format.h

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/*
 * Copyright (c) 2014-2020 Seagate Technology LLC and/or its Affiliates
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * For any questions about this software or licensing,
 * please email opensource@seagate.com or cortx-questions@seagate.com.
 *
 */

#pragma once
#ifndef __MOTR_FORMAT_FORMAT_H__
#define __MOTR_FORMAT_FORMAT_H__

#include "lib/types.h"  /* uint64_t */
#include "lib/misc.h"   /* M0_FIELD_VALUE */
#include "lib/mutex.h"
#include "lib/rwlock.h"
#include "lib/chan.h"   /* m0_clink */

struct m0_format_header {
        uint64_t hd_magic;
        uint64_t hd_bits;
} M0_XCA_RECORD M0_XCA_DOMAIN(be|rpc);

struct m0_format_footer {
        uint64_t ft_magic;
        uint64_t ft_checksum;
} M0_XCA_RECORD M0_XCA_DOMAIN(be|rpc);

struct m0_format_tag {
        uint16_t ot_version;
        uint16_t ot_type;
        union {
                /*
                 * these are aliases to support different semantics of this
                 * field:
                 *
                 *   size   - can be used when header and footer don't belong
                 *            to the same container struct
                 *   offset - can be used when header and footer contained
                 *            withing the same struct
                 */
                uint32_t ot_size;
                uint32_t ot_footer_offset;
                /* NOTE: size and offset measured in bytes */
        };
};

enum m0_format_type {
        /*
         * ORDER MATTERS!!!
         * Never rearrange items, add new at the end before placeholder
         */
        M0_FORMAT_TYPE_BEGIN = 1,
        M0_FORMAT_TYPE_RPC_PACKET = M0_FORMAT_TYPE_BEGIN,
        M0_FORMAT_TYPE_RPC_ITEM,
        M0_FORMAT_TYPE_BE_BTREE,
        M0_FORMAT_TYPE_BE_BNODE,
        M0_FORMAT_TYPE_BE_EMAP_KEY,
        M0_FORMAT_TYPE_BE_EMAP_REC,
        M0_FORMAT_TYPE_BE_EMAP,
        M0_FORMAT_TYPE_BE_LIST,
        M0_FORMAT_TYPE_BE_SEG_HDR,
        M0_FORMAT_TYPE_BALLOC,
        M0_FORMAT_TYPE_ADDB2_FRAME_HEADER,
        M0_FORMAT_TYPE_STOB_AD_0TYPE_REC,
        M0_FORMAT_TYPE_STOB_AD_DOMAIN,
        M0_FORMAT_TYPE_COB_DOMAIN,
        M0_FORMAT_TYPE_COB_NSREC,
        M0_FORMAT_TYPE_BALLOC_GROUP_DESC,
        M0_FORMAT_TYPE_EXT,
        M0_FORMAT_TYPE_CAS_INDEX, /* Unused */
        M0_FORMAT_TYPE_POOLNODE,
        M0_FORMAT_TYPE_POOLDEV,
        M0_FORMAT_TYPE_POOL_SPARE_USAGE,
        M0_FORMAT_TYPE_CAS_STATE,
        M0_FORMAT_TYPE_CAS_CTG,

        /* ---> new items go here <--- */

        /* format types counter */
        M0_FORMAT_TYPE_NR
} M0_XCA_ENUM;

/* format type IDs should fit into m0_format_tag::ot_type */
M0_BASSERT(M0_FORMAT_TYPE_NR < UINT16_MAX);

M0_INTERNAL void m0_format_header_pack(struct m0_format_header *dest,
                                       const struct m0_format_tag *src);

M0_INTERNAL void m0_format_header_unpack(struct m0_format_tag *dest,
                                         const struct m0_format_header *src);

M0_INTERNAL void m0_format_footer_generate(struct m0_format_footer *footer,
                                           const void              *buffer,
                                           uint32_t                 size);

M0_INTERNAL void m0_format_footer_update(const void *buffer);

M0_INTERNAL int m0_format_footer_verify_generic(
                        const struct m0_format_footer *footer,
                        const void                    *buffer,
                        uint32_t                       size,
                        bool                           iem);

M0_INTERNAL int m0_format_footer_verify(const void *buffer, bool iem);

#ifdef FORMAT_BE_STRUCT_CONVERTED

/*
 * Kernel doesn't store BE structure to a persistent storage. Therefore,
 * padding doesn't have to be the same for kernelspace and ondisk format.
 * Formula is the next: actual size of original structure plus ~20%.
 * Numbers are calculated for debug kernel.
 */
#ifdef __KERNEL__
#define M0_BE_MUTEX_PAD (184 + 56)
#define M0_BE_RWLOCK_PAD (144 + 48)
#define M0_BE_CLINK_PAD (152 + 48)
#else
#define M0_BE_MUTEX_PAD (56 + 16)
#define M0_BE_RWLOCK_PAD (56 + 16)
#define M0_BE_CLINK_PAD (88 + 24)
#endif /* __KERNEL__ */

#else /* !FORMAT_BE_STRUCT_CONVERTED */

/* These values are for "teacake" compatibility. */
#define M0_BE_MUTEX_PAD 168
#define M0_BE_RWLOCK_PAD 144
#define M0_BE_CLINK_PAD sizeof(struct m0_clink)

#endif /* FORMAT_BE_STRUCT_CONVERTED */

struct m0_be_mutex {
        union {
                struct m0_mutex mutex;
                char            pad[M0_BE_MUTEX_PAD];
        } bm_u;
} M0_XCA_BLOB M0_XCA_DOMAIN(be);
M0_BASSERT(sizeof(struct m0_mutex) <=
           sizeof(M0_FIELD_VALUE(struct m0_be_mutex, bm_u.pad)));

struct m0_be_rwlock {
        union {
                struct m0_rwlock rwlock;
                char             pad[M0_BE_RWLOCK_PAD];
        } bl_u;
} M0_XCA_BLOB M0_XCA_DOMAIN(be);
M0_BASSERT(sizeof(struct m0_rwlock) <=
           sizeof(M0_FIELD_VALUE(struct m0_be_rwlock, bl_u.pad)));

struct m0_be_clink {
        union {
                struct m0_clink clink;
                char            pad[M0_BE_CLINK_PAD];
        } bc_u;
} M0_XCA_BLOB M0_XCA_DOMAIN(be);
M0_BASSERT(sizeof(struct m0_clink) <=
           sizeof(M0_FIELD_VALUE(struct m0_be_clink, bc_u.pad)));

struct m0_be_chan {
        struct m0_chan bch_chan;
} M0_XCA_BLOB M0_XCA_DOMAIN(be);

#endif /* __MOTR_FORMAT_FORMAT_H__ */

/*
 *  Local variables:
 *  c-indentation-style: "K&R"
 *  c-basic-offset: 8
 *  tab-width: 8
 *  fill-column: 80
 *  scroll-step: 1
 *  End:
 */
/*
 * vim: tabstop=8 shiftwidth=8 noexpandtab textwidth=80 nowrap
 */