[linux.git] / fs / xfs / xfs_ag.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_AG_H__
#define	__XFS_AG_H__

/*
 * Allocation group header
 * This is divided into three structures, placed in sequential 512-byte
 * buffers after a copy of the superblock (also in a 512-byte buffer).
 */

struct xfs_buf;
struct xfs_mount;
struct xfs_trans;

#define	XFS_AGF_MAGIC	0x58414746	/* 'XAGF' */
#define	XFS_AGI_MAGIC	0x58414749	/* 'XAGI' */
#define	XFS_AGF_VERSION	1
#define	XFS_AGI_VERSION	1

#define	XFS_AGF_GOOD_VERSION(v)	((v) == XFS_AGF_VERSION)
#define	XFS_AGI_GOOD_VERSION(v)	((v) == XFS_AGI_VERSION)

/*
 * Btree number 0 is bno, 1 is cnt.  This value gives the size of the
 * arrays below.
 */
#define	XFS_BTNUM_AGF	((int)XFS_BTNUM_CNTi + 1)

/*
 * The second word of agf_levels in the first a.g. overlaps the EFS
 * superblock's magic number.  Since the magic numbers valid for EFS
 * are > 64k, our value cannot be confused for an EFS superblock's.
 */

typedef struct xfs_agf {
	/*
	 * Common allocation group header information
	 */
	__be32		agf_magicnum;	/* magic number == XFS_AGF_MAGIC */
	__be32		agf_versionnum;	/* header version == XFS_AGF_VERSION */
	__be32		agf_seqno;	/* sequence # starting from 0 */
	__be32		agf_length;	/* size in blocks of a.g. */
	/*
	 * Freespace information
	 */
	__be32		agf_roots[XFS_BTNUM_AGF];	/* root blocks */
	__be32		agf_spare0;	/* spare field */
	__be32		agf_levels[XFS_BTNUM_AGF];	/* btree levels */
	__be32		agf_spare1;	/* spare field */
	__be32		agf_flfirst;	/* first freelist block's index */
	__be32		agf_fllast;	/* last freelist block's index */
	__be32		agf_flcount;	/* count of blocks in freelist */
	__be32		agf_freeblks;	/* total free blocks */
	__be32		agf_longest;	/* longest free space */
} xfs_agf_t;

#define	XFS_AGF_MAGICNUM	0x00000001
#define	XFS_AGF_VERSIONNUM	0x00000002
#define	XFS_AGF_SEQNO		0x00000004
#define	XFS_AGF_LENGTH		0x00000008
#define	XFS_AGF_ROOTS		0x00000010
#define	XFS_AGF_LEVELS		0x00000020
#define	XFS_AGF_FLFIRST		0x00000040
#define	XFS_AGF_FLLAST		0x00000080
#define	XFS_AGF_FLCOUNT		0x00000100
#define	XFS_AGF_FREEBLKS	0x00000200
#define	XFS_AGF_LONGEST		0x00000400
#define	XFS_AGF_NUM_BITS	11
#define	XFS_AGF_ALL_BITS	((1 << XFS_AGF_NUM_BITS) - 1)

/* disk block (xfs_daddr_t) in the AG */
#define XFS_AGF_DADDR(mp)	((xfs_daddr_t)(1 << (mp)->m_sectbb_log))
#define	XFS_AGF_BLOCK(mp)	XFS_HDR_BLOCK(mp, XFS_AGF_DADDR(mp))
#define	XFS_BUF_TO_AGF(bp)	((xfs_agf_t *)XFS_BUF_PTR(bp))


/*
 * Size of the unlinked inode hash table in the agi.
 */
#define	XFS_AGI_UNLINKED_BUCKETS	64

typedef struct xfs_agi {
	/*
	 * Common allocation group header information
	 */
	__be32		agi_magicnum;	/* magic number == XFS_AGI_MAGIC */
	__be32		agi_versionnum;	/* header version == XFS_AGI_VERSION */
	__be32		agi_seqno;	/* sequence # starting from 0 */
	__be32		agi_length;	/* size in blocks of a.g. */
	/*
	 * Inode information
	 * Inodes are mapped by interpreting the inode number, so no
	 * mapping data is needed here.
	 */
	__be32		agi_count;	/* count of allocated inodes */
	__be32		agi_root;	/* root of inode btree */
	__be32		agi_level;	/* levels in inode btree */
	__be32		agi_freecount;	/* number of free inodes */
	__be32		agi_newino;	/* new inode just allocated */
	__be32		agi_dirino;	/* last directory inode chunk */
	/*
	 * Hash table of inodes which have been unlinked but are
	 * still being referenced.
	 */
	__be32		agi_unlinked[XFS_AGI_UNLINKED_BUCKETS];
} xfs_agi_t;

#define	XFS_AGI_MAGICNUM	0x00000001
#define	XFS_AGI_VERSIONNUM	0x00000002
#define	XFS_AGI_SEQNO		0x00000004
#define	XFS_AGI_LENGTH		0x00000008
#define	XFS_AGI_COUNT		0x00000010
#define	XFS_AGI_ROOT		0x00000020
#define	XFS_AGI_LEVEL		0x00000040
#define	XFS_AGI_FREECOUNT	0x00000080
#define	XFS_AGI_NEWINO		0x00000100
#define	XFS_AGI_DIRINO		0x00000200
#define	XFS_AGI_UNLINKED	0x00000400
#define	XFS_AGI_NUM_BITS	11
#define	XFS_AGI_ALL_BITS	((1 << XFS_AGI_NUM_BITS) - 1)

/* disk block (xfs_daddr_t) in the AG */
#define XFS_AGI_DADDR(mp)	((xfs_daddr_t)(2 << (mp)->m_sectbb_log))
#define	XFS_AGI_BLOCK(mp)	XFS_HDR_BLOCK(mp, XFS_AGI_DADDR(mp))
#define	XFS_BUF_TO_AGI(bp)	((xfs_agi_t *)XFS_BUF_PTR(bp))

/*
 * The third a.g. block contains the a.g. freelist, an array
 * of block pointers to blocks owned by the allocation btree code.
 */
#define XFS_AGFL_DADDR(mp)	((xfs_daddr_t)(3 << (mp)->m_sectbb_log))
#define	XFS_AGFL_BLOCK(mp)	XFS_HDR_BLOCK(mp, XFS_AGFL_DADDR(mp))
#define XFS_AGFL_SIZE(mp)	((mp)->m_sb.sb_sectsize / sizeof(xfs_agblock_t))
#define	XFS_BUF_TO_AGFL(bp)	((xfs_agfl_t *)XFS_BUF_PTR(bp))

typedef struct xfs_agfl {
	__be32		agfl_bno[1];	/* actually XFS_AGFL_SIZE(mp) */
} xfs_agfl_t;

/*
 * Busy block/extent entry.  Used in perag to mark blocks that have been freed
 * but whose transactions aren't committed to disk yet.
 */
typedef struct xfs_perag_busy {
	xfs_agblock_t	busy_start;
	xfs_extlen_t	busy_length;
	struct xfs_trans *busy_tp;	/* transaction that did the free */
} xfs_perag_busy_t;

/*
 * Per-ag incore structure, copies of information in agf and agi,
 * to improve the performance of allocation group selection.
 *
 * pick sizes which fit in allocation buckets well
 */
#if (BITS_PER_LONG == 32)
#define XFS_PAGB_NUM_SLOTS	84
#elif (BITS_PER_LONG == 64)
#define XFS_PAGB_NUM_SLOTS	128
#endif

typedef struct xfs_perag
{
	char		pagf_init;	/* this agf's entry is initialized */
	char		pagi_init;	/* this agi's entry is initialized */
	char		pagf_metadata;	/* the agf is preferred to be metadata */
	char		pagi_inodeok;	/* The agi is ok for inodes */
	__uint8_t	pagf_levels[XFS_BTNUM_AGF];
					/* # of levels in bno & cnt btree */
	__uint32_t	pagf_flcount;	/* count of blocks in freelist */
	xfs_extlen_t	pagf_freeblks;	/* total free blocks */
	xfs_extlen_t	pagf_longest;	/* longest free space */
	xfs_agino_t	pagi_freecount;	/* number of free inodes */
#ifdef __KERNEL__
	lock_t		pagb_lock;	/* lock for pagb_list */
#endif
	int		pagb_count;	/* pagb slots in use */
	xfs_perag_busy_t *pagb_list;	/* unstable blocks */
} xfs_perag_t;

#define	XFS_AG_MAXLEVELS(mp)		((mp)->m_ag_maxlevels)
#define	XFS_MIN_FREELIST_RAW(bl,cl,mp)	\
	(MIN(bl + 1, XFS_AG_MAXLEVELS(mp)) + MIN(cl + 1, XFS_AG_MAXLEVELS(mp)))
#define	XFS_MIN_FREELIST(a,mp)		\
	(XFS_MIN_FREELIST_RAW(		\
		be32_to_cpu((a)->agf_levels[XFS_BTNUM_BNOi]), \
		be32_to_cpu((a)->agf_levels[XFS_BTNUM_CNTi]), mp))
#define	XFS_MIN_FREELIST_PAG(pag,mp)	\
	(XFS_MIN_FREELIST_RAW(		\
		(uint_t)(pag)->pagf_levels[XFS_BTNUM_BNOi], \
		(uint_t)(pag)->pagf_levels[XFS_BTNUM_CNTi], mp))

#define XFS_AGB_TO_FSB(mp,agno,agbno)	\
	(((xfs_fsblock_t)(agno) << (mp)->m_sb.sb_agblklog) | (agbno))
#define	XFS_FSB_TO_AGNO(mp,fsbno)	\
	((xfs_agnumber_t)((fsbno) >> (mp)->m_sb.sb_agblklog))
#define	XFS_FSB_TO_AGBNO(mp,fsbno)	\
	((xfs_agblock_t)((fsbno) & XFS_MASK32LO((mp)->m_sb.sb_agblklog)))
#define	XFS_AGB_TO_DADDR(mp,agno,agbno)	\
	((xfs_daddr_t)XFS_FSB_TO_BB(mp, \
		(xfs_fsblock_t)(agno) * (mp)->m_sb.sb_agblocks + (agbno)))
#define	XFS_AG_DADDR(mp,agno,d)		(XFS_AGB_TO_DADDR(mp, agno, 0) + (d))

/*
 * For checking for bad ranges of xfs_daddr_t's, covering multiple
 * allocation groups or a single xfs_daddr_t that's a superblock copy.
 */
#define	XFS_AG_CHECK_DADDR(mp,d,len)	\
	((len) == 1 ? \
	    ASSERT((d) == XFS_SB_DADDR || \
		   XFS_DADDR_TO_AGBNO(mp, d) != XFS_SB_DADDR) : \
	    ASSERT(XFS_DADDR_TO_AGNO(mp, d) == \
		   XFS_DADDR_TO_AGNO(mp, (d) + (len) - 1)))

#endif	/* __XFS_AG_H__ */
Commit	Line	Data
1da177e4	1	/*
7b718769 NS	2	* Copyright (c) 2000-2003,2005 Silicon Graphics, Inc.
7b718769 NS	3	* All Rights Reserved.
1da177e4	4	*
7b718769 NS	5	* This program is free software; you can redistribute it and/or
7b718769 NS	6	* modify it under the terms of the GNU General Public License as
1da177e4 LT	7	* published by the Free Software Foundation.
1da177e4 LT	8	*
7b718769 NS	9	* This program is distributed in the hope that it would be useful,
	10	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	11	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	12	* GNU General Public License for more details.
1da177e4	13	*
7b718769 NS	14	* You should have received a copy of the GNU General Public License
	15	* along with this program; if not, write the Free Software Foundation,
	16	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
1da177e4 LT	17	*/
	18	#ifndef __XFS_AG_H__
	19	#define __XFS_AG_H__
	20
	21	/*
	22	* Allocation group header
	23	* This is divided into three structures, placed in sequential 512-byte
	24	* buffers after a copy of the superblock (also in a 512-byte buffer).
	25	*/
	26
	27	struct xfs_buf;
	28	struct xfs_mount;
	29	struct xfs_trans;
	30
	31	#define XFS_AGF_MAGIC 0x58414746 /* 'XAGF' */
	32	#define XFS_AGI_MAGIC 0x58414749 /* 'XAGI' */
	33	#define XFS_AGF_VERSION 1
	34	#define XFS_AGI_VERSION 1
a844f451 NS	35
	36	#define XFS_AGF_GOOD_VERSION(v) ((v) == XFS_AGF_VERSION)
	37	#define XFS_AGI_GOOD_VERSION(v) ((v) == XFS_AGI_VERSION)
1da177e4 LT	38
	39	/*
	40	* Btree number 0 is bno, 1 is cnt. This value gives the size of the
	41	* arrays below.
	42	*/
	43	#define XFS_BTNUM_AGF ((int)XFS_BTNUM_CNTi + 1)
	44
	45	/*
	46	* The second word of agf_levels in the first a.g. overlaps the EFS
	47	* superblock's magic number. Since the magic numbers valid for EFS
	48	* are > 64k, our value cannot be confused for an EFS superblock's.
	49	*/
	50
16259e7d	51	typedef struct xfs_agf {
1da177e4 LT	52	/*
	53	* Common allocation group header information
	54	*/
16259e7d CH	55	__be32 agf_magicnum; /* magic number == XFS_AGF_MAGIC */
	56	__be32 agf_versionnum; /* header version == XFS_AGF_VERSION */
	57	__be32 agf_seqno; /* sequence # starting from 0 */
	58	__be32 agf_length; /* size in blocks of a.g. */
1da177e4 LT	59	/*
	60	* Freespace information
	61	*/
16259e7d CH	62	__be32 agf_roots[XFS_BTNUM_AGF]; /* root blocks */
	63	__be32 agf_spare0; /* spare field */
	64	__be32 agf_levels[XFS_BTNUM_AGF]; /* btree levels */
	65	__be32 agf_spare1; /* spare field */
	66	__be32 agf_flfirst; /* first freelist block's index */
	67	__be32 agf_fllast; /* last freelist block's index */
	68	__be32 agf_flcount; /* count of blocks in freelist */
	69	__be32 agf_freeblks; /* total free blocks */
	70	__be32 agf_longest; /* longest free space */
1da177e4 LT	71	} xfs_agf_t;
	72
	73	#define XFS_AGF_MAGICNUM 0x00000001
	74	#define XFS_AGF_VERSIONNUM 0x00000002
	75	#define XFS_AGF_SEQNO 0x00000004
	76	#define XFS_AGF_LENGTH 0x00000008
	77	#define XFS_AGF_ROOTS 0x00000010
	78	#define XFS_AGF_LEVELS 0x00000020
	79	#define XFS_AGF_FLFIRST 0x00000040
	80	#define XFS_AGF_FLLAST 0x00000080
	81	#define XFS_AGF_FLCOUNT 0x00000100
	82	#define XFS_AGF_FREEBLKS 0x00000200
	83	#define XFS_AGF_LONGEST 0x00000400
	84	#define XFS_AGF_NUM_BITS 11
	85	#define XFS_AGF_ALL_BITS ((1 << XFS_AGF_NUM_BITS) - 1)
	86
	87	/* disk block (xfs_daddr_t) in the AG */
	88	#define XFS_AGF_DADDR(mp) ((xfs_daddr_t)(1 << (mp)->m_sectbb_log))
a844f451 NS	89	#define XFS_AGF_BLOCK(mp) XFS_HDR_BLOCK(mp, XFS_AGF_DADDR(mp))
	90	#define XFS_BUF_TO_AGF(bp) ((xfs_agf_t *)XFS_BUF_PTR(bp))
	91
1da177e4 LT	92
	93	/*
	94	* Size of the unlinked inode hash table in the agi.
	95	*/
	96	#define XFS_AGI_UNLINKED_BUCKETS 64
	97
16259e7d	98	typedef struct xfs_agi {
1da177e4 LT	99	/*
	100	* Common allocation group header information
	101	*/
16259e7d CH	102	__be32 agi_magicnum; /* magic number == XFS_AGI_MAGIC */
	103	__be32 agi_versionnum; /* header version == XFS_AGI_VERSION */
	104	__be32 agi_seqno; /* sequence # starting from 0 */
	105	__be32 agi_length; /* size in blocks of a.g. */
1da177e4 LT	106	/*
	107	* Inode information
	108	* Inodes are mapped by interpreting the inode number, so no
	109	* mapping data is needed here.
	110	*/
16259e7d CH	111	__be32 agi_count; /* count of allocated inodes */
	112	__be32 agi_root; /* root of inode btree */
	113	__be32 agi_level; /* levels in inode btree */
	114	__be32 agi_freecount; /* number of free inodes */
	115	__be32 agi_newino; /* new inode just allocated */
	116	__be32 agi_dirino; /* last directory inode chunk */
1da177e4 LT	117	/*
	118	* Hash table of inodes which have been unlinked but are
	119	* still being referenced.
	120	*/
16259e7d	121	__be32 agi_unlinked[XFS_AGI_UNLINKED_BUCKETS];
1da177e4 LT	122	} xfs_agi_t;
	123
	124	#define XFS_AGI_MAGICNUM 0x00000001
	125	#define XFS_AGI_VERSIONNUM 0x00000002
	126	#define XFS_AGI_SEQNO 0x00000004
	127	#define XFS_AGI_LENGTH 0x00000008
	128	#define XFS_AGI_COUNT 0x00000010
	129	#define XFS_AGI_ROOT 0x00000020
	130	#define XFS_AGI_LEVEL 0x00000040
	131	#define XFS_AGI_FREECOUNT 0x00000080
	132	#define XFS_AGI_NEWINO 0x00000100
	133	#define XFS_AGI_DIRINO 0x00000200
	134	#define XFS_AGI_UNLINKED 0x00000400
	135	#define XFS_AGI_NUM_BITS 11
	136	#define XFS_AGI_ALL_BITS ((1 << XFS_AGI_NUM_BITS) - 1)
	137
	138	/* disk block (xfs_daddr_t) in the AG */
	139	#define XFS_AGI_DADDR(mp) ((xfs_daddr_t)(2 << (mp)->m_sectbb_log))
a844f451 NS	140	#define XFS_AGI_BLOCK(mp) XFS_HDR_BLOCK(mp, XFS_AGI_DADDR(mp))
a844f451 NS	141	#define XFS_BUF_TO_AGI(bp) ((xfs_agi_t *)XFS_BUF_PTR(bp))
1da177e4 LT	142
	143	/*
	144	* The third a.g. block contains the a.g. freelist, an array
	145	* of block pointers to blocks owned by the allocation btree code.
	146	*/
	147	#define XFS_AGFL_DADDR(mp) ((xfs_daddr_t)(3 << (mp)->m_sectbb_log))
a844f451	148	#define XFS_AGFL_BLOCK(mp) XFS_HDR_BLOCK(mp, XFS_AGFL_DADDR(mp))
1da177e4	149	#define XFS_AGFL_SIZE(mp) ((mp)->m_sb.sb_sectsize / sizeof(xfs_agblock_t))
a844f451	150	#define XFS_BUF_TO_AGFL(bp) ((xfs_agfl_t *)XFS_BUF_PTR(bp))
1da177e4 LT	151
1da177e4 LT	152	typedef struct xfs_agfl {
e2101005	153	__be32 agfl_bno[1]; /* actually XFS_AGFL_SIZE(mp) */
1da177e4 LT	154	} xfs_agfl_t;
	155
	156	/*
	157	* Busy block/extent entry. Used in perag to mark blocks that have been freed
	158	* but whose transactions aren't committed to disk yet.
	159	*/
	160	typedef struct xfs_perag_busy {
	161	xfs_agblock_t busy_start;
	162	xfs_extlen_t busy_length;
	163	struct xfs_trans busy_tp; / transaction that did the free */
	164	} xfs_perag_busy_t;
	165
	166	/*
	167	* Per-ag incore structure, copies of information in agf and agi,
	168	* to improve the performance of allocation group selection.
	169	*
	170	* pick sizes which fit in allocation buckets well
	171	*/
	172	#if (BITS_PER_LONG == 32)
	173	#define XFS_PAGB_NUM_SLOTS 84
	174	#elif (BITS_PER_LONG == 64)
	175	#define XFS_PAGB_NUM_SLOTS 128
	176	#endif
	177
	178	typedef struct xfs_perag
	179	{
	180	char pagf_init; /* this agf's entry is initialized */
	181	char pagi_init; /* this agi's entry is initialized */
c41564b5	182	char pagf_metadata; /* the agf is preferred to be metadata */
1da177e4 LT	183	char pagi_inodeok; /* The agi is ok for inodes */
	184	__uint8_t pagf_levels[XFS_BTNUM_AGF];
	185	/* # of levels in bno & cnt btree */
	186	__uint32_t pagf_flcount; /* count of blocks in freelist */
	187	xfs_extlen_t pagf_freeblks; /* total free blocks */
	188	xfs_extlen_t pagf_longest; /* longest free space */
	189	xfs_agino_t pagi_freecount; /* number of free inodes */
	190	#ifdef __KERNEL__
	191	lock_t pagb_lock; /* lock for pagb_list */
	192	#endif
	193	int pagb_count; /* pagb slots in use */
	194	xfs_perag_busy_t pagb_list; / unstable blocks */
	195	} xfs_perag_t;
	196
a844f451 NS	197	#define XFS_AG_MAXLEVELS(mp) ((mp)->m_ag_maxlevels)
	198	#define XFS_MIN_FREELIST_RAW(bl,cl,mp) \
	199	(MIN(bl + 1, XFS_AG_MAXLEVELS(mp)) + MIN(cl + 1, XFS_AG_MAXLEVELS(mp)))
	200	#define XFS_MIN_FREELIST(a,mp) \
	201	(XFS_MIN_FREELIST_RAW( \
16259e7d CH	202	be32_to_cpu((a)->agf_levels[XFS_BTNUM_BNOi]), \
16259e7d CH	203	be32_to_cpu((a)->agf_levels[XFS_BTNUM_CNTi]), mp))
1da177e4	204	#define XFS_MIN_FREELIST_PAG(pag,mp) \
a844f451 NS	205	(XFS_MIN_FREELIST_RAW( \
	206	(uint_t)(pag)->pagf_levels[XFS_BTNUM_BNOi], \
	207	(uint_t)(pag)->pagf_levels[XFS_BTNUM_CNTi], mp))
1da177e4	208
a844f451	209	#define XFS_AGB_TO_FSB(mp,agno,agbno) \
1da177e4	210	(((xfs_fsblock_t)(agno) << (mp)->m_sb.sb_agblklog) \| (agbno))
a844f451	211	#define XFS_FSB_TO_AGNO(mp,fsbno) \
1da177e4	212	((xfs_agnumber_t)((fsbno) >> (mp)->m_sb.sb_agblklog))
a844f451	213	#define XFS_FSB_TO_AGBNO(mp,fsbno) \
1da177e4	214	((xfs_agblock_t)((fsbno) & XFS_MASK32LO((mp)->m_sb.sb_agblklog)))
a844f451 NS	215	#define XFS_AGB_TO_DADDR(mp,agno,agbno) \
	216	((xfs_daddr_t)XFS_FSB_TO_BB(mp, \
	217	(xfs_fsblock_t)(agno) * (mp)->m_sb.sb_agblocks + (agbno)))
	218	#define XFS_AG_DADDR(mp,agno,d) (XFS_AGB_TO_DADDR(mp, agno, 0) + (d))
1da177e4 LT	219
	220	/*
	221	* For checking for bad ranges of xfs_daddr_t's, covering multiple
	222	* allocation groups or a single xfs_daddr_t that's a superblock copy.
	223	*/
1da177e4 LT	224	#define XFS_AG_CHECK_DADDR(mp,d,len) \
	225	((len) == 1 ? \
	226	ASSERT((d) == XFS_SB_DADDR \|\| \
	227	XFS_DADDR_TO_AGBNO(mp, d) != XFS_SB_DADDR) : \
	228	ASSERT(XFS_DADDR_TO_AGNO(mp, d) == \
	229	XFS_DADDR_TO_AGNO(mp, (d) + (len) - 1)))
1da177e4 LT	230
1da177e4 LT	231	#endif /* __XFS_AG_H__ */