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Add arguments to xfs_bunmapi to support limiting the number of extents
freed in one transaction.

Add comments for function prototypes.

#ifndef _FS_XFS_BMAP_H
#define	_FS_XFS_BMAP_H

#ident "$Revision: 1.22 $"

/*
 * List of extents to be free "later".
 * The list is kept sorted on xbf_startblock.
 */
typedef struct xfs_bmap_free_item
{
	xfs_fsblock_t		xbfi_startblock;/* starting fs block number */
	xfs_extlen_t		xbfi_blockcount;/* number of blocks in extent */
	struct xfs_bmap_free_item *xbfi_next;	/* link to next entry */
} xfs_bmap_free_item_t;

/*
 * Header for free extent list.
 */
typedef	struct xfs_bmap_free
{
	xfs_bmap_free_item_t	*xbf_first;
	int			xbf_count;
} xfs_bmap_free_t;

#define	XFS_BMAP_MAX_NMAP	4

/*
 * Flags for xfs_bmapi
 */
#define	XFS_BMAPI_WRITE		0x1	/* write operation: allocate space */
#define	XFS_BMAPI_DELAY		0x2	/* delayed write operation */
#define	XFS_BMAPI_ENTIRE	0x4	/* return entire extent, not trimmed */

/*
 * Special values for xfs_bmbt_irec_t br_startblock field.
 */
#define	DELAYSTARTBLOCK		((xfs_fsblock_t)-1LL)
#define	HOLESTARTBLOCK		((xfs_fsblock_t)-2LL)


/*
 * Add the extent to the list of extents to be free at transaction end.
 * The list is maintained sorted (by block number).
 */
void
xfs_bmap_add_free(
	xfs_fsblock_t		bno,		/* fs block number of extent */
	xfs_extlen_t		len,		/* length of extent */
	xfs_bmap_free_t		*flist);	/* list of extents */

/*
 * Routine to be called at transaction's end by xfs_bmapi, xfs_bunmapi 
 * caller.  Frees all the extents that need freeing, which must be done
 * last due to locking considerations.
 */
void
xfs_bmap_finish(
	xfs_trans_t		**tp,		/* transaction pointer addr */
	xfs_bmap_free_t		*flist,		/* i/o: list extents to free */
	xfs_fsblock_t		firstblock);	/* controlled a.g. for allocs */

/*
 * Read in the extents to iu_extents.
 * All inode fields are set up by caller, we just traverse the btree
 * and copy the records in.
 */
void
xfs_bmap_read_extents(
	xfs_trans_t		*tp,		/* transaction pointer */
	struct xfs_inode	*ip);		/* incore inode */

/*
 * Map file blocks to filesystem blocks.
 * File range is given by the bno/len pair.
 * Adds blocks to file if a write ("flags & XFS_BMAPI_WRITE" set)
 * into a hole or past eof.
 * Only allocates blocks from a single allocation group,
 * to avoid locking problems.
 * The return value from the first call in a transaction must be remembered
 * and presented to subsequent calls in "firstblock".  An upper bound for
 * the number of blocks to be allocated is supplied to the first call 
 * in "total"; if no allocation group has that many free blocks then 
 * the call will fail (return NULLFSBLOCK).
 */
xfs_fsblock_t					/* first allocated block */
xfs_bmapi(
	xfs_trans_t		*tp,		/* transaction pointer */
	struct xfs_inode	*ip,		/* incore inode */
	xfs_fsblock_t		bno,		/* starting file offs. mapped */
	xfs_extlen_t		len,		/* length to map in file */
	int			flags,		/* XFS_BMAPI_... */
	xfs_fsblock_t		firstblock,	/* controls a.g. for allocs */
	xfs_extlen_t		total,		/* total blocks needed */
	xfs_bmbt_irec_t		*mval,		/* output: map values */
	int			*nmap,		/* i/o: mval size/count */
	xfs_bmap_free_t		*flist);	/* i/o: list extents to free */

/*
 * Unmap (remove) blocks from a file.
 * If nexts is nonzero then the number of extents to remove is limited to
 * that value.  If not all extents in the block range can be removed then
 * *done is set.
 */
xfs_fsblock_t					/* first allocated block */
xfs_bunmapi(
	xfs_trans_t		*tp,		/* transaction pointer */
	struct xfs_inode	*ip,		/* incore inode */
	xfs_fsblock_t		bno,		/* starting offset to unmap */
	xfs_extlen_t		len,		/* length to unmap in file */
	xfs_extnum_t		nexts,		/* number of extents max */
	xfs_fsblock_t		firstblock,	/* controls a.g. for allocs */
	xfs_bmap_free_t		*flist,		/* i/o: list extents to free */
	int			*done);		/* set if not done yet */

#endif	/* _FS_XFS_BMAP_H */