Archipelago » blktap-utils

/* 

 * Copyright (c) 2008, XenSource Inc.

 * All rights reserved.

 *

 * 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 XenSource 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

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 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 */

#ifndef _TAPDISK_IMAGE_H_

#define _TAPDISK_IMAGE_H_

#include "tapdisk.h"

struct td_image_handle {

        int                          type;

        char                        *name;

        td_flag_t                    flags;

        td_driver_t                 *driver;

        td_disk_info_t               info;

        struct list_head             next;

        /*

         * Basic datapath statistics, in sectors read/written.

         *

         * hits:  requests completed by this image.

         * fail:  requests completed with failure by this image.

         *

         * Not that we do not count e.g.

         * miss:  requests forwarded.

         * total: requests processed by this image.

         *

         * This is because we'd have to compensate for restarts due to

         * -EBUSY conditions. Those can be extrapolated by following

         * the chain instead: sum(image[i].hits, i=0..) == vbd.secs;

         */

        struct {

                td_sector_count_t    hits;

                td_sector_count_t    fail;

        } stats;

};

#define tapdisk_for_each_image(_image, _head)                        \

        list_for_each_entry(_image, _head, next)

#define tapdisk_for_each_image_safe(_image, _next, _head)        \

        list_for_each_entry_safe(_image, _next, _head, next)

#define tapdisk_for_each_image_reverse(_image, _head)                \

        list_for_each_entry_reverse(_image, _head, next)

#define tapdisk_image_entry(_head)                \

        list_entry(_head, td_image_t, next)

int tapdisk_image_open(int, const char *, int, td_image_t **);

void tapdisk_image_close(td_image_t *);

int tapdisk_image_open_chain(const char *, int, int, struct list_head *);

void tapdisk_image_close_chain(struct list_head *);

int tapdisk_image_validate_chain(struct list_head *);

td_image_t *tapdisk_image_allocate(const char *, int, td_flag_t);

void tapdisk_image_free(td_image_t *);

int tapdisk_image_check_td_request(td_image_t *, td_request_t);

int tapdisk_image_check_request(td_image_t *, struct td_vbd_request *);

void tapdisk_image_stats(td_image_t *, td_stats_t *);

#endif