8354 sync regcomp(3C) with upstream (fix make catalog)

[unleashed/tickless.git] / usr / src / cmd / svc / configd / object.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 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#pragma ident   "%Z%%M% %I%     %E% SMI"

/*
 * This file only contains the transaction commit logic.
 */

#include <assert.h>
#include <alloca.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <strings.h>
#include <sys/sysmacros.h>
#include "configd.h"

#define INVALID_OBJ_ID ((uint32_t)-1)
#define INVALID_TYPE ((uint32_t)-1)

struct tx_cmd {
        const struct rep_protocol_transaction_cmd *tx_cmd;
        const char      *tx_prop;
        uint32_t        *tx_values;
        uint32_t        tx_nvalues;
        uint32_t        tx_orig_value_id;
        char            tx_found;
        char            tx_processed;
        char            tx_bad;
};

static int
tx_cmd_compare(const void *key, const void *elem_arg)
{
        const struct tx_cmd *elem = elem_arg;

        return (strcmp((const char *)key, elem->tx_prop));
}

struct tx_commit_data {
        uint32_t        txc_pg_id;
        uint32_t        txc_gen;
        uint32_t        txc_oldgen;
        short           txc_backend;
        backend_tx_t    *txc_tx;
        backend_query_t *txc_inserts;
        size_t          txc_count;
        rep_protocol_responseid_t txc_result;
        struct tx_cmd   txc_cmds[1];            /* actually txc_count */
};
#define TX_COMMIT_DATA_SIZE(count) \
        offsetof(struct tx_commit_data, txc_cmds[count])

/*ARGSUSED*/
static int
tx_check_genid(void *data_arg, int columns, char **vals, char **names)
{
        tx_commit_data_t *data = data_arg;
        assert(columns == 1);
        if (atoi(vals[0]) != data->txc_oldgen)
                data->txc_result = REP_PROTOCOL_FAIL_NOT_LATEST;
        else
                data->txc_result = REP_PROTOCOL_SUCCESS;
        return (BACKEND_CALLBACK_CONTINUE);
}

/*
 * tx_process_property() is called once for each property in current
 * property group generation.  Its purpose is threefold:
 *
 *      1. copy properties not mentioned in the transaction over unchanged.
 *      2. mark DELETEd properties as seen (they will be left out of the new
 *         generation).
 *      3. consistancy-check NEW, CLEAR, and REPLACE commands.
 *
 * Any consistancy problems set tx_bad, and seen properties are marked
 * tx_found.  These is used later, in tx_process_cmds().
 */
/*ARGSUSED*/
static int
tx_process_property(void *data_arg, int columns, char **vals, char **names)
{
        tx_commit_data_t *data = data_arg;
        struct tx_cmd *elem;

        const char *prop_name = vals[0];
        const char *prop_type = vals[1];
        const char *lnk_val_id = vals[2];

        char *endptr;

        assert(columns == 3);

        elem = bsearch(prop_name, data->txc_cmds, data->txc_count,
            sizeof (*data->txc_cmds), tx_cmd_compare);

        if (elem == NULL) {
                backend_query_add(data->txc_inserts,
                    "INSERT INTO prop_lnk_tbl"
                    "    (lnk_pg_id, lnk_gen_id, lnk_prop_name, lnk_prop_type,"
                    "    lnk_val_id) "
                    "VALUES ( %d, %d, '%q', '%q', %Q );",
                    data->txc_pg_id, data->txc_gen, prop_name, prop_type,
                    lnk_val_id);
        } else {
                assert(!elem->tx_found);
                elem->tx_found = 1;

                if (lnk_val_id != NULL) {
                        errno = 0;
                        elem->tx_orig_value_id =
                            strtoul(lnk_val_id, &endptr, 10);
                        if (elem->tx_orig_value_id == 0 || *endptr != 0 ||
                            errno != 0) {
                                return (BACKEND_CALLBACK_ABORT);
                        }
                } else {
                        elem->tx_orig_value_id = 0;
                }

                switch (elem->tx_cmd->rptc_action) {
                case REP_PROTOCOL_TX_ENTRY_NEW:
                        elem->tx_bad = 1;
                        data->txc_result = REP_PROTOCOL_FAIL_EXISTS;
                        break;
                case REP_PROTOCOL_TX_ENTRY_CLEAR:
                        if (REP_PROTOCOL_BASE_TYPE(elem->tx_cmd->rptc_type) !=
                            prop_type[0] &&
                            REP_PROTOCOL_SUBTYPE(elem->tx_cmd->rptc_type) !=
                            prop_type[1]) {
                                elem->tx_bad = 1;
                                data->txc_result =
                                    REP_PROTOCOL_FAIL_TYPE_MISMATCH;
                        }
                        break;
                case REP_PROTOCOL_TX_ENTRY_REPLACE:
                        break;
                case REP_PROTOCOL_TX_ENTRY_DELETE:
                        elem->tx_processed = 1;
                        break;
                default:
                        assert(0);
                        break;
                }
        }
        return (BACKEND_CALLBACK_CONTINUE);
}

/*
 * tx_process_cmds() finishes the job tx_process_property() started:
 *
 *      1. if tx_process_property() marked a command as bad, we skip it.
 *      2. if a DELETE, REPLACE, or CLEAR operated on a non-existant property,
 *          we mark it as bad.
 *      3. we complete the work of NEW, REPLACE, and CLEAR, by inserting the
 *          appropriate values into the database.
 *      4. we delete all replaced data, if it is no longer referenced.
 *
 * Finally, we check all of the commands, and fail if anything was marked bad.
 */
static int
tx_process_cmds(tx_commit_data_t *data)
{
        int idx;
        int r;
        int count = data->txc_count;
        struct tx_cmd *elem;
        uint32_t val_id = 0;
        uint8_t type[3];

        backend_query_t *q;
        int do_delete;

        /*
         * For persistent pgs, we use backend_fail_if_seen to abort the
         * deletion if there is a snapshot using our current state.
         *
         * All of the deletions in this function are safe, since
         * rc_tx_commit() guarantees that all the data is in-cache.
         */
        q = backend_query_alloc();

        if (data->txc_backend != BACKEND_TYPE_NONPERSIST) {
                backend_query_add(q,
                    "SELECT 1 FROM snaplevel_lnk_tbl "
                    "    WHERE (snaplvl_pg_id = %d AND snaplvl_gen_id = %d); ",
                    data->txc_pg_id, data->txc_oldgen);
        }
        backend_query_add(q,
            "DELETE FROM prop_lnk_tbl"
            "    WHERE (lnk_pg_id = %d AND lnk_gen_id = %d)",
            data->txc_pg_id, data->txc_oldgen);
        r = backend_tx_run(data->txc_tx, q, backend_fail_if_seen, NULL);
        backend_query_free(q);

        if (r == REP_PROTOCOL_SUCCESS)
                do_delete = 1;
        else if (r == REP_PROTOCOL_DONE)
                do_delete = 0;          /* old gen_id is in use */
        else
                return (r);

        for (idx = 0; idx < count; idx++) {
                elem = &data->txc_cmds[idx];

                if (elem->tx_bad)
                        continue;

                switch (elem->tx_cmd->rptc_action) {
                case REP_PROTOCOL_TX_ENTRY_DELETE:
                case REP_PROTOCOL_TX_ENTRY_REPLACE:
                case REP_PROTOCOL_TX_ENTRY_CLEAR:
                        if (!elem->tx_found) {
                                elem->tx_bad = 1;
                                continue;
                        }
                        break;
                case REP_PROTOCOL_TX_ENTRY_NEW:
                        break;
                default:
                        assert(0);
                        break;
                }

                if (do_delete &&
                    elem->tx_cmd->rptc_action != REP_PROTOCOL_TX_ENTRY_NEW &&
                    elem->tx_orig_value_id != 0) {
                        /*
                         * delete the old values, if they are not in use
                         */
                        q = backend_query_alloc();
                        backend_query_add(q,
                            "SELECT 1 FROM prop_lnk_tbl "
                            "    WHERE (lnk_val_id = %d); "
                            "DELETE FROM value_tbl"
                            "    WHERE (value_id = %d)",
                            elem->tx_orig_value_id, elem->tx_orig_value_id);
                        r = backend_tx_run(data->txc_tx, q,
                            backend_fail_if_seen, NULL);
                        backend_query_free(q);
                        if (r != REP_PROTOCOL_SUCCESS && r != REP_PROTOCOL_DONE)
                                return (r);
                }

                if (elem->tx_cmd->rptc_action == REP_PROTOCOL_TX_ENTRY_DELETE)
                        continue;               /* no further work to do */

                type[0] = REP_PROTOCOL_BASE_TYPE(elem->tx_cmd->rptc_type);
                type[1] = REP_PROTOCOL_SUBTYPE(elem->tx_cmd->rptc_type);
                type[2] = 0;

                if (elem->tx_nvalues == 0) {
                        r = backend_tx_run_update(data->txc_tx,
                            "INSERT INTO prop_lnk_tbl"
                            "    (lnk_pg_id, lnk_gen_id, "
                            "    lnk_prop_name, lnk_prop_type, lnk_val_id) "
                            "VALUES ( %d, %d, '%q', '%q', NULL );",
                            data->txc_pg_id, data->txc_gen, elem->tx_prop,
                            type);
                } else {
                        uint32_t *v, i = 0;
                        const char *str;

                        val_id = backend_new_id(data->txc_tx, BACKEND_ID_VALUE);
                        if (val_id == 0)
                                return (REP_PROTOCOL_FAIL_NO_RESOURCES);
                        r = backend_tx_run_update(data->txc_tx,
                            "INSERT INTO prop_lnk_tbl "
                            "    (lnk_pg_id, lnk_gen_id, "
                            "    lnk_prop_name, lnk_prop_type, lnk_val_id) "
                            "VALUES ( %d, %d, '%q', '%q', %d );",
                            data->txc_pg_id, data->txc_gen, elem->tx_prop,
                            type, val_id);

                        v = elem->tx_values;

                        for (i = 0; i < elem->tx_nvalues; i++) {
                                str = (const char *)&v[1];

                                /*
                                 * Update values in backend,  imposing
                                 * ordering via the value_order column.
                                 * This ordering is then used in subseqent
                                 * value retrieval operations.  We can
                                 * safely assume that the repository schema
                                 * has been upgraded (and hence has the
                                 * value_order column in value_tbl),  since
                                 * it is upgraded as soon as the repository
                                 * is writable.
                                 */
                                r = backend_tx_run_update(data->txc_tx,
                                    "INSERT INTO value_tbl (value_id, "
                                    "value_type, value_value, "
                                    "value_order) VALUES (%d, '%c', "
                                    "'%q', '%d');\n",
                                    val_id, elem->tx_cmd->rptc_type,
                                    str, i);
                                if (r != REP_PROTOCOL_SUCCESS)
                                        break;

                                /*LINTED alignment*/
                                v = (uint32_t *)((caddr_t)str + TX_SIZE(*v));
                        }
                }
                if (r != REP_PROTOCOL_SUCCESS)
                        return (REP_PROTOCOL_FAIL_UNKNOWN);
                elem->tx_processed = 1;
        }

        for (idx = 0; idx < count; idx++) {
                elem = &data->txc_cmds[idx];

                if (elem->tx_bad)
                        return (REP_PROTOCOL_FAIL_BAD_TX);
        }
        return (REP_PROTOCOL_SUCCESS);
}

static boolean_t
check_string(uintptr_t loc, uint32_t len, uint32_t sz)
{
        const char *ptr = (const char *)loc;

        if (len == 0 || len > sz || ptr[len - 1] != 0 || strlen(ptr) != len - 1)
                return (0);
        return (1);
}

static int
tx_check_and_setup(tx_commit_data_t *data, const void *cmds_arg,
    uint32_t count)
{
        const struct rep_protocol_transaction_cmd *cmds;
        struct tx_cmd *cur;
        struct tx_cmd *prev = NULL;

        uintptr_t loc;
        uint32_t sz, len;
        int idx;

        loc = (uintptr_t)cmds_arg;

        for (idx = 0; idx < count; idx++) {
                cur = &data->txc_cmds[idx];

                cmds = (struct rep_protocol_transaction_cmd *)loc;
                cur->tx_cmd = cmds;

                sz = cmds->rptc_size;

                loc += REP_PROTOCOL_TRANSACTION_CMD_MIN_SIZE;
                sz -= REP_PROTOCOL_TRANSACTION_CMD_MIN_SIZE;

                len = cmds->rptc_name_len;
                if (len <= 1 || !check_string(loc, len, sz)) {
                        return (REP_PROTOCOL_FAIL_BAD_REQUEST);
                }
                cur->tx_prop = (const char *)loc;

                len = TX_SIZE(len);
                loc += len;
                sz -= len;

                cur->tx_nvalues = 0;
                cur->tx_values = (uint32_t *)loc;

                while (sz > 0) {
                        if (sz < sizeof (uint32_t))
                                return (REP_PROTOCOL_FAIL_BAD_REQUEST);

                        cur->tx_nvalues++;

                        len = *(uint32_t *)loc;
                        loc += sizeof (uint32_t);
                        sz -= sizeof (uint32_t);

                        if (!check_string(loc, len, sz))
                                return (REP_PROTOCOL_FAIL_BAD_REQUEST);

                        /*
                         * XXX here, we should be checking that the values
                         * match the purported type
                         */

                        len = TX_SIZE(len);

                        if (len > sz)
                                return (REP_PROTOCOL_FAIL_BAD_REQUEST);

                        loc += len;
                        sz -= len;
                }

                if (prev != NULL && strcmp(prev->tx_prop, cur->tx_prop) >= 0)
                        return (REP_PROTOCOL_FAIL_BAD_REQUEST);

                prev = cur;
        }
        return (REP_PROTOCOL_SUCCESS);
}

/*
 * Free the memory associated with a tx_commit_data structure.
 */
void
tx_commit_data_free(tx_commit_data_t *tx_data)
{
        uu_free(tx_data);
}

/*
 * Parse the data of a REP_PROTOCOL_PROPERTYGRP_TX_COMMIT message into a
 * more useful form.  The data in the message will be represented by a
 * tx_commit_data_t structure which is allocated by this function.  The
 * address of the allocated structure is returned to *tx_data and must be
 * freed by calling tx_commit_data_free().
 *
 * Parameters:
 *      cmds_arg        Address of the commands in the
 *                      REP_PROTOCOL_PROPERTYGRP_TX_COMMIT message.
 *
 *      cmds_sz         Number of message bytes at cmds_arg.
 *
 *      tx_data         Points to the place to receive the address of the
 *                      allocated memory.
 *
 * Fails with
 *      _BAD_REQUEST
 *      _NO_RESOURCES
 */
int
tx_commit_data_new(const void *cmds_arg, size_t cmds_sz,
    tx_commit_data_t **tx_data)
{
        const struct rep_protocol_transaction_cmd *cmds;
        tx_commit_data_t *data;
        uintptr_t loc;
        uint32_t count;
        uint32_t sz;
        int ret;

        /*
         * First, verify that the reported sizes make sense, and count
         * the number of commands.
         */
        count = 0;
        loc = (uintptr_t)cmds_arg;

        while (cmds_sz > 0) {
                cmds = (struct rep_protocol_transaction_cmd *)loc;

                if (cmds_sz <= REP_PROTOCOL_TRANSACTION_CMD_MIN_SIZE)
                        return (REP_PROTOCOL_FAIL_BAD_REQUEST);

                sz = cmds->rptc_size;
                if (sz <= REP_PROTOCOL_TRANSACTION_CMD_MIN_SIZE)
                        return (REP_PROTOCOL_FAIL_BAD_REQUEST);

                sz = TX_SIZE(sz);
                if (sz > cmds_sz)
                        return (REP_PROTOCOL_FAIL_BAD_REQUEST);

                loc += sz;
                cmds_sz -= sz;
                count++;
        }

        data = uu_zalloc(TX_COMMIT_DATA_SIZE(count));
        if (data == NULL)
                return (REP_PROTOCOL_FAIL_NO_RESOURCES);

        /*
         * verify that everything looks okay, and set up our command
         * datastructures.
         */
        data->txc_count = count;
        ret = tx_check_and_setup(data, cmds_arg, count);
        if (ret == REP_PROTOCOL_SUCCESS) {
                *tx_data = data;
        } else {
                *tx_data = NULL;
                uu_free(data);
        }
        return (ret);
}

/*
 * The following are a set of accessor functions to retrieve data from a
 * tx_commit_data_t that has been allocated by tx_commit_data_new().
 */

/*
 * Return the action of the transaction command whose command number is
 * cmd_no.  The action is placed at *action.
 *
 * Returns:
 *      _FAIL_BAD_REQUEST       cmd_no is out of range.
 */
int
tx_cmd_action(tx_commit_data_t *tx_data, size_t cmd_no,
    enum rep_protocol_transaction_action *action)
{
        struct tx_cmd *cur;

        assert(cmd_no < tx_data->txc_count);
        if (cmd_no >= tx_data->txc_count)
                return (REP_PROTOCOL_FAIL_BAD_REQUEST);

        cur = &tx_data->txc_cmds[cmd_no];
        *action = cur->tx_cmd->rptc_action;
        return (REP_PROTOCOL_SUCCESS);
}

/*
 * Return the number of transaction commands held in tx_data.
 */
size_t
tx_cmd_count(tx_commit_data_t *tx_data)
{
        return (tx_data->txc_count);
}

/*
 * Return the number of property values that are associated with the
 * transaction command whose number is cmd_no.  The number of values is
 * returned to *nvalues.
 *
 * Returns:
 *      _FAIL_BAD_REQUEST       cmd_no is out of range.
 */
int
tx_cmd_nvalues(tx_commit_data_t *tx_data, size_t cmd_no, uint32_t *nvalues)
{
        struct tx_cmd *cur;

        assert(cmd_no < tx_data->txc_count);
        if (cmd_no >= tx_data->txc_count)
                return (REP_PROTOCOL_FAIL_BAD_REQUEST);

        cur = &tx_data->txc_cmds[cmd_no];
        *nvalues = cur->tx_nvalues;
        return (REP_PROTOCOL_SUCCESS);
}

/*
 * Return a pointer to the property name of the command whose number is
 * cmd_no.  The property name pointer is returned to *pname.
 *
 * Returns:
 *      _FAIL_BAD_REQUEST       cmd_no is out of range.
 */
int
tx_cmd_prop(tx_commit_data_t *tx_data, size_t cmd_no, const char **pname)
{
        struct tx_cmd *cur;

        assert(cmd_no < tx_data->txc_count);
        if (cmd_no >= tx_data->txc_count)
                return (REP_PROTOCOL_FAIL_BAD_REQUEST);

        cur = &tx_data->txc_cmds[cmd_no];
        *pname = cur->tx_prop;
        return (REP_PROTOCOL_SUCCESS);
}

/*
 * Return the property type of the property whose command number is
 * cmd_no.  The property type is returned to *ptype.
 *
 * Returns:
 *      _FAIL_BAD_REQUEST       cmd_no is out of range.
 */
int
tx_cmd_prop_type(tx_commit_data_t *tx_data, size_t cmd_no, uint32_t *ptype)
{
        struct tx_cmd *cur;

        assert(cmd_no < tx_data->txc_count);
        if (cmd_no >= tx_data->txc_count)
                return (REP_PROTOCOL_FAIL_BAD_REQUEST);

        cur = &tx_data->txc_cmds[cmd_no];
        *ptype = cur->tx_cmd->rptc_type;
        return (REP_PROTOCOL_SUCCESS);
}

/*
 * This function is used to retrieve a property value from the transaction
 * data.  val_no specifies which value is to be retrieved from the
 * transaction command whose number is cmd_no.  A pointer to the specified
 * value is placed in *val.
 *
 * Returns:
 *      _FAIL_BAD_REQUEST       cmd_no or val_no is out of range.
 */
int
tx_cmd_value(tx_commit_data_t *tx_data, size_t cmd_no, uint32_t val_no,
    const char **val)
{
        const char *bp;
        struct tx_cmd *cur;
        uint32_t i;
        uint32_t value_len;

        assert(cmd_no < tx_data->txc_count);
        if (cmd_no >= tx_data->txc_count)
                return (REP_PROTOCOL_FAIL_BAD_REQUEST);

        cur = &tx_data->txc_cmds[cmd_no];
        assert(val_no < cur->tx_nvalues);
        if (val_no >= cur->tx_nvalues)
                return (REP_PROTOCOL_FAIL_BAD_REQUEST);

        /* Find the correct value */
        bp = (char *)cur->tx_values;
        for (i = 0; i < val_no; i++) {
                /* LINTED alignment */
                value_len = *(uint32_t *)bp;
                bp += sizeof (uint32_t) + TX_SIZE(value_len);
        }

        /* Bypass the count & return pointer to value. */
        bp += sizeof (uint32_t);
        *val = bp;
        return (REP_PROTOCOL_SUCCESS);
}

int
object_tx_commit(rc_node_lookup_t *lp, tx_commit_data_t *data, uint32_t *gen)
{
        uint32_t new_gen;
        int ret;
        rep_protocol_responseid_t r;
        backend_tx_t *tx;
        backend_query_t *q;
        int backend = lp->rl_backend;

        ret = backend_tx_begin(backend, &tx);
        if (ret != REP_PROTOCOL_SUCCESS)
                return (ret);

        /* Make sure the pg is up-to-date. */
        data->txc_oldgen = *gen;
        data->txc_backend = backend;
        data->txc_result = REP_PROTOCOL_FAIL_NOT_FOUND;

        q = backend_query_alloc();
        backend_query_add(q, "SELECT pg_gen_id FROM pg_tbl WHERE (pg_id = %d);",
            lp->rl_main_id);
        r = backend_tx_run(tx, q, tx_check_genid, data);
        backend_query_free(q);

        if (r != REP_PROTOCOL_SUCCESS ||
            (r = data->txc_result) != REP_PROTOCOL_SUCCESS) {
                backend_tx_rollback(tx);
                goto end;
        }

        /* If the transaction is empty, cut out early. */
        if (data->txc_count == 0) {
                backend_tx_rollback(tx);
                r = REP_PROTOCOL_DONE;
                goto end;
        }

        new_gen = backend_new_id(tx, BACKEND_ID_GENERATION);
        if (new_gen == 0) {
                backend_tx_rollback(tx);
                return (REP_PROTOCOL_FAIL_NO_RESOURCES);
        }

        data->txc_pg_id = lp->rl_main_id;
        data->txc_gen = new_gen;
        data->txc_tx = tx;

        r = backend_tx_run_update(tx,
            "UPDATE pg_tbl SET pg_gen_id = %d "
            "    WHERE (pg_id = %d AND pg_gen_id = %d);",
            new_gen, lp->rl_main_id, *gen);

        if (r != REP_PROTOCOL_SUCCESS) {
                backend_tx_rollback(tx);
                goto end;
        }

        q = backend_query_alloc();

        backend_query_add(q,
            "SELECT lnk_prop_name, lnk_prop_type, lnk_val_id "
            "FROM prop_lnk_tbl "
            "WHERE (lnk_pg_id = %d AND lnk_gen_id = %d)",
            lp->rl_main_id, *gen);

        data->txc_inserts = backend_query_alloc();
        r = backend_tx_run(tx, q, tx_process_property, data);
        backend_query_free(q);

        if (r == REP_PROTOCOL_DONE)
                r = REP_PROTOCOL_FAIL_UNKNOWN;          /* corruption */

        if (r != REP_PROTOCOL_SUCCESS ||
            (r = data->txc_result) != REP_PROTOCOL_SUCCESS) {
                backend_query_free(data->txc_inserts);
                backend_tx_rollback(tx);
                goto end;
        }

        r = backend_tx_run(tx, data->txc_inserts, NULL, NULL);
        backend_query_free(data->txc_inserts);

        if (r != REP_PROTOCOL_SUCCESS) {
                backend_tx_rollback(tx);
                goto end;
        }

        r = tx_process_cmds(data);
        if (r != REP_PROTOCOL_SUCCESS) {
                backend_tx_rollback(tx);
                goto end;
        }
        r = backend_tx_commit(tx);

        if (r == REP_PROTOCOL_SUCCESS)
                *gen = new_gen;
end:
        return (r);
}