IS_LOG, is_log) == 0);
+	if (is_log)
+		verify(nvlist_add_string(vdev, ZPOOL_CONFIG_ALLOCATION_BIAS,
+		    VDEV_ALLOC_BIAS_LOG) == 0);
+	if (strcmp(type, VDEV_TYPE_DISK) == 0)
+		verify(nvlist_add_uint64(vdev, ZPOOL_CONFIG_WHOLE_DISK,
+		    (uint64_t)wholedisk) == 0);
+
+	/*
+	 * Override defaults if custom properties are provided.
+	 */
+	if (props != NULL) {
+		char *value = NULL;
+
+		if (nvlist_lookup_string(props,
+		    zpool_prop_to_name(ZPOOL_PROP_ASHIFT), &value) == 0) {
+			if (zfs_nicestrtonum(NULL, value, &ashift) != 0) {
+				(void) fprintf(stderr,
+				    gettext("ashift must be a number.\n"));
+				return (NULL);
+			}
+			if (ashift != 0 &&
+			    (ashift < ASHIFT_MIN || ashift > ASHIFT_MAX)) {
+				(void) fprintf(stderr,
+				    gettext("invalid 'ashift=%" PRIu64 "' "
+				    "property: only values between %" PRId32 " "
+				    "and %" PRId32 " are allowed.\n"),
+				    ashift, ASHIFT_MIN, ASHIFT_MAX);
+				return (NULL);
+			}
+		}
+	}
+
+	/*
+	 * If the device is known to incorrectly report its physical sector
+	 * size explicitly provide the known correct value.
+	 */
+	if (ashift == 0) {
+		int sector_size;
+
+		if (check_sector_size_database(path, &sector_size) == B_TRUE)
+			ashift = highbit64(sector_size) - 1;
+	}
+
+	if (ashift > 0)
+		(void) nvlist_add_uint64(vdev, ZPOOL_CONFIG_ASHIFT, ashift);
+
+	return (vdev);
+}
+
+/*
+ * Go through and verify the replication level of the pool is consistent.
+ * Performs the following checks:
+ *
+ * 	For the new spec, verifies that devices in mirrors and raidz are the
+ * 	same size.
+ *
+ * 	If the current configuration already has inconsistent replication
+ * 	levels, ignore any other potential problems in the new spec.
+ *
+ * 	Otherwise, make sure that the current spec (if there is one) and the new
+ * 	spec have consistent replication levels.
+ *
+ *	If there is no current spec (create), make sure new spec has at least
+ *	one general purpose vdev.
+ */
+typedef struct replication_level {
+	char *zprl_type;
+	uint64_t zprl_children;
+	uint64_t zprl_parity;
+} replication_level_t;
+
+#define	ZPOOL_FUZZ	(16 * 1024 * 1024)
+
+static boolean_t
+is_raidz_mirror(replication_level_t *a, replication_level_t *b,
+    replication_level_t **raidz, replication_level_t **mirror)
+{
+	if (strcmp(a->zprl_type, "raidz") == 0 &&
+	    strcmp(b->zprl_type, "mirror") == 0) {
+		*raidz = a;
+		*mirror = b;
+		return (B_TRUE);
+	}
+	return (B_FALSE);
+}
+
+/*
+ * Given a list of toplevel vdevs, return the current replication level.  If
+ * the config is inconsistent, then NULL is returned.  If 'fatal' is set, then
+ * an error message will be displayed for each self-inconsistent vdev.
+ */
+static replication_level_t *
+get_replication(nvlist_t *nvroot, boolean_t fatal)
+{
+	nvlist_t **top;
+	uint_t t, toplevels;
+	nvlist_t **child;
+	uint_t c, children;
+	nvlist_t *nv;
+	char *type;
+	replication_level_t lastrep = {0};
+	replication_level_t rep;
+	replication_level_t *ret;
+	replication_level_t *raidz, *mirror;
+	boolean_t dontreport;
+
+	ret = safe_malloc(sizeof (replication_level_t));
+
+	verify(nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_CHILDREN,
+	    &top, &toplevels) == 0);
+
+	for (t = 0; t < toplevels; t++) {
+		uint64_t is_log = B_FALSE;
+
+		nv = top[t];
+
+		/*
+		 * For separate logs we ignore the top level vdev replication
+		 * constraints.
+		 */
+		(void) nvlist_lookup_uint64(nv, ZPOOL_CONFIG_IS_LOG, &is_log);
+		if (is_log)
+			continue;
+
+		/* Ignore holes introduced by removing aux devices */
+		verify(nvlist_lookup_string(nv, ZPOOL_CONFIG_TYPE, &type) == 0);
+		if (strcmp(type, VDEV_TYPE_HOLE) == 0)
+			continue;
+
+		if (nvlist_lookup_nvlist_array(nv, ZPOOL_CONFIG_CHILDREN,
+		    &child, &children) != 0) {
+			/*
+			 * This is a 'file' or 'disk' vdev.
+			 */
+			rep.zprl_type = type;
+			rep.zprl_children = 1;
+			rep.zprl_parity = 0;
+		} else {
+			int64_t vdev_size;
+
+			/*
+			 * This is a mirror or RAID-Z vdev.  Go through and make
+			 * sure the contents are all the same (files vs. disks),
+			 * keeping track of the number of elements in the
+			 * process.
+			 *
+			 * We also check that the size of each vdev (if it can
+			 * be determined) is the same.
+			 */
+			rep.zprl_type = type;
+			rep.zprl_children = 0;
+
+			if (strcmp(type, VDEV_TYPE_RAIDZ) == 0) {
+				verify(nvlist_lookup_uint64(nv,
+				    ZPOOL_CONFIG_NPARITY,
+				    &rep.zprl_parity) == 0);
+				assert(rep.zprl_parity != 0);
+			} else {
+				rep.zprl_parity = 0;
+			}
+
+			/*
+			 * The 'dontreport' variable indicates that we've
+			 * already reported an error for this spec, so don't
+			 * bother doing it again.
+			 */
+			type = NULL;
+			dontreport = 0;
+			vdev_size = -1LL;
+			for (c = 0; c < children; c++) {
+				nvlist_t *cnv = child[c];
+				char *path;
+				struct stat64 statbuf;
+				int64_t size = -1LL;
+				char *childtype;
+				int fd, err;
+
+				rep.zprl_children++;
+
+				verify(nvlist_lookup_string(cnv,
+				    ZPOOL_CONFIG_TYPE, &childtype) == 0);
+
+				/*
+				 * If this is a replacing or spare vdev, then
+				 * get the real first child of the vdev: do this
+				 * in a loop because replacing and spare vdevs
+				 * can be nested.
+				 */
+				while (strcmp(childtype,
+				    VDEV_TYPE_REPLACING) == 0 ||
+				    strcmp(childtype, VDEV_TYPE_SPARE) == 0) {
+					nvlist_t **rchild;
+					uint_t rchildren;
+
+					verify(nvlist_lookup_nvlist_array(cnv,
+					    ZPOOL_CONFIG_CHILDREN, &rchild,
+					    &rchildren) == 0);
+					assert(rchildren == 2);
+					cnv = rchild[0];
+
+					verify(nvlist_lookup_string(cnv,
+					    ZPOOL_CONFIG_TYPE,
+					    &childtype) == 0);
+				}
+
+				verify(nvlist_lookup_string(cnv,
+				    ZPOOL_CONFIG_PATH, &path) == 0);
+
+				/*
+				 * If we have a raidz/mirror that combines disks
+				 * with files, report it as an error.
+				 */
+				if (!dontreport && type != NULL &&
+				    strcmp(type, childtype) != 0) {
+					if (ret != NULL)
+						free(ret);
+					ret = NULL;
+					if (fatal)
+						vdev_error(gettext(
+						    "mismatched replication "
+						    "level: %s contains both "
+						    "files and devices\n"),
+						    rep.zprl_type);
+					else
+						return (NULL);
+					dontreport = B_TRUE;
+				}
+
+				/*
+				 * According to stat(2), the value of 'st_size'
+				 * is undefined for block devices and character
+				 * devices.  But there is no effective way to
+				 * determine the real size in userland.
+				 *
+				 * Instead, we'll take advantage of an
+				 * implementation detail of spec_size().  If the
+				 * device is currently open, then we (should)
+				 * return a valid size.
+				 *
+				 * If we still don't get a valid size (indicated
+				 * by a size of 0 or MAXOFFSET_T), then ignore
+				 * this device altogether.
+				 */
+				if ((fd = open(path, O_RDONLY)) >= 0) {
+					err = fstat64_blk(fd, &statbuf);
+					(void) close(fd);
+				} else {
+					err = stat64(path, &statbuf);
+				}
+
+				if (err != 0 ||
+				    statbuf.st_size == 0 ||
+				    statbuf.st_size == MAXOFFSET_T)
+					continue;
+
+				size = statbuf.st_size;
+
+				/*
+				 * Also make sure that devices and
+				 * slices have a consistent size.  If
+				 * they differ by a significant amount
+				 * (~16MB) then report an error.
+				 */
+				if (!dontreport &&
+				    (vdev_size != -1LL &&
+				    (llabs(size - vdev_size) >
+				    ZPOOL_FUZZ))) {
+					if (ret != NULL)
+						free(ret);
+					ret = NULL;
+					if (fatal)
+						vdev_error(gettext(
+						    "%s contains devices of "
+						    "different sizes\n"),
+						    rep.zprl_type);
+					else
+						return (NULL);
+					dontreport = B_TRUE;
+				}
+
+				type = childtype;
+				vdev_size = size;
+			}
+		}
+
+		/*
+		 * At this point, we have the replication of the last toplevel
+		 * vdev in 'rep'.  Compare it to 'lastrep' to see if it is
+		 * different.
+		 */
+		if (lastrep.zprl_type != NULL) {
+			if (is_raidz_mirror(&lastrep, &rep, &raidz, &mirror) ||
+			    is_raidz_mirror(&rep, &lastrep, &raidz, &mirror)) {
+				/*
+				 * Accepted raidz and mirror when they can
+				 * handle the same number of disk failures.
+				 */
+				if (raidz->zprl_parity !=
+				    mirror->zprl_children - 1) {
+					if (ret != NULL)
+						free(ret);
+					ret = NULL;
+					if (fatal)
+						vdev_error(gettext(
+						    "mismatched replication "
+						    "level: "
+						    "%s and %s vdevs with "
+						    "different redundancy, "
+						    "%llu vs. %llu (%llu-way) "
+						    "are present\n"),
+						    raidz->zprl_type,
+						    mirror->zprl_type,
+						    raidz->zprl_parity,
+						    mirror->zprl_children - 1,
+						    mirror->zprl_children);
+					else
+						return (NULL);
+				}
+			} else if (strcmp(lastrep.zprl_type, rep.zprl_type) !=
+			    0) {
+				if (ret != NULL)
+					free(ret);
+				ret = NULL;
+				if (fatal)
+					vdev_error(gettext(
+					    "mismatched replication level: "
+					    "both %s and %s vdevs are "
+					    "present\n"),
+					    lastrep.zprl_type, rep.zprl_type);
+				else
+					return (NULL);
+			} else if (lastrep.zprl_parity != rep.zprl_parity) {
+				if (ret)
+					free(ret);
+				ret = NULL;
+				if (fatal)
+					vdev_error(gettext(
+					    "mismatched replication level: "
+					    "both %llu and %llu device parity "
+					    "%s vdevs are present\n"),
+					    lastrep.zprl_parity,
+					    rep.zprl_parity,
+					    rep.zprl_type);
+				else
+					return (NULL);
+			} else if (lastrep.zprl_children != rep.zprl_children) {
+				if (ret)
+					free(ret);
+				ret = NULL;
+				if (fatal)
+					vdev_error(gettext(
+					    "mismatched replication level: "
+					    "both %llu-way and %llu-way %s "
+					    "vdevs are present\n"),
+					    lastrep.zprl_children,
+					    rep.zprl_children,
+					    rep.zprl_type);
+				else
+					return (NULL);
+			}
+		}
+		lastrep = rep;
+	}
+
+	if (ret != NULL)
+		*ret = rep;
+
+	return (ret);
+}
+
+/*
+ * Check the replication level of the vdev spec against the current pool.  Calls
+ * get_replication() to make sure the new spec is self-consistent.  If the pool
+ * has a consistent replication level, then we ignore any errors.  Otherwise,
+ * report any difference between the two.
+ */
+static int
+check_replication(nvlist_t *config, nvlist_t *newroot)
+{
+	nvlist_t **child;
+	uint_t	children;
+	replication_level_t *current = NULL, *new;
+	replication_level_t *raidz, *mirror;
+	int ret;
+
+	/*
+	 * If we have a current pool configuration, check to see if it's
+	 * self-consistent.  If not, simply return success.
+	 */
+	if (config != NULL) {
+		nvlist_t *nvroot;
+
+		verify(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE,
+		    &nvroot) == 0);
+		if ((current = get_replication(nvroot, B_FALSE)) == NULL)
+			return (0);
+	}
+	/*
+	 * for spares there may be no children, and therefore no
+	 * replication level to check
+	 */
+	if ((nvlist_lookup_nvlist_array(newroot, ZPOOL_CONFIG_CHILDREN,
+	    &child, &children) != 0) || (children == 0)) {
+		free(current);
+		return (0);
+	}
+
+	/*
+	 * If all we have is logs then there's no replication level to check.
+	 */
+	if (num_logs(newroot) == children) {
+		free(current);
+		return (0);
+	}
+
+	/*
+	 * Get the replication level of the new vdev spec, reporting any
+	 * inconsistencies found.
+	 */
+	if ((new = get_replication(newroot, B_TRUE)) == NULL) {
+		free(current);
+		return (-1);
+	}
+
+	/*
+	 * Check to see if the new vdev spec matches the replication level of
+	 * the current pool.
+	 */
+	ret = 0;
+	if (current != NULL) {
+		if (is_raidz_mirror(current, new, &raidz, &mirror) ||
+		    is_raidz_mirror(new, current, &raidz, &mirror)) {
+			if (raidz->zprl_parity != mirror->zprl_children - 1) {
+				vdev_error(gettext(
+				    "mismatched replication level: pool and "
+				    "new vdev with different redundancy, %s "
+				    "and %s vdevs, %llu vs. %llu (%llu-way)\n"),
+				    raidz->zprl_type,
+				    mirror->zprl_type,
+				    raidz->zprl_parity,
+				    mirror->zprl_children - 1,
+				    mirror->zprl_children);
+				ret = -1;
+			}
+		} else if (strcmp(current->zprl_type, new->zprl_type) != 0) {
+			vdev_error(gettext(
+			    "mismatched replication level: pool uses %s "
+			    "and new vdev is %s\n"),
+			    current->zprl_type, new->zprl_type);
+			ret = -1;
+		} else if (current->zprl_parity != new->zprl_parity) {
+			vdev_error(gettext(
+			    "mismatched replication level: pool uses %llu "
+			    "device parity and new vdev uses %llu\n"),
+			    current->zprl_parity, new->zprl_parity);
+			ret = -1;
+		} else if (current->zprl_children != new->zprl_children) {
+			vdev_error(gettext(
+			    "mismatched replication level: pool uses %llu-way "
+			    "%s and new vdev uses %llu-way %s\n"),
+			    current->zprl_children, current->zprl_type,
+			    new->zprl_children, new->zprl_type);
+			ret = -1;
+		}
+	}
+
+	free(new);
+	if (current != NULL)
+		free(current);
+
+	return (ret);
+}
+
+static int
+zero_label(char *path)
+{
+	const int size = 4096;
+	char buf[size];
+	int err, fd;
+
+	if ((fd = open(path, O_WRONLY|O_EXCL)) < 0) {
+		(void) fprintf(stderr, gettext("cannot open '%s': %s\n"),
+		    path, strerror(errno));
+		return (-1);
+	}
+
+	memset(buf, 0, size);
+	err = write(fd, buf, size);
+	(void) fdatasync(fd);
+	(void) close(fd);
+
+	if (err == -1) {
+		(void) fprintf(stderr, gettext("cannot zero first %d bytes "
+		    "of '%s': %s\n"), size, path, strerror(errno));
+		return (-1);
+	}
+
+	if (err != size) {
+		(void) fprintf(stderr, gettext("could only zero %d/%d bytes "
+		    "of '%s'\n"), err, size, path);
+		return (-1);
+	}
+
+	return (0);
+}
+
+/*
+ * Go through and find any whole disks in the vdev specification, labelling them
+ * as appropriate.  When constructing the vdev spec, we were unable to open this
+ * device in order to provide a devid.  Now that we have labelled the disk and
+ * know that slice 0 is valid, we can construct the devid now.
+ *
+ * If the disk was already labeled with an EFI label, we will have gotten the
+ * devid already (because we were able to open the whole disk).  Otherwise, we
+ * need to get the devid after we label the disk.
+ */
+static int
+make_disks(zpool_handle_t *zhp, nvlist_t *nv)
+{
+	nvlist_t **child;
+	uint_t c, children;
+	char *type, *path;
+	char devpath[MAXPATHLEN];
+	char udevpath[MAXPATHLEN];
+	uint64_t wholedisk;
+	struct stat64 statbuf;
+	int is_exclusive = 0;
+	int fd;
+	int ret;
+
+	verify(nvlist_lookup_string(nv, ZPOOL_CONFIG_TYPE, &type) == 0);
+
+	if (nvlist_lookup_nvlist_array(nv, ZPOOL_CONFIG_CHILDREN,
+	    &child, &children) != 0) {
+
+		if (strcmp(type, VDEV_TYPE_DISK) != 0)
+			return (0);
+
+		/*
+		 * We have a disk device.  If this is a whole disk write
+		 * out the efi partition table, otherwise write zero's to
+		 * the first 4k of the partition.  This is to ensure that
+		 * libblkid will not misidentify the partition due to a
+		 * magic value left by the previous filesystem.
+		 */
+		verify(!nvlist_lookup_string(nv, ZPOOL_CONFIG_PATH, &path));
+		verify(!nvlist_lookup_uint64(nv, ZPOOL_CONFIG_WHOLE_DISK,
+		    &wholedisk));
+
+		if (!wholedisk) {
+			/*
+			 * Update device id string for mpath nodes (Linux only)
+			 */
+			if (is_mpath_whole_disk(path))
+				update_vdev_config_dev_strs(nv);
+
+			if (!is_spare(NULL, path))
+				(void) zero_label(path);
+			return (0);
+		}
+
+		if (realpath(path, devpath) == NULL) {
+			ret = errno;
+			(void) fprintf(stderr,
+			    gettext("cannot resolve path '%s'\n"), path);
+			return (ret);
+		}
+
+		/*
+		 * Remove any previously existing symlink from a udev path to
+		 * the device before labeling the disk.  This ensures that
+		 * only newly created links are used.  Otherwise there is a
+		 * window between when udev deletes and recreates the link
+		 * during which access attempts will fail with ENOENT.
+		 */
+		strlcpy(udevpath, path, MAXPATHLEN);
+		(void) zfs_append_partition(udevpath, MAXPATHLEN);
+
+		fd = open(devpath, O_RDWR|O_EXCL);
+		if (fd == -1) {
+			if (errno == EBUSY)
+				is_exclusive = 1;
+#ifdef __FreeBSD__
+			if (errno == EPERM)
+				is_exclusive = 1;
+#endif
+		} else {
+			(void) close(fd);
+		}
+
+		/*
+		 * If the partition exists, contains a valid spare label,
+		 * and is opened exclusively there is no need to partition
+		 * it.  Hot spares have already been partitioned and are
+		 * held open exclusively by the kernel as a safety measure.
+		 *
+		 * If the provided path is for a /dev/disk/ device its
+		 * symbolic link will be removed, partition table created,
+		 * and then block until udev creates the new link.
+		 */
+		if (!is_exclusive && !is_spare(NULL, udevpath)) {
+			char *devnode = strrchr(devpath, '/') + 1;
+
+			ret = strncmp(udevpath, UDISK_ROOT, strlen(UDISK_ROOT));
+			if (ret == 0) {
+				ret = lstat64(udevpath, &statbuf);
+				if (ret == 0 && S_ISLNK(statbuf.st_mode))
+					(void) unlink(udevpath);
+			}
+
+			/*
+			 * When labeling a pool the raw device node name
+			 * is provided as it appears under /dev/.
+			 */
+			if (zpool_label_disk(g_zfs, zhp, devnode) == -1)
+				return (-1);
+
+			/*
+			 * Wait for udev to signal the device is available
+			 * by the provided path.
+			 */
+			ret = zpool_label_disk_wait(udevpath, DISK_LABEL_WAIT);
+			if (ret) {
+				(void) fprintf(stderr,
+				    gettext("missing link: %s was "
+				    "partitioned but %s is missing\n"),
+				    devnode, udevpath);
+				return (ret);
+			}
+
+			ret = zero_label(udevpath);
+			if (ret)
+				return (ret);
+		}
+
+		/*
+		 * Update the path to refer to the partition.  The presence of
+		 * the 'whole_disk' field indicates to the CLI that we should
+		 * chop off the partition number when displaying the device in
+		 * future output.
+		 */
+		verify(nvlist_add_string(nv, ZPOOL_CONFIG_PATH, udevpath) == 0);
+
+		/*
+		 * Update device id strings for whole disks (Linux only)
+		 */
+		update_vdev_config_dev_strs(nv);
+
+		return (0);
+	}
+
+	for (c = 0; c < children; c++)
+		if ((ret = make_disks(zhp, child[c])) != 0)
+			return (ret);
+
+	if (nvlist_lookup_nvlist_array(nv, ZPOOL_CONFIG_SPARES,
+	    &child, &children) == 0)
+		for (c = 0; c < children; c++)
+			if ((ret = make_disks(zhp, child[c])) != 0)
+				return (ret);
+
+	if (nvlist_lookup_nvlist_array(nv, ZPOOL_CONFIG_L2CACHE,
+	    &child, &children) == 0)
+		for (c = 0; c < children; c++)
+			if ((ret = make_disks(zhp, child[c])) != 0)
+				return (ret);
+
+	return (0);
+}
+
+/*
+ * Go through and find any devices that are in use.  We rely on libdiskmgt for
+ * the majority of this task.
+ */
+static boolean_t
+is_device_in_use(nvlist_t *config, nvlist_t *nv, boolean_t force,
+    boolean_t replacing, boolean_t isspare)
+{
+	nvlist_t **child;
+	uint_t c, children;
+	char *type, *path;
+	int ret = 0;
+	char buf[MAXPATHLEN];
+	uint64_t wholedisk = B_FALSE;
+	boolean_t anyinuse = B_FALSE;
+
+	verify(nvlist_lookup_string(nv, ZPOOL_CONFIG_TYPE, &type) == 0);
+
+	if (nvlist_lookup_nvlist_array(nv, ZPOOL_CONFIG_CHILDREN,
+	    &child, &children) != 0) {
+
+		verify(!nvlist_lookup_string(nv, ZPOOL_CONFIG_PATH, &path));
+		if (strcmp(type, VDEV_TYPE_DISK) == 0)
+			verify(!nvlist_lookup_uint64(nv,
+			    ZPOOL_CONFIG_WHOLE_DISK, &wholedisk));
+
+		/*
+		 * As a generic check, we look to see if this is a replace of a
+		 * hot spare within the same pool.  If so, we allow it
+		 * regardless of what libblkid or zpool_in_use() says.
+		 */
+		if (replacing) {
+			(void) strlcpy(buf, path, sizeof (buf));
+			if (wholedisk) {
+				ret = zfs_append_partition(buf,  sizeof (buf));
+				if (ret == -1)
+					return (-1);
+			}
+
+			if (is_spare(config, buf))
+				return (B_FALSE);
+		}
+
+		if (strcmp(type, VDEV_TYPE_DISK) == 0)
+			ret = check_device(path, force, isspare, wholedisk);
+
+		else if (strcmp(type, VDEV_TYPE_FILE) == 0)
+			ret = check_file(path, force, isspare);
+
+		return (ret != 0);
+	}
+
+	for (c = 0; c < children; c++)
+		if (is_device_in_use(config, child[c], force, replacing,
+		    B_FALSE))
+			anyinuse = B_TRUE;
+
+	if (nvlist_lookup_nvlist_array(nv, ZPOOL_CONFIG_SPARES,
+	    &child, &children) == 0)
+		for (c = 0; c < children; c++)
+			if (is_device_in_use(config, child[c], force, replacing,
+			    B_TRUE))
+				anyinuse = B_TRUE;
+
+	if (nvlist_lookup_nvlist_array(nv, ZPOOL_CONFIG_L2CACHE,
+	    &child, &children) == 0)
+		for (c = 0; c < children; c++)
+			if (is_device_in_use(config, child[c], force, replacing,
+			    B_FALSE))
+				anyinuse = B_TRUE;
+
+	return (anyinuse);
+}
+
+static const char *
+is_grouping(const char *type, int *mindev, int *maxdev)
+{
+	if (strncmp(type, "raidz", 5) == 0) {
+		const char *p = type + 5;
+		char *end;
+		long nparity;
+
+		if (*p == '\0') {
+			nparity = 1;
+		} else if (*p == '0') {
+			return (NULL); /* no zero prefixes allowed */
+		} else {
+			errno = 0;
+			nparity = strtol(p, &end, 10);
+			if (errno != 0 || nparity < 1 || nparity >= 255 ||
+			    *end != '\0')
+				return (NULL);
+		}
+
+		if (mindev != NULL)
+			*mindev = nparity + 1;
+		if (maxdev != NULL)
+			*maxdev = 255;
+		return (VDEV_TYPE_RAIDZ);
+	}
+
+	if (maxdev != NULL)
+		*maxdev = INT_MAX;
+
+	if (strcmp(type, "mirror") == 0) {
+		if (mindev != NULL)
+			*mindev = 2;
+		return (VDEV_TYPE_MIRROR);
+	}
+
+	if (strcmp(type, "spare") == 0) {
+		if (mindev != NULL)
+			*mindev = 1;
+		return (VDEV_TYPE_SPARE);
+	}
+
+	if (strcmp(type, "log") == 0) {
+		if (mindev != NULL)
+			*mindev = 1;
+		return (VDEV_TYPE_LOG);
+	}
+
+	if (strcmp(type, VDEV_ALLOC_BIAS_SPECIAL) == 0 ||
+	    strcmp(type, VDEV_ALLOC_BIAS_DEDUP) == 0) {
+		if (mindev != NULL)
+			*mindev = 1;
+		return (type);
+	}
+
+	if (strcmp(type, "cache") == 0) {
+		if (mindev != NULL)
+			*mindev = 1;
+		return (VDEV_TYPE_L2CACHE);
+	}
+
+	return (NULL);
+}
+
+/*
+ * Construct a syntactically valid vdev specification,
+ * and ensure that all devices and files exist and can be opened.
+ * Note: we don't bother freeing anything in the error paths
+ * because the program is just going to exit anyway.
+ */
+static nvlist_t *
+construct_spec(nvlist_t *props, int argc, char **argv)
+{
+	nvlist_t *nvroot, *nv, **top, **spares, **l2cache;
+	int t, toplevels, mindev, maxdev, nspares, nlogs, nl2cache;
+	const char *type;
+	uint64_t is_log, is_special, is_dedup;
+	boolean_t seen_logs;
+
+	top = NULL;
+	toplevels = 0;
+	spares = NULL;
+	l2cache = NULL;
+	nspares = 0;
+	nlogs = 0;
+	nl2cache = 0;
+	is_log = is_special = is_dedup = B_FALSE;
+	seen_logs = B_FALSE;
+	nvroot = NULL;
+
+	while (argc > 0) {
+		nv = NULL;
+
+		/*
+		 * If it's a mirror or raidz, the subsequent arguments are
+		 * its leaves -- until we encounter the next mirror or raidz.
+		 */
+		if ((type = is_grouping(argv[0], &mindev, &maxdev)) != NULL) {
+			nvlist_t **child = NULL;
+			int c, children = 0;
+
+			if (strcmp(type, VDEV_TYPE_SPARE) == 0) {
+				if (spares != NULL) {
+					(void) fprintf(stderr,
+					    gettext("invalid vdev "
+					    "specification: 'spare' can be "
+					    "specified only once\n"));
+					goto spec_out;
+				}
+				is_log = is_special = is_dedup = B_FALSE;
+			}
+
+			if (strcmp(type, VDEV_TYPE_LOG) == 0) {
+				if (seen_logs) {
+					(void) fprintf(stderr,
+					    gettext("invalid vdev "
+					    "specification: 'log' can be "
+					    "specified only once\n"));
+					goto spec_out;
+				}
+				seen_logs = B_TRUE;
+				is_log = B_TRUE;
+				is_special = B_FALSE;
+				is_dedup = B_FALSE;
+				argc--;
+				argv++;
+				/*
+				 * A log is not a real grouping device.
+				 * We just set is_log and continue.
+				 */
+				continue;
+			}
+
+			if (strcmp(type, VDEV_ALLOC_BIAS_SPECIAL) == 0) {
+				is_special = B_TRUE;
+				is_log = B_FALSE;
+				is_dedup = B_FALSE;
+				argc--;
+				argv++;
+				continue;
+			}
+
+			if (strcmp(type, VDEV_ALLOC_BIAS_DEDUP) == 0) {
+				is_dedup = B_TRUE;
+				is_log = B_FALSE;
+				is_special = B_FALSE;
+				argc--;
+				argv++;
+				continue;
+			}
+
+			if (strcmp(type, VDEV_TYPE_L2CACHE) == 0) {
+				if (l2cache != NULL) {
+					(void) fprintf(stderr,
+					    gettext("invalid vdev "
+					    "specification: 'cache' can be "
+					    "specified only once\n"));
+					goto spec_out;
+				}
+				is_log = is_special = is_dedup = B_FALSE;
+			}
+
+			if (is_log || is_special || is_dedup) {
+				if (strcmp(type, VDEV_TYPE_MIRROR) != 0) {
+					(void) fprintf(stderr,
+					    gettext("invalid vdev "
+					    "specification: unsupported '%s' "
+					    "device: %s\n"), is_log ? "log" :
+					    "special", type);
+					goto spec_out;
+				}
+				nlogs++;
+			}
+
+			for (c = 1; c < argc; c++) {
+				if (is_grouping(argv[c], NULL, NULL) != NULL)
+					break;
+				children++;
+				child = realloc(child,
+				    children * sizeof (nvlist_t *));
+				if (child == NULL)
+					zpool_no_memory();
+				if ((nv = make_leaf_vdev(props, argv[c],
+				    B_FALSE)) == NULL) {
+					for (c = 0; c < children - 1; c++)
+						nvlist_free(child[c]);
+					free(child);
+					goto spec_out;
+				}
+
+				child[children - 1] = nv;
+			}
+
+			if (children < mindev) {
+				(void) fprintf(stderr, gettext("invalid vdev "
+				    "specification: %s requires at least %d "
+				    "devices\n"), argv[0], mindev);
+				for (c = 0; c < children; c++)
+					nvlist_free(child[c]);
+				free(child);
+				goto spec_out;
+			}
+
+			if (children > maxdev) {
+				(void) fprintf(stderr, gettext("invalid vdev "
+				    "specification: %s supports no more than "
+				    "%d devices\n"), argv[0], maxdev);
+				for (c = 0; c < children; c++)
+					nvlist_free(child[c]);
+				free(child);
+				goto spec_out;
+			}
+
+			argc -= c;
+			argv += c;
+
+			if (strcmp(type, VDEV_TYPE_SPARE) == 0) {
+				spares = child;
+				nspares = children;
+				continue;
+			} else if (strcmp(type, VDEV_TYPE_L2CACHE) == 0) {
+				l2cache = child;
+				nl2cache = children;
+				continue;
+			} else {
+				/* create a top-level vdev with children */
+				verify(nvlist_alloc(&nv, NV_UNIQUE_NAME,
+				    0) == 0);
+				verify(nvlist_add_string(nv, ZPOOL_CONFIG_TYPE,
+				    type) == 0);
+				verify(nvlist_add_uint64(nv,
+				    ZPOOL_CONFIG_IS_LOG, is_log) == 0);
+				if (is_log)
+					verify(nvlist_add_string(nv,
+					    ZPOOL_CONFIG_ALLOCATION_BIAS,
+					    VDEV_ALLOC_BIAS_LOG) == 0);
+				if (is_special) {
+					verify(nvlist_add_string(nv,
+					    ZPOOL_CONFIG_ALLOCATION_BIAS,
+					    VDEV_ALLOC_BIAS_SPECIAL) == 0);
+				}
+				if (is_dedup) {
+					verify(nvlist_add_string(nv,
+					    ZPOOL_CONFIG_ALLOCATION_BIAS,
+					    VDEV_ALLOC_BIAS_DEDUP) == 0);
+				}
+				if (strcmp(type, VDEV_TYPE_RAIDZ) == 0) {
+					verify(nvlist_add_uint64(nv,
+					    ZPOOL_CONFIG_NPARITY,
+					    mindev - 1) == 0);
+				}
+				verify(nvlist_add_nvlist_array(nv,
+				    ZPOOL_CONFIG_CHILDREN, child,
+				    children) == 0);
+
+				for (c = 0; c < children; c++)
+					nvlist_free(child[c]);
+				free(child);
+			}
+		} else {
+			/*
+			 * We have a device.  Pass off to make_leaf_vdev() to
+			 * construct the appropriate nvlist describing the vdev.
+			 */
+			if ((nv = make_leaf_vdev(props, argv[0],
+			    is_log)) == NULL)
+				goto spec_out;
+
+			if (is_log)
+				nlogs++;
+			if (is_special) {
+				verify(nvlist_add_string(nv,
+				    ZPOOL_CONFIG_ALLOCATION_BIAS,
+				    VDEV_ALLOC_BIAS_SPECIAL) == 0);
+			}
+			if (is_dedup) {
+				verify(nvlist_add_string(nv,
+				    ZPOOL_CONFIG_ALLOCATION_BIAS,
+				    VDEV_ALLOC_BIAS_DEDUP) == 0);
+			}
+			argc--;
+			argv++;
+		}
+
+		toplevels++;
+		top = realloc(top, toplevels * sizeof (nvlist_t *));
+		if (top == NULL)
+			zpool_no_memory();
+		top[toplevels - 1] = nv;
+	}
+
+	if (toplevels == 0 && nspares == 0 && nl2cache == 0) {
+		(void) fprintf(stderr, gettext("invalid vdev "
+		    "specification: at least one toplevel vdev must be "
+		    "specified\n"));
+		goto spec_out;
+	}
+
+	if (seen_logs && nlogs == 0) {
+		(void) fprintf(stderr, gettext("invalid vdev specification: "
+		    "log requires at least 1 device\n"));
+		goto spec_out;
+	}
+
+	/*
+	 * Finally, create nvroot and add all top-level vdevs to it.
+	 */
+	verify(nvlist_alloc(&nvroot, NV_UNIQUE_NAME, 0) == 0);
+	verify(nvlist_add_string(nvroot, ZPOOL_CONFIG_TYPE,
+	    VDEV_TYPE_ROOT) == 0);
+	verify(nvlist_add_nvlist_array(nvroot, ZPOOL_CONFIG_CHILDREN,
+	    top, toplevels) == 0);
+	if (nspares != 0)
+		verify(nvlist_add_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES,
+		    spares, nspares) == 0);
+	if (nl2cache != 0)
+		verify(nvlist_add_nvlist_array(nvroot, ZPOOL_CONFIG_L2CACHE,
+		    l2cache, nl2cache) == 0);
+
+spec_out:
+	for (t = 0; t < toplevels; t++)
+		nvlist_free(top[t]);
+	for (t = 0; t < nspares; t++)
+		nvlist_free(spares[t]);
+	for (t = 0; t < nl2cache; t++)
+		nvlist_free(l2cache[t]);
+
+	free(spares);
+	free(l2cache);
+	free(top);
+
+	return (nvroot);
+}
+
+nvlist_t *
+split_mirror_vdev(zpool_handle_t *zhp, char *newname, nvlist_t *props,
+    splitflags_t flags, int argc, char **argv)
+{
+	nvlist_t *newroot = NULL, **child;
+	uint_t c, children;
+
+	if (argc > 0) {
+		if ((newroot = construct_spec(props, argc, argv)) == NULL) {
+			(void) fprintf(stderr, gettext("Unable to build a "
+			    "pool from the specified devices\n"));
+			return (NULL);
+		}
+
+		if (!flags.dryrun && make_disks(zhp, newroot) != 0) {
+			nvlist_free(newroot);
+			return (NULL);
+		}
+
+		/* avoid any tricks in the spec */
+		verify(nvlist_lookup_nvlist_array(newroot,
+		    ZPOOL_CONFIG_CHILDREN, &child, &children) == 0);
+		for (c = 0; c < children; c++) {
+			char *path;
+			const char *type;
+			int min, max;
+
+			verify(nvlist_lookup_string(child[c],
+			    ZPOOL_CONFIG_PATH, &path) == 0);
+			if ((type = is_grouping(path, &min, &max)) != NULL) {
+				(void) fprintf(stderr, gettext("Cannot use "
+				    "'%s' as a device for splitting\n"), type);
+				nvlist_free(newroot);
+				return (NULL);
+			}
+		}
+	}
+
+	if (zpool_vdev_split(zhp, newname, &newroot, props, flags) != 0) {
+		nvlist_free(newroot);
+		return (NULL);
+	}
+
+	return (newroot);
+}
+
+static int
+num_normal_vdevs(nvlist_t *nvroot)
+{
+	nvlist_t **top;
+	uint_t t, toplevels, normal = 0;
+
+	verify(nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_CHILDREN,
+	    &top, &toplevels) == 0);
+
+	for (t = 0; t < toplevels; t++) {
+		uint64_t log = B_FALSE;
+
+		(void) nvlist_lookup_uint64(top[t], ZPOOL_CONFIG_IS_LOG, &log);
+		if (log)
+			continue;
+		if (nvlist_exists(top[t], ZPOOL_CONFIG_ALLOCATION_BIAS))
+			continue;
+
+		normal++;
+	}
+
+	return (normal);
+}
+
+/*
+ * Get and validate the contents of the given vdev specification.  This ensures
+ * that the nvlist returned is well-formed, that all the devices exist, and that
+ * they are not currently in use by any other known consumer.  The 'poolconfig'
+ * parameter is the current configuration of the pool when adding devices
+ * existing pool, and is used to perform additional checks, such as changing the
+ * replication level of the pool.  It can be 'NULL' to indicate that this is a
+ * new pool.  The 'force' flag controls whether devices should be forcefully
+ * added, even if they appear in use.
+ */
+nvlist_t *
+make_root_vdev(zpool_handle_t *zhp, nvlist_t *props, int force, int check_rep,
+    boolean_t replacing, boolean_t dryrun, int argc, char **argv)
+{
+	nvlist_t *newroot;
+	nvlist_t *poolconfig = NULL;
+	is_force = force;
+
+	/*
+	 * Construct the vdev specification.  If this is successful, we know
+	 * that we have a valid specification, and that all devices can be
+	 * opened.
+	 */
+	if ((newroot = construct_spec(props, argc, argv)) == NULL)
+		return (NULL);
+
+	if (zhp && ((poolconfig = zpool_get_config(zhp, NULL)) == NULL)) {
+		nvlist_free(newroot);
+		return (NULL);
+	}
+
+	/*
+	 * Validate each device to make sure that it's not shared with another
+	 * subsystem.  We do this even if 'force' is set, because there are some
+	 * uses (such as a dedicated dump device) that even '-f' cannot
+	 * override.
+	 */
+	if (is_device_in_use(poolconfig, newroot, force, replacing, B_FALSE)) {
+		nvlist_free(newroot);
+		return (NULL);
+	}
+
+	/*
+	 * Check the replication level of the given vdevs and report any errors
+	 * found.  We include the existing pool spec, if any, as we need to
+	 * catch changes against the existing replication level.
+	 */
+	if (check_rep && check_replication(poolconfig, newroot) != 0) {
+		nvlist_free(newroot);
+		return (NULL);
+	}
+
+	/*
+	 * On pool create the new vdev spec must have one normal vdev.
+	 */
+	if (poolconfig == NULL && num_normal_vdevs(newroot) == 0) {
+		vdev_error(gettext("at least one general top-level vdev must "
+		    "be specified\n"));
+		nvlist_free(newroot);
+		return (NULL);
+	}
+
+	/*
+	 * Run through the vdev specification and label any whole disks found.
+	 */
+	if (!dryrun && make_disks(zhp, newroot) != 0) {
+		nvlist_free(newroot);
+		return (NULL);
+	}
+
+	return (newroot);
+}