[illumos-gate merge]

commit 04e56356520b98d5a93c496b10f02530bb6647e0
    5882 Temporary pool names
commit 36acdd115a7d14b9a0ffd968d084ebeac2451a7e
    10062 illumos.sh could be re-organized
commit 4da7ed37ba5e1e12c0618eef16411d6fd67dd8c6
    10060 loader: fix DEBUG messages in disk/part interfaces
commit 922a2a1681b0f92b4d65daff3cbcd841293d5778
    10058 loader: Add an ISO9660 "partition table" type to loader.
commit 67deef8cbc83060db238a0f4ee252d1ba74641ef

	Conflicts:
	usr/src/tools/env/illumos.sh
	usr/src/cmd/zpool/zpool_main.c

21 files changed, 558 insertions, 246 deletions

diff --git a/usr/src/boot/Makefile.version b/usr/src/boot/Makefile.version
index 143e416056..f7de1f0e03 100644
--- a/usr/src/boot/Makefile.version
+++ b/usr/src/boot/Makefile.version
@@ -33,4 +33,4 @@ LOADER_VERSION = 1.1
 # Use date like formatting here, YYYY.MM.DD.XX, without leading zeroes.
 # The version is processed from left to right, the version number can only
 # be increased.
-BOOT_VERSION = $(LOADER_VERSION)-2018.11.05.1
+BOOT_VERSION = $(LOADER_VERSION)-2018.12.11.1
diff --git a/usr/src/boot/sys/boot/common/disk.c b/usr/src/boot/sys/boot/common/disk.c
index 7d48e2842a..9e70f5256d 100644
--- a/usr/src/boot/sys/boot/common/disk.c
+++ b/usr/src/boot/sys/boot/common/disk.c
@@ -1,4 +1,4 @@
-/*-
+/*
  * Copyright (c) 1998 Michael Smith <msmith@freebsd.org>
  * Copyright (c) 2012 Andrey V. Elsukov <ae@FreeBSD.org>
  * All rights reserved.
@@ -30,22 +30,23 @@
 #include <sys/queue.h>
 #include <stand.h>
 #include <stdarg.h>
+#include <inttypes.h>
 #include <bootstrap.h>
 #include <part.h>
 
 #include "disk.h"
 
 #ifdef DISK_DEBUG
-# define DEBUG(fmt, args...)	printf("%s: " fmt "\n" , __func__ , ## args)
+#define	DEBUG(fmt, args...)	printf("%s: " fmt "\n", __func__, ## args)
 #else
-# define DEBUG(fmt, args...)
+#define	DEBUG(fmt, args...)
 #endif
 
 struct open_disk {
 	struct ptable		*table;
 	uint64_t		mediasize;
 	uint64_t		entrysize;
-	u_int			sectorsize;
+	uint_t			sectorsize;
 };
 
 struct print_args {
@@ -56,7 +57,7 @@ struct print_args {
 
 /* Convert size to a human-readable number. */
 static char *
-display_size(uint64_t size, u_int sectorsize)
+display_size(uint64_t size, uint_t sectorsize)
 {
 	static char buf[80];
 	char unit;
@@ -73,7 +74,7 @@ display_size(uint64_t size, u_int sectorsize)
 		size /= 1024;
 		unit = 'M';
 	}
-	sprintf(buf, "%ld%cB", (long)size, unit);
+	snprintf(buf, sizeof (buf), "%" PRIu64 "%cB", size, unit);
 	return (buf);
 }
 
@@ -96,7 +97,7 @@ ptblread(void *d, void *buf, size_t blocks, uint64_t offset)
 	 * As the GPT backup partition is located at the end of the disk,
 	 * to avoid reading past disk end, flag bcache not to use RA.
 	 */
-	return (dev->dd.d_dev->dv_strategy(dev, F_READ | F_NORA , offset,
+	return (dev->dd.d_dev->dv_strategy(dev, F_READ | F_NORA, offset,
 	    blocks * od->sectorsize, (char *)buf, NULL));
 }
 
@@ -170,7 +171,7 @@ disk_print(struct disk_devdesc *dev, char *prefix, int verbose)
 }
 
 int
-disk_read(struct disk_devdesc *dev, void *buf, uint64_t offset, u_int blocks)
+disk_read(struct disk_devdesc *dev, void *buf, uint64_t offset, uint_t blocks)
 {
 	struct open_disk *od;
 	int ret;
@@ -183,7 +184,7 @@ disk_read(struct disk_devdesc *dev, void *buf, uint64_t offset, u_int blocks)
 }
 
 int
-disk_write(struct disk_devdesc *dev, void *buf, uint64_t offset, u_int blocks)
+disk_write(struct disk_devdesc *dev, void *buf, uint64_t offset, uint_t blocks)
 {
 	struct open_disk *od;
 	int ret;
@@ -196,7 +197,7 @@ disk_write(struct disk_devdesc *dev, void *buf, uint64_t offset, u_int blocks)
 }
 
 int
-disk_ioctl(struct disk_devdesc *dev, u_long cmd, void *data)
+disk_ioctl(struct disk_devdesc *dev, unsigned long cmd, void *data)
 {
 	struct open_disk *od = dev->dd.d_opendata;
 
@@ -205,7 +206,7 @@ disk_ioctl(struct disk_devdesc *dev, u_long cmd, void *data)
 
 	switch (cmd) {
 	case DIOCGSECTORSIZE:
-		*(u_int *)data = od->sectorsize;
+		*(uint_t *)data = od->sectorsize;
 		break;
 	case DIOCGMEDIASIZE:
 		if (dev->d_offset == 0)
@@ -221,7 +222,7 @@ disk_ioctl(struct disk_devdesc *dev, u_long cmd, void *data)
 }
 
 int
-disk_open(struct disk_devdesc *dev, uint64_t mediasize, u_int sectorsize)
+disk_open(struct disk_devdesc *dev, uint64_t mediasize, uint_t sectorsize)
 {
 	struct open_disk *od;
 	struct ptable *table;
@@ -237,7 +238,7 @@ disk_open(struct disk_devdesc *dev, uint64_t mediasize, u_int sectorsize)
 	table = NULL;
 	slice = dev->d_slice;
 	partition = dev->d_partition;
-	od = (struct open_disk *)malloc(sizeof(struct open_disk));
+	od = (struct open_disk *)malloc(sizeof (struct open_disk));
 	if (od == NULL) {
 		DEBUG("no memory");
 		return (ENOMEM);
@@ -246,8 +247,8 @@ disk_open(struct disk_devdesc *dev, uint64_t mediasize, u_int sectorsize)
 	od->entrysize = 0;
 	od->mediasize = mediasize;
 	od->sectorsize = sectorsize;
-	DEBUG("%s unit %d, slice %d, partition %d => %p",
-	    disk_fmtdev(dev), dev->d_unit, dev->d_slice, dev->d_partition, od);
+	DEBUG("%s unit %d, slice %d, partition %d => %p", disk_fmtdev(dev),
+	    dev->dd.d_unit, dev->d_slice, dev->d_partition, od);
 
 	/* Determine disk layout. */
 	od->table = ptable_open(dev, mediasize / sectorsize, sectorsize,
@@ -272,6 +273,9 @@ disk_open(struct disk_devdesc *dev, uint64_t mediasize, u_int sectorsize)
 			dev->d_offset = part.start;
 			od->entrysize = part.end - part.start + 1;
 		}
+	} else if (ptable_gettype(od->table) == PTABLE_ISO9660) {
+		dev->d_offset = 0;
+		od->entrysize = mediasize;
 	} else if (slice >= 0) {
 		/* Try to get information about partition */
 		if (slice == 0)
@@ -340,8 +344,8 @@ out:
 		/* Save the slice and partition number to the dev */
 		dev->d_slice = slice;
 		dev->d_partition = partition;
-		DEBUG("%s offset %lld => %p", disk_fmtdev(dev),
-		    (long long)dev->d_offset, od);
+		DEBUG("%s offset %" PRIu64 " => %p", disk_fmtdev(dev),
+		    dev->d_offset, od);
 	}
 	return (rc);
 }
@@ -358,7 +362,7 @@ disk_close(struct disk_devdesc *dev)
 	return (0);
 }
 
-char*
+char *
 disk_fmtdev(struct disk_devdesc *dev)
 {
 	static char buf[128];
diff --git a/usr/src/boot/sys/boot/common/part.c b/usr/src/boot/sys/boot/common/part.c
index 25a9cf98a0..8a24eb2920 100644
--- a/usr/src/boot/sys/boot/common/part.c
+++ b/usr/src/boot/sys/boot/common/part.c
@@ -36,6 +36,8 @@
 #include <sys/queue.h>
 #include <sys/vtoc.h>
 
+#include <fs/cd9660/iso.h>
+
 #include <zlib.h>
 #include <part.h>
 #include <uuid.h>
@@ -101,6 +103,7 @@ static struct parttypes {
 	{ PART_LINUX,		"Linux" },
 	{ PART_LINUX_SWAP,	"Linux swap" },
 	{ PART_DOS,		"DOS/Windows" },
+	{ PART_ISO9660,		"ISO9660" },
 	{ PART_SOLARIS2,	"Solaris 2" },
 	{ PART_ILLUMOS_UFS,	"illumos UFS" },
 	{ PART_ILLUMOS_ZFS,	"illumos ZFS" },
@@ -180,7 +183,7 @@ gpt_checkhdr(struct gpt_hdr *hdr, uint64_t lba_self,
 	}
 	sz = le32toh(hdr->hdr_size);
 	if (sz < 92 || sz > sectorsize) {
-		DEBUG("invalid GPT header size: %d", sz);
+		DEBUG("invalid GPT header size: %u", sz);
 		return (NULL);
 	}
 	crc = le32toh(hdr->hdr_crc_self);
@@ -192,7 +195,7 @@ gpt_checkhdr(struct gpt_hdr *hdr, uint64_t lba_self,
 	hdr->hdr_crc_self = crc;
 	hdr->hdr_revision = le32toh(hdr->hdr_revision);
 	if (hdr->hdr_revision < GPT_HDR_REVISION) {
-		DEBUG("unsupported GPT revision %d", hdr->hdr_revision);
+		DEBUG("unsupported GPT revision %u", hdr->hdr_revision);
 		return (NULL);
 	}
 	hdr->hdr_lba_self = le64toh(hdr->hdr_lba_self);
@@ -710,6 +713,45 @@ out:
 	return (table);
 }
 
+#define	cdb2devb(bno)	((bno) * ISO_DEFAULT_BLOCK_SIZE / table->sectorsize)
+
+static struct ptable *
+ptable_iso9660read(struct ptable *table, void *dev, diskread_t dread)
+{
+	uint8_t *buf;
+	struct iso_primary_descriptor *vd;
+	struct pentry *entry;
+
+	buf = malloc(table->sectorsize);
+	if (buf == NULL)
+		return (table);
+
+	if (dread(dev, buf, 1, cdb2devb(16)) != 0) {
+		DEBUG("read failed");
+		ptable_close(table);
+		table = NULL;
+		goto out;
+	}
+	vd = (struct iso_primary_descriptor *)buf;
+	if (bcmp(vd->id, ISO_STANDARD_ID, sizeof (vd->id)) != 0)
+		goto out;
+
+	entry = malloc(sizeof (*entry));
+	if (entry == NULL)
+		goto out;
+	entry->part.start = 0;
+	entry->part.end = table->sectors;
+	entry->part.type = PART_ISO9660;
+	entry->part.index = 0;
+	STAILQ_INSERT_TAIL(&table->entries, entry, entry);
+
+	table->type = PTABLE_ISO9660;
+
+out:
+	free(buf);
+	return (table);
+}
+
 struct ptable *
 ptable_open(void *dev, uint64_t sectors, uint16_t sectorsize, diskread_t *dread)
 {
@@ -740,6 +782,13 @@ ptable_open(void *dev, uint64_t sectors, uint16_t sectorsize, diskread_t *dread)
 	table->type = PTABLE_NONE;
 	STAILQ_INIT(&table->entries);
 
+	if (ptable_iso9660read(table, dev, dread) == NULL) {
+		/* Read error. */
+		table = NULL;
+		goto out;
+	} else if (table->type == PTABLE_ISO9660)
+		goto out;
+
 	if (ptable_dklabelread(table, dev, dread) == NULL) { /* Read error. */
 		table = NULL;
 		goto out;
diff --git a/usr/src/boot/sys/boot/common/part.h b/usr/src/boot/sys/boot/common/part.h
index a554016d92..2881c78b64 100644
--- a/usr/src/boot/sys/boot/common/part.h
+++ b/usr/src/boot/sys/boot/common/part.h
@@ -1,4 +1,4 @@
-/*-
+/*
  * Copyright (c) 2012 Andrey V. Elsukov <ae@FreeBSD.org>
  * All rights reserved.
  *
@@ -22,8 +22,6 @@
  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
- *
- * $FreeBSD$
  */
 
 #ifndef _PART_H_
@@ -37,7 +35,8 @@ enum ptable_type {
 	PTABLE_MBR,
 	PTABLE_GPT,
 	PTABLE_VTOC8,
-	PTABLE_VTOC
+	PTABLE_VTOC,
+	PTABLE_ISO9660
 };
 
 enum partition_type {
@@ -53,6 +52,7 @@ enum partition_type {
 	PART_LINUX,
 	PART_LINUX_SWAP,
 	PART_DOS,
+	PART_ISO9660,
 	PART_SOLARIS2,
 	PART_ILLUMOS_UFS,
 	PART_ILLUMOS_ZFS,
@@ -64,7 +64,7 @@ enum partition_type {
 	PART_VTOC_BACKUP,
 	PART_VTOC_STAND,
 	PART_VTOC_VAR,
-	PART_VTOC_HOME,
+	PART_VTOC_HOME
 };
 
 struct ptable_entry {
diff --git a/usr/src/cmd/zpool/zpool_main.c b/usr/src/cmd/zpool/zpool_main.c
index 742891a2a4..e82d8a089e 100644
--- a/usr/src/cmd/zpool/zpool_main.c
+++ b/usr/src/cmd/zpool/zpool_main.c
@@ -221,8 +221,9 @@ get_usage(zpool_help_t idx)
 	case HELP_CREATE:
 		return (gettext("\tcreate [-fnd] [-B] "
 		    "[-o property=value] ... \n"
-		    "\t    [-O file-system-property=value] ... \n"
-		    "\t    [-m mountpoint] [-R root] <pool> <vdev> ...\n"));
+		    "\t    [-O file-system-property=value] ...\n"
+		    "\t    [-m mountpoint] [-R root] [-t tempname] "
+		    "<pool> <vdev> ...\n"));
 	case HELP_CHECKPOINT:
 		return (gettext("\tcheckpoint [--discard] <pool> ...\n"));
 	case HELP_DESTROY:
@@ -240,7 +241,7 @@ get_usage(zpool_help_t idx)
 		    "[-R root] [-F [-n]] -a\n"
 		    "\timport [-o mntopts] [-o property=value] ... \n"
 		    "\t    [-d dir | -c cachefile] [-D] [-f] [-m] [-N] "
-		    "[-R root] [-F [-n]]\n"
+		    "[-R root] [-F [-n]] [-t]\n"
 		    "\t    [--rewind-to-checkpoint] <pool | id> [newpool]\n"));
 	case HELP_IOSTAT:
 		return (gettext("\tiostat [-v] [-T d|u] [pool] ... [interval "
@@ -493,6 +494,21 @@ add_prop_list(const char *propname, char *propval, nvlist_t **props,
 }
 
 /*
+ * Set a default property pair (name, string-value) in a property nvlist
+ */
+static int
+add_prop_list_default(const char *propname, char *propval, nvlist_t **props,
+    boolean_t poolprop)
+{
+	char *pval;
+
+	if (nvlist_lookup_string(*props, propname, &pval) == 0)
+		return (0);
+
+	return (add_prop_list(propname, propval, props, poolprop));
+}
+
+/*
  * zpool add [-fn] <pool> <vdev> ...
  *
  *	-f	Force addition of devices, even if they appear in use
@@ -850,15 +866,16 @@ errout:
 /*
  * zpool create [-fnd] [-B] [-o property=value] ...
  *		[-O file-system-property=value] ...
- *		[-R root] [-m mountpoint] <pool> <dev> ...
+ *		[-R root] [-m mountpoint] [-t tempname] <pool> <dev> ...
  *
  *	-B	Create boot partition.
  *	-f	Force creation, even if devices appear in use
  *	-n	Do not create the pool, but display the resulting layout if it
  *		were to be created.
- *      -R	Create a pool under an alternate root
- *      -m	Set default mountpoint for the root dataset.  By default it's
+ *	-R	Create a pool under an alternate root
+ *	-m	Set default mountpoint for the root dataset.  By default it's
  *		'/<pool>'
+ *	-t	Use the temporary name until the pool is exported.
  *	-o	Set property=value.
  *	-d	Don't automatically enable all supported pool features
  *		(individual features can be enabled with -o).
@@ -882,6 +899,7 @@ zpool_do_create(int argc, char **argv)
 	int c;
 	nvlist_t *nvroot = NULL;
 	char *poolname;
+	char *tname = NULL;
 	int ret = 1;
 	char *altroot = NULL;
 	char *mountpoint = NULL;
@@ -890,7 +908,7 @@ zpool_do_create(int argc, char **argv)
 	char *propval;
 
 	/* check options */
-	while ((c = getopt(argc, argv, ":fndBR:m:o:O:")) != -1) {
+	while ((c = getopt(argc, argv, ":fndBR:m:o:O:t:")) != -1) {
 		switch (c) {
 		case 'f':
 			force = B_TRUE;
@@ -915,11 +933,7 @@ zpool_do_create(int argc, char **argv)
 			if (add_prop_list(zpool_prop_to_name(
 			    ZPOOL_PROP_ALTROOT), optarg, &props, B_TRUE))
 				goto errout;
-			if (nvlist_lookup_string(props,
-			    zpool_prop_to_name(ZPOOL_PROP_CACHEFILE),
-			    &propval) == 0)
-				break;
-			if (add_prop_list(zpool_prop_to_name(
+			if (add_prop_list_default(zpool_prop_to_name(
 			    ZPOOL_PROP_CACHEFILE), "none", &props, B_TRUE))
 				goto errout;
 			break;
@@ -992,6 +1006,27 @@ zpool_do_create(int argc, char **argv)
 				goto errout;
 			}
 			break;
+		case 't':
+			/*
+			 * Sanity check temporary pool name.
+			 */
+			if (strchr(optarg, '/') != NULL) {
+				(void) fprintf(stderr, gettext("cannot create "
+				    "'%s': invalid character '/' in temporary "
+				    "name\n"), optarg);
+				(void) fprintf(stderr, gettext("use 'zfs "
+				    "create' to create a dataset\n"));
+				goto errout;
+			}
+
+			if (add_prop_list(zpool_prop_to_name(
+			    ZPOOL_PROP_TNAME), optarg, &props, B_TRUE))
+				goto errout;
+			if (add_prop_list_default(zpool_prop_to_name(
+			    ZPOOL_PROP_CACHEFILE), "none", &props, B_TRUE))
+				goto errout;
+			tname = optarg;
+			break;
 		case ':':
 			(void) fprintf(stderr, gettext("missing argument for "
 			    "'%c' option\n"), optopt);
@@ -1197,8 +1232,8 @@ zpool_do_create(int argc, char **argv)
 		ret = 1;
 		if (zpool_create(g_zfs, poolname,
 		    nvroot, props, fsprops) == 0) {
-			zfs_handle_t *pool = zfs_open(g_zfs, poolname,
-			    ZFS_TYPE_FILESYSTEM);
+			zfs_handle_t *pool = zfs_open(g_zfs,
+			    tname ? tname : poolname, ZFS_TYPE_FILESYSTEM);
 			if (pool != NULL) {
 				if (zfs_mount(pool, NULL, 0) == 0)
 					ret = zfs_shareall(pool);
@@ -1225,7 +1260,7 @@ badusage:
 /*
  * zpool destroy <pool>
  *
- * 	-f	Forcefully unmount any datasets
+ *	-f	Forcefully unmount any datasets
  *
  * Destroy the given pool.  Automatically unmounts any datasets in the pool.
  */
@@ -2099,8 +2134,8 @@ do_import(nvlist_t *config, const char *newname, const char *mntopts,
  * zpool checkpoint <pool>
  *       checkpoint --discard <pool>
  *
- *       -d         Discard the checkpoint from a checkpointed
- *       --discard  pool.
+ *	-d	Discard the checkpoint from a checkpointed
+ *	--discard  pool.
  *
  * Checkpoints the specified pool, by taking a "snapshot" of its
  * current state. A pool can only have one checkpoint at a time.
@@ -2173,46 +2208,50 @@ zpool_do_checkpoint(int argc, char **argv)
  *       import [-o mntopts] [-o prop=value] ... [-R root] [-D]
  *              [-d dir | -c cachefile] [-f] -a
  *       import [-o mntopts] [-o prop=value] ... [-R root] [-D]
- *              [-d dir | -c cachefile] [-f] [-n] [-F] <pool | id> [newpool]
+ *              [-d dir | -c cachefile] [-f] [-n] [-F] [-t]
+ *              <pool | id> [newpool]
  *
- *	 -c	Read pool information from a cachefile instead of searching
+ *	-c	Read pool information from a cachefile instead of searching
  *		devices.
  *
- *       -d	Scan in a specific directory, other than /dev/dsk.  More than
+ *	-d	Scan in a specific directory, other than /dev/dsk.  More than
  *		one directory can be specified using multiple '-d' options.
  *
- *       -D     Scan for previously destroyed pools or import all or only
- *              specified destroyed pools.
+ *	-D	Scan for previously destroyed pools or import all or only
+ *		specified destroyed pools.
  *
- *       -R	Temporarily import the pool, with all mountpoints relative to
+ *	-R	Temporarily import the pool, with all mountpoints relative to
  *		the given root.  The pool will remain exported when the machine
  *		is rebooted.
  *
- *       -V	Import even in the presence of faulted vdevs.  This is an
- *       	intentionally undocumented option for testing purposes, and
- *       	treats the pool configuration as complete, leaving any bad
+ *	-V	Import even in the presence of faulted vdevs.  This is an
+ *		intentionally undocumented option for testing purposes, and
+ *		treats the pool configuration as complete, leaving any bad
  *		vdevs in the FAULTED state. In other words, it does verbatim
  *		import.
  *
- *       -f	Force import, even if it appears that the pool is active.
+ *	-f	Force import, even if it appears that the pool is active.
+ *
+ *	-F	Attempt rewind if necessary.
  *
- *       -F     Attempt rewind if necessary.
+ *      -m     Allow import with a missing log device.
  *
- *       -m     Allow import with a missing log device.
+ *	-n	See if rewind would work, but don't actually rewind.
  *
- *       -n     See if rewind would work, but don't actually rewind.
+ *	-N	Import the pool but don't mount datasets.
  *
- *       -N     Import the pool but don't mount datasets.
+ *	-t	Use newpool as a temporary pool name instead of renaming
+ *		the pool.
  *
- *       -T     Specify a starting txg to use for import. This option is
- *       	intentionally undocumented option for testing purposes.
+ *	-T	Specify a starting txg to use for import. This option is
+ *		intentionally undocumented option for testing purposes.
  *
- *       -a	Import all pools found.
+ *	-a	Import all pools found.
  *
- *       -o	Set property=value and/or temporary mount options (without '=').
+ *	-o	Set property=value and/or temporary mount options (without '=').
  *
- *       --rewind-to-checkpoint
- *       	Import the pool and revert back to the checkpoint.
+ *	--rewind-to-checkpoint
+ *		Import the pool and revert back to the checkpoint.
  *
  * The import command scans for pools to import, and import pools based on pool
  * name and GUID.  The pool can also be renamed as part of the import process.
@@ -2254,7 +2293,7 @@ zpool_do_import(int argc, char **argv)
 	};
 
 	/* check options */
-	while ((c = getopt_long(argc, argv, ":aCc:d:DEfFmnNo:rR:T:VX",
+	while ((c = getopt_long(argc, argv, ":aCc:d:DEfFmnNo:rR:tT:VX",
 	    long_options, NULL)) != -1) {
 		switch (c) {
 		case 'a':
@@ -2309,11 +2348,13 @@ zpool_do_import(int argc, char **argv)
 			if (add_prop_list(zpool_prop_to_name(
 			    ZPOOL_PROP_ALTROOT), optarg, &props, B_TRUE))
 				goto error;
-			if (nvlist_lookup_string(props,
-			    zpool_prop_to_name(ZPOOL_PROP_CACHEFILE),
-			    &propval) == 0)
-				break;
-			if (add_prop_list(zpool_prop_to_name(
+			if (add_prop_list_default(zpool_prop_to_name(
+			    ZPOOL_PROP_CACHEFILE), "none", &props, B_TRUE))
+				goto error;
+			break;
+		case 't':
+			flags |= ZFS_IMPORT_TEMP_NAME;
+			if (add_prop_list_default(zpool_prop_to_name(
 			    ZPOOL_PROP_CACHEFILE), "none", &props, B_TRUE))
 				goto error;
 			break;
@@ -2452,9 +2493,9 @@ zpool_do_import(int argc, char **argv)
 		(void) fprintf(stderr, gettext("cannot import '%s': "
 		    "a pool with that name already exists\n"),
 		    argv[0]);
-		(void) fprintf(stderr, gettext("use the form '%s "
-		    "<pool | id> <newpool>' to give it a new name\n"),
-		    "zpool import");
+		(void) fprintf(stderr, gettext("use the form 'zpool import "
+		    "[-t] <pool | id> <newpool>' to give it a new temporary "
+		    "or permanent name\n"));
 		err = 1;
 	} else if (pools == NULL && idata.exists) {
 		(void) fprintf(stderr, gettext("cannot import '%s': "
@@ -3370,7 +3411,7 @@ list_callback(zpool_handle_t *zhp, void *data)
  *	-o	List of properties to display.  Defaults to
  *		"name,size,allocated,free,expandsize,fragmentation,capacity,"
  *		"dedupratio,health,altroot"
- * 	-p	Diplay values in parsable (exact) format.
+ *	-p	Diplay values in parsable (exact) format.
  *	-T	Display a timestamp in date(1) or Unix format
  *
  * List all pools in the system, whether or not they're healthy.  Output space
@@ -5842,7 +5883,7 @@ get_callback(zpool_handle_t *zhp, void *data)
  *		by a single tab.
  *	-o	List of columns to display.  Defaults to
  *		"name,property,value,source".
- * 	-p	Diplay values in parsable (exact) format.
+ *	-p	Diplay values in parsable (exact) format.
  *
  * Get properties of pools in the system. Output space statistics
  * for each one as well as other attributes.
diff --git a/usr/src/common/zfs/zpool_prop.c b/usr/src/common/zfs/zpool_prop.c
index 0ee864ade5..0a69a51207 100644
--- a/usr/src/common/zfs/zpool_prop.c
+++ b/usr/src/common/zfs/zpool_prop.c
@@ -136,6 +136,8 @@ zpool_prop_init(void)
 	    PROP_READONLY, ZFS_TYPE_POOL, "NAME");
 	zprop_register_hidden(ZPOOL_PROP_MAXBLOCKSIZE, "maxblocksize",
 	    PROP_TYPE_NUMBER, PROP_READONLY, ZFS_TYPE_POOL, "MAXBLOCKSIZE");
+	zprop_register_hidden(ZPOOL_PROP_TNAME, "tname", PROP_TYPE_STRING,
+	    PROP_ONETIME, ZFS_TYPE_POOL, "TNAME");
 }
 
 /*
diff --git a/usr/src/lib/libzfs/common/libzfs_pool.c b/usr/src/lib/libzfs/common/libzfs_pool.c
index 3d2cb06ac9..56e1d7032e 100644
--- a/usr/src/lib/libzfs/common/libzfs_pool.c
+++ b/usr/src/lib/libzfs/common/libzfs_pool.c
@@ -645,6 +645,7 @@ zpool_valid_proplist(libzfs_handle_t *hdl, const char *poolname,
 				goto error;
 			}
 			break;
+
 		case ZPOOL_PROP_READONLY:
 			if (!flags.import) {
 				zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
@@ -655,6 +656,16 @@ zpool_valid_proplist(libzfs_handle_t *hdl, const char *poolname,
 			}
 			break;
 
+		case ZPOOL_PROP_TNAME:
+			if (!flags.create) {
+				zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
+				    "property '%s' can only be set at "
+				    "creation time"), propname);
+				(void) zfs_error(hdl, EZFS_BADPROP, errbuf);
+				goto error;
+			}
+			break;
+
 		default:
 			zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
 			    "property '%s'(%d) not defined"), propname, prop);
diff --git a/usr/src/man/man1m/zpool.1m b/usr/src/man/man1m/zpool.1m
index 1e7b2b8cfc..9e7f36afed 100644
--- a/usr/src/man/man1m/zpool.1m
+++ b/usr/src/man/man1m/zpool.1m
@@ -59,6 +59,7 @@
 .Oo Fl o Ar property Ns = Ns Ar value Oc Ns ...
 .Oo Fl O Ar file-system-property Ns = Ns Ar value Oc Ns ...
 .Op Fl R Ar root
+.Op Fl t Ar tempname
 .Ar pool vdev Ns ...
 .Nm
 .Cm destroy
@@ -96,7 +97,7 @@
 .Op Fl R Ar root
 .Nm
 .Cm import
-.Op Fl Dfm
+.Op Fl Dfmt
 .Op Fl F Op Fl n
 .Op Fl -rewind-to-checkpoint
 .Op Fl c Ar cachefile Ns | Ns Fl d Ar dir
@@ -868,6 +869,7 @@ specified device or devices are cleared.
 .Oo Fl o Ar property Ns = Ns Ar value Oc Ns ...
 .Oo Fl O Ar file-system-property Ns = Ns Ar value Oc Ns ...
 .Op Fl R Ar root
+.Op Fl t Ar tempname
 .Ar pool vdev Ns ...
 .Xc
 Creates a new storage pool containing the virtual devices specified on the
@@ -989,6 +991,16 @@ for a list of valid properties that can be set.
 .It Fl R Ar root
 Equivalent to
 .Fl o Sy cachefile Ns = Ns Sy none Fl o Sy altroot Ns = Ns Ar root
+.It Fl t Ar tempname
+Sets the in-core pool name to
+.Pa tempname
+while the on-disk name will be the name specified as the pool name
+.Pa pool .
+This will set the default cachefile property to
+.Sy none.
+This is intended to handle name space collisions when creating pools
+for other systems, such as virtual machines or physical machines
+whose pools live on network block devices.
 .El
 .It Xo
 .Nm
@@ -1234,7 +1246,7 @@ property to
 .It Xo
 .Nm
 .Cm import
-.Op Fl Dfm
+.Op Fl Dfmt
 .Op Fl F Op Fl n
 .Op Fl -rewind-to-checkpoint
 .Op Fl c Ar cachefile Ns | Ns Fl d Ar dir
@@ -1325,6 +1337,20 @@ and the
 .Sy altroot
 property to
 .Ar root .
+.It Fl t
+Used with
+.Ar newpool .
+Specifies that
+.Ar newpool
+is temporary.
+Temporary pool names last until export.
+Ensures that the original pool name will be used in all label updates and
+therefore is retained upon export.
+Will also set
+.Sy cachefile
+property to
+.Sy none
+when not explicitly specified.
 .It Fl -rewind-to-checkpoint
 Rewinds pool to the checkpointed state.
 Once the pool is imported with this flag there is no way to undo the rewind.
diff --git a/usr/src/pkg/manifests/system-test-zfstest.mf b/usr/src/pkg/manifests/system-test-zfstest.mf
index ccd9d94f48..88f6f6bdc6 100644
--- a/usr/src/pkg/manifests/system-test-zfstest.mf
+++ b/usr/src/pkg/manifests/system-test-zfstest.mf
@@ -1420,6 +1420,9 @@ file \
     path=opt/zfs-tests/tests/functional/cli_root/zpool_create/zpool_create_features_004_neg \
     mode=0555
 file \
+    path=opt/zfs-tests/tests/functional/cli_root/zpool_create/zpool_create_tempname \
+    mode=0555
+file \
     path=opt/zfs-tests/tests/functional/cli_root/zpool_destroy/zpool_destroy.cfg \
     mode=0444
 file \
@@ -1571,6 +1574,9 @@ file \
     path=opt/zfs-tests/tests/functional/cli_root/zpool_import/zpool_import_013_neg \
     mode=0555
 file \
+    path=opt/zfs-tests/tests/functional/cli_root/zpool_import/zpool_import_014_pos \
+    mode=0555
+file \
     path=opt/zfs-tests/tests/functional/cli_root/zpool_import/zpool_import_all_001_pos \
     mode=0555
 file \
diff --git a/usr/src/test/zfs-tests/runfiles/delphix.run b/usr/src/test/zfs-tests/runfiles/delphix.run
index fac8836b72..57ed0506e3 100644
--- a/usr/src/test/zfs-tests/runfiles/delphix.run
+++ b/usr/src/test/zfs-tests/runfiles/delphix.run
@@ -251,7 +251,8 @@ tests = ['zpool_create_001_pos', 'zpool_create_002_pos',
     'zpool_create_018_pos', 'zpool_create_019_pos', 'zpool_create_020_pos',
     'zpool_create_021_pos', 'zpool_create_022_pos', 'zpool_create_023_neg',
     'zpool_create_features_001_pos', 'zpool_create_features_002_pos',
-    'zpool_create_features_003_pos', 'zpool_create_features_004_neg']
+    'zpool_create_features_003_pos', 'zpool_create_features_004_neg',
+    'zpool_create_tempname']
 
 [/opt/zfs-tests/tests/functional/cli_root/zpool_destroy]
 tests = ['zpool_destroy_001_pos', 'zpool_destroy_002_pos',
@@ -282,7 +283,8 @@ tests = ['zpool_import_001_pos', 'zpool_import_002_pos',
     'zpool_import_003_pos', 'zpool_import_004_pos', 'zpool_import_005_pos',
     'zpool_import_006_pos', 'zpool_import_007_pos', 'zpool_import_008_pos',
     'zpool_import_009_neg', 'zpool_import_010_pos', 'zpool_import_011_neg',
-    'zpool_import_012_pos', 'zpool_import_013_neg', 'zpool_import_all_001_pos',
+    'zpool_import_012_pos', 'zpool_import_013_neg', 'zpool_import_014_pos',
+    'zpool_import_all_001_pos',
     'zpool_import_features_001_pos', 'zpool_import_features_002_neg',
     'zpool_import_features_003_pos', 'zpool_import_missing_001_pos',
     'zpool_import_missing_002_pos', 'zpool_import_missing_003_pos',
diff --git a/usr/src/test/zfs-tests/runfiles/omnios.run b/usr/src/test/zfs-tests/runfiles/omnios.run
index 761e06c1cf..ca3181af77 100644
--- a/usr/src/test/zfs-tests/runfiles/omnios.run
+++ b/usr/src/test/zfs-tests/runfiles/omnios.run
@@ -243,7 +243,8 @@ tests = ['zpool_create_001_pos', 'zpool_create_002_pos',
     'zpool_create_018_pos', 'zpool_create_019_pos', 'zpool_create_020_pos',
     'zpool_create_021_pos', 'zpool_create_022_pos', 'zpool_create_023_neg',
     'zpool_create_features_001_pos', 'zpool_create_features_002_pos',
-    'zpool_create_features_003_pos', 'zpool_create_features_004_neg']
+    'zpool_create_features_003_pos', 'zpool_create_features_004_neg',
+    'zpool_create_tempname']
 
 [/opt/zfs-tests/tests/functional/cli_root/zpool_destroy]
 tests = ['zpool_destroy_001_pos', 'zpool_destroy_002_pos',
@@ -274,7 +275,8 @@ tests = ['zpool_import_001_pos', 'zpool_import_002_pos',
     'zpool_import_003_pos', 'zpool_import_004_pos', 'zpool_import_005_pos',
     'zpool_import_006_pos', 'zpool_import_007_pos', 'zpool_import_008_pos',
     'zpool_import_009_neg', 'zpool_import_010_pos', 'zpool_import_011_neg',
-    'zpool_import_012_pos', 'zpool_import_013_neg', 'zpool_import_all_001_pos',
+    'zpool_import_012_pos', 'zpool_import_013_neg', 'zpool_import_014_pos',
+    'zpool_import_all_001_pos',
     'zpool_import_features_001_pos', 'zpool_import_features_002_neg',
     'zpool_import_features_003_pos', 'zpool_import_missing_001_pos',
     'zpool_import_missing_002_pos', 'zpool_import_missing_003_pos',
diff --git a/usr/src/test/zfs-tests/runfiles/openindiana.run b/usr/src/test/zfs-tests/runfiles/openindiana.run
index 5c6d853984..43a2a641c8 100644
--- a/usr/src/test/zfs-tests/runfiles/openindiana.run
+++ b/usr/src/test/zfs-tests/runfiles/openindiana.run
@@ -243,7 +243,8 @@ tests = ['zpool_create_001_pos', 'zpool_create_002_pos',
     'zpool_create_018_pos', 'zpool_create_019_pos', 'zpool_create_020_pos',
     'zpool_create_021_pos', 'zpool_create_022_pos', 'zpool_create_023_neg',
     'zpool_create_features_001_pos', 'zpool_create_features_002_pos',
-    'zpool_create_features_003_pos', 'zpool_create_features_004_neg']
+    'zpool_create_features_003_pos', 'zpool_create_features_004_neg',
+    'zpool_create_tempname']
 
 [/opt/zfs-tests/tests/functional/cli_root/zpool_destroy]
 tests = ['zpool_destroy_001_pos', 'zpool_destroy_002_pos',
@@ -274,7 +275,8 @@ tests = ['zpool_import_001_pos', 'zpool_import_002_pos',
     'zpool_import_003_pos', 'zpool_import_004_pos', 'zpool_import_005_pos',
     'zpool_import_006_pos', 'zpool_import_007_pos', 'zpool_import_008_pos',
     'zpool_import_009_neg', 'zpool_import_010_pos', 'zpool_import_011_neg',
-    'zpool_import_012_pos', 'zpool_import_013_neg', 'zpool_import_all_001_pos',
+    'zpool_import_012_pos', 'zpool_import_013_neg', 'zpool_import_014_pos',
+    'zpool_import_all_001_pos',
     'zpool_import_features_001_pos', 'zpool_import_features_002_neg',
     'zpool_import_features_003_pos', 'zpool_import_missing_001_pos',
     'zpool_import_missing_002_pos', 'zpool_import_missing_003_pos',
diff --git a/usr/src/test/zfs-tests/tests/functional/cli_root/zpool_create/zpool_create_tempname.ksh b/usr/src/test/zfs-tests/tests/functional/cli_root/zpool_create/zpool_create_tempname.ksh
new file mode 100644
index 0000000000..eb0a1375f5
--- /dev/null
+++ b/usr/src/test/zfs-tests/tests/functional/cli_root/zpool_create/zpool_create_tempname.ksh
@@ -0,0 +1,68 @@
+#!/bin/ksh -p
+#
+# This file and its contents are supplied under the terms of the
+# Common Development and Distribution License ("CDDL"), version 1.0.
+# You may only use this file in accordance with the terms of version
+# 1.0 of the CDDL.
+#
+# A full copy of the text of the CDDL should have accompanied this
+# source.  A copy of the CDDL is also available via the Internet at
+# http://www.illumos.org/license/CDDL.
+#
+
+#
+# Copyright 2018, loli10K <ezomori.nozomu@gmail.com>. All rights reserved.
+#
+
+. $STF_SUITE/include/libtest.shlib
+
+#
+# DESCRIPTION:
+# 'zpool create -t <tempname>' can create a pool with the specified temporary
+# name. The pool should be present in the namespace as <tempname> until exported
+#
+# STRATEGY:
+# 1. Create a pool with '-t' option
+# 2. Verify the pool is created with the specified temporary name
+#
+
+verify_runnable "global"
+
+function cleanup
+{
+	destroy_pool $TESTPOOL
+	destroy_pool $TEMPPOOL
+
+}
+
+log_assert "'zpool create -t <tempname>' can create a pool with the specified" \
+	" temporary name."
+log_onexit cleanup
+
+TEMPPOOL="tempname.$$"
+typeset poolprops=('comment=text' 'listsnapshots=on' 'autoexpand=on'
+    'autoreplace=on' 'delegation=off' 'failmode=continue')
+typeset fsprops=('canmount=off' 'mountpoint=none' 'utf8only=on'
+    'casesensitivity=mixed' 'version=1' 'normalization=formKD')
+
+for poolprop in "${poolprops[@]}"; do
+	for fsprop in "${fsprops[@]}"; do
+		# 1. Create a pool with '-t' option
+		log_must zpool create -t $TEMPPOOL \
+			-O $fsprop -o $poolprop $TESTPOOL $DISKS
+		# 2. Verify the pool is created with the specified temporary name
+		log_must poolexists $TEMPPOOL
+		log_mustnot poolexists $TESTPOOL
+		propname="$(awk -F= '{print $1}' <<< $fsprop)"
+		propval="$(awk -F= '{print $2}' <<< $fsprop)"
+		log_must test "$(get_prop $propname $TEMPPOOL)" == "$propval"
+		propname="$(awk -F= '{print $1}' <<< $poolprop)"
+		propval="$(awk -F= '{print $2}' <<< $poolprop)"
+		log_must test "$(get_pool_prop $propname $TEMPPOOL)" == "$propval"
+		# Cleanup
+		destroy_pool $TEMPPOOL
+	done
+done
+
+log_pass "'zpool create -t <tempname>' successfully creates pools with" \
+	" temporary names"
diff --git a/usr/src/test/zfs-tests/tests/functional/cli_root/zpool_import/zpool_import_014_pos.ksh b/usr/src/test/zfs-tests/tests/functional/cli_root/zpool_import/zpool_import_014_pos.ksh
new file mode 100644
index 0000000000..d70bced265
--- /dev/null
+++ b/usr/src/test/zfs-tests/tests/functional/cli_root/zpool_import/zpool_import_014_pos.ksh
@@ -0,0 +1,91 @@
+#!/bin/ksh -p
+#
+# 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 2016, loli10K. All rights reserved.
+#
+
+. $STF_SUITE/include/libtest.shlib
+. $STF_SUITE/tests/functional/cli_root/zpool_import/zpool_import.cfg
+
+#
+# DESCRIPTION:
+#	Temporary pool names should not be persisted on devices.
+#
+# STRATEGY:
+#	1. Create pool A, then export it.
+#	2. Re-import the pool with a temporary name B, then export it.
+#	3. Verify device labels still contain the expected pool name (A).
+#
+
+verify_runnable "global"
+
+function cleanup
+{
+	typeset dt
+	for dt in $poolB $poolA; do
+		destroy_pool $dt
+	done
+
+	log_must rm -rf $DEVICE_DIR/*
+	typeset i=0
+	while (( i < $MAX_NUM )); do
+		log_must mkfile $FILE_SIZE ${DEVICE_DIR}/${DEVICE_FILE}$i
+		((i += 1))
+	done
+}
+
+#
+# Verify name of (exported) pool from device $1 label is equal to $2
+# $1 device
+# $2 pool name
+#
+function verify_pool_name
+{
+	typeset device=$1
+	typeset poolname=$2
+	typeset labelname
+
+	zdb -e -l $device | grep " name:" | {
+		while read labelname ; do
+			if [[ "name: '$poolname'" != "$labelname" ]]; then
+				return 1
+			fi
+		done
+	}
+	return 0
+}
+
+log_assert "Temporary pool names should not be persisted on devices."
+log_onexit cleanup
+
+poolA=poolA.$$; poolB=poolB.$$;
+
+log_must zpool create $poolA $VDEV0
+log_must zpool export $poolA
+
+log_must zpool import -t $poolA $poolB -d $DEVICE_DIR
+log_must zpool export $poolB
+
+log_must eval "verify_pool_name $VDEV0 $poolA"
+
+log_pass "Temporary pool names are not persisted on devices."
diff --git a/usr/src/tools/cw/cw.1onbld b/usr/src/tools/cw/cw.1onbld
index 62800bb727..da3f224cd2 100644
--- a/usr/src/tools/cw/cw.1onbld
+++ b/usr/src/tools/cw/cw.1onbld
@@ -137,10 +137,11 @@ will invoke each shadow compiler, with the outputs modified (as well as any
 translation for compiler style) as follows:
 .Bl -enum
 .It
-If
-.Nm cw
-is invoked to link-edit without compilation (the input files are all objects),
-the shadow compiler is not invoked.
+If neither of
+.Fl c ,
+.Fl S
+appears in the argument list (that is, linking is attempted or only the
+pre-processor is invoked), the shadow compilers will not be invoked.
 .It
 If the
 .Fl o Ar filename
diff --git a/usr/src/tools/cw/cw.c b/usr/src/tools/cw/cw.c
index 91d62075dc..c68ace9848 100644
--- a/usr/src/tools/cw/cw.c
+++ b/usr/src/tools/cw/cw.c
@@ -308,7 +308,7 @@ typedef struct cw_ictx {
 	int		i_oldargc;
 	char		**i_oldargv;
 	pid_t		i_pid;
-	char		*i_discard;
+	char		i_discard[MAXPATHLEN];
 	char		*i_stderr;
 } cw_ictx_t;
 
@@ -553,35 +553,6 @@ xlate(struct aelist *h, const char *xarg, const char **table)
 	}
 }
 
-/*
- * The compiler wants the output file to end in appropriate extension.  If
- * we're generating a name from whole cloth (path == NULL), we assume that
- * extension to be .o, otherwise we match the extension of the caller.
- */
-static char *
-discard_file_name(const char *path)
-{
-	char *ret, *ext, *file;
-
-	if (path == NULL) {
-		ext = ".o";
-	} else {
-		ext = strrchr(path, '.');
-	}
-
-	if ((ret = calloc(MAXPATHLEN, sizeof (char))) == NULL)
-		nomem();
-
-	if ((file = tempnam(NULL, ".cw")) == NULL)
-		nomem();
-
-	(void) strlcpy(ret, file, MAXPATHLEN);
-	if (ext != NULL)
-		(void) strlcat(ret, ext, MAXPATHLEN);
-	free(file);
-	return (ret);
-}
-
 static void
 do_gcc(cw_ictx_t *ctx)
 {
@@ -591,7 +562,7 @@ do_gcc(cw_ictx_t *ctx)
 	cw_op_t op = CW_O_LINK;
 	char *model = NULL;
 	char *nameflag;
-	int mflag = 0;
+	int	mflag = 0;
 
 	if (ctx->i_flags & CW_F_PROG) {
 		newae(ctx->i_ae, "--version");
@@ -659,12 +630,10 @@ do_gcc(cw_ictx_t *ctx)
 			 * output is always discarded for the secondary
 			 * compiler.
 			 */
-			if ((ctx->i_flags & CW_F_SHADOW) && in_output) {
-				ctx->i_discard = discard_file_name(arg);
+			if ((ctx->i_flags & CW_F_SHADOW) && in_output)
 				newae(ctx->i_ae, ctx->i_discard);
-			} else {
+			else
 				newae(ctx->i_ae, arg);
-			}
 			in_output = 0;
 			continue;
 		}
@@ -780,7 +749,6 @@ do_gcc(cw_ictx_t *ctx)
 				newae(ctx->i_ae, arg);
 			} else if (ctx->i_flags & CW_F_SHADOW) {
 				newae(ctx->i_ae, "-o");
-				ctx->i_discard = discard_file_name(arg);
 				newae(ctx->i_ae, ctx->i_discard);
 			} else {
 				newae(ctx->i_ae, arg);
@@ -1219,16 +1187,8 @@ do_gcc(cw_ictx_t *ctx)
 
 	free(nameflag);
 
-	/*
-	 * When compiling multiple source files in a single invocation some
-	 * compilers output objects into the current directory with
-	 * predictable and conventional names.
-	 *
-	 * We prevent any attempt to compile multiple files at once so that
-	 * any such objects created by a shadow can't escape into a later
-	 * link-edit.
-	 */
-	if (c_files > 1 && op != CW_O_PREPROCESS) {
+	if (c_files > 1 && (ctx->i_flags & CW_F_SHADOW) &&
+	    op != CW_O_PREPROCESS) {
 		errx(2, "multiple source files are "
 		    "allowed only with -E or -P");
 	}
@@ -1296,19 +1256,15 @@ do_gcc(cw_ictx_t *ctx)
 		exit(2);
 	}
 
-	if (ctx->i_flags & CW_F_SHADOW) {
-		if (op == CW_O_PREPROCESS)
-			exit(0);
-		else if (op == CW_O_LINK && c_files == 0)
-			exit(0);
-	}
+	if ((op == CW_O_LINK || op == CW_O_PREPROCESS) &&
+	    (ctx->i_flags & CW_F_SHADOW))
+		exit(0);
 
 	if (model != NULL)
 		newae(ctx->i_ae, model);
 	if (!nolibc)
 		newae(ctx->i_ae, "-lc");
 	if (!seen_o && (ctx->i_flags & CW_F_SHADOW)) {
-		ctx->i_discard = discard_file_name(NULL);
 		newae(ctx->i_ae, "-o");
 		newae(ctx->i_ae, ctx->i_discard);
 	}
@@ -1317,7 +1273,7 @@ do_gcc(cw_ictx_t *ctx)
 static void
 do_cc(cw_ictx_t *ctx)
 {
-	int in_output = 0, seen_o = 0, c_files = 0;
+	int in_output = 0, seen_o = 0;
 	cw_op_t op = CW_O_LINK;
 	char *nameflag;
 
@@ -1331,7 +1287,6 @@ do_cc(cw_ictx_t *ctx)
 
 	while (--ctx->i_oldargc > 0) {
 		char *arg = *++ctx->i_oldargv;
-		size_t arglen = strlen(arg);
 
 		if (strncmp(arg, "-_CC=", 5) == 0) {
 			newae(ctx->i_ae, strchr(arg, '=') + 1);
@@ -1339,17 +1294,10 @@ do_cc(cw_ictx_t *ctx)
 		}
 
 		if (*arg != '-') {
-			if (!in_output && arglen > 2 &&
-			    arg[arglen - 2] == '.' &&
-			    (arg[arglen - 1] == 'S' || arg[arglen - 1] == 's' ||
-			    arg[arglen - 1] == 'c' || arg[arglen - 1] == 'i'))
-				c_files++;
-
 			if (in_output == 0 || !(ctx->i_flags & CW_F_SHADOW)) {
 				newae(ctx->i_ae, arg);
 			} else {
 				in_output = 0;
-				ctx->i_discard = discard_file_name(arg);
 				newae(ctx->i_ae, ctx->i_discard);
 			}
 			continue;
@@ -1374,7 +1322,6 @@ do_cc(cw_ictx_t *ctx)
 				newae(ctx->i_ae, arg);
 			} else if (ctx->i_flags & CW_F_SHADOW) {
 				newae(ctx->i_ae, "-o");
-				ctx->i_discard = discard_file_name(arg);
 				newae(ctx->i_ae, ctx->i_discard);
 			} else {
 				newae(ctx->i_ae, arg);
@@ -1398,22 +1345,12 @@ do_cc(cw_ictx_t *ctx)
 
 	free(nameflag);
 
-	/* See the comment on this same code in do_gcc() */
-	if (c_files > 1 && op != CW_O_PREPROCESS) {
-		errx(2, "multiple source files are "
-		    "allowed only with -E or -P");
-	}
-
-	if (ctx->i_flags & CW_F_SHADOW) {
-		if (op == CW_O_PREPROCESS)
-			exit(0);
-		else if (op == CW_O_LINK && c_files == 0)
-			exit(0);
-	}
+	if ((op == CW_O_LINK || op == CW_O_PREPROCESS) &&
+	    (ctx->i_flags & CW_F_SHADOW))
+		exit(0);
 
 	if (!seen_o && (ctx->i_flags & CW_F_SHADOW)) {
 		newae(ctx->i_ae, "-o");
-		ctx->i_discard = discard_file_name(NULL);
 		newae(ctx->i_ae, ctx->i_discard);
 	}
 }
@@ -1523,7 +1460,6 @@ reap(cw_ictx_t *ctx)
 	} while (!WIFEXITED(status) && !WIFSIGNALED(status));
 
 	(void) unlink(ctx->i_discard);
-	free(ctx->i_discard);
 
 	if (stat(ctx->i_stderr, &s) < 0) {
 		warn("stat failed on child cleanup");
@@ -1554,6 +1490,20 @@ reap(cw_ictx_t *ctx)
 static int
 exec_ctx(cw_ictx_t *ctx, int block)
 {
+	char *file;
+
+	/*
+	 * To avoid offending cc's sensibilities, the name of its output
+	 * file must end in '.o'.
+	 */
+	if ((file = tempnam(NULL, ".cw")) == NULL) {
+		nomem();
+		return (-1);
+	}
+	(void) strlcpy(ctx->i_discard, file, MAXPATHLEN);
+	(void) strlcat(ctx->i_discard, ".o", MAXPATHLEN);
+	free(file);
+
 	if ((ctx->i_stderr = tempnam(NULL, ".cw")) == NULL) {
 		nomem();
 		return (-1);
diff --git a/usr/src/tools/env/illumos.sh b/usr/src/tools/env/illumos.sh
index 51c2a458c1..a47b711347 100644
--- a/usr/src/tools/env/illumos.sh
+++ b/usr/src/tools/env/illumos.sh
@@ -23,14 +23,18 @@
 # Copyright 2012 Joshua M. Clulow <josh@sysmgr.org>
 # Copyright 2015, OmniTI Computer Consulting, Inc. All rights reserved.
 # Copyright 2018 OmniOS Community Edition (OmniOSce) Association.
+# Copyright (c) 2018, Joyent, Inc.
 #
+# - This file is sourced by "bldenv.sh" and "nightly.sh" and should not
+#   be executed directly.
+# - This script is only interpreted by ksh93 and explicitly allows the
+#   use of ksh93 language extensions.
+
+
+# -----------------------------------------------------------------------------
+# Parameters you are likely to want to change
+# -----------------------------------------------------------------------------
 
-# Configuration variables for the runtime environment of the nightly
-# build script and other tools for construction and packaging of
-# releases.
-# This example is suitable for building an illumos workspace, which
-# will contain the resulting archives. It is based off the onnv
-# release. It sets NIGHTLY_OPTIONS to make nightly do:
 #       DEBUG build only (-D, -F)
 #       do not bringover from the parent (-n)
 #       runs 'make check' (-C)
@@ -39,18 +43,83 @@
 #       creates packages for PIT/RE (-p)
 #       checks for changes in ELF runpaths (-r)
 #       build and use this workspace's tools in $SRC/tools (-t)
-#
-# - This file is sourced by "bldenv.sh" and "nightly.sh" and should not
-#   be executed directly.
-# - This script is only interpreted by ksh93 and explicitly allows the
-#   use of ksh93 language extensions.
-#
 export NIGHTLY_OPTIONS='-FnCDAmprt'
 
+# Some scripts optionally send mail messages to MAILTO.
+#export MAILTO=
+
 # CODEMGR_WS - where is your workspace at
-#export CODEMGR_WS="$HOME/ws/illumos-gate"
 export CODEMGR_WS="`git rev-parse --show-toplevel`"
 
+# Compilers may be specified using the following variables:
+# PRIMARY_CC	- primary C compiler
+# PRIMARY_CCC	- primary C++ compiler
+#
+# SHADOW_CCS    - list of shadow C compilers
+# SHADOW_CCCS	- list of shadow C++ compilers
+#
+# Each entry has the form <name>,<path to binary>,<style> where name is a
+# free-form name (possibly used in the makefiles to guard options), path is
+# the path to the executable.  style is the 'style' of command line taken by
+# the compiler, currently either gnu (or gcc) or sun (or cc), which is also
+# used by Makefiles to guard options.
+#
+# __SUNC and __GNUC must still be set to reflect the style of the primary
+# compiler (and to influence the default primary, otherwise)
+#
+# for example:
+# export PRIMARY_CC=gcc4,/opt/gcc/4.4.4/bin/gcc,gnu
+# export PRIMARY_CCC=gcc4,/opt/gcc/4.4.4/bin/g++,gnu
+# export SHADOW_CCS=studio12,/opt/SUNWspro/bin/cc,sun
+# export SHADOW_CCCS=studio12,/opt/SUNWspro/bin/CC,sun
+#
+# There can be several space-separated entries in SHADOW_* to run multiple
+# shadow compilers.
+#
+# To disable shadow compilation, unset SHADOW_* or set them to the empty string.
+#
+export SHADOW_CCS=gcc7,/usr/gcc/7/bin/gcc,gnu
+export SHADOW_CCCS=gcc7,/usr/gcc/7/bin/g++,gnu
+
+# Comment this out to disable support for SMB printing, i.e. if you
+# don't want to bother providing the CUPS headers this needs.
+export ENABLE_SMB_PRINTING=
+
+# If your distro uses certain versions of Perl, make sure either Makefile.master
+# contains your new defaults OR your .env file sets them.
+# These are how you would override for building on OmniOS r151028, for example.
+#export PERL_VERSION=5.28
+#export PERL_ARCH=i86pc-solaris-thread-multi-64int
+#export PERL_PKGVERS=
+
+# If your distro uses certain versions of Python, make sure either
+# Makefile.master contains your new defaults OR your .env file sets them.
+#export PYTHON_VERSION=2.7
+#export PYTHON_PKGVERS=-27
+#export PYTHON_SUFFIX=
+#export PYTHON3_VERSION=3.5
+#export PYTHON3_PKGVERS=-35
+#export PYTHON3_SUFFIX=m
+
+# To disable building with either Python2 or Python 3 (or both), uncomment
+# these lines:
+#export BUILDPY2='#'
+#export BUILDPY3='#'
+
+# Set if your distribution has different package versioning
+#export PKGVERS_BRANCH=2018.0.0.17900
+
+# Skip Java 8 builds on distributions that don't support it
+#export BLD_JAVA_8=
+
+# POST_NIGHTLY can be any command to be run at the end of nightly.  See
+# nightly(1) for interactions between environment variables and this command.
+#POST_NIGHTLY=
+
+# -----------------------------------------------------------------------------
+# You are less likely to need to modify parameters below.
+# -----------------------------------------------------------------------------
+
 # Maximum number of dmake jobs.  The recommended number is 2 + NCPUS,
 # where NCPUS is the number of logical CPUs on your build system.
 function maxjobs
@@ -98,16 +167,14 @@ ONBLD_BIN='/opt/onbld/bin'
 export PARENT_WS=''
 
 # CLONE_WS is the workspace nightly should do a bringover from.
+# The bringover, if any, is done as STAFFER.
 export CLONE_WS='ssh://anonhg@hg.illumos.org/illumos-gate'
 
-# The bringover, if any, is done as STAFFER.
 # Set STAFFER to your own login as gatekeeper or developer
 # The point is to use group "staff" and avoid referencing the parent
 # workspace as root.
-# Some scripts optionally send mail messages to MAILTO.
-#
 export STAFFER="$LOGNAME"
-export MAILTO="$STAFFER"
+export MAILTO="${MAILTO:-$STAFFER}"
 
 # If you wish the mail messages to be From: an arbitrary address, export
 # MAILFROM.
@@ -196,36 +263,6 @@ export BUILD_TOOLS='/opt'
 export SPRO_ROOT='/opt/SUNWspro'
 export SPRO_VROOT="$SPRO_ROOT"
 
-# Compilers may be specified using the following variables:
-# PRIMARY_CC	- primary C compiler
-# PRIMARY_CCC	- primary C++ compiler
-#
-# SHADOW_CCS    - list of shadow C compilers
-# SHADOW_CCCS	- list of shadow C++ compilers
-#
-# Each entry has the form <name>,<path to binary>,<style> where name is a
-# free-form name (possibly used in the makefiles to guard options), path is
-# the path to the executable.  style is the 'style' of command line taken by
-# the compiler, currently either gnu (or gcc) or sun (or cc), which is also
-# used by Makefiles to guard options.
-#
-# __SUNC and __GNUC must still be set to reflect the style of the primary
-# compiler (and to influence the default primary, otherwise)
-#
-# for example:
-# export PRIMARY_CC=gcc4,/opt/gcc/4.4.4/bin/gcc,gnu
-# export PRIMARY_CCC=gcc4,/opt/gcc/4.4.4/bin/g++,gnu
-# export SHADOW_CCS=studio12,/opt/SUNWspro/bin/cc,sun
-# export SHADOW_CCCS=studio12,/opt/SUNWspro/bin/CC,sun
-#
-# There can be several space-separated entries in SHADOW_* to run multiple
-# shadow compilers.
-#
-# To disable shadow compilation, unset SHADOW_* or set them to the empty string.
-#
-export SHADOW_CCS=gcc7,/usr/gcc/7/bin/gcc,gnu
-export SHADOW_CCCS=gcc7,/usr/gcc/7/bin/g++,gnu
-
 # This goes along with lint - it is a series of the form "A [y|n]" which
 # means "go to directory A and run 'make lint'" Then mail me (y) the
 # difference in the lint output. 'y' should only be used if the area you're
@@ -237,37 +274,8 @@ export SHADOW_CCCS=gcc7,/usr/gcc/7/bin/g++,gnu
 # if the 'N' option is not specified, is to run this test.
 #CHECK_PATHS='y'
 
-# POST_NIGHTLY can be any command to be run at the end of nightly.  See
-# nightly(1) for interactions between environment variables and this command.
-#POST_NIGHTLY=
-
-# Comment this out to disable support for SMB printing, i.e. if you
-# don't want to bother providing the CUPS headers this needs.
-export ENABLE_SMB_PRINTING=
-
-# If your distro uses certain versions of Perl, make sure either Makefile.master
-# contains your new defaults OR your .env file sets them.
-# These are how you would override for building on OmniOS r151028, for example.
-#export PERL_VERSION=5.28
-#export PERL_ARCH=i86pc-solaris-thread-multi-64int
-#export PERL_PKGVERS=-5161
-
 #
 # These checks ensure that if we accidentally run a program linked against the
 # proto area, that we then fail the build.
 #
 export LD_TOXIC_PATH="$ROOT/lib:$ROOT/usr/lib"
-
-# If your distro uses certain versions of Python, make sure either
-# Makefile.master contains your new defaults OR your .env file sets them.
-#export PYTHON_VERSION=2.7
-#export PYTHON_PKGVERS=-27
-#export PYTHON_SUFFIX=
-#export PYTHON3_VERSION=3.5
-#export PYTHON3_PKGVERS=-35
-#export PYTHON3_SUFFIX=m
-
-# To disable building with either Python2 or Python 3 (or both), uncomment
-# these lines:
-#export BUILDPY2='#'
-#export BUILDPY3='#'
diff --git a/usr/src/uts/common/fs/zfs/spa.c b/usr/src/uts/common/fs/zfs/spa.c
index dcfaf2902a..92ec682e29 100644
--- a/usr/src/uts/common/fs/zfs/spa.c
+++ b/usr/src/uts/common/fs/zfs/spa.c
@@ -4600,12 +4600,18 @@ spa_create(const char *pool, nvlist_t *nvroot, nvlist_t *props,
 	uint_t nspares, nl2cache;
 	uint64_t version, obj;
 	boolean_t has_features;
+	char *poolname;
+	nvlist_t *nvl;
+
+	if (nvlist_lookup_string(props,
+	    zpool_prop_to_name(ZPOOL_PROP_TNAME), &poolname) != 0)
+		poolname = (char *)pool;
 
 	/*
 	 * If this pool already exists, return failure.
 	 */
 	mutex_enter(&spa_namespace_lock);
-	if (spa_lookup(pool) != NULL) {
+	if (spa_lookup(poolname) != NULL) {
 		mutex_exit(&spa_namespace_lock);
 		return (SET_ERROR(EEXIST));
 	}
@@ -4613,9 +4619,12 @@ spa_create(const char *pool, nvlist_t *nvroot, nvlist_t *props,
 	/*
 	 * Allocate a new spa_t structure.
 	 */
+	nvl = fnvlist_alloc();
+	fnvlist_add_string(nvl, ZPOOL_CONFIG_POOL_NAME, pool);
 	(void) nvlist_lookup_string(props,
 	    zpool_prop_to_name(ZPOOL_PROP_ALTROOT), &altroot);
-	spa = spa_add(pool, NULL, altroot);
+	spa = spa_add(poolname, nvl, altroot);
+	fnvlist_free(nvl);
 	spa_activate(spa, spa_mode_global);
 
 	if (props && (error = spa_prop_validate(spa, props))) {
@@ -4625,6 +4634,12 @@ spa_create(const char *pool, nvlist_t *nvroot, nvlist_t *props,
 		return (error);
 	}
 
+	/*
+	 * Temporary pool names should never be written to disk.
+	 */
+	if (poolname != pool)
+		spa->spa_import_flags |= ZFS_IMPORT_TEMP_NAME;
+
 	has_features = B_FALSE;
 	for (nvpair_t *elem = nvlist_next_nvpair(props, NULL);
 	    elem != NULL; elem = nvlist_next_nvpair(props, elem)) {
diff --git a/usr/src/uts/common/fs/zfs/spa_config.c b/usr/src/uts/common/fs/zfs/spa_config.c
index 7d568ffcf8..ad61dd0723 100644
--- a/usr/src/uts/common/fs/zfs/spa_config.c
+++ b/usr/src/uts/common/fs/zfs/spa_config.c
@@ -208,6 +208,7 @@ spa_write_cachefile(spa_t *target, boolean_t removing, boolean_t postsysevent)
 	nvlist_t *nvl;
 	boolean_t ccw_failure;
 	int error;
+	char *pool_name;
 
 	ASSERT(MUTEX_HELD(&spa_namespace_lock));
 
@@ -254,7 +255,14 @@ spa_write_cachefile(spa_t *target, boolean_t removing, boolean_t postsysevent)
 			if (nvl == NULL)
 				nvl = fnvlist_alloc();
 
-			fnvlist_add_nvlist(nvl, spa->spa_name,
+			if (spa->spa_import_flags & ZFS_IMPORT_TEMP_NAME) {
+				pool_name = fnvlist_lookup_string(
+				    spa->spa_config, ZPOOL_CONFIG_POOL_NAME);
+			} else {
+				pool_name = spa_name(spa);
+			}
+
+			fnvlist_add_nvlist(nvl, pool_name,
 			    spa->spa_config);
 			mutex_exit(&spa->spa_props_lock);
 		}
@@ -359,6 +367,7 @@ spa_config_generate(spa_t *spa, vdev_t *vd, uint64_t txg, int getstats)
 	unsigned long hostid = 0;
 	boolean_t locked = B_FALSE;
 	uint64_t split_guid;
+	char *pool_name;
 
 	if (vd == NULL) {
 		vd = rvd;
@@ -375,10 +384,27 @@ spa_config_generate(spa_t *spa, vdev_t *vd, uint64_t txg, int getstats)
 	if (txg == -1ULL)
 		txg = spa->spa_config_txg;
 
+	/*
+	 * Originally, users had to handle spa namespace collisions by either
+	 * exporting the already imported pool or by specifying a new name for
+	 * the pool with a conflicting name. In the case of root pools from
+	 * virtual guests, neither approach to collision resolution is
+	 * reasonable. This is addressed by extending the new name syntax with
+	 * an option to specify that the new name is temporary. When specified,
+	 * ZFS_IMPORT_TEMP_NAME will be set in spa->spa_import_flags to tell us
+	 * to use the previous name, which we do below.
+	 */
+	if (spa->spa_import_flags & ZFS_IMPORT_TEMP_NAME) {
+		pool_name = fnvlist_lookup_string(spa->spa_config,
+		    ZPOOL_CONFIG_POOL_NAME);
+	} else {
+		pool_name = spa_name(spa);
+	}
+
 	config = fnvlist_alloc();
 
 	fnvlist_add_uint64(config, ZPOOL_CONFIG_VERSION, spa_version(spa));
-	fnvlist_add_string(config, ZPOOL_CONFIG_POOL_NAME, spa_name(spa));
+	fnvlist_add_string(config, ZPOOL_CONFIG_POOL_NAME, pool_name);
 	fnvlist_add_uint64(config, ZPOOL_CONFIG_POOL_STATE, spa_state(spa));
 	fnvlist_add_uint64(config, ZPOOL_CONFIG_POOL_TXG, txg);
 	fnvlist_add_uint64(config, ZPOOL_CONFIG_POOL_GUID, spa_guid(spa));
diff --git a/usr/src/uts/common/fs/zfs/zfs_ioctl.c b/usr/src/uts/common/fs/zfs/zfs_ioctl.c
index 3f3798c1c7..fa9d7028c2 100644
--- a/usr/src/uts/common/fs/zfs/zfs_ioctl.c
+++ b/usr/src/uts/common/fs/zfs/zfs_ioctl.c
@@ -1496,6 +1496,7 @@ zfs_ioc_pool_create(zfs_cmd_t *zc)
 	nvlist_t *config, *props = NULL;
 	nvlist_t *rootprops = NULL;
 	nvlist_t *zplprops = NULL;
+	char *spa_name = zc->zc_name;
 
 	if (error = get_nvlist(zc->zc_nvlist_conf, zc->zc_nvlist_conf_size,
 	    zc->zc_iflags, &config))
@@ -1511,6 +1512,7 @@ zfs_ioc_pool_create(zfs_cmd_t *zc)
 	if (props) {
 		nvlist_t *nvl = NULL;
 		uint64_t version = SPA_VERSION;
+		char *tname;
 
 		(void) nvlist_lookup_uint64(props,
 		    zpool_prop_to_name(ZPOOL_PROP_VERSION), &version);
@@ -1533,6 +1535,10 @@ zfs_ioc_pool_create(zfs_cmd_t *zc)
 		    zplprops, NULL);
 		if (error != 0)
 			goto pool_props_bad;
+
+		if (nvlist_lookup_string(props,
+		    zpool_prop_to_name(ZPOOL_PROP_TNAME), &tname) == 0)
+			spa_name = tname;
 	}
 
 	error = spa_create(zc->zc_name, config, props, zplprops);
@@ -1540,9 +1546,9 @@ zfs_ioc_pool_create(zfs_cmd_t *zc)
 	/*
 	 * Set the remaining root properties
 	 */
-	if (!error && (error = zfs_set_prop_nvlist(zc->zc_name,
+	if (!error && (error = zfs_set_prop_nvlist(spa_name,
 	    ZPROP_SRC_LOCAL, rootprops, NULL)) != 0)
-		(void) spa_destroy(zc->zc_name);
+		(void) spa_destroy(spa_name);
 
 pool_props_bad:
 	nvlist_free(rootprops);
diff --git a/usr/src/uts/common/sys/fs/zfs.h b/usr/src/uts/common/sys/fs/zfs.h
index f85062f66b..4c26edaecd 100644
--- a/usr/src/uts/common/sys/fs/zfs.h
+++ b/usr/src/uts/common/sys/fs/zfs.h
@@ -210,6 +210,7 @@ typedef enum {
 	ZPOOL_PROP_MAXBLOCKSIZE,
 	ZPOOL_PROP_BOOTSIZE,
 	ZPOOL_PROP_CHECKPOINT,
+	ZPOOL_PROP_TNAME,
 	ZPOOL_NUM_PROPS
 } zpool_prop_t;
 
@@ -855,7 +856,7 @@ typedef struct vdev_stat {
  * is passed between kernel and userland as an nvlist uint64 array.
  */
 typedef struct ddt_object {
-	uint64_t	ddo_count;	/* number of elments in ddt 	*/
+	uint64_t	ddo_count;	/* number of elments in ddt	*/
 	uint64_t	ddo_dspace;	/* size of ddt on disk		*/
 	uint64_t	ddo_mspace;	/* size of ddt in-core		*/
 } ddt_object_t;
@@ -1061,6 +1062,7 @@ typedef enum {
 #define	ZFS_IMPORT_MISSING_LOG	0x4
 #define	ZFS_IMPORT_ONLY		0x8
 #define	ZFS_IMPORT_CHECKPOINT	0x10
+#define	ZFS_IMPORT_TEMP_NAME	0x20
 
 /*
  * Channel program argument/return nvlist keys and defaults.