PSARC 2010/059 SNAP BE Management

[illumos-gate.git] / usr / src / lib / libbe / common / be_zones.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 http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
 */

/*
 * System includes
 */
#include <assert.h>
#include <errno.h>
#include <libintl.h>
#include <libnvpair.h>
#include <libzfs.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mntent.h>
#include <sys/mnttab.h>
#include <sys/mount.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/vfstab.h>
#include <unistd.h>

#include <libbe.h>
#include <libbe_priv.h>

typedef struct active_zone_root_data {
        uuid_t  parent_uuid;
        char    *zoneroot_ds;
} active_zone_root_data_t;

typedef struct mounted_zone_root_data {
        char    *zone_altroot;
        char    *zoneroot_ds;
} mounted_zone_root_data_t;

/* Private function prototypes */
static int be_find_active_zone_root_callback(zfs_handle_t *, void *);
static int be_find_mounted_zone_root_callback(zfs_handle_t *, void *);
static boolean_t be_zone_get_active(zfs_handle_t *);


/* ******************************************************************** */
/*                      Semi-Private Functions                          */
/* ******************************************************************** */

/*
 * Function:    be_make_zoneroot
 * Description: Generate a string for a zone's zoneroot given the
 *              zone's zonepath.
 * Parameters:
 *              zonepath - pointer to zonepath
 *              zoneroot - pointer to buffer to retrn zoneroot in.
 *              zoneroot_size - size of zoneroot
 * Returns:
 *              None
 * Scope:
 *              Semi-private (library wise use only)
 */
void
be_make_zoneroot(char *zonepath, char *zoneroot, int zoneroot_size)
{
        (void) snprintf(zoneroot, zoneroot_size, "%s/root", zonepath);
}

/*
 * Function:    be_find_active_zone_root
 * Description: This function will find the active zone root of a zone for
 *              a given global BE.  It will iterate all of the zone roots
 *              under a zonepath, find the zone roots that belong to the
 *              specified global BE, and return the one that is active.
 * Parameters:
 *              be_zhp - zfs handle to global BE root dataset.
 *              zonepath_ds - pointer to zone's zonepath dataset.
 *              zoneroot_ds - pointer to a buffer to store the dataset name of
 *                      the zone's zoneroot that's currently active for this
 *                      given global BE..
 *              zoneroot-ds_size - size of zoneroot_ds.
 * Returns:
 *              BE_SUCCESS - Success
 *              be_errno_t - Failure
 * Scope:
 *              Semi-private (library wide use only)
 */
int
be_find_active_zone_root(zfs_handle_t *be_zhp, char *zonepath_ds,
    char *zoneroot_ds, int zoneroot_ds_size)
{
        active_zone_root_data_t         azr_data = { 0 };
        zfs_handle_t                    *zhp;
        char                            zone_container_ds[MAXPATHLEN];
        int                             ret = BE_SUCCESS;

        /* Get the uuid of the parent global BE */
        if ((ret = be_get_uuid(zfs_get_name(be_zhp), &azr_data.parent_uuid))
            != BE_SUCCESS) {
                be_print_err(gettext("be_find_active_zone_root: failed to "
                    "get uuid for BE root dataset %s\n"), zfs_get_name(be_zhp));
                return (ret);
        }

        /* Generate string for the root container dataset for this zone. */
        be_make_container_ds(zonepath_ds, zone_container_ds,
            sizeof (zone_container_ds));

        /* Get handle to this zone's root container dataset */
        if ((zhp = zfs_open(g_zfs, zone_container_ds, ZFS_TYPE_FILESYSTEM))
            == NULL) {
                be_print_err(gettext("be_find_active_zone_root: failed to "
                    "open zone root container dataset (%s): %s\n"),
                    zone_container_ds, libzfs_error_description(g_zfs));
                return (zfs_err_to_be_err(g_zfs));
        }

        /*
         * Iterate through all of this zone's BEs, looking for ones
         * that belong to the parent global BE, and finding the one
         * that is marked active.
         */
        if ((ret = zfs_iter_filesystems(zhp, be_find_active_zone_root_callback,
            &azr_data)) != 0) {
                be_print_err(gettext("be_find_active_zone_root: failed to "
                    "find active zone root in zonepath dataset %s: %s\n"),
                    zonepath_ds, be_err_to_str(ret));
                goto done;
        }

        if (azr_data.zoneroot_ds != NULL) {
                (void) strlcpy(zoneroot_ds, azr_data.zoneroot_ds,
                    zoneroot_ds_size);
                free(azr_data.zoneroot_ds);
        } else {
                be_print_err(gettext("be_find_active_zone_root: failed to "
                    "find active zone root in zonepath dataset %s\n"),
                    zonepath_ds);
                ret = BE_ERR_ZONE_NO_ACTIVE_ROOT;
        }

done:
        ZFS_CLOSE(zhp);
        return (ret);
}

/*
 * Function:    be_find_mounted_zone_root
 * Description: This function will find the dataset mounted as the zoneroot
 *              of a zone for a given mounted global BE.
 * Parameters:
 *              zone_altroot - path of zoneroot wrt the mounted global BE.
 *              zonepath_ds - dataset of the zone's zonepath.
 *              zoneroot_ds - pointer to a buffer to store the dataset of
 *                      the zoneroot that currently mounted for this zone
 *                      in the mounted global BE.
 *              zoneroot_ds_size - size of zoneroot_ds
 * Returns:
 *              BE_SUCCESS - Success
 *              be_errno_t - Failure
 * Scope:
 *              Semi-private (library wide use only)
 */
int
be_find_mounted_zone_root(char *zone_altroot, char *zonepath_ds,
    char *zoneroot_ds, int zoneroot_ds_size)
{
        mounted_zone_root_data_t        mzr_data = { 0 };
        zfs_handle_t    *zhp = NULL;
        char            zone_container_ds[MAXPATHLEN];
        int             ret = BE_SUCCESS;
        int             zret = 0;

        /* Generate string for the root container dataset for this zone. */
        be_make_container_ds(zonepath_ds, zone_container_ds,
            sizeof (zone_container_ds));

        /* Get handle to this zone's root container dataset. */
        if ((zhp = zfs_open(g_zfs, zone_container_ds, ZFS_TYPE_FILESYSTEM))
            == NULL) {
                be_print_err(gettext("be_find_mounted_zone_root: failed to "
                    "open zone root container dataset (%s): %s\n"),
                    zone_container_ds, libzfs_error_description(g_zfs));
                return (zfs_err_to_be_err(g_zfs));
        }

        mzr_data.zone_altroot = zone_altroot;

        /*
         * Iterate through all of the zone's BEs, looking for the one
         * that is currently mounted at the zone altroot in the mounted
         * global BE.
         */
        if ((zret = zfs_iter_filesystems(zhp,
            be_find_mounted_zone_root_callback, &mzr_data)) == 0) {
                be_print_err(gettext("be_find_mounted_zone_root: did not "
                    "find mounted zone under altroot zonepath %s\n"),
                    zonepath_ds);
                ret = BE_ERR_NO_MOUNTED_ZONE;
                goto done;
        } else if (zret < 0) {
                be_print_err(gettext("be_find_mounted_zone_root: "
                    "zfs_iter_filesystems failed: %s\n"),
                    libzfs_error_description(g_zfs));
                ret = zfs_err_to_be_err(g_zfs);
                goto done;
        }

        if (mzr_data.zoneroot_ds != NULL) {
                (void) strlcpy(zoneroot_ds, mzr_data.zoneroot_ds,
                    zoneroot_ds_size);
                free(mzr_data.zoneroot_ds);
        }

done:
        ZFS_CLOSE(zhp);
        return (ret);
}

/*
 * Function:    be_zone_supported
 * Description: This function will determine if a zone is supported
 *              based on its zonepath dataset.  The zonepath dataset
 *              must:
 *                 - not be under any global BE root dataset.
 *                 - have a root container dataset underneath it.
 *
 * Parameters:
 *              zonepath_ds - name of dataset of the zonepath of the
 *              zone to check.
 * Returns:
 *              B_TRUE - zone is supported
 *              B_FALSE - zone is not supported
 * Scope:
 *              Semi-private (library wide use only)
 */
boolean_t
be_zone_supported(char *zonepath_ds)
{
        char    zone_container_ds[MAXPATHLEN];
        int     ret = 0;

        /*
         * Make sure the dataset for the zonepath is not hierarchically
         * under any reserved BE root container dataset of any pool.
         */
        if ((ret = zpool_iter(g_zfs, be_check_be_roots_callback,
            zonepath_ds)) > 0) {
                be_print_err(gettext("be_zone_supported: "
                    "zonepath dataset %s not supported\n"), zonepath_ds);
                return (B_FALSE);
        } else if (ret < 0) {
                be_print_err(gettext("be_zone_supported: "
                "zpool_iter failed: %s\n"),
                    libzfs_error_description(g_zfs));
                return (B_FALSE);
        }

        /*
         * Make sure the zonepath has a zone root container dataset
         * underneath it.
         */
        be_make_container_ds(zonepath_ds, zone_container_ds,
            sizeof (zone_container_ds));

        if (!zfs_dataset_exists(g_zfs, zone_container_ds,
            ZFS_TYPE_FILESYSTEM)) {
                be_print_err(gettext("be_zone_supported: "
                    "zonepath dataset (%s) does not have a zone root container "
                    "dataset, zone is not supported, skipping ...\n"),
                    zonepath_ds);
                return (B_FALSE);
        }

        return (B_TRUE);
}

/*
 * Function:    be_get_supported_brandlist
 * Desciption:  This functions retuns a list of supported brands in
 *              a zoneBrandList_t object.
 * Parameters:
 *              None
 * Returns:
 *              Failure - NULL if no supported brands found.
 *              Success - pointer to zoneBrandList structure.
 * Scope:
 *              Semi-private (library wide use only)
 */
zoneBrandList_t *
be_get_supported_brandlist(void)
{
        return (z_make_brand_list(BE_ZONE_SUPPORTED_BRANDS,
            BE_ZONE_SUPPORTED_BRANDS_DELIM));
}

/*
 * Function:    be_zone_get_parent_uuid
 * Description: This function gets the parentbe property of a zone root
 *              dataset, parsed it into internal uuid format, and returns
 *              it in the uuid_t reference pointer passed in.
 * Parameters:
 *              root_ds - dataset name of a zone root dataset
 *              uu - pointer to a uuid_t to return the parentbe uuid in
 * Returns:
 *              BE_SUCCESS - Success
 *              be_errno_t - Failure
 * Scope:
 *              Private
 */
int
be_zone_get_parent_uuid(const char *root_ds, uuid_t *uu)
{
        zfs_handle_t    *zhp = NULL;
        nvlist_t        *userprops = NULL;
        nvlist_t        *propname = NULL;
        char            *uu_string = NULL;
        int             ret = BE_SUCCESS;

        /* Get handle to zone root dataset */
        if ((zhp = zfs_open(g_zfs, root_ds, ZFS_TYPE_FILESYSTEM)) == NULL) {
                be_print_err(gettext("be_zone_get_parent_uuid: failed to "
                    "open zone root dataset (%s): %s\n"), root_ds,
                    libzfs_error_description(g_zfs));
                return (zfs_err_to_be_err(g_zfs));
        }

        /* Get user properties for zone root dataset */
        if ((userprops = zfs_get_user_props(zhp)) == NULL) {
                be_print_err(gettext("be_zone_get_parent_uuid: "
                    "failed to get user properties for zone root "
                    "dataset (%s): %s\n"), root_ds,
                    libzfs_error_description(g_zfs));
                ret = zfs_err_to_be_err(g_zfs);
                goto done;
        }

        /* Get UUID string from zone's root dataset user properties */
        if (nvlist_lookup_nvlist(userprops, BE_ZONE_PARENTBE_PROPERTY,
            &propname) != 0 || nvlist_lookup_string(propname, ZPROP_VALUE,
            &uu_string) != 0) {
                be_print_err(gettext("be_zone_get_parent_uuid: failed to "
                    "get parent uuid property from zone root dataset user "
                    "properties.\n"));
                ret = BE_ERR_ZONE_NO_PARENTBE;
                goto done;
        }

        /* Parse the uuid string into internal format */
        if (uuid_parse(uu_string, *uu) != 0 || uuid_is_null(*uu)) {
                be_print_err(gettext("be_zone_get_parent_uuid: failed to "
                    "parse parentuuid\n"));
                ret = BE_ERR_PARSE_UUID;
        }

done:
        ZFS_CLOSE(zhp);
        return (ret);
}

/* ******************************************************************** */
/*                      Private Functions                               */
/* ******************************************************************** */

/*
 * Function:    be_find_active_zone_root_callback
 * Description: This function is used as a callback to iterate over all of
 *              a zone's root datasets, finding the one that is marked active
 *              for the parent BE specified in the data passed in.  The name
 *              of the zone's active root dataset is returned in heap storage
 *              in the active_zone_root_data_t structure passed in, so the
 *              caller is responsible for freeing it.
 * Parameters:
 *              zhp - zfs_handle_t pointer to current dataset being processed
 *              data - active_zone_root_data_t pointer
 * Returns:
 *              0 - Success
 *              >0 - Failure
 * Scope:
 *              Private
 */
static int
be_find_active_zone_root_callback(zfs_handle_t *zhp, void *data)
{
        active_zone_root_data_t *azr_data = data;
        uuid_t                  parent_uuid = { 0 };
        int                     iret = 0;
        int                     ret = 0;

        if ((iret = be_zone_get_parent_uuid(zfs_get_name(zhp), &parent_uuid))
            != BE_SUCCESS) {
                be_print_err(gettext("be_find_active_zone_root_callback: "
                    "skipping zone root dataset (%s): %s\n"),
                    zfs_get_name(zhp), be_err_to_str(iret));
                goto done;
        }

        if (uuid_compare(azr_data->parent_uuid, parent_uuid) == 0) {
                /*
                 * Found a zone root dataset belonging to the right parent,
                 * check if its active.
                 */
                if (be_zone_get_active(zhp)) {
                        /*
                         * Found active zone root dataset, if its already
                         * set in the callback data, that means this
                         * is the second one we've found.  Return error.
                         */
                        if (azr_data->zoneroot_ds != NULL) {
                                ret = BE_ERR_ZONE_MULTIPLE_ACTIVE;
                                goto done;
                        }

                        azr_data->zoneroot_ds = strdup(zfs_get_name(zhp));
                        if (azr_data->zoneroot_ds == NULL) {
                                ret = BE_ERR_NOMEM;
                        }
                }
        }

done:
        ZFS_CLOSE(zhp);
        return (ret);
}

/*
 * Function:    be_find_mounted_zone_root_callback
 * Description: This function is used as a callback to iterate over all of
 *              a zone's root datasets, find the one that is currently
 *              mounted for the parent BE specified in the data passed in.
 *              The name of the zone's mounted root dataset is returned in
 *              heap storage the mounted_zone_data_t structure passed in,
 *              so the caller is responsible for freeing it.
 * Parameters:
 *              zhp - zfs_handle_t pointer to the current dataset being
 *                      processed
 *              data - mounted_zone_data_t pointer
 * Returns:
 *              0 - not mounted as zone's root
 *              1 - this dataset is mounted as zone's root
 * Scope:
 *              Private
 */
static int
be_find_mounted_zone_root_callback(zfs_handle_t *zhp, void *data)
{
        mounted_zone_root_data_t        *mzr_data = data;
        char                            *mp = NULL;

        if (zfs_is_mounted(zhp, &mp) && mp != NULL &&
            strcmp(mp, mzr_data->zone_altroot) == 0) {
                mzr_data->zoneroot_ds = strdup(zfs_get_name(zhp));
                free(mp);
                return (1);
        }

        free(mp);
        return (0);
}

/*
 * Function:    be_zone_get_active
 * Description: This function gets the active property of a zone root
 *              dataset, and returns true if active property is on.
 * Parameters:
 *              zfs - zfs_handle_t pointer to zone root dataset to check
 * Returns:
 *              B_TRUE - zone root dataset is active
 *              B_FALSE - zone root dataset is not active
 * Scope:
 *              Private
 */
static boolean_t
be_zone_get_active(zfs_handle_t *zhp)
{
        nvlist_t        *userprops = NULL;
        nvlist_t        *propname = NULL;
        char            *active_str = NULL;

        /* Get user properties for the zone root dataset */
        if ((userprops = zfs_get_user_props(zhp)) == NULL) {
                be_print_err(gettext("be_zone_get_active: "
                    "failed to get user properties for zone root "
                    "dataset (%s): %s\n"), zfs_get_name(zhp),
                    libzfs_error_description(g_zfs));
                return (B_FALSE);
        }

        /* Get active property from the zone root dataset user properties */
        if (nvlist_lookup_nvlist(userprops, BE_ZONE_ACTIVE_PROPERTY, &propname)
            != 0 || nvlist_lookup_string(propname, ZPROP_VALUE, &active_str)
            != 0) {
                return (B_FALSE);
        }

        if (strcmp(active_str, "on") == 0)
                return (B_TRUE);

        return (B_FALSE);
}