linux/fs/xfs/xfs_log_format.h

/*
 * Copyright (c) 2000-2003,2005 Silicon Graphics, Inc.
 * All Rights Reserved.
 *
 * 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.
 *
 * This program is distributed in the hope that it would 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 the Free Software Foundation,
 * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
#ifndef	__XFS_LOG_FORMAT_H__
#define __XFS_LOG_FORMAT_H__

typedef __uint32_t xlog_tid_t;

#define XLOG_MIN_ICLOGS		2
#define XLOG_MAX_ICLOGS		8
#define XLOG_HEADER_MAGIC_NUM	0xFEEDbabe	/* Invalid cycle number */
#define XLOG_VERSION_1		1
#define XLOG_VERSION_2		2		/* Large IClogs, Log sunit */
#define XLOG_VERSION_OKBITS	(XLOG_VERSION_1 | XLOG_VERSION_2)
#define XLOG_MIN_RECORD_BSIZE	(16*1024)	/* eventually 32k */
#define XLOG_BIG_RECORD_BSIZE	(32*1024)	/* 32k buffers */
#define XLOG_MAX_RECORD_BSIZE	(256*1024)
#define XLOG_HEADER_CYCLE_SIZE	(32*1024)	/* cycle data in header */
#define XLOG_MIN_RECORD_BSHIFT	14		/* 16384 == 1 << 14 */
#define XLOG_BIG_RECORD_BSHIFT	15		/* 32k == 1 << 15 */
#define XLOG_MAX_RECORD_BSHIFT	18		/* 256k == 1 << 18 */
#define XLOG_BTOLSUNIT(log, b)  (((b)+(log)->l_mp->m_sb.sb_logsunit-1) / \
                                 (log)->l_mp->m_sb.sb_logsunit)
#define XLOG_LSUNITTOB(log, su) ((su) * (log)->l_mp->m_sb.sb_logsunit)

#define XLOG_HEADER_SIZE	512

#define XLOG_REC_SHIFT(log) \
	BTOBB(1 << (xfs_sb_version_haslogv2(&log->l_mp->m_sb) ? \
	 XLOG_MAX_RECORD_BSHIFT : XLOG_BIG_RECORD_BSHIFT))
#define XLOG_TOTAL_REC_SHIFT(log) \
	BTOBB(XLOG_MAX_ICLOGS << (xfs_sb_version_haslogv2(&log->l_mp->m_sb) ? \
	 XLOG_MAX_RECORD_BSHIFT : XLOG_BIG_RECORD_BSHIFT))

/* get lsn fields */
#define CYCLE_LSN(lsn) ((uint)((lsn)>>32))
#define BLOCK_LSN(lsn) ((uint)(lsn))

/* this is used in a spot where we might otherwise double-endian-flip */
#define CYCLE_LSN_DISK(lsn) (((__be32 *)&(lsn))[0])

static inline xfs_lsn_t xlog_assign_lsn(uint cycle, uint block)
{
	return ((xfs_lsn_t)cycle << 32) | block;
}

static inline uint xlog_get_cycle(char *ptr)
{
	if (be32_to_cpu(*(__be32 *)ptr) == XLOG_HEADER_MAGIC_NUM)
		return be32_to_cpu(*((__be32 *)ptr + 1));
	else
		return be32_to_cpu(*(__be32 *)ptr);
}

/* Log Clients */
#define XFS_TRANSACTION		0x69
#define XFS_VOLUME		0x2
#define XFS_LOG			0xaa

#define XLOG_UNMOUNT_TYPE	0x556e	/* Un for Unmount */

/* Region types for iovec's i_type */
#define XLOG_REG_TYPE_BFORMAT		1
#define XLOG_REG_TYPE_BCHUNK		2
#define XLOG_REG_TYPE_EFI_FORMAT	3
#define XLOG_REG_TYPE_EFD_FORMAT	4
#define XLOG_REG_TYPE_IFORMAT		5
#define XLOG_REG_TYPE_ICORE		6
#define XLOG_REG_TYPE_IEXT		7
#define XLOG_REG_TYPE_IBROOT		8
#define XLOG_REG_TYPE_ILOCAL		9
#define XLOG_REG_TYPE_IATTR_EXT		10
#define XLOG_REG_TYPE_IATTR_BROOT	11
#define XLOG_REG_TYPE_IATTR_LOCAL	12
#define XLOG_REG_TYPE_QFORMAT		13
#define XLOG_REG_TYPE_DQUOT		14
#define XLOG_REG_TYPE_QUOTAOFF		15
#define XLOG_REG_TYPE_LRHEADER		16
#define XLOG_REG_TYPE_UNMOUNT		17
#define XLOG_REG_TYPE_COMMIT		18
#define XLOG_REG_TYPE_TRANSHDR		19
#define XLOG_REG_TYPE_ICREATE		20
#define XLOG_REG_TYPE_MAX		20

/*
 * Flags to log operation header
 *
 * The first write of a new transaction will be preceded with a start
 * record, XLOG_START_TRANS.  Once a transaction is committed, a commit
 * record is written, XLOG_COMMIT_TRANS.  If a single region can not fit into
 * the remainder of the current active in-core log, it is split up into
 * multiple regions.  Each partial region will be marked with a
 * XLOG_CONTINUE_TRANS until the last one, which gets marked with XLOG_END_TRANS.
 *
 */
#define XLOG_START_TRANS	0x01	/* Start a new transaction */
#define XLOG_COMMIT_TRANS	0x02	/* Commit this transaction */
#define XLOG_CONTINUE_TRANS	0x04	/* Cont this trans into new region */
#define XLOG_WAS_CONT_TRANS	0x08	/* Cont this trans into new region */
#define XLOG_END_TRANS		0x10	/* End a continued transaction */
#define XLOG_UNMOUNT_TRANS	0x20	/* Unmount a filesystem transaction */


typedef struct xlog_op_header {
	__be32	   oh_tid;	/* transaction id of operation	:  4 b */
	__be32	   oh_len;	/* bytes in data region		:  4 b */
	__u8	   oh_clientid;	/* who sent me this		:  1 b */
	__u8	   oh_flags;	/*				:  1 b */
	__u16	   oh_res2;	/* 32 bit align			:  2 b */
} xlog_op_header_t;


/* valid values for h_fmt */
#define XLOG_FMT_UNKNOWN  0
#define XLOG_FMT_LINUX_LE 1
#define XLOG_FMT_LINUX_BE 2
#define XLOG_FMT_IRIX_BE  3

/* our fmt */
#ifdef XFS_NATIVE_HOST
#define XLOG_FMT XLOG_FMT_LINUX_BE
#else
#define XLOG_FMT XLOG_FMT_LINUX_LE
#endif

typedef struct xlog_rec_header {
	__be32	  h_magicno;	/* log record (LR) identifier		:  4 */
	__be32	  h_cycle;	/* write cycle of log			:  4 */
	__be32	  h_version;	/* LR version				:  4 */
	__be32	  h_len;	/* len in bytes; should be 64-bit aligned: 4 */
	__be64	  h_lsn;	/* lsn of this LR			:  8 */
	__be64	  h_tail_lsn;	/* lsn of 1st LR w/ buffers not committed: 8 */
	__le32	  h_crc;	/* crc of log record                    :  4 */
	__be32	  h_prev_block; /* block number to previous LR		:  4 */
	__be32	  h_num_logops;	/* number of log operations in this LR	:  4 */
	__be32	  h_cycle_data[XLOG_HEADER_CYCLE_SIZE / BBSIZE];
	/* new fields */
	__be32    h_fmt;        /* format of log record                 :  4 */
	uuid_t	  h_fs_uuid;    /* uuid of FS                           : 16 */
	__be32	  h_size;	/* iclog size				:  4 */
} xlog_rec_header_t;

typedef struct xlog_rec_ext_header {
	__be32	  xh_cycle;	/* write cycle of log			: 4 */
	__be32	  xh_cycle_data[XLOG_HEADER_CYCLE_SIZE / BBSIZE]; /*	: 256 */
} xlog_rec_ext_header_t;

/*
 * Quite misnamed, because this union lays out the actual on-disk log buffer.
 */
typedef union xlog_in_core2 {
	xlog_rec_header_t	hic_header;
	xlog_rec_ext_header_t	hic_xheader;
	char			hic_sector[XLOG_HEADER_SIZE];
} xlog_in_core_2_t;

/* not an on-disk structure, but needed by log recovery in userspace */
typedef struct xfs_log_iovec {
	void		*i_addr;	/* beginning address of region */
	int		i_len;		/* length in bytes of region */
	uint		i_type;		/* type of region */
} xfs_log_iovec_t;

#endif /* __XFS_LOG_FORMAT_H__ */