zpool: Add slot power control, print power status

[mirror_zfs.git] / lib / libzutil / os / linux / zutil_import_os.c

/*
 * 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 https://opensource.org/licenses/CDDL-1.0.
 * 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 2015 Nexenta Systems, Inc. All rights reserved.
 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
 * Copyright (c) 2012, 2018 by Delphix. All rights reserved.
 * Copyright 2015 RackTop Systems.
 * Copyright (c) 2016, Intel Corporation.
 */

/*
 * Pool import support functions.
 *
 * Used by zpool, ztest, zdb, and zhack to locate importable configs. Since
 * these commands are expected to run in the global zone, we can assume
 * that the devices are all readable when called.
 *
 * 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 <ctype.h>
#include <dirent.h>
#include <errno.h>
#include <libintl.h>
#include <libgen.h>
#include <stddef.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <sys/stat.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/dktp/fdisk.h>
#include <sys/vdev_impl.h>
#include <sys/fs/zfs.h>

#include <thread_pool.h>
#include <libzutil.h>
#include <libnvpair.h>
#include <libzfs.h>

#include "zutil_import.h"

#ifdef HAVE_LIBUDEV
#include <libudev.h>
#include <sched.h>
#endif
#include <blkid/blkid.h>

#define DEV_BYID_PATH   "/dev/disk/by-id/"

/*
 * Skip devices with well known prefixes:
 * there can be side effects when opening devices which need to be avoided.
 *
 * hpet        - High Precision Event Timer
 * watchdog[N] - Watchdog must be closed in a special way.
 */
static boolean_t
should_skip_dev(const char *dev)
{
        return ((strcmp(dev, "watchdog") == 0) ||
            (strncmp(dev, "watchdog", 8) == 0 && isdigit(dev[8])) ||
            (strcmp(dev, "hpet") == 0));
}

int
zfs_dev_flush(int fd)
{
        return (ioctl(fd, BLKFLSBUF));
}

void
zpool_open_func(void *arg)
{
        rdsk_node_t *rn = arg;
        libpc_handle_t *hdl = rn->rn_hdl;
        struct stat64 statbuf;
        nvlist_t *config;
        uint64_t vdev_guid = 0;
        int error;
        int num_labels = 0;
        int fd;

        if (should_skip_dev(zfs_basename(rn->rn_name)))
                return;

        /*
         * Ignore failed stats.  We only want regular files and block devices.
         * Ignore files that are too small to hold a zpool.
         */
        if (stat64(rn->rn_name, &statbuf) != 0 ||
            (!S_ISREG(statbuf.st_mode) && !S_ISBLK(statbuf.st_mode)) ||
            (S_ISREG(statbuf.st_mode) && statbuf.st_size < SPA_MINDEVSIZE))
                return;

        /*
         * Preferentially open using O_DIRECT to bypass the block device
         * cache which may be stale for multipath devices.  An EINVAL errno
         * indicates O_DIRECT is unsupported so fallback to just O_RDONLY.
         */
        fd = open(rn->rn_name, O_RDONLY | O_DIRECT | O_CLOEXEC);
        if ((fd < 0) && (errno == EINVAL))
                fd = open(rn->rn_name, O_RDONLY | O_CLOEXEC);
        if ((fd < 0) && (errno == EACCES))
                hdl->lpc_open_access_error = B_TRUE;
        if (fd < 0)
                return;

        error = zpool_read_label(fd, &config, &num_labels);
        if (error != 0) {
                (void) close(fd);
                return;
        }

        if (num_labels == 0) {
                (void) close(fd);
                nvlist_free(config);
                return;
        }

        /*
         * Check that the vdev is for the expected guid.  Additional entries
         * are speculatively added based on the paths stored in the labels.
         * Entries with valid paths but incorrect guids must be removed.
         */
        error = nvlist_lookup_uint64(config, ZPOOL_CONFIG_GUID, &vdev_guid);
        if (error || (rn->rn_vdev_guid && rn->rn_vdev_guid != vdev_guid)) {
                (void) close(fd);
                nvlist_free(config);
                return;
        }

        (void) close(fd);

        rn->rn_config = config;
        rn->rn_num_labels = num_labels;

        /*
         * Add additional entries for paths described by this label.
         */
        if (rn->rn_labelpaths) {
                const char *path = NULL;
                const char *devid = NULL;
                rdsk_node_t *slice;
                avl_index_t where;
                int error;

                if (label_paths(rn->rn_hdl, rn->rn_config, &path, &devid))
                        return;

                /*
                 * Allow devlinks to stabilize so all paths are available.
                 */
                zpool_disk_wait(rn->rn_name);

                if (path != NULL) {
                        slice = zutil_alloc(hdl, sizeof (rdsk_node_t));
                        slice->rn_name = zutil_strdup(hdl, path);
                        slice->rn_vdev_guid = vdev_guid;
                        slice->rn_avl = rn->rn_avl;
                        slice->rn_hdl = hdl;
                        slice->rn_order = IMPORT_ORDER_PREFERRED_1;
                        slice->rn_labelpaths = B_FALSE;
                        pthread_mutex_lock(rn->rn_lock);
                        if (avl_find(rn->rn_avl, slice, &where)) {
                        pthread_mutex_unlock(rn->rn_lock);
                                free(slice->rn_name);
                                free(slice);
                        } else {
                                avl_insert(rn->rn_avl, slice, where);
                                pthread_mutex_unlock(rn->rn_lock);
                                zpool_open_func(slice);
                        }
                }

                if (devid != NULL) {
                        slice = zutil_alloc(hdl, sizeof (rdsk_node_t));
                        error = asprintf(&slice->rn_name, "%s%s",
                            DEV_BYID_PATH, devid);
                        if (error == -1) {
                                free(slice);
                                return;
                        }

                        slice->rn_vdev_guid = vdev_guid;
                        slice->rn_avl = rn->rn_avl;
                        slice->rn_hdl = hdl;
                        slice->rn_order = IMPORT_ORDER_PREFERRED_2;
                        slice->rn_labelpaths = B_FALSE;
                        pthread_mutex_lock(rn->rn_lock);
                        if (avl_find(rn->rn_avl, slice, &where)) {
                                pthread_mutex_unlock(rn->rn_lock);
                                free(slice->rn_name);
                                free(slice);
                        } else {
                                avl_insert(rn->rn_avl, slice, where);
                                pthread_mutex_unlock(rn->rn_lock);
                                zpool_open_func(slice);
                        }
                }
        }
}

static const char * const
zpool_default_import_path[] = {
        "/dev/disk/by-vdev",    /* Custom rules, use first if they exist */
        "/dev/mapper",          /* Use multipath devices before components */
        "/dev/disk/by-partlabel", /* Single unique entry set by user */
        "/dev/disk/by-partuuid", /* Generated partition uuid */
        "/dev/disk/by-label",   /* Custom persistent labels */
        "/dev/disk/by-uuid",    /* Single unique entry and persistent */
        "/dev/disk/by-id",      /* May be multiple entries and persistent */
        "/dev/disk/by-path",    /* Encodes physical location and persistent */
        "/dev"                  /* UNSAFE device names will change */
};

const char * const *
zpool_default_search_paths(size_t *count)
{
        *count = ARRAY_SIZE(zpool_default_import_path);
        return (zpool_default_import_path);
}

/*
 * Given a full path to a device determine if that device appears in the
 * import search path.  If it does return the first match and store the
 * index in the passed 'order' variable, otherwise return an error.
 */
static int
zfs_path_order(const char *name, int *order)
{
        const char *env = getenv("ZPOOL_IMPORT_PATH");

        if (env) {
                for (int i = 0; ; ++i) {
                        env += strspn(env, ":");
                        size_t dirlen = strcspn(env, ":");
                        if (dirlen) {
                                if (strncmp(name, env, dirlen) == 0) {
                                        *order = i;
                                        return (0);
                                }

                                env += dirlen;
                        } else
                                break;
                }
        } else {
                for (int i = 0; i < ARRAY_SIZE(zpool_default_import_path);
                    ++i) {
                        if (strncmp(name, zpool_default_import_path[i],
                            strlen(zpool_default_import_path[i])) == 0) {
                                *order = i;
                                return (0);
                        }
                }
        }

        return (ENOENT);
}

/*
 * Use libblkid to quickly enumerate all known zfs devices.
 */
int
zpool_find_import_blkid(libpc_handle_t *hdl, pthread_mutex_t *lock,
    avl_tree_t **slice_cache)
{
        rdsk_node_t *slice;
        blkid_cache cache;
        blkid_dev_iterate iter;
        blkid_dev dev;
        avl_index_t where;
        int error;

        *slice_cache = NULL;

        error = blkid_get_cache(&cache, NULL);
        if (error != 0)
                return (error);

        error = blkid_probe_all_new(cache);
        if (error != 0) {
                blkid_put_cache(cache);
                return (error);
        }

        iter = blkid_dev_iterate_begin(cache);
        if (iter == NULL) {
                blkid_put_cache(cache);
                return (EINVAL);
        }

        /* Only const char *s since 2.32 */
        error = blkid_dev_set_search(iter,
            (char *)"TYPE", (char *)"zfs_member");
        if (error != 0) {
                blkid_dev_iterate_end(iter);
                blkid_put_cache(cache);
                return (error);
        }

        *slice_cache = zutil_alloc(hdl, sizeof (avl_tree_t));
        avl_create(*slice_cache, slice_cache_compare, sizeof (rdsk_node_t),
            offsetof(rdsk_node_t, rn_node));

        while (blkid_dev_next(iter, &dev) == 0) {
                slice = zutil_alloc(hdl, sizeof (rdsk_node_t));
                slice->rn_name = zutil_strdup(hdl, blkid_dev_devname(dev));
                slice->rn_vdev_guid = 0;
                slice->rn_lock = lock;
                slice->rn_avl = *slice_cache;
                slice->rn_hdl = hdl;
                slice->rn_labelpaths = B_TRUE;

                error = zfs_path_order(slice->rn_name, &slice->rn_order);
                if (error == 0)
                        slice->rn_order += IMPORT_ORDER_SCAN_OFFSET;
                else
                        slice->rn_order = IMPORT_ORDER_DEFAULT;

                pthread_mutex_lock(lock);
                if (avl_find(*slice_cache, slice, &where)) {
                        free(slice->rn_name);
                        free(slice);
                } else {
                        avl_insert(*slice_cache, slice, where);
                }
                pthread_mutex_unlock(lock);
        }

        blkid_dev_iterate_end(iter);
        blkid_put_cache(cache);

        return (0);
}

/*
 * Linux persistent device strings for vdev labels
 *
 * based on libudev for consistency with libudev disk add/remove events
 */

typedef struct vdev_dev_strs {
        char    vds_devid[128];
        char    vds_devphys[128];
} vdev_dev_strs_t;

#ifdef HAVE_LIBUDEV

/*
 * Obtain the persistent device id string (describes what)
 *
 * used by ZED vdev matching for auto-{online,expand,replace}
 */
int
zfs_device_get_devid(struct udev_device *dev, char *bufptr, size_t buflen)
{
        struct udev_list_entry *entry;
        const char *bus;
        char devbyid[MAXPATHLEN];

        /* The bus based by-id path is preferred */
        bus = udev_device_get_property_value(dev, "ID_BUS");

        if (bus == NULL) {
                const char *dm_uuid;

                /*
                 * For multipath nodes use the persistent uuid based identifier
                 *
                 * Example: /dev/disk/by-id/dm-uuid-mpath-35000c5006304de3f
                 */
                dm_uuid = udev_device_get_property_value(dev, "DM_UUID");
                if (dm_uuid != NULL) {
                        (void) snprintf(bufptr, buflen, "dm-uuid-%s", dm_uuid);
                        return (0);
                }

                /*
                 * For volumes use the persistent /dev/zvol/dataset identifier
                 */
                entry = udev_device_get_devlinks_list_entry(dev);
                while (entry != NULL) {
                        const char *name;

                        name = udev_list_entry_get_name(entry);
                        if (strncmp(name, ZVOL_ROOT, strlen(ZVOL_ROOT)) == 0) {
                                (void) strlcpy(bufptr, name, buflen);
                                return (0);
                        }
                        entry = udev_list_entry_get_next(entry);
                }

                /*
                 * NVME 'by-id' symlinks are similar to bus case
                 */
                struct udev_device *parent;

                parent = udev_device_get_parent_with_subsystem_devtype(dev,
                    "nvme", NULL);
                if (parent != NULL)
                        bus = "nvme";   /* continue with bus symlink search */
                else
                        return (ENODATA);
        }

        /*
         * locate the bus specific by-id link
         */
        (void) snprintf(devbyid, sizeof (devbyid), "%s%s-", DEV_BYID_PATH, bus);
        entry = udev_device_get_devlinks_list_entry(dev);
        while (entry != NULL) {
                const char *name;

                name = udev_list_entry_get_name(entry);
                if (strncmp(name, devbyid, strlen(devbyid)) == 0) {
                        name += strlen(DEV_BYID_PATH);
                        (void) strlcpy(bufptr, name, buflen);
                        return (0);
                }
                entry = udev_list_entry_get_next(entry);
        }

        return (ENODATA);
}

/*
 * Obtain the persistent physical location string (describes where)
 *
 * used by ZED vdev matching for auto-{online,expand,replace}
 */
int
zfs_device_get_physical(struct udev_device *dev, char *bufptr, size_t buflen)
{
        const char *physpath = NULL;
        struct udev_list_entry *entry;

        /*
         * Normal disks use ID_PATH for their physical path.
         */
        physpath = udev_device_get_property_value(dev, "ID_PATH");
        if (physpath != NULL && strlen(physpath) > 0) {
                (void) strlcpy(bufptr, physpath, buflen);
                return (0);
        }

        /*
         * Device mapper devices are virtual and don't have a physical
         * path. For them we use ID_VDEV instead, which is setup via the
         * /etc/vdev_id.conf file.  ID_VDEV provides a persistent path
         * to a virtual device.  If you don't have vdev_id.conf setup,
         * you cannot use multipath autoreplace with device mapper.
         */
        physpath = udev_device_get_property_value(dev, "ID_VDEV");
        if (physpath != NULL && strlen(physpath) > 0) {
                (void) strlcpy(bufptr, physpath, buflen);
                return (0);
        }

        /*
         * For ZFS volumes use the persistent /dev/zvol/dataset identifier
         */
        entry = udev_device_get_devlinks_list_entry(dev);
        while (entry != NULL) {
                physpath = udev_list_entry_get_name(entry);
                if (strncmp(physpath, ZVOL_ROOT, strlen(ZVOL_ROOT)) == 0) {
                        (void) strlcpy(bufptr, physpath, buflen);
                        return (0);
                }
                entry = udev_list_entry_get_next(entry);
        }

        /*
         * For all other devices fallback to using the by-uuid name.
         */
        entry = udev_device_get_devlinks_list_entry(dev);
        while (entry != NULL) {
                physpath = udev_list_entry_get_name(entry);
                if (strncmp(physpath, "/dev/disk/by-uuid", 17) == 0) {
                        (void) strlcpy(bufptr, physpath, buflen);
                        return (0);
                }
                entry = udev_list_entry_get_next(entry);
        }

        return (ENODATA);
}

/*
 * A disk is considered a multipath whole disk when:
 *      DEVNAME key value has "dm-"
 *      DM_NAME key value has "mpath" prefix
 *      DM_UUID key exists
 *      ID_PART_TABLE_TYPE key does not exist or is not gpt
 */
static boolean_t
udev_mpath_whole_disk(struct udev_device *dev)
{
        const char *devname, *type, *uuid;

        devname = udev_device_get_property_value(dev, "DEVNAME");
        type = udev_device_get_property_value(dev, "ID_PART_TABLE_TYPE");
        uuid = udev_device_get_property_value(dev, "DM_UUID");

        if ((devname != NULL && strncmp(devname, "/dev/dm-", 8) == 0) &&
            ((type == NULL) || (strcmp(type, "gpt") != 0)) &&
            (uuid != NULL)) {
                return (B_TRUE);
        }

        return (B_FALSE);
}

static int
udev_device_is_ready(struct udev_device *dev)
{
#ifdef HAVE_LIBUDEV_UDEV_DEVICE_GET_IS_INITIALIZED
        return (udev_device_get_is_initialized(dev));
#else
        /* wait for DEVLINKS property to be initialized */
        return (udev_device_get_property_value(dev, "DEVLINKS") != NULL);
#endif
}

#else

int
zfs_device_get_devid(struct udev_device *dev, char *bufptr, size_t buflen)
{
        (void) dev, (void) bufptr, (void) buflen;
        return (ENODATA);
}

int
zfs_device_get_physical(struct udev_device *dev, char *bufptr, size_t buflen)
{
        (void) dev, (void) bufptr, (void) buflen;
        return (ENODATA);
}

#endif /* HAVE_LIBUDEV */

/*
 * Wait up to timeout_ms for udev to set up the device node.  The device is
 * considered ready when libudev determines it has been initialized, all of
 * the device links have been verified to exist, and it has been allowed to
 * settle.  At this point the device can be accessed reliably. Depending on
 * the complexity of the udev rules this process could take several seconds.
 */
int
zpool_label_disk_wait(const char *path, int timeout_ms)
{
#ifdef HAVE_LIBUDEV
        struct udev *udev;
        struct udev_device *dev = NULL;
        char nodepath[MAXPATHLEN];
        char *sysname = NULL;
        int ret = ENODEV;
        int settle_ms = 50;
        long sleep_ms = 10;
        hrtime_t start, settle;

        if ((udev = udev_new()) == NULL)
                return (ENXIO);

        start = gethrtime();
        settle = 0;

        do {
                if (sysname == NULL) {
                        if (realpath(path, nodepath) != NULL) {
                                sysname = strrchr(nodepath, '/') + 1;
                        } else {
                                (void) usleep(sleep_ms * MILLISEC);
                                continue;
                        }
                }

                dev = udev_device_new_from_subsystem_sysname(udev,
                    "block", sysname);
                if ((dev != NULL) && udev_device_is_ready(dev)) {
                        struct udev_list_entry *links, *link = NULL;

                        ret = 0;
                        links = udev_device_get_devlinks_list_entry(dev);

                        udev_list_entry_foreach(link, links) {
                                struct stat64 statbuf;
                                const char *name;

                                name = udev_list_entry_get_name(link);
                                errno = 0;
                                if (stat64(name, &statbuf) == 0 && errno == 0)
                                        continue;

                                settle = 0;
                                ret = ENODEV;
                                break;
                        }

                        if (ret == 0) {
                                if (settle == 0) {
                                        settle = gethrtime();
                                } else if (NSEC2MSEC(gethrtime() - settle) >=
                                    settle_ms) {
                                        udev_device_unref(dev);
                                        break;
                                }
                        }
                }

                udev_device_unref(dev);
                (void) usleep(sleep_ms * MILLISEC);

        } while (NSEC2MSEC(gethrtime() - start) < timeout_ms);

        udev_unref(udev);

        return (ret);
#else
        int settle_ms = 50;
        long sleep_ms = 10;
        hrtime_t start, settle;
        struct stat64 statbuf;

        start = gethrtime();
        settle = 0;

        do {
                errno = 0;
                if ((stat64(path, &statbuf) == 0) && (errno == 0)) {
                        if (settle == 0)
                                settle = gethrtime();
                        else if (NSEC2MSEC(gethrtime() - settle) >= settle_ms)
                                return (0);
                } else if (errno != ENOENT) {
                        return (errno);
                }

                usleep(sleep_ms * MILLISEC);
        } while (NSEC2MSEC(gethrtime() - start) < timeout_ms);

        return (ENODEV);
#endif /* HAVE_LIBUDEV */
}

/*
 * Simplified version of zpool_label_disk_wait() where we wait for a device
 * to appear using the default timeouts.
 */
int
zpool_disk_wait(const char *path)
{
        int timeout;
        timeout = zpool_getenv_int("ZPOOL_IMPORT_UDEV_TIMEOUT_MS",
            DISK_LABEL_WAIT);

        return (zpool_label_disk_wait(path, timeout));
}

/*
 * Encode the persistent devices strings
 * used for the vdev disk label
 */
static int
encode_device_strings(const char *path, vdev_dev_strs_t *ds,
    boolean_t wholedisk)
{
#ifdef HAVE_LIBUDEV
        struct udev *udev;
        struct udev_device *dev = NULL;
        char nodepath[MAXPATHLEN];
        char *sysname;
        int ret = ENODEV;
        hrtime_t start;

        if ((udev = udev_new()) == NULL)
                return (ENXIO);

        /* resolve path to a runtime device node instance */
        if (realpath(path, nodepath) == NULL)
                goto no_dev;

        sysname = strrchr(nodepath, '/') + 1;

        /*
         * Wait up to 3 seconds for udev to set up the device node context
         */
        start = gethrtime();
        do {
                dev = udev_device_new_from_subsystem_sysname(udev, "block",
                    sysname);
                if (dev == NULL)
                        goto no_dev;
                if (udev_device_is_ready(dev))
                        break;  /* udev ready */

                udev_device_unref(dev);
                dev = NULL;

                if (NSEC2MSEC(gethrtime() - start) < 10)
                        (void) sched_yield();   /* yield/busy wait up to 10ms */
                else
                        (void) usleep(10 * MILLISEC);

        } while (NSEC2MSEC(gethrtime() - start) < (3 * MILLISEC));

        if (dev == NULL)
                goto no_dev;

        /*
         * Only whole disks require extra device strings
         */
        if (!wholedisk && !udev_mpath_whole_disk(dev))
                goto no_dev;

        ret = zfs_device_get_devid(dev, ds->vds_devid, sizeof (ds->vds_devid));
        if (ret != 0)
                goto no_dev_ref;

        /* physical location string (optional) */
        if (zfs_device_get_physical(dev, ds->vds_devphys,
            sizeof (ds->vds_devphys)) != 0) {
                ds->vds_devphys[0] = '\0'; /* empty string --> not available */
        }

no_dev_ref:
        udev_device_unref(dev);
no_dev:
        udev_unref(udev);

        return (ret);
#else
        (void) path;
        (void) ds;
        (void) wholedisk;
        return (ENOENT);
#endif
}

/*
 * Rescan the enclosure sysfs path for turning on enclosure LEDs and store it
 * in the nvlist * (if applicable).  Like:
 *    vdev_enc_sysfs_path: '/sys/class/enclosure/11:0:1:0/SLOT 4'
 *
 * If an old path was in the nvlist, and the rescan can not find a new path,
 * then keep the old path, since the disk may have been removed.
 *
 * path: The vdev path (value from ZPOOL_CONFIG_PATH)
 * key: The nvlist_t name (like ZPOOL_CONFIG_VDEV_ENC_SYSFS_PATH)
 */
void
update_vdev_config_dev_sysfs_path(nvlist_t *nv, const char *path,
    const char *key)
{
        char *upath, *spath;
        const char *oldpath = NULL;

        (void) nvlist_lookup_string(nv, key, &oldpath);

        /* Add enclosure sysfs path (if disk is in an enclosure). */
        upath = zfs_get_underlying_path(path);
        spath = zfs_get_enclosure_sysfs_path(upath);

        if (spath) {
                (void) nvlist_add_string(nv, key, spath);
        } else {
                /*
                 * We couldn't dynamically scan the disk's enclosure sysfs path.
                 * This could be because the disk went away.  If there's an old
                 * enclosure sysfs path in the nvlist, then keep using it.
                 */
                if (!oldpath) {
                        (void) nvlist_remove_all(nv, key);
                }
        }

        free(upath);
        free(spath);
}

/*
 * This will get called for each leaf vdev.
 */
static int
sysfs_path_pool_vdev_iter_f(void *hdl_data, nvlist_t *nv, void *data)
{
        (void) hdl_data, (void) data;

        const char *path = NULL;
        if (nvlist_lookup_string(nv, ZPOOL_CONFIG_PATH, &path) != 0)
                return (1);

        /* Rescan our enclosure sysfs path for this vdev */
        update_vdev_config_dev_sysfs_path(nv, path,
            ZPOOL_CONFIG_VDEV_ENC_SYSFS_PATH);
        return (0);
}

/*
 * Given an nvlist for our pool (with vdev tree), iterate over all the
 * leaf vdevs and update their ZPOOL_CONFIG_VDEV_ENC_SYSFS_PATH.
 */
void
update_vdevs_config_dev_sysfs_path(nvlist_t *config)
{
        nvlist_t *nvroot = NULL;
        verify(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE,
            &nvroot) == 0);
        for_each_vdev_in_nvlist(nvroot, sysfs_path_pool_vdev_iter_f, NULL);
}

/*
 * Update a leaf vdev's persistent device strings
 *
 * - only applies for a dedicated leaf vdev (aka whole disk)
 * - updated during pool create|add|attach|import
 * - used for matching device matching during auto-{online,expand,replace}
 * - stored in a leaf disk config label (i.e. alongside 'path' NVP)
 * - these strings are currently not used in kernel (i.e. for vdev_disk_open)
 *
 * single device node example:
 *      devid:          'scsi-MG03SCA300_350000494a8cb3d67-part1'
 *      phys_path:      'pci-0000:04:00.0-sas-0x50000394a8cb3d67-lun-0'
 *
 * multipath device node example:
 *      devid:          'dm-uuid-mpath-35000c5006304de3f'
 *
 * We also store the enclosure sysfs path for turning on enclosure LEDs
 * (if applicable):
 *      vdev_enc_sysfs_path: '/sys/class/enclosure/11:0:1:0/SLOT 4'
 */
void
update_vdev_config_dev_strs(nvlist_t *nv)
{
        vdev_dev_strs_t vds;
        const char *env, *type, *path;
        uint64_t wholedisk = 0;

        /*
         * For the benefit of legacy ZFS implementations, allow
         * for opting out of devid strings in the vdev label.
         *
         * example use:
         *      env ZFS_VDEV_DEVID_OPT_OUT=YES zpool import dozer
         *
         * explanation:
         * Older OpenZFS implementations had issues when attempting to
         * display pool config VDEV names if a "devid" NVP value is
         * present in the pool's config.
         *
         * For example, a pool that originated on illumos platform would
         * have a devid value in the config and "zpool status" would fail
         * when listing the config.
         *
         * A pool can be stripped of any "devid" values on import or
         * prevented from adding them on zpool create|add by setting
         * ZFS_VDEV_DEVID_OPT_OUT.
         */
        env = getenv("ZFS_VDEV_DEVID_OPT_OUT");
        if (env && (strtoul(env, NULL, 0) > 0 ||
            !strncasecmp(env, "YES", 3) || !strncasecmp(env, "ON", 2))) {
                (void) nvlist_remove_all(nv, ZPOOL_CONFIG_DEVID);
                (void) nvlist_remove_all(nv, ZPOOL_CONFIG_PHYS_PATH);
                return;
        }

        if (nvlist_lookup_string(nv, ZPOOL_CONFIG_TYPE, &type) != 0 ||
            strcmp(type, VDEV_TYPE_DISK) != 0) {
                return;
        }
        if (nvlist_lookup_string(nv, ZPOOL_CONFIG_PATH, &path) != 0)
                return;
        (void) nvlist_lookup_uint64(nv, ZPOOL_CONFIG_WHOLE_DISK, &wholedisk);

        /*
         * Update device string values in the config nvlist.
         */
        if (encode_device_strings(path, &vds, (boolean_t)wholedisk) == 0) {
                (void) nvlist_add_string(nv, ZPOOL_CONFIG_DEVID, vds.vds_devid);
                if (vds.vds_devphys[0] != '\0') {
                        (void) nvlist_add_string(nv, ZPOOL_CONFIG_PHYS_PATH,
                            vds.vds_devphys);
                }
                update_vdev_config_dev_sysfs_path(nv, path,
                    ZPOOL_CONFIG_VDEV_ENC_SYSFS_PATH);
        } else {
                /* Clear out any stale entries. */
                (void) nvlist_remove_all(nv, ZPOOL_CONFIG_DEVID);
                (void) nvlist_remove_all(nv, ZPOOL_CONFIG_PHYS_PATH);
                (void) nvlist_remove_all(nv, ZPOOL_CONFIG_VDEV_ENC_SYSFS_PATH);
        }
}