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1.  Fix iodone() complete routines to perform locking correctly.
2.  Correct some problems in the log_write() code w.r.t. the offset in the
	current in-core log.
3.  Add the notion of a start record for transactions.
4.  Every 512 byte block will have a pass number stamped in the first word
	of the block.  However, log record headers have their magic number
	in the first word with the pass number in the second word.
5. Add notion of splitting individual regions across multiple log record
	writes.

#ifndef	_XFS_LOG_H
#define _XFS_LOG_H

#define	XFS_LSN_CMP(x,y)	((x) - (y))
#define	XFS_LSN_DIFF(x,y)	((x) - (y))

/*
 * Macros, structures, prototypes for interface to the log manager.
 */

/*
 * Flags to xfs_log_mount
 */
#define XFS_LOG_RECOVER		0x1

/*
 * Flags to xfs_log_reserve()
 *
 *	XFS_LOG_SLEEP:	 If space is not available, sleep
 *	XFS_LOG_NOSLEEP: If space is not available, return error
 *	XFS_LOG_PERM_RESERV: Permanent reservation.  When writes are
 *		performed against this type of reservation, the reservation
 *		is not decreased.  Long running transactions should use this.
 */
#define XFS_LOG_SLEEP		0x1
#define XFS_LOG_NOSLEEP		0x2
#define XFS_LOG_PERM_RESERV	0x4


/*
 * Flags to xfs_log_force()
 *
 *	XFS_LOG_SYNC:	Synchronous force in-core log to disk.
 *	default:	Force out asynchronously
 *	XFS_LOG_FORCE:	Start in-core log write now.
 *	XFS_LOG_URGE:	Start write within some window of time.
 */
#define XFS_LOG_SYNC		0x1
#define XFS_LOG_FORCE		0x2
#define XFS_LOG_URGE		0x4


/* Log Clients */
#define XFS_TRANSACTION_MANAGER	1
#define XFS_VOLUME_MANAGER	2


typedef struct xfs_log_iovec {
	caddr_t		i_addr;		/* beginning address of region */
	uint		i_len;		/* length in bytes of region */
	xfs_lsn_t	i_lsn;		/* log sequence number of region */
} xfs_log_iovec_t;

typedef void* xfs_log_ticket_t;

/*
 * Structure used to pass callback function and the function's argument
 * to the log manager.
 */
typedef struct xfs_log_callback {
	struct xfs_log_callback	*cb_next;
	void			(*cb_func)(void *);
	void 			*cb_arg;
} xfs_log_callback_t;


/* Log manager interfaces */
struct xfs_mount;
void xfs_log_done(struct xfs_mount *mp, xfs_log_ticket_t ticket, uint flags);
int  xfs_log_force(struct xfs_mount *mp, xfs_lsn_t lsn, uint flags);
int  xfs_log_init();
int  xfs_log_mount(struct xfs_mount *mp, dev_t log_dev, uint flags);
void xfs_log_notify(struct xfs_mount *mp, xfs_lsn_t lsn,
		    xfs_log_callback_t *callback_entry);
int  xfs_log_reserve(struct xfs_mount *mp, uint length,
		     xfs_log_ticket_t *ticket, char clientid, uint flags);
int  xfs_log_write(struct xfs_mount *mp, xfs_log_iovec_t region[], int nentries,
		   xfs_log_ticket_t ticket);

/* Log manager utility interfaces */
void xfs_log_print(struct xfs_mount *mp, dev_t log_dev);

#define XFS_ERECOVER	1	/* Failure to recover log */
#define XFS_ELOGSTAT	2	/* Failure to stat log in user space */
#define XFS_ENOLOGSPACE	3	/* Reservation too large */
#define XFS_ENOTSUP	4

#endif	/* _XFS_LOG_H */