cmd/zfs/zfs_iter.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) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
 * Copyright (c) 2012 Pawel Jakub Dawidek. All rights reserved.
 * Copyright 2013 Nexenta Systems, Inc.  All rights reserved.
 * Copyright (c) 2013 by Delphix. All rights reserved.
 */

#include <libintl.h>
#include <libuutil.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <strings.h>

#include <libzfs.h>

#include "zfs_util.h"
#include "zfs_iter.h"

/*
 * This is a private interface used to gather up all the datasets specified on
 * the command line so that we can iterate over them in order.
 *
 * First, we iterate over all filesystems, gathering them together into an
 * AVL tree.  We report errors for any explicitly specified datasets
 * that we couldn't open.
 *
 * When finished, we have an AVL tree of ZFS handles.  We go through and execute
 * the provided callback for each one, passing whatever data the user supplied.
 */

typedef struct zfs_node {
    zfs_handle_t    *zn_handle;
    uu_avl_node_t   zn_avlnode;
} zfs_node_t;

typedef struct callback_data {
    uu_avl_t        *cb_avl;
    int         cb_flags;
    zfs_type_t      cb_types;
    zfs_sort_column_t   *cb_sortcol;
    zprop_list_t        **cb_proplist;
    int         cb_depth_limit;
    int         cb_depth;
    uint8_t         cb_props_table[ZFS_NUM_PROPS];
} callback_data_t;

uu_avl_pool_t *avl_pool;

/*
 * Include snaps if they were requested or if this a zfs list where types
 * were not specified and the "listsnapshots" property is set on this pool.
 */
static boolean_t
zfs_include_snapshots(zfs_handle_t *zhp, callback_data_t *cb)
{
    zpool_handle_t *zph;

    if ((cb->cb_flags & ZFS_ITER_PROP_LISTSNAPS) == 0)
        return (cb->cb_types & ZFS_TYPE_SNAPSHOT);

    zph = zfs_get_pool_handle(zhp);
    return (zpool_get_prop_int(zph, ZPOOL_PROP_LISTSNAPS, NULL));
}

/*
 * Called for each dataset.  If the object is of an appropriate type,
 * add it to the avl tree and recurse over any children as necessary.
 */
static int
zfs_callback(zfs_handle_t *zhp, void *data)
{
    callback_data_t *cb = data;
    boolean_t should_close = B_TRUE;
    boolean_t include_snaps = zfs_include_snapshots(zhp, cb);
    boolean_t include_bmarks = (cb->cb_types & ZFS_TYPE_BOOKMARK);

    if ((zfs_get_type(zhp) & cb->cb_types) ||
        ((zfs_get_type(zhp) == ZFS_TYPE_SNAPSHOT) && include_snaps)) {
        uu_avl_index_t idx;
        zfs_node_t *node = safe_malloc(sizeof (zfs_node_t));

        node->zn_handle = zhp;
        uu_avl_node_init(node, &node->zn_avlnode, avl_pool);
        if (uu_avl_find(cb->cb_avl, node, cb->cb_sortcol,
            &idx) == NULL) {
            if (cb->cb_proplist) {
                if ((*cb->cb_proplist) &&
                    !(*cb->cb_proplist)->pl_all)
                    zfs_prune_proplist(zhp,
                        cb->cb_props_table);

                if (zfs_expand_proplist(zhp, cb->cb_proplist,
                    (cb->cb_flags & ZFS_ITER_RECVD_PROPS),
                    (cb->cb_flags & ZFS_ITER_LITERAL_PROPS))
                    != 0) {
                    free(node);
                    return (-1);
                }
            }
            uu_avl_insert(cb->cb_avl, node, idx);
            should_close = B_FALSE;
        } else {
            free(node);
        }
    }

    /*
     * Recurse if necessary.
     */
    if (cb->cb_flags & ZFS_ITER_RECURSE &&
        ((cb->cb_flags & ZFS_ITER_DEPTH_LIMIT) == 0 ||
        cb->cb_depth < cb->cb_depth_limit)) {
        cb->cb_depth++;
        if (zfs_get_type(zhp) == ZFS_TYPE_FILESYSTEM)
            (void) zfs_iter_filesystems(zhp, zfs_callback, data);
        if (((zfs_get_type(zhp) & (ZFS_TYPE_SNAPSHOT |
            ZFS_TYPE_BOOKMARK)) == 0) && include_snaps)
            (void) zfs_iter_snapshots(zhp,
                (cb->cb_flags & ZFS_ITER_SIMPLE) != 0, zfs_callback,
                data);
        if (((zfs_get_type(zhp) & (ZFS_TYPE_SNAPSHOT |
            ZFS_TYPE_BOOKMARK)) == 0) && include_bmarks)
            (void) zfs_iter_bookmarks(zhp, zfs_callback, data);
        cb->cb_depth--;
    }

    if (should_close)
        zfs_close(zhp);

    return (0);
}

int
zfs_add_sort_column(zfs_sort_column_t **sc, const char *name,
    boolean_t reverse)
{
    zfs_sort_column_t *col;
    zfs_prop_t prop;

    if ((prop = zfs_name_to_prop(name)) == ZPROP_INVAL &&
        !zfs_prop_user(name))
        return (-1);

    col = safe_malloc(sizeof (zfs_sort_column_t));

    col->sc_prop = prop;
    col->sc_reverse = reverse;
    if (prop == ZPROP_INVAL) {
        col->sc_user_prop = safe_malloc(strlen(name) + 1);
        (void) strcpy(col->sc_user_prop, name);
    }

    if (*sc == NULL) {
        col->sc_last = col;
        *sc = col;
    } else {
        (*sc)->sc_last->sc_next = col;
        (*sc)->sc_last = col;
    }

    return (0);
}

void
zfs_free_sort_columns(zfs_sort_column_t *sc)
{
    zfs_sort_column_t *col;

    while (sc != NULL) {
        col = sc->sc_next;
        free(sc->sc_user_prop);
        free(sc);
        sc = col;
    }
}

boolean_t
zfs_sort_only_by_name(const zfs_sort_column_t *sc)
{

    return (sc != NULL && sc->sc_next == NULL &&
        sc->sc_prop == ZFS_PROP_NAME);
}

/* ARGSUSED */
static int
zfs_compare(const void *larg, const void *rarg, void *unused)
{
    zfs_handle_t *l = ((zfs_node_t *)larg)->zn_handle;
    zfs_handle_t *r = ((zfs_node_t *)rarg)->zn_handle;
    const char *lname = zfs_get_name(l);
    const char *rname = zfs_get_name(r);
    char *lat, *rat;
    uint64_t lcreate, rcreate;
    int ret;

    lat = (char *)strchr(lname, '@');
    rat = (char *)strchr(rname, '@');

    if (lat != NULL)
        *lat = '\0';
    if (rat != NULL)
        *rat = '\0';

    ret = strcmp(lname, rname);
    if (ret == 0) {
        /*
         * If we're comparing a dataset to one of its snapshots, we
         * always make the full dataset first.
         */
        if (lat == NULL) {
            ret = -1;
        } else if (rat == NULL) {
            ret = 1;
        } else {
            /*
             * If we have two snapshots from the same dataset, then
             * we want to sort them according to creation time.  We
             * use the hidden CREATETXG property to get an absolute
             * ordering of snapshots.
             */
            lcreate = zfs_prop_get_int(l, ZFS_PROP_CREATETXG);
            rcreate = zfs_prop_get_int(r, ZFS_PROP_CREATETXG);

            /*
             * Both lcreate and rcreate being 0 means we don't have
             * properties and we should compare full name.
             */
            if (lcreate == 0 && rcreate == 0)
                ret = strcmp(lat + 1, rat + 1);
            else if (lcreate < rcreate)
                ret = -1;
            else if (lcreate > rcreate)
                ret = 1;
        }
    }

    if (lat != NULL)
        *lat = '@';
    if (rat != NULL)
        *rat = '@';

    return (ret);
}

/*
 * Sort datasets by specified columns.
 *
 * o  Numeric types sort in ascending order.
 * o  String types sort in alphabetical order.
 * o  Types inappropriate for a row sort that row to the literal
 *    bottom, regardless of the specified ordering.
 *
 * If no sort columns are specified, or two datasets compare equally
 * across all specified columns, they are sorted alphabetically by name
 * with snapshots grouped under their parents.
 */
static int
zfs_sort(const void *larg, const void *rarg, void *data)
{
    zfs_handle_t *l = ((zfs_node_t *)larg)->zn_handle;
    zfs_handle_t *r = ((zfs_node_t *)rarg)->zn_handle;
    zfs_sort_column_t *sc = (zfs_sort_column_t *)data;
    zfs_sort_column_t *psc;

    for (psc = sc; psc != NULL; psc = psc->sc_next) {
        char lbuf[ZFS_MAXPROPLEN], rbuf[ZFS_MAXPROPLEN];
        char *lstr, *rstr;
        uint64_t lnum, rnum;
        boolean_t lvalid, rvalid;
        int ret = 0;

        /*
         * We group the checks below the generic code.  If 'lstr' and
         * 'rstr' are non-NULL, then we do a string based comparison.
         * Otherwise, we compare 'lnum' and 'rnum'.
         */
        lstr = rstr = NULL;
        if (psc->sc_prop == ZPROP_INVAL) {
            nvlist_t *luser, *ruser;
            nvlist_t *lval, *rval;

            luser = zfs_get_user_props(l);
            ruser = zfs_get_user_props(r);

            lvalid = (nvlist_lookup_nvlist(luser,
                psc->sc_user_prop, &lval) == 0);
            rvalid = (nvlist_lookup_nvlist(ruser,
                psc->sc_user_prop, &rval) == 0);

            if (lvalid)
                verify(nvlist_lookup_string(lval,
                    ZPROP_VALUE, &lstr) == 0);
            if (rvalid)
                verify(nvlist_lookup_string(rval,
                    ZPROP_VALUE, &rstr) == 0);
        } else if (psc->sc_prop == ZFS_PROP_NAME) {
            lvalid = rvalid = B_TRUE;

            (void) strlcpy(lbuf, zfs_get_name(l), sizeof (lbuf));
            (void) strlcpy(rbuf, zfs_get_name(r), sizeof (rbuf));

            lstr = lbuf;
            rstr = rbuf;
        } else if (zfs_prop_is_string(psc->sc_prop)) {
            lvalid = (zfs_prop_get(l, psc->sc_prop, lbuf,
                sizeof (lbuf), NULL, NULL, 0, B_TRUE) == 0);
            rvalid = (zfs_prop_get(r, psc->sc_prop, rbuf,
                sizeof (rbuf), NULL, NULL, 0, B_TRUE) == 0);

            lstr = lbuf;
            rstr = rbuf;
        } else {
            lvalid = zfs_prop_valid_for_type(psc->sc_prop,
                zfs_get_type(l));
            rvalid = zfs_prop_valid_for_type(psc->sc_prop,
                zfs_get_type(r));

            if (lvalid)
                (void) zfs_prop_get_numeric(l, psc->sc_prop,
                    &lnum, NULL, NULL, 0);
            if (rvalid)
                (void) zfs_prop_get_numeric(r, psc->sc_prop,
                    &rnum, NULL, NULL, 0);
        }

        if (!lvalid && !rvalid)
            continue;
        else if (!lvalid)
            return (1);
        else if (!rvalid)
            return (-1);

        if (lstr)
            ret = strcmp(lstr, rstr);
        else if (lnum < rnum)
            ret = -1;
        else if (lnum > rnum)
            ret = 1;

        if (ret != 0) {
            if (psc->sc_reverse == B_TRUE)
                ret = (ret < 0) ? 1 : -1;
            return (ret);
        }
    }

    return (zfs_compare(larg, rarg, NULL));
}

int
zfs_for_each(int argc, char **argv, int flags, zfs_type_t types,
    zfs_sort_column_t *sortcol, zprop_list_t **proplist, int limit,
    zfs_iter_f callback, void *data)
{
    callback_data_t cb = {0};
    int ret = 0;
    zfs_node_t *node;
    uu_avl_walk_t *walk;

    avl_pool = uu_avl_pool_create("zfs_pool", sizeof (zfs_node_t),
        offsetof(zfs_node_t, zn_avlnode), zfs_sort, UU_DEFAULT);

    if (avl_pool == NULL)
        nomem();

    cb.cb_sortcol = sortcol;
    cb.cb_flags = flags;
    cb.cb_proplist = proplist;
    cb.cb_types = types;
    cb.cb_depth_limit = limit;
    /*
     * If cb_proplist is provided then in the zfs_handles created we
     * retain only those properties listed in cb_proplist and sortcol.
     * The rest are pruned. So, the caller should make sure that no other
     * properties other than those listed in cb_proplist/sortcol are
     * accessed.
     *
     * If cb_proplist is NULL then we retain all the properties.  We
     * always retain the zoned property, which some other properties
     * need (userquota & friends), and the createtxg property, which
     * we need to sort snapshots.
     */
    if (cb.cb_proplist && *cb.cb_proplist) {
        zprop_list_t *p = *cb.cb_proplist;

        while (p) {
            if (p->pl_prop >= ZFS_PROP_TYPE &&
                p->pl_prop < ZFS_NUM_PROPS) {
                cb.cb_props_table[p->pl_prop] = B_TRUE;
            }
            p = p->pl_next;
        }

        while (sortcol) {
            if (sortcol->sc_prop >= ZFS_PROP_TYPE &&
                sortcol->sc_prop < ZFS_NUM_PROPS) {
                cb.cb_props_table[sortcol->sc_prop] = B_TRUE;
            }
            sortcol = sortcol->sc_next;
        }

        cb.cb_props_table[ZFS_PROP_ZONED] = B_TRUE;
        cb.cb_props_table[ZFS_PROP_CREATETXG] = B_TRUE;
    } else {
        (void) memset(cb.cb_props_table, B_TRUE,
            sizeof (cb.cb_props_table));
    }

    if ((cb.cb_avl = uu_avl_create(avl_pool, NULL, UU_DEFAULT)) == NULL)
        nomem();

    if (argc == 0) {
        /*
         * If given no arguments, iterate over all datasets.
         */
        cb.cb_flags |= ZFS_ITER_RECURSE;
        ret = zfs_iter_root(g_zfs, zfs_callback, &cb);
    } else {
        int i;
        zfs_handle_t *zhp;
        zfs_type_t argtype;

        /*
         * If we're recursive, then we always allow filesystems as
         * arguments.  If we also are interested in snapshots, then we
         * can take volumes as well.
         */
        argtype = types;
        if (flags & ZFS_ITER_RECURSE) {
            argtype |= ZFS_TYPE_FILESYSTEM;
            if (types & ZFS_TYPE_SNAPSHOT)
                argtype |= ZFS_TYPE_VOLUME;
        }

        for (i = 0; i < argc; i++) {
            if (flags & ZFS_ITER_ARGS_CAN_BE_PATHS) {
                zhp = zfs_path_to_zhandle(g_zfs, argv[i],
                    argtype);
            } else {
                zhp = zfs_open(g_zfs, argv[i], argtype);
            }
            if (zhp != NULL)
                ret |= zfs_callback(zhp, &cb);
            else
                ret = 1;
        }
    }

    /*
     * At this point we've got our AVL tree full of zfs handles, so iterate
     * over each one and execute the real user callback.
     */
    for (node = uu_avl_first(cb.cb_avl); node != NULL;
        node = uu_avl_next(cb.cb_avl, node))
        ret |= callback(node->zn_handle, data);

    /*
     * Finally, clean up the AVL tree.
     */
    if ((walk = uu_avl_walk_start(cb.cb_avl, UU_WALK_ROBUST)) == NULL)
        nomem();

    while ((node = uu_avl_walk_next(walk)) != NULL) {
        uu_avl_remove(cb.cb_avl, node);
        zfs_close(node->zn_handle);
        free(node);
    }

    uu_avl_walk_end(walk);
    uu_avl_destroy(cb.cb_avl);
    uu_avl_pool_destroy(avl_pool);

    return (ret);
}