Move the world out of /zfs/ and seperate out module build tree

1 files changed, 1311 insertions, 0 deletions

diff --git a/lib/libzfs/libzfs_import.c b/lib/libzfs/libzfs_import.c
new file mode 100644
index 000000000..d67776889
--- /dev/null
+++ b/lib/libzfs/libzfs_import.c
@@ -0,0 +1,1311 @@
+/*
+ * 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 2008 Sun Microsystems, Inc.  All rights reserved.
+ * Use is subject to license terms.
+ */
+
+#pragma ident	"%Z%%M%	%I%	%E% SMI"
+
+/*
+ * Pool import support functions.
+ *
+ * To import a pool, we rely on reading the configuration information from the
+ * ZFS label of each device.  If we successfully read the label, then we
+ * organize the configuration information in the following hierarchy:
+ *
+ * 	pool guid -> toplevel vdev guid -> label txg
+ *
+ * Duplicate entries matching this same tuple will be discarded.  Once we have
+ * examined every device, we pick the best label txg config for each toplevel
+ * vdev.  We then arrange these toplevel vdevs into a complete pool config, and
+ * update any paths that have changed.  Finally, we attempt to import the pool
+ * using our derived config, and record the results.
+ */
+
+#include <devid.h>
+#include <dirent.h>
+#include <errno.h>
+#include <libintl.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <fcntl.h>
+
+#include <sys/vdev_impl.h>
+
+#include "libzfs.h"
+#include "libzfs_impl.h"
+
+/*
+ * Intermediate structures used to gather configuration information.
+ */
+typedef struct config_entry {
+	uint64_t		ce_txg;
+	nvlist_t		*ce_config;
+	struct config_entry	*ce_next;
+} config_entry_t;
+
+typedef struct vdev_entry {
+	uint64_t		ve_guid;
+	config_entry_t		*ve_configs;
+	struct vdev_entry	*ve_next;
+} vdev_entry_t;
+
+typedef struct pool_entry {
+	uint64_t		pe_guid;
+	vdev_entry_t		*pe_vdevs;
+	struct pool_entry	*pe_next;
+} pool_entry_t;
+
+typedef struct name_entry {
+	char			*ne_name;
+	uint64_t		ne_guid;
+	struct name_entry	*ne_next;
+} name_entry_t;
+
+typedef struct pool_list {
+	pool_entry_t		*pools;
+	name_entry_t		*names;
+} pool_list_t;
+
+static char *
+get_devid(const char *path)
+{
+	int fd;
+	ddi_devid_t devid;
+	char *minor, *ret;
+
+	if ((fd = open(path, O_RDONLY)) < 0)
+		return (NULL);
+
+	minor = NULL;
+	ret = NULL;
+	if (devid_get(fd, &devid) == 0) {
+		if (devid_get_minor_name(fd, &minor) == 0)
+			ret = devid_str_encode(devid, minor);
+		if (minor != NULL)
+			devid_str_free(minor);
+		devid_free(devid);
+	}
+	(void) close(fd);
+
+	return (ret);
+}
+
+
+/*
+ * Go through and fix up any path and/or devid information for the given vdev
+ * configuration.
+ */
+static int
+fix_paths(nvlist_t *nv, name_entry_t *names)
+{
+	nvlist_t **child;
+	uint_t c, children;
+	uint64_t guid;
+	name_entry_t *ne, *best;
+	char *path, *devid;
+	int matched;
+
+	if (nvlist_lookup_nvlist_array(nv, ZPOOL_CONFIG_CHILDREN,
+	    &child, &children) == 0) {
+		for (c = 0; c < children; c++)
+			if (fix_paths(child[c], names) != 0)
+				return (-1);
+		return (0);
+	}
+
+	/*
+	 * This is a leaf (file or disk) vdev.  In either case, go through
+	 * the name list and see if we find a matching guid.  If so, replace
+	 * the path and see if we can calculate a new devid.
+	 *
+	 * There may be multiple names associated with a particular guid, in
+	 * which case we have overlapping slices or multiple paths to the same
+	 * disk.  If this is the case, then we want to pick the path that is
+	 * the most similar to the original, where "most similar" is the number
+	 * of matching characters starting from the end of the path.  This will
+	 * preserve slice numbers even if the disks have been reorganized, and
+	 * will also catch preferred disk names if multiple paths exist.
+	 */
+	verify(nvlist_lookup_uint64(nv, ZPOOL_CONFIG_GUID, &guid) == 0);
+	if (nvlist_lookup_string(nv, ZPOOL_CONFIG_PATH, &path) != 0)
+		path = NULL;
+
+	matched = 0;
+	best = NULL;
+	for (ne = names; ne != NULL; ne = ne->ne_next) {
+		if (ne->ne_guid == guid) {
+			const char *src, *dst;
+			int count;
+
+			if (path == NULL) {
+				best = ne;
+				break;
+			}
+
+			src = ne->ne_name + strlen(ne->ne_name) - 1;
+			dst = path + strlen(path) - 1;
+			for (count = 0; src >= ne->ne_name && dst >= path;
+			    src--, dst--, count++)
+				if (*src != *dst)
+					break;
+
+			/*
+			 * At this point, 'count' is the number of characters
+			 * matched from the end.
+			 */
+			if (count > matched || best == NULL) {
+				best = ne;
+				matched = count;
+			}
+		}
+	}
+
+	if (best == NULL)
+		return (0);
+
+	if (nvlist_add_string(nv, ZPOOL_CONFIG_PATH, best->ne_name) != 0)
+		return (-1);
+
+	if ((devid = get_devid(best->ne_name)) == NULL) {
+		(void) nvlist_remove_all(nv, ZPOOL_CONFIG_DEVID);
+	} else {
+		if (nvlist_add_string(nv, ZPOOL_CONFIG_DEVID, devid) != 0)
+			return (-1);
+		devid_str_free(devid);
+	}
+
+	return (0);
+}
+
+/*
+ * Add the given configuration to the list of known devices.
+ */
+static int
+add_config(libzfs_handle_t *hdl, pool_list_t *pl, const char *path,
+    nvlist_t *config)
+{
+	uint64_t pool_guid, vdev_guid, top_guid, txg, state;
+	pool_entry_t *pe;
+	vdev_entry_t *ve;
+	config_entry_t *ce;
+	name_entry_t *ne;
+
+	/*
+	 * If this is a hot spare not currently in use or level 2 cache
+	 * device, add it to the list of names to translate, but don't do
+	 * anything else.
+	 */
+	if (nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_STATE,
+	    &state) == 0 &&
+	    (state == POOL_STATE_SPARE || state == POOL_STATE_L2CACHE) &&
+	    nvlist_lookup_uint64(config, ZPOOL_CONFIG_GUID, &vdev_guid) == 0) {
+		if ((ne = zfs_alloc(hdl, sizeof (name_entry_t))) == NULL)
+			return (-1);
+
+		if ((ne->ne_name = zfs_strdup(hdl, path)) == NULL) {
+			free(ne);
+			return (-1);
+		}
+		ne->ne_guid = vdev_guid;
+		ne->ne_next = pl->names;
+		pl->names = ne;
+		return (0);
+	}
+
+	/*
+	 * If we have a valid config but cannot read any of these fields, then
+	 * it means we have a half-initialized label.  In vdev_label_init()
+	 * we write a label with txg == 0 so that we can identify the device
+	 * in case the user refers to the same disk later on.  If we fail to
+	 * create the pool, we'll be left with a label in this state
+	 * which should not be considered part of a valid pool.
+	 */
+	if (nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_GUID,
+	    &pool_guid) != 0 ||
+	    nvlist_lookup_uint64(config, ZPOOL_CONFIG_GUID,
+	    &vdev_guid) != 0 ||
+	    nvlist_lookup_uint64(config, ZPOOL_CONFIG_TOP_GUID,
+	    &top_guid) != 0 ||
+	    nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_TXG,
+	    &txg) != 0 || txg == 0) {
+		nvlist_free(config);
+		return (0);
+	}
+
+	/*
+	 * First, see if we know about this pool.  If not, then add it to the
+	 * list of known pools.
+	 */
+	for (pe = pl->pools; pe != NULL; pe = pe->pe_next) {
+		if (pe->pe_guid == pool_guid)
+			break;
+	}
+
+	if (pe == NULL) {
+		if ((pe = zfs_alloc(hdl, sizeof (pool_entry_t))) == NULL) {
+			nvlist_free(config);
+			return (-1);
+		}
+		pe->pe_guid = pool_guid;
+		pe->pe_next = pl->pools;
+		pl->pools = pe;
+	}
+
+	/*
+	 * Second, see if we know about this toplevel vdev.  Add it if its
+	 * missing.
+	 */
+	for (ve = pe->pe_vdevs; ve != NULL; ve = ve->ve_next) {
+		if (ve->ve_guid == top_guid)
+			break;
+	}
+
+	if (ve == NULL) {
+		if ((ve = zfs_alloc(hdl, sizeof (vdev_entry_t))) == NULL) {
+			nvlist_free(config);
+			return (-1);
+		}
+		ve->ve_guid = top_guid;
+		ve->ve_next = pe->pe_vdevs;
+		pe->pe_vdevs = ve;
+	}
+
+	/*
+	 * Third, see if we have a config with a matching transaction group.  If
+	 * so, then we do nothing.  Otherwise, add it to the list of known
+	 * configs.
+	 */
+	for (ce = ve->ve_configs; ce != NULL; ce = ce->ce_next) {
+		if (ce->ce_txg == txg)
+			break;
+	}
+
+	if (ce == NULL) {
+		if ((ce = zfs_alloc(hdl, sizeof (config_entry_t))) == NULL) {
+			nvlist_free(config);
+			return (-1);
+		}
+		ce->ce_txg = txg;
+		ce->ce_config = config;
+		ce->ce_next = ve->ve_configs;
+		ve->ve_configs = ce;
+	} else {
+		nvlist_free(config);
+	}
+
+	/*
+	 * At this point we've successfully added our config to the list of
+	 * known configs.  The last thing to do is add the vdev guid -> path
+	 * mappings so that we can fix up the configuration as necessary before
+	 * doing the import.
+	 */
+	if ((ne = zfs_alloc(hdl, sizeof (name_entry_t))) == NULL)
+		return (-1);
+
+	if ((ne->ne_name = zfs_strdup(hdl, path)) == NULL) {
+		free(ne);
+		return (-1);
+	}
+
+	ne->ne_guid = vdev_guid;
+	ne->ne_next = pl->names;
+	pl->names = ne;
+
+	return (0);
+}
+
+/*
+ * Returns true if the named pool matches the given GUID.
+ */
+static int
+pool_active(libzfs_handle_t *hdl, const char *name, uint64_t guid,
+    boolean_t *isactive)
+{
+	zpool_handle_t *zhp;
+	uint64_t theguid;
+
+	if (zpool_open_silent(hdl, name, &zhp) != 0)
+		return (-1);
+
+	if (zhp == NULL) {
+		*isactive = B_FALSE;
+		return (0);
+	}
+
+	verify(nvlist_lookup_uint64(zhp->zpool_config, ZPOOL_CONFIG_POOL_GUID,
+	    &theguid) == 0);
+
+	zpool_close(zhp);
+
+	*isactive = (theguid == guid);
+	return (0);
+}
+
+static nvlist_t *
+refresh_config(libzfs_handle_t *hdl, nvlist_t *config)
+{
+	nvlist_t *nvl;
+	zfs_cmd_t zc = { 0 };
+	int err;
+
+	if (zcmd_write_conf_nvlist(hdl, &zc, config) != 0)
+		return (NULL);
+
+	if (zcmd_alloc_dst_nvlist(hdl, &zc,
+	    zc.zc_nvlist_conf_size * 2) != 0) {
+		zcmd_free_nvlists(&zc);
+		return (NULL);
+	}
+
+	while ((err = ioctl(hdl->libzfs_fd, ZFS_IOC_POOL_TRYIMPORT,
+	    &zc)) != 0 && errno == ENOMEM) {
+		if (zcmd_expand_dst_nvlist(hdl, &zc) != 0) {
+			zcmd_free_nvlists(&zc);
+			return (NULL);
+		}
+	}
+
+	if (err) {
+		(void) zpool_standard_error(hdl, errno,
+		    dgettext(TEXT_DOMAIN, "cannot discover pools"));
+		zcmd_free_nvlists(&zc);
+		return (NULL);
+	}
+
+	if (zcmd_read_dst_nvlist(hdl, &zc, &nvl) != 0) {
+		zcmd_free_nvlists(&zc);
+		return (NULL);
+	}
+
+	zcmd_free_nvlists(&zc);
+	return (nvl);
+}
+
+/*
+ * Convert our list of pools into the definitive set of configurations.  We
+ * start by picking the best config for each toplevel vdev.  Once that's done,
+ * we assemble the toplevel vdevs into a full config for the pool.  We make a
+ * pass to fix up any incorrect paths, and then add it to the main list to
+ * return to the user.
+ */
+static nvlist_t *
+get_configs(libzfs_handle_t *hdl, pool_list_t *pl, boolean_t active_ok)
+{
+	pool_entry_t *pe;
+	vdev_entry_t *ve;
+	config_entry_t *ce;
+	nvlist_t *ret = NULL, *config = NULL, *tmp, *nvtop, *nvroot;
+	nvlist_t **spares, **l2cache;
+	uint_t i, nspares, nl2cache;
+	boolean_t config_seen;
+	uint64_t best_txg;
+	char *name, *hostname;
+	uint64_t version, guid;
+	uint_t children = 0;
+	nvlist_t **child = NULL;
+	uint_t c;
+	boolean_t isactive;
+	uint64_t hostid;
+	nvlist_t *nvl;
+	boolean_t found_one = B_FALSE;
+
+	if (nvlist_alloc(&ret, 0, 0) != 0)
+		goto nomem;
+
+	for (pe = pl->pools; pe != NULL; pe = pe->pe_next) {
+		uint64_t id;
+
+		if (nvlist_alloc(&config, NV_UNIQUE_NAME, 0) != 0)
+			goto nomem;
+		config_seen = B_FALSE;
+
+		/*
+		 * Iterate over all toplevel vdevs.  Grab the pool configuration
+		 * from the first one we find, and then go through the rest and
+		 * add them as necessary to the 'vdevs' member of the config.
+		 */
+		for (ve = pe->pe_vdevs; ve != NULL; ve = ve->ve_next) {
+
+			/*
+			 * Determine the best configuration for this vdev by
+			 * selecting the config with the latest transaction
+			 * group.
+			 */
+			best_txg = 0;
+			for (ce = ve->ve_configs; ce != NULL;
+			    ce = ce->ce_next) {
+
+				if (ce->ce_txg > best_txg) {
+					tmp = ce->ce_config;
+					best_txg = ce->ce_txg;
+				}
+			}
+
+			if (!config_seen) {
+				/*
+				 * Copy the relevant pieces of data to the pool
+				 * configuration:
+				 *
+				 *	version
+				 * 	pool guid
+				 * 	name
+				 * 	pool state
+				 *	hostid (if available)
+				 *	hostname (if available)
+				 */
+				uint64_t state;
+
+				verify(nvlist_lookup_uint64(tmp,
+				    ZPOOL_CONFIG_VERSION, &version) == 0);
+				if (nvlist_add_uint64(config,
+				    ZPOOL_CONFIG_VERSION, version) != 0)
+					goto nomem;
+				verify(nvlist_lookup_uint64(tmp,
+				    ZPOOL_CONFIG_POOL_GUID, &guid) == 0);
+				if (nvlist_add_uint64(config,
+				    ZPOOL_CONFIG_POOL_GUID, guid) != 0)
+					goto nomem;
+				verify(nvlist_lookup_string(tmp,
+				    ZPOOL_CONFIG_POOL_NAME, &name) == 0);
+				if (nvlist_add_string(config,
+				    ZPOOL_CONFIG_POOL_NAME, name) != 0)
+					goto nomem;
+				verify(nvlist_lookup_uint64(tmp,
+				    ZPOOL_CONFIG_POOL_STATE, &state) == 0);
+				if (nvlist_add_uint64(config,
+				    ZPOOL_CONFIG_POOL_STATE, state) != 0)
+					goto nomem;
+				hostid = 0;
+				if (nvlist_lookup_uint64(tmp,
+				    ZPOOL_CONFIG_HOSTID, &hostid) == 0) {
+					if (nvlist_add_uint64(config,
+					    ZPOOL_CONFIG_HOSTID, hostid) != 0)
+						goto nomem;
+					verify(nvlist_lookup_string(tmp,
+					    ZPOOL_CONFIG_HOSTNAME,
+					    &hostname) == 0);
+					if (nvlist_add_string(config,
+					    ZPOOL_CONFIG_HOSTNAME,
+					    hostname) != 0)
+						goto nomem;
+				}
+
+				config_seen = B_TRUE;
+			}
+
+			/*
+			 * Add this top-level vdev to the child array.
+			 */
+			verify(nvlist_lookup_nvlist(tmp,
+			    ZPOOL_CONFIG_VDEV_TREE, &nvtop) == 0);
+			verify(nvlist_lookup_uint64(nvtop, ZPOOL_CONFIG_ID,
+			    &id) == 0);
+			if (id >= children) {
+				nvlist_t **newchild;
+
+				newchild = zfs_alloc(hdl, (id + 1) *
+				    sizeof (nvlist_t *));
+				if (newchild == NULL)
+					goto nomem;
+
+				for (c = 0; c < children; c++)
+					newchild[c] = child[c];
+
+				free(child);
+				child = newchild;
+				children = id + 1;
+			}
+			if (nvlist_dup(nvtop, &child[id], 0) != 0)
+				goto nomem;
+
+		}
+
+		verify(nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_GUID,
+		    &guid) == 0);
+
+		/*
+		 * Look for any missing top-level vdevs.  If this is the case,
+		 * create a faked up 'missing' vdev as a placeholder.  We cannot
+		 * simply compress the child array, because the kernel performs
+		 * certain checks to make sure the vdev IDs match their location
+		 * in the configuration.
+		 */
+		for (c = 0; c < children; c++)
+			if (child[c] == NULL) {
+				nvlist_t *missing;
+				if (nvlist_alloc(&missing, NV_UNIQUE_NAME,
+				    0) != 0)
+					goto nomem;
+				if (nvlist_add_string(missing,
+				    ZPOOL_CONFIG_TYPE,
+				    VDEV_TYPE_MISSING) != 0 ||
+				    nvlist_add_uint64(missing,
+				    ZPOOL_CONFIG_ID, c) != 0 ||
+				    nvlist_add_uint64(missing,
+				    ZPOOL_CONFIG_GUID, 0ULL) != 0) {
+					nvlist_free(missing);
+					goto nomem;
+				}
+				child[c] = missing;
+			}
+
+		/*
+		 * Put all of this pool's top-level vdevs into a root vdev.
+		 */
+		if (nvlist_alloc(&nvroot, NV_UNIQUE_NAME, 0) != 0)
+			goto nomem;
+		if (nvlist_add_string(nvroot, ZPOOL_CONFIG_TYPE,
+		    VDEV_TYPE_ROOT) != 0 ||
+		    nvlist_add_uint64(nvroot, ZPOOL_CONFIG_ID, 0ULL) != 0 ||
+		    nvlist_add_uint64(nvroot, ZPOOL_CONFIG_GUID, guid) != 0 ||
+		    nvlist_add_nvlist_array(nvroot, ZPOOL_CONFIG_CHILDREN,
+		    child, children) != 0) {
+			nvlist_free(nvroot);
+			goto nomem;
+		}
+
+		for (c = 0; c < children; c++)
+			nvlist_free(child[c]);
+		free(child);
+		children = 0;
+		child = NULL;
+
+		/*
+		 * Go through and fix up any paths and/or devids based on our
+		 * known list of vdev GUID -> path mappings.
+		 */
+		if (fix_paths(nvroot, pl->names) != 0) {
+			nvlist_free(nvroot);
+			goto nomem;
+		}
+
+		/*
+		 * Add the root vdev to this pool's configuration.
+		 */
+		if (nvlist_add_nvlist(config, ZPOOL_CONFIG_VDEV_TREE,
+		    nvroot) != 0) {
+			nvlist_free(nvroot);
+			goto nomem;
+		}
+		nvlist_free(nvroot);
+
+		/*
+		 * zdb uses this path to report on active pools that were
+		 * imported or created using -R.
+		 */
+		if (active_ok)
+			goto add_pool;
+
+		/*
+		 * Determine if this pool is currently active, in which case we
+		 * can't actually import it.
+		 */
+		verify(nvlist_lookup_string(config, ZPOOL_CONFIG_POOL_NAME,
+		    &name) == 0);
+		verify(nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_GUID,
+		    &guid) == 0);
+
+		if (pool_active(hdl, name, guid, &isactive) != 0)
+			goto error;
+
+		if (isactive) {
+			nvlist_free(config);
+			config = NULL;
+			continue;
+		}
+
+		if ((nvl = refresh_config(hdl, config)) == NULL)
+			goto error;
+
+		nvlist_free(config);
+		config = nvl;
+
+		/*
+		 * Go through and update the paths for spares, now that we have
+		 * them.
+		 */
+		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++) {
+				if (fix_paths(spares[i], pl->names) != 0)
+					goto nomem;
+			}
+		}
+
+		/*
+		 * Update the paths for l2cache devices.
+		 */
+		if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_L2CACHE,
+		    &l2cache, &nl2cache) == 0) {
+			for (i = 0; i < nl2cache; i++) {
+				if (fix_paths(l2cache[i], pl->names) != 0)
+					goto nomem;
+			}
+		}
+
+		/*
+		 * Restore the original information read from the actual label.
+		 */
+		(void) nvlist_remove(config, ZPOOL_CONFIG_HOSTID,
+		    DATA_TYPE_UINT64);
+		(void) nvlist_remove(config, ZPOOL_CONFIG_HOSTNAME,
+		    DATA_TYPE_STRING);
+		if (hostid != 0) {
+			verify(nvlist_add_uint64(config, ZPOOL_CONFIG_HOSTID,
+			    hostid) == 0);
+			verify(nvlist_add_string(config, ZPOOL_CONFIG_HOSTNAME,
+			    hostname) == 0);
+		}
+
+add_pool:
+		/*
+		 * Add this pool to the list of configs.
+		 */
+		verify(nvlist_lookup_string(config, ZPOOL_CONFIG_POOL_NAME,
+		    &name) == 0);
+		if (nvlist_add_nvlist(ret, name, config) != 0)
+			goto nomem;
+
+		found_one = B_TRUE;
+		nvlist_free(config);
+		config = NULL;
+	}
+
+	if (!found_one) {
+		nvlist_free(ret);
+		ret = NULL;
+	}
+
+	return (ret);
+
+nomem:
+	(void) no_memory(hdl);
+error:
+	nvlist_free(config);
+	nvlist_free(ret);
+	for (c = 0; c < children; c++)
+		nvlist_free(child[c]);
+	free(child);
+
+	return (NULL);
+}
+
+/*
+ * Return the offset of the given label.
+ */
+static uint64_t
+label_offset(uint64_t size, int l)
+{
+	ASSERT(P2PHASE_TYPED(size, sizeof (vdev_label_t), uint64_t) == 0);
+	return (l * sizeof (vdev_label_t) + (l < VDEV_LABELS / 2 ?
+	    0 : size - VDEV_LABELS * sizeof (vdev_label_t)));
+}
+
+/*
+ * Given a file descriptor, read the label information and return an nvlist
+ * describing the configuration, if there is one.
+ */
+int
+zpool_read_label(int fd, nvlist_t **config)
+{
+	struct stat64 statbuf;
+	int l;
+	vdev_label_t *label;
+	uint64_t state, txg, size;
+
+	*config = NULL;
+
+	if (fstat64(fd, &statbuf) == -1)
+		return (0);
+	size = P2ALIGN_TYPED(statbuf.st_size, sizeof (vdev_label_t), uint64_t);
+
+	if ((label = malloc(sizeof (vdev_label_t))) == NULL)
+		return (-1);
+
+	for (l = 0; l < VDEV_LABELS; l++) {
+		if (pread64(fd, label, sizeof (vdev_label_t),
+		    label_offset(size, l)) != sizeof (vdev_label_t))
+			continue;
+
+		if (nvlist_unpack(label->vl_vdev_phys.vp_nvlist,
+		    sizeof (label->vl_vdev_phys.vp_nvlist), config, 0) != 0)
+			continue;
+
+		if (nvlist_lookup_uint64(*config, ZPOOL_CONFIG_POOL_STATE,
+		    &state) != 0 || state > POOL_STATE_L2CACHE) {
+			nvlist_free(*config);
+			continue;
+		}
+
+		if (state != POOL_STATE_SPARE && state != POOL_STATE_L2CACHE &&
+		    (nvlist_lookup_uint64(*config, ZPOOL_CONFIG_POOL_TXG,
+		    &txg) != 0 || txg == 0)) {
+			nvlist_free(*config);
+			continue;
+		}
+
+		free(label);
+		return (0);
+	}
+
+	free(label);
+	*config = NULL;
+	return (0);
+}
+
+/*
+ * Given a list of directories to search, find all pools stored on disk.  This
+ * includes partial pools which are not available to import.  If no args are
+ * given (argc is 0), then the default directory (/dev/dsk) is searched.
+ * poolname or guid (but not both) are provided by the caller when trying
+ * to import a specific pool.
+ */
+static nvlist_t *
+zpool_find_import_impl(libzfs_handle_t *hdl, int argc, char **argv,
+    boolean_t active_ok, char *poolname, uint64_t guid)
+{
+	int i;
+	DIR *dirp = NULL;
+	struct dirent64 *dp;
+	char path[MAXPATHLEN];
+	char *end;
+	size_t pathleft;
+	struct stat64 statbuf;
+	nvlist_t *ret = NULL, *config;
+	static char *default_dir = "/dev/dsk";
+	int fd;
+	pool_list_t pools = { 0 };
+	pool_entry_t *pe, *penext;
+	vdev_entry_t *ve, *venext;
+	config_entry_t *ce, *cenext;
+	name_entry_t *ne, *nenext;
+
+	verify(poolname == NULL || guid == 0);
+
+	if (argc == 0) {
+		argc = 1;
+		argv = &default_dir;
+	}
+
+	/*
+	 * Go through and read the label configuration information from every
+	 * possible device, organizing the information according to pool GUID
+	 * and toplevel GUID.
+	 */
+	for (i = 0; i < argc; i++) {
+		char *rdsk;
+		int dfd;
+
+		/* use realpath to normalize the path */
+		if (realpath(argv[i], path) == 0) {
+			(void) zfs_error_fmt(hdl, EZFS_BADPATH,
+			    dgettext(TEXT_DOMAIN, "cannot open '%s'"),
+			    argv[i]);
+			goto error;
+		}
+		end = &path[strlen(path)];
+		*end++ = '/';
+		*end = 0;
+		pathleft = &path[sizeof (path)] - end;
+
+		/*
+		 * Using raw devices instead of block devices when we're
+		 * reading the labels skips a bunch of slow operations during
+		 * close(2) processing, so we replace /dev/dsk with /dev/rdsk.
+		 */
+		if (strcmp(path, "/dev/dsk/") == 0)
+			rdsk = "/dev/rdsk/";
+		else
+			rdsk = path;
+
+		if ((dfd = open64(rdsk, O_RDONLY)) < 0 ||
+		    (dirp = fdopendir(dfd)) == NULL) {
+			zfs_error_aux(hdl, strerror(errno));
+			(void) zfs_error_fmt(hdl, EZFS_BADPATH,
+			    dgettext(TEXT_DOMAIN, "cannot open '%s'"),
+			    rdsk);
+			goto error;
+		}
+
+		/*
+		 * This is not MT-safe, but we have no MT consumers of libzfs
+		 */
+		while ((dp = readdir64(dirp)) != NULL) {
+			const char *name = dp->d_name;
+			if (name[0] == '.' &&
+			    (name[1] == 0 || (name[1] == '.' && name[2] == 0)))
+				continue;
+
+			if ((fd = openat64(dfd, name, O_RDONLY)) < 0)
+				continue;
+
+			/*
+			 * Ignore failed stats.  We only want regular
+			 * files, character devs and block devs.
+			 */
+			if (fstat64(fd, &statbuf) != 0 ||
+			    (!S_ISREG(statbuf.st_mode) &&
+			    !S_ISCHR(statbuf.st_mode) &&
+			    !S_ISBLK(statbuf.st_mode))) {
+				(void) close(fd);
+				continue;
+			}
+
+			if ((zpool_read_label(fd, &config)) != 0) {
+				(void) close(fd);
+				(void) no_memory(hdl);
+				goto error;
+			}
+
+			(void) close(fd);
+
+			if (config != NULL) {
+				boolean_t matched = B_TRUE;
+
+				if (poolname != NULL) {
+					char *pname;
+
+					matched = nvlist_lookup_string(config,
+					    ZPOOL_CONFIG_POOL_NAME,
+					    &pname) == 0 &&
+					    strcmp(poolname, pname) == 0;
+				} else if (guid != 0) {
+					uint64_t this_guid;
+
+					matched = nvlist_lookup_uint64(config,
+					    ZPOOL_CONFIG_POOL_GUID,
+					    &this_guid) == 0 &&
+					    guid == this_guid;
+				}
+				if (!matched) {
+					nvlist_free(config);
+					config = NULL;
+					continue;
+				}
+				/* use the non-raw path for the config */
+				(void) strlcpy(end, name, pathleft);
+				if (add_config(hdl, &pools, path, config) != 0)
+					goto error;
+			}
+		}
+
+		(void) closedir(dirp);
+		dirp = NULL;
+	}
+
+	ret = get_configs(hdl, &pools, active_ok);
+
+error:
+	for (pe = pools.pools; pe != NULL; pe = penext) {
+		penext = pe->pe_next;
+		for (ve = pe->pe_vdevs; ve != NULL; ve = venext) {
+			venext = ve->ve_next;
+			for (ce = ve->ve_configs; ce != NULL; ce = cenext) {
+				cenext = ce->ce_next;
+				if (ce->ce_config)
+					nvlist_free(ce->ce_config);
+				free(ce);
+			}
+			free(ve);
+		}
+		free(pe);
+	}
+
+	for (ne = pools.names; ne != NULL; ne = nenext) {
+		nenext = ne->ne_next;
+		if (ne->ne_name)
+			free(ne->ne_name);
+		free(ne);
+	}
+
+	if (dirp)
+		(void) closedir(dirp);
+
+	return (ret);
+}
+
+nvlist_t *
+zpool_find_import(libzfs_handle_t *hdl, int argc, char **argv)
+{
+	return (zpool_find_import_impl(hdl, argc, argv, B_FALSE, NULL, 0));
+}
+
+nvlist_t *
+zpool_find_import_byname(libzfs_handle_t *hdl, int argc, char **argv,
+    char *pool)
+{
+	return (zpool_find_import_impl(hdl, argc, argv, B_FALSE, pool, 0));
+}
+
+nvlist_t *
+zpool_find_import_byguid(libzfs_handle_t *hdl, int argc, char **argv,
+    uint64_t guid)
+{
+	return (zpool_find_import_impl(hdl, argc, argv, B_FALSE, NULL, guid));
+}
+
+nvlist_t *
+zpool_find_import_activeok(libzfs_handle_t *hdl, int argc, char **argv)
+{
+	return (zpool_find_import_impl(hdl, argc, argv, B_TRUE, NULL, 0));
+}
+
+/*
+ * Given a cache file, return the contents as a list of importable pools.
+ * poolname or guid (but not both) are provided by the caller when trying
+ * to import a specific pool.
+ */
+nvlist_t *
+zpool_find_import_cached(libzfs_handle_t *hdl, const char *cachefile,
+    char *poolname, uint64_t guid)
+{
+	char *buf;
+	int fd;
+	struct stat64 statbuf;
+	nvlist_t *raw, *src, *dst;
+	nvlist_t *pools;
+	nvpair_t *elem;
+	char *name;
+	uint64_t this_guid;
+	boolean_t active;
+
+	verify(poolname == NULL || guid == 0);
+
+	if ((fd = open(cachefile, O_RDONLY)) < 0) {
+		zfs_error_aux(hdl, "%s", strerror(errno));
+		(void) zfs_error(hdl, EZFS_BADCACHE,
+		    dgettext(TEXT_DOMAIN, "failed to open cache file"));
+		return (NULL);
+	}
+
+	if (fstat64(fd, &statbuf) != 0) {
+		zfs_error_aux(hdl, "%s", strerror(errno));
+		(void) close(fd);
+		(void) zfs_error(hdl, EZFS_BADCACHE,
+		    dgettext(TEXT_DOMAIN, "failed to get size of cache file"));
+		return (NULL);
+	}
+
+	if ((buf = zfs_alloc(hdl, statbuf.st_size)) == NULL) {
+		(void) close(fd);
+		return (NULL);
+	}
+
+	if (read(fd, buf, statbuf.st_size) != statbuf.st_size) {
+		(void) close(fd);
+		free(buf);
+		(void) zfs_error(hdl, EZFS_BADCACHE,
+		    dgettext(TEXT_DOMAIN,
+		    "failed to read cache file contents"));
+		return (NULL);
+	}
+
+	(void) close(fd);
+
+	if (nvlist_unpack(buf, statbuf.st_size, &raw, 0) != 0) {
+		free(buf);
+		(void) zfs_error(hdl, EZFS_BADCACHE,
+		    dgettext(TEXT_DOMAIN,
+		    "invalid or corrupt cache file contents"));
+		return (NULL);
+	}
+
+	free(buf);
+
+	/*
+	 * Go through and get the current state of the pools and refresh their
+	 * state.
+	 */
+	if (nvlist_alloc(&pools, 0, 0) != 0) {
+		(void) no_memory(hdl);
+		nvlist_free(raw);
+		return (NULL);
+	}
+
+	elem = NULL;
+	while ((elem = nvlist_next_nvpair(raw, elem)) != NULL) {
+		verify(nvpair_value_nvlist(elem, &src) == 0);
+
+		verify(nvlist_lookup_string(src, ZPOOL_CONFIG_POOL_NAME,
+		    &name) == 0);
+		if (poolname != NULL && strcmp(poolname, name) != 0)
+			continue;
+
+		verify(nvlist_lookup_uint64(src, ZPOOL_CONFIG_POOL_GUID,
+		    &this_guid) == 0);
+		if (guid != 0) {
+			verify(nvlist_lookup_uint64(src, ZPOOL_CONFIG_POOL_GUID,
+			    &this_guid) == 0);
+			if (guid != this_guid)
+				continue;
+		}
+
+		if (pool_active(hdl, name, this_guid, &active) != 0) {
+			nvlist_free(raw);
+			nvlist_free(pools);
+			return (NULL);
+		}
+
+		if (active)
+			continue;
+
+		if ((dst = refresh_config(hdl, src)) == NULL) {
+			nvlist_free(raw);
+			nvlist_free(pools);
+			return (NULL);
+		}
+
+		if (nvlist_add_nvlist(pools, nvpair_name(elem), dst) != 0) {
+			(void) no_memory(hdl);
+			nvlist_free(dst);
+			nvlist_free(raw);
+			nvlist_free(pools);
+			return (NULL);
+		}
+		nvlist_free(dst);
+	}
+
+	nvlist_free(raw);
+	return (pools);
+}
+
+
+boolean_t
+find_guid(nvlist_t *nv, uint64_t guid)
+{
+	uint64_t tmp;
+	nvlist_t **child;
+	uint_t c, children;
+
+	verify(nvlist_lookup_uint64(nv, ZPOOL_CONFIG_GUID, &tmp) == 0);
+	if (tmp == guid)
+		return (B_TRUE);
+
+	if (nvlist_lookup_nvlist_array(nv, ZPOOL_CONFIG_CHILDREN,
+	    &child, &children) == 0) {
+		for (c = 0; c < children; c++)
+			if (find_guid(child[c], guid))
+				return (B_TRUE);
+	}
+
+	return (B_FALSE);
+}
+
+typedef struct aux_cbdata {
+	const char	*cb_type;
+	uint64_t	cb_guid;
+	zpool_handle_t	*cb_zhp;
+} aux_cbdata_t;
+
+static int
+find_aux(zpool_handle_t *zhp, void *data)
+{
+	aux_cbdata_t *cbp = data;
+	nvlist_t **list;
+	uint_t i, count;
+	uint64_t guid;
+	nvlist_t *nvroot;
+
+	verify(nvlist_lookup_nvlist(zhp->zpool_config, ZPOOL_CONFIG_VDEV_TREE,
+	    &nvroot) == 0);
+
+	if (nvlist_lookup_nvlist_array(nvroot, cbp->cb_type,
+	    &list, &count) == 0) {
+		for (i = 0; i < count; i++) {
+			verify(nvlist_lookup_uint64(list[i],
+			    ZPOOL_CONFIG_GUID, &guid) == 0);
+			if (guid == cbp->cb_guid) {
+				cbp->cb_zhp = zhp;
+				return (1);
+			}
+		}
+	}
+
+	zpool_close(zhp);
+	return (0);
+}
+
+/*
+ * Determines if the pool is in use.  If so, it returns true and the state of
+ * the pool as well as the name of the pool.  Both strings are allocated and
+ * must be freed by the caller.
+ */
+int
+zpool_in_use(libzfs_handle_t *hdl, int fd, pool_state_t *state, char **namestr,
+    boolean_t *inuse)
+{
+	nvlist_t *config;
+	char *name;
+	boolean_t ret;
+	uint64_t guid, vdev_guid;
+	zpool_handle_t *zhp;
+	nvlist_t *pool_config;
+	uint64_t stateval, isspare;
+	aux_cbdata_t cb = { 0 };
+	boolean_t isactive;
+
+	*inuse = B_FALSE;
+
+	if (zpool_read_label(fd, &config) != 0) {
+		(void) no_memory(hdl);
+		return (-1);
+	}
+
+	if (config == NULL)
+		return (0);
+
+	verify(nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_STATE,
+	    &stateval) == 0);
+	verify(nvlist_lookup_uint64(config, ZPOOL_CONFIG_GUID,
+	    &vdev_guid) == 0);
+
+	if (stateval != POOL_STATE_SPARE && stateval != POOL_STATE_L2CACHE) {
+		verify(nvlist_lookup_string(config, ZPOOL_CONFIG_POOL_NAME,
+		    &name) == 0);
+		verify(nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_GUID,
+		    &guid) == 0);
+	}
+
+	switch (stateval) {
+	case POOL_STATE_EXPORTED:
+		ret = B_TRUE;
+		break;
+
+	case POOL_STATE_ACTIVE:
+		/*
+		 * For an active pool, we have to determine if it's really part
+		 * of a currently active pool (in which case the pool will exist
+		 * and the guid will be the same), or whether it's part of an
+		 * active pool that was disconnected without being explicitly
+		 * exported.
+		 */
+		if (pool_active(hdl, name, guid, &isactive) != 0) {
+			nvlist_free(config);
+			return (-1);
+		}
+
+		if (isactive) {
+			/*
+			 * Because the device may have been removed while
+			 * offlined, we only report it as active if the vdev is
+			 * still present in the config.  Otherwise, pretend like
+			 * it's not in use.
+			 */
+			if ((zhp = zpool_open_canfail(hdl, name)) != NULL &&
+			    (pool_config = zpool_get_config(zhp, NULL))
+			    != NULL) {
+				nvlist_t *nvroot;
+
+				verify(nvlist_lookup_nvlist(pool_config,
+				    ZPOOL_CONFIG_VDEV_TREE, &nvroot) == 0);
+				ret = find_guid(nvroot, vdev_guid);
+			} else {
+				ret = B_FALSE;
+			}
+
+			/*
+			 * If this is an active spare within another pool, we
+			 * treat it like an unused hot spare.  This allows the
+			 * user to create a pool with a hot spare that currently
+			 * in use within another pool.  Since we return B_TRUE,
+			 * libdiskmgt will continue to prevent generic consumers
+			 * from using the device.
+			 */
+			if (ret && nvlist_lookup_uint64(config,
+			    ZPOOL_CONFIG_IS_SPARE, &isspare) == 0 && isspare)
+				stateval = POOL_STATE_SPARE;
+
+			if (zhp != NULL)
+				zpool_close(zhp);
+		} else {
+			stateval = POOL_STATE_POTENTIALLY_ACTIVE;
+			ret = B_TRUE;
+		}
+		break;
+
+	case POOL_STATE_SPARE:
+		/*
+		 * For a hot spare, it can be either definitively in use, or
+		 * potentially active.  To determine if it's in use, we iterate
+		 * over all pools in the system and search for one with a spare
+		 * with a matching guid.
+		 *
+		 * Due to the shared nature of spares, we don't actually report
+		 * the potentially active case as in use.  This means the user
+		 * can freely create pools on the hot spares of exported pools,
+		 * but to do otherwise makes the resulting code complicated, and
+		 * we end up having to deal with this case anyway.
+		 */
+		cb.cb_zhp = NULL;
+		cb.cb_guid = vdev_guid;
+		cb.cb_type = ZPOOL_CONFIG_SPARES;
+		if (zpool_iter(hdl, find_aux, &cb) == 1) {
+			name = (char *)zpool_get_name(cb.cb_zhp);
+			ret = TRUE;
+		} else {
+			ret = FALSE;
+		}
+		break;
+
+	case POOL_STATE_L2CACHE:
+
+		/*
+		 * Check if any pool is currently using this l2cache device.
+		 */
+		cb.cb_zhp = NULL;
+		cb.cb_guid = vdev_guid;
+		cb.cb_type = ZPOOL_CONFIG_L2CACHE;
+		if (zpool_iter(hdl, find_aux, &cb) == 1) {
+			name = (char *)zpool_get_name(cb.cb_zhp);
+			ret = TRUE;
+		} else {
+			ret = FALSE;
+		}
+		break;
+
+	default:
+		ret = B_FALSE;
+	}
+
+
+	if (ret) {
+		if ((*namestr = zfs_strdup(hdl, name)) == NULL) {
+			if (cb.cb_zhp)
+				zpool_close(cb.cb_zhp);
+			nvlist_free(config);
+			return (-1);
+		}
+		*state = (pool_state_t)stateval;
+	}
+
+	if (cb.cb_zhp)
+		zpool_close(cb.cb_zhp);
+
+	nvlist_free(config);
+	*inuse = ret;
+	return (0);
+}