evms_bbr.h

unxi下共享内存的使用

/*
 *
 *   Copyright (c) International Business Machines  Corp., 2000
 *
 *   This program is free software;  you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
 *   the GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program;  if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 */
/*
 * linux/include/linux/evms_bbr.h
 *
 * EVMS Bad Block Relocation Feature kernel header file
 *
 */

#ifndef EVMS_BBR_INCLUDED

#define EVMS_BBR_INCLUDED

#define EVMS_BBR_VERSION_MAJOR            1
#define EVMS_BBR_VERSION_MINOR            0
#define EVMS_BBR_VERSION_PATCHLEVEL       0

#define EVMS_BBR_FEATURE_ID       6
#define EVMS_BBR_SIGNATURE        0x42627246   /* BbrF */

/* The following defines establish the minimum and maximum number of
 * replacement sectors which can be allocated for Bad Block Relocation.
 * Otherwise, 1 replacement sector per MB of disk space is allocated. */
#define EVMS_BBR_ENTRIES_PER_SECT    31 /* Assume sector size is 512 bytes*/
#define EVMS_BBR_LIMIT  4096

#define EVMS_BBR_TABLE_SIGNATURE         0x42627254 /* BbrT */

typedef struct evms_bbr_table_entry_s {
    u_int64_t bad_sect;
    u_int64_t replacement_sect;
} evms_bbr_table_entry_t;

typedef struct evms_bbr_table_s {
    u_int32_t signature;                /* Signature for a sector of the bbr table (EVMS_BBR_TABLE_SIGNATURE) */
    u_int32_t crc;                      /* CRC for this sector of the BBR Table. */
    u_int32_t sequence_number;          /* Used to resolve conflicts when the primary and secondary tables do not match. */
    u_int32_t in_use_cnt;               /* number of in-use entries */
    evms_bbr_table_entry_t entries[EVMS_BBR_ENTRIES_PER_SECT];   /* BBR table entries available for this sector of the BBR table */
} evms_bbr_table_t;

/* description of on disk meta data sector for bbr feature */
typedef struct evms_bbr_metadata_s {
/* 0*/        u_int32_t signature;                /* EVMS_BBR_SIGNATURE */
/* 4*/        u_int32_t crc;
/* 8*/        u_int32_t block_size;               /* block size in bytes */
/*12*/        u_int32_t flags;                    /* Global flag used by BBR */
/*16*/        u_int64_t sequence_number;
/*24*/        u_int64_t start_sect_bbr_table;     /* start 64-bit LBA of the BBR table */
/*32*/        u_int64_t nr_sects_bbr_table;       /* number of sectors to hold the BBR table */
/*40*/        u_int64_t start_replacement_sect;   /* start 64-bit LBA of the replacement sectors */
/*48*/        u_int64_t nr_replacement_blks;      /* number of replacement blocks. */
/*56*/        char      pads[456];                /* padding for 512-byte sector alignment */
} evms_bbr_metadata_t;


// BBR direct ioctl commands.
#define BBR_GET_INFO_CMD	1	// Return the total number of sectors
					// that are currently remapped for the
					// bbr object.
#define BBR_STOP_REMAP_CMD	2	// Stop ... do not remap any new sectors
					// or even honor any existing remaps for
					// the bbr object until after the next
					// rediscover command is received.
#define BBR_SECTOR_IO_CMD	3	// Process an I/O from the engine directly
					// through the bbr object.

typedef struct evms_notify_bbr_s {
	char		object_name[EVMS_VOLUME_NAME_SIZE+1];	// Input  - Name of bbr object from feature header
	u_int64_t	count;		// Output - Count of remapped sectors
	u_int64_t	start_sect;	// Input - Starting sector for sector_io
	u_int64_t	nr_sect;	// Input - Number of sectors for sector_io
	unsigned long	buffer;		// Input - Pointer to buffer for sector_io
	int		rw;		// Input - READ or WRITE for sector_io
} evms_notify_bbr_t;



#endif