lib/quorum.c

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/*
 * Copyright (c) 2008-2012 Red Hat, Inc.
 *
 * All rights reserved.
 *
 * Author: Christine Caulfield (ccaulfie@redhat.com)
 *
 * This software licensed under BSD license, the text of which follows:
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * - Redistributions of source code must retain the above copyright notice,
 *   this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright notice,
 *   this list of conditions and the following disclaimer in the documentation
 *   and/or other materials provided with the distribution.
 * - Neither the name of the MontaVista Software, Inc. nor the names of its
 *   contributors may be used to endorse or promote products derived from this
 *   software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGE.
 */
/*
 * Provides a quorum API using the corosync executive
 */
 
#include <config.h>
 
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/uio.h>
#include <errno.h>
 
#include <qb/qbipcc.h>
#include <corosync/corotypes.h>
#include <corosync/corodefs.h>
#include <corosync/hdb.h>
 
#include <corosync/quorum.h>
#include <corosync/ipc_quorum.h>
 
#include "util.h"
 
struct quorum_inst {
        qb_ipcc_connection_t *c;
        int finalize;
        const void *context;
        quorum_callbacks_t callbacks;
};
 
static void quorum_inst_free (void *inst);
 
DECLARE_HDB_DATABASE(quorum_handle_t_db, quorum_inst_free);
 
cs_error_t quorum_initialize (
        quorum_handle_t *handle,
        quorum_callbacks_t *callbacks,
        uint32_t *quorum_type)
{
        cs_error_t error;
        struct quorum_inst *quorum_inst;
        struct iovec iov;
        struct qb_ipc_request_header req;
        struct res_lib_quorum_gettype res_lib_quorum_gettype;
 
        error = hdb_error_to_cs(hdb_handle_create (&quorum_handle_t_db, sizeof (struct quorum_inst), handle));
        if (error != CS_OK) {
                goto error_no_destroy;
        }
 
        error = hdb_error_to_cs(hdb_handle_get (&quorum_handle_t_db, *handle, (void *)&quorum_inst));
        if (error != CS_OK) {
                goto error_destroy;
        }
 
        error = CS_OK;
        quorum_inst->finalize = 0;
        quorum_inst->c = qb_ipcc_connect ("quorum", IPC_REQUEST_SIZE);
        if (quorum_inst->c == NULL) {
                error = qb_to_cs_error(-errno);
                goto error_put_destroy;
        }
 
        req.size = sizeof (req);
        req.id = MESSAGE_REQ_QUORUM_GETTYPE;
 
        iov.iov_base = (char *)&req;
        iov.iov_len = sizeof (req);
 
        error = qb_to_cs_error(qb_ipcc_sendv_recv (
                quorum_inst->c,
                &iov,
                1,
                &res_lib_quorum_gettype,
                sizeof (struct res_lib_quorum_gettype), -1));
 
        if (error != CS_OK) {
                goto error_put_destroy;
        }
 
        error = res_lib_quorum_gettype.header.error;
 
        *quorum_type = res_lib_quorum_gettype.quorum_type;
 
        if (callbacks)
                memcpy(&quorum_inst->callbacks, callbacks, sizeof (*callbacks));
        else
                memset(&quorum_inst->callbacks, 0, sizeof (*callbacks));
 
        (void)hdb_handle_put (&quorum_handle_t_db, *handle);
 
        return (CS_OK);
 
error_put_destroy:
        (void)hdb_handle_put (&quorum_handle_t_db, *handle);
error_destroy:
        (void)hdb_handle_destroy (&quorum_handle_t_db, *handle);
error_no_destroy:
        return (error);
}
 
static void quorum_inst_free (void *inst)
{
        struct quorum_inst *quorum_inst = (struct quorum_inst *)inst;
        qb_ipcc_disconnect(quorum_inst->c);
}
 
cs_error_t quorum_finalize (
        quorum_handle_t handle)
{
        struct quorum_inst *quorum_inst;
        cs_error_t error;
 
        error = hdb_error_to_cs(hdb_handle_get (&quorum_handle_t_db, handle, (void *)&quorum_inst));
        if (error != CS_OK) {
                return (error);
        }
 
        /*
         * Another thread has already started finalizing
         */
        if (quorum_inst->finalize) {
                (void)hdb_handle_put (&quorum_handle_t_db, handle);
                return (CS_ERR_BAD_HANDLE);
        }
 
        quorum_inst->finalize = 1;
 
        (void)hdb_handle_destroy (&quorum_handle_t_db, handle);
 
        (void)hdb_handle_put (&quorum_handle_t_db, handle);
 
        return (CS_OK);
}
 
cs_error_t quorum_getquorate (
        quorum_handle_t handle,
        int *quorate)
{
        cs_error_t error;
        struct quorum_inst *quorum_inst;
        struct iovec iov;
        struct qb_ipc_request_header req;
        struct res_lib_quorum_getquorate res_lib_quorum_getquorate;
 
        error = hdb_error_to_cs(hdb_handle_get (&quorum_handle_t_db, handle, (void *)&quorum_inst));
        if (error != CS_OK) {
                return (error);
        }
 
        req.size = sizeof (req);
        req.id = MESSAGE_REQ_QUORUM_GETQUORATE;
 
        iov.iov_base = (char *)&req;
        iov.iov_len = sizeof (req);
 
        error = qb_to_cs_error(qb_ipcc_sendv_recv (
                quorum_inst->c,
                &iov,
                1,
                &res_lib_quorum_getquorate,
                sizeof (struct res_lib_quorum_getquorate), CS_IPC_TIMEOUT_MS));
 
        if (error != CS_OK) {
                goto error_exit;
        }
 
        error = res_lib_quorum_getquorate.header.error;
 
        *quorate = res_lib_quorum_getquorate.quorate;
 
error_exit:
        (void)hdb_handle_put (&quorum_handle_t_db, handle);
 
        return (error);
}
 
cs_error_t quorum_fd_get (
        quorum_handle_t handle,
        int *fd)
{
        cs_error_t error;
        struct quorum_inst *quorum_inst;
 
        error = hdb_error_to_cs(hdb_handle_get (&quorum_handle_t_db, handle, (void *)&quorum_inst));
        if (error != CS_OK) {
                return (error);
        }
 
        error = qb_to_cs_error(qb_ipcc_fd_get (quorum_inst->c, fd));
 
        (void)hdb_handle_put (&quorum_handle_t_db, handle);
 
        return (error);
}
 
 
cs_error_t quorum_context_get (
        quorum_handle_t handle,
        const void **context)
{
        cs_error_t error;
        struct quorum_inst *quorum_inst;
 
        error = hdb_error_to_cs(hdb_handle_get (&quorum_handle_t_db, handle, (void *)&quorum_inst));
        if (error != CS_OK) {
                return (error);
        }
 
        *context = quorum_inst->context;
 
        (void)hdb_handle_put (&quorum_handle_t_db, handle);
 
        return (CS_OK);
}
 
cs_error_t quorum_context_set (
        quorum_handle_t handle,
        const void *context)
{
        cs_error_t error;
        struct quorum_inst *quorum_inst;
 
        error = hdb_error_to_cs(hdb_handle_get (&quorum_handle_t_db, handle, (void *)&quorum_inst));
        if (error != CS_OK) {
                return (error);
        }
 
        quorum_inst->context = context;
 
        (void)hdb_handle_put (&quorum_handle_t_db, handle);
 
        return (CS_OK);
}
 
 
cs_error_t quorum_trackstart (
        quorum_handle_t handle,
        unsigned int flags )
{
        cs_error_t error;
        struct quorum_inst *quorum_inst;
        struct iovec iov;
        struct req_lib_quorum_trackstart req_lib_quorum_trackstart;
        struct qb_ipc_response_header res;
 
        error = hdb_error_to_cs(hdb_handle_get (&quorum_handle_t_db, handle, (void *)&quorum_inst));
        if (error != CS_OK) {
                return (error);
        }
 
        req_lib_quorum_trackstart.header.size = sizeof (struct req_lib_quorum_trackstart);
        req_lib_quorum_trackstart.header.id = MESSAGE_REQ_QUORUM_TRACKSTART;
        req_lib_quorum_trackstart.track_flags = flags;
 
        iov.iov_base = (char *)&req_lib_quorum_trackstart;
        iov.iov_len = sizeof (struct req_lib_quorum_trackstart);
 
       error = qb_to_cs_error(qb_ipcc_sendv_recv (
                quorum_inst->c,
                &iov,
                1,
                &res,
                sizeof (res), CS_IPC_TIMEOUT_MS));
 
        if (error != CS_OK) {
                goto error_exit;
        }
 
        error = res.error;
 
error_exit:
        (void)hdb_handle_put (&quorum_handle_t_db, handle);
 
        return (error);
}
 
cs_error_t quorum_trackstop (
        quorum_handle_t handle)
{
        cs_error_t error;
        struct quorum_inst *quorum_inst;
        struct iovec iov;
        struct qb_ipc_request_header req;
        struct qb_ipc_response_header res;
 
        error = hdb_error_to_cs(hdb_handle_get (&quorum_handle_t_db, handle, (void *)&quorum_inst));
        if (error != CS_OK) {
                return (error);
        }
 
        req.size = sizeof (req);
        req.id = MESSAGE_REQ_QUORUM_TRACKSTOP;
 
        iov.iov_base = (char *)&req;
        iov.iov_len = sizeof (req);
 
       error = qb_to_cs_error(qb_ipcc_sendv_recv (
                quorum_inst->c,
                &iov,
                1,
                &res,
                sizeof (res), CS_IPC_TIMEOUT_MS));
 
        if (error != CS_OK) {
                goto error_exit;
        }
 
        error = res.error;
 
error_exit:
        (void)hdb_handle_put (&quorum_handle_t_db, handle);
 
        return (error);
}
 
cs_error_t quorum_dispatch (
        quorum_handle_t handle,
        cs_dispatch_flags_t dispatch_types)
{
        int timeout = -1;
        cs_error_t error;
        int cont = 1; /* always continue do loop except when set to 0 */
        struct quorum_inst *quorum_inst;
        quorum_callbacks_t callbacks;
        struct qb_ipc_response_header *dispatch_data;
        char dispatch_buf[IPC_DISPATCH_SIZE];
        struct res_lib_quorum_notification *res_lib_quorum_notification;
 
        if (dispatch_types != CS_DISPATCH_ONE &&
                dispatch_types != CS_DISPATCH_ALL &&
                dispatch_types != CS_DISPATCH_BLOCKING &&
                dispatch_types != CS_DISPATCH_ONE_NONBLOCKING) {
 
                return (CS_ERR_INVALID_PARAM);
        }
 
        error = hdb_error_to_cs(hdb_handle_get (&quorum_handle_t_db, handle,
                (void *)&quorum_inst));
        if (error != CS_OK) {
                return (error);
        }
 
        /*
         * Timeout instantly for CS_DISPATCH_ONE_NONBLOCKING or CS_DISPATCH_ALL and
         * wait indefinately for CS_DISPATCH_ONE or CS_DISPATCH_BLOCKING
         */
        if (dispatch_types == CS_DISPATCH_ALL || dispatch_types == CS_DISPATCH_ONE_NONBLOCKING) {
                timeout = 0;
        }
 
        dispatch_data = (struct qb_ipc_response_header *)dispatch_buf;
        do {
                error = qb_to_cs_error (qb_ipcc_event_recv (
                        quorum_inst->c,
                        dispatch_buf,
                        IPC_DISPATCH_SIZE,
                        timeout));
                if (error == CS_ERR_BAD_HANDLE) {
                        error = CS_OK;
                        goto error_put;
                }
                if (error == CS_ERR_TRY_AGAIN) {
                        if (dispatch_types == CS_DISPATCH_ONE_NONBLOCKING) {
                                /*
                                 * Don't mask error
                                 */
                                goto error_put;
                        }
                        error = CS_OK;
                        if (dispatch_types == CS_DISPATCH_ALL) {
                                break; /* exit do while cont is 1 loop */
                        } else {
                                continue; /* next poll */
                        }
                }
                if (error != CS_OK) {
                        goto error_put;
                }
 
                /*
                 * Make copy of callbacks, message data, unlock instance, and call callback
                 * A risk of this dispatch method is that the callback routines may
                 * operate at the same time that quorum_finalize has been called in another thread.
                 */
                memcpy (&callbacks, &quorum_inst->callbacks, sizeof (quorum_callbacks_t));
                /*
                 * Dispatch incoming message
                 */
                switch (dispatch_data->id) {
 
                case MESSAGE_RES_QUORUM_NOTIFICATION:
                        if (callbacks.quorum_notify_fn == NULL) {
                                break;
                        }
                        res_lib_quorum_notification = (struct res_lib_quorum_notification *)dispatch_data;
 
                        callbacks.quorum_notify_fn ( handle,
                                res_lib_quorum_notification->quorate,
                                res_lib_quorum_notification->ring_seq,
                                res_lib_quorum_notification->view_list_entries,
                                res_lib_quorum_notification->view_list);
                        break;
 
                default:
                        error = CS_ERR_LIBRARY;
                        goto error_put;
                        break;
                }
                if (quorum_inst->finalize) {
                        /*
                         * If the finalize has been called then get out of the dispatch.
                         */
                        error = CS_ERR_BAD_HANDLE;
                        goto error_put;
                }
 
                /*
                 * Determine if more messages should be processed
                 */
                if (dispatch_types == CS_DISPATCH_ONE || dispatch_types == CS_DISPATCH_ONE_NONBLOCKING) {
                        cont = 0;
                }
        } while (cont);
 
error_put:
        (void)hdb_handle_put (&quorum_handle_t_db, handle);
        return (error);
}