1. 根目录:
2. fs
3. xfs
4. xfs_rtalloc.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_RTALLOC_H__
#define	__XFS_RTALLOC_H__

/* kernel only definitions and functions */

struct xfs_mount;
struct xfs_trans;

#ifdef CONFIG_XFS_RT
/*
 * Function prototypes for exported functions.
 */

/*
 * Allocate an extent in the realtime subvolume, with the usual allocation
 * parameters.  The length units are all in realtime extents, as is the
 * result block number.
 */
int					/* error */
xfs_rtallocate_extent(
	struct xfs_trans	*tp,	/* transaction pointer */
	xfs_rtblock_t		bno,	/* starting block number to allocate */
	xfs_extlen_t		minlen,	/* minimum length to allocate */
	xfs_extlen_t		maxlen,	/* maximum length to allocate */
	xfs_extlen_t		*len,	/* out: actual length allocated */
	xfs_alloctype_t		type,	/* allocation type XFS_ALLOCTYPE... */
	int			wasdel,	/* was a delayed allocation extent */
	xfs_extlen_t		prod,	/* extent product factor */
	xfs_rtblock_t		*rtblock); /* out: start block allocated */

/*
 * Free an extent in the realtime subvolume.  Length is expressed in
 * realtime extents, as is the block number.
 */
int					/* error */
xfs_rtfree_extent(
	struct xfs_trans	*tp,	/* transaction pointer */
	xfs_rtblock_t		bno,	/* starting block number to free */
	xfs_extlen_t		len);	/* length of extent freed */

/*
 * Initialize realtime fields in the mount structure.
 */
int					/* error */
xfs_rtmount_init(
	struct xfs_mount	*mp);	/* file system mount structure */
void
xfs_rtunmount_inodes(
	struct xfs_mount	*mp);

/*
 * Get the bitmap and summary inodes into the mount structure
 * at mount time.
 */
int					/* error */
xfs_rtmount_inodes(
	struct xfs_mount	*mp);	/* file system mount structure */

/*
 * Pick an extent for allocation at the start of a new realtime file.
 * Use the sequence number stored in the atime field of the bitmap inode.
 * Translate this to a fraction of the rtextents, and return the product
 * of rtextents and the fraction.
 * The fraction sequence is 0, 1/2, 1/4, 3/4, 1/8, ..., 7/8, 1/16, ...
 */
int					/* error */
xfs_rtpick_extent(
	struct xfs_mount	*mp,	/* file system mount point */
	struct xfs_trans	*tp,	/* transaction pointer */
	xfs_extlen_t		len,	/* allocation length (rtextents) */
	xfs_rtblock_t		*pick);	/* result rt extent */

/*
 * Grow the realtime area of the filesystem.
 */
int
xfs_growfs_rt(
	struct xfs_mount	*mp,	/* file system mount structure */
	xfs_growfs_rt_t		*in);	/* user supplied growfs struct */

/*
 * From xfs_rtbitmap.c
 */
int xfs_rtbuf_get(struct xfs_mount *mp, struct xfs_trans *tp,
		  xfs_rtblock_t block, int issum, struct xfs_buf **bpp);
int xfs_rtcheck_range(struct xfs_mount *mp, struct xfs_trans *tp,
		      xfs_rtblock_t start, xfs_extlen_t len, int val,
		      xfs_rtblock_t *new, int *stat);
int xfs_rtfind_back(struct xfs_mount *mp, struct xfs_trans *tp,
		    xfs_rtblock_t start, xfs_rtblock_t limit,
		    xfs_rtblock_t *rtblock);
int xfs_rtfind_forw(struct xfs_mount *mp, struct xfs_trans *tp,
		    xfs_rtblock_t start, xfs_rtblock_t limit,
		    xfs_rtblock_t *rtblock);
int xfs_rtmodify_range(struct xfs_mount *mp, struct xfs_trans *tp,
		       xfs_rtblock_t start, xfs_extlen_t len, int val);
int xfs_rtmodify_summary(struct xfs_mount *mp, struct xfs_trans *tp, int log,
			 xfs_rtblock_t bbno, int delta, xfs_buf_t **rbpp,
			 xfs_fsblock_t *rsb);
int xfs_rtfree_range(struct xfs_mount *mp, struct xfs_trans *tp,
		     xfs_rtblock_t start, xfs_extlen_t len,
		     struct xfs_buf **rbpp, xfs_fsblock_t *rsb);


#else
# define xfs_rtallocate_extent(t,b,min,max,l,a,f,p,rb)  (ENOSYS)
# define xfs_rtfree_extent(t,b,l)                       (ENOSYS)
# define xfs_rtpick_extent(m,t,l,rb)                    (ENOSYS)
# define xfs_growfs_rt(mp,in)                           (ENOSYS)
static inline int		/* error */
xfs_rtmount_init(
	xfs_mount_t	*mp)	/* file system mount structure */
{
	if (mp->m_sb.sb_rblocks == 0)
		return 0;

	xfs_warn(mp, "Not built with CONFIG_XFS_RT");
	return ENOSYS;
}
# define xfs_rtmount_inodes(m)  (((mp)->m_sb.sb_rblocks == 0)? 0 : (ENOSYS))
# define xfs_rtunmount_inodes(m)
#endif	/* CONFIG_XFS_RT */

#endif	/* __XFS_RTALLOC_H__ */