fs/xfs/xfs_ag.h - maze/linux - Git at Google

 /*
  * 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 */
 	__be32		agf_btreeblks;	/* # of blocks held in AGF btrees */
 } 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_BTREEBLKS	0x00000800
 #define	XFS_AGF_NUM_BITS	12
 #define	XFS_AGF_ALL_BITS	((1 << XFS_AGF_NUM_BITS) - 1)

 #define XFS_AGF_FLAGS \
 	{ XFS_AGF_MAGICNUM,	"MAGICNUM" }, \
 	{ XFS_AGF_VERSIONNUM,	"VERSIONNUM" }, \
 	{ XFS_AGF_SEQNO,	"SEQNO" }, \
 	{ XFS_AGF_LENGTH,	"LENGTH" }, \
 	{ XFS_AGF_ROOTS,	"ROOTS" }, \
 	{ XFS_AGF_LEVELS,	"LEVELS" }, \
 	{ XFS_AGF_FLFIRST,	"FLFIRST" }, \
 	{ XFS_AGF_FLLAST,	"FLLAST" }, \
 	{ XFS_AGF_FLCOUNT,	"FLCOUNT" }, \
 	{ XFS_AGF_FREEBLKS,	"FREEBLKS" }, \
 	{ XFS_AGF_LONGEST,	"LONGEST" }, \
 	{ XFS_AGF_BTREEBLKS,	"BTREEBLKS" }

 /* 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))

 extern int xfs_read_agf(struct xfs_mount *mp, struct xfs_trans *tp,
 			xfs_agnumber_t agno, int flags, struct xfs_buf **bpp);

 /*
  * 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))

 extern int xfs_read_agi(struct xfs_mount *mp, struct xfs_trans *tp,
 				xfs_agnumber_t agno, struct xfs_buf **bpp);

 /*
  * 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.  Indexed by a rbtree in perag to mark blocks that
  * have been freed but whose transactions aren't committed to disk yet.
  *
  * Note that we use the transaction ID to record the transaction, not the
  * transaction structure itself. See xfs_alloc_busy_insert() for details.
  */
 struct xfs_busy_extent {
 	struct rb_node	rb_node;	/* ag by-bno indexed search tree */
 	struct list_head list;		/* transaction busy extent list */
 	xfs_agnumber_t	agno;
 	xfs_agblock_t	bno;
 	xfs_extlen_t	length;
 };

 /*
  * Per-ag incore structure, copies of information in agf and agi,
  * to improve the performance of allocation group selection.
  */
 #define XFS_PAGB_NUM_SLOTS	128

 typedef struct xfs_perag {
 	struct xfs_mount *pag_mount;	/* owner filesystem */
 	xfs_agnumber_t	pag_agno;	/* AG this structure belongs to */
 	atomic_t	pag_ref;	/* perag reference count */
 	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 */
 	__uint32_t	pagf_btreeblks;	/* # of blocks held in AGF btrees */
 	xfs_agino_t	pagi_freecount;	/* number of free inodes */
 	xfs_agino_t	pagi_count;	/* number of allocated inodes */

 	/*
 	 * Inode allocation search lookup optimisation.
 	 * If the pagino matches, the search for new inodes
 	 * doesn't need to search the near ones again straight away
 	 */
 	xfs_agino_t	pagl_pagino;
 	xfs_agino_t	pagl_leftrec;
 	xfs_agino_t	pagl_rightrec;
 #ifdef __KERNEL__
 	spinlock_t	pagb_lock;	/* lock for pagb_tree */
 	struct rb_root	pagb_tree;	/* ordered tree of busy extents */

 	atomic_t        pagf_fstrms;    /* # of filestreams active in this AG */

 	spinlock_t	pag_ici_lock;	/* incore inode cache lock */
 	struct radix_tree_root pag_ici_root;	/* incore inode cache root */
 	int		pag_ici_reclaimable;	/* reclaimable inodes */
 	struct mutex	pag_ici_reclaim_lock;	/* serialisation point */
 	unsigned long	pag_ici_reclaim_cursor;	/* reclaim restart point */

 	/* buffer cache index */
 	spinlock_t	pag_buf_lock;	/* lock for pag_buf_tree */
 	struct rb_root	pag_buf_tree;	/* ordered tree of active buffers */

 	/* for rcu-safe freeing */
 	struct rcu_head	rcu_head;
 #endif
 	int		pagb_count;	/* pagb slots in use */
 } xfs_perag_t;

 /*
  * tags for inode radix tree
  */
 #define XFS_ICI_NO_TAG		(-1)	/* special flag for an untagged lookup
 					   in xfs_inode_ag_iterator */
 #define XFS_ICI_RECLAIM_TAG	0	/* inode is to be reclaimed */

 #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(		\
 		(unsigned int)(pag)->pagf_levels[XFS_BTNUM_BNOi], \
 		(unsigned int)(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__ */
	/*
	* 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 */
	__be32 agf_btreeblks; /* # of blocks held in AGF btrees */
	} 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_BTREEBLKS 0x00000800
	#define XFS_AGF_NUM_BITS 12
	#define XFS_AGF_ALL_BITS ((1 << XFS_AGF_NUM_BITS) - 1)

	#define XFS_AGF_FLAGS \
	{ XFS_AGF_MAGICNUM, "MAGICNUM" }, \
	{ XFS_AGF_VERSIONNUM, "VERSIONNUM" }, \
	{ XFS_AGF_SEQNO, "SEQNO" }, \
	{ XFS_AGF_LENGTH, "LENGTH" }, \
	{ XFS_AGF_ROOTS, "ROOTS" }, \
	{ XFS_AGF_LEVELS, "LEVELS" }, \
	{ XFS_AGF_FLFIRST, "FLFIRST" }, \
	{ XFS_AGF_FLLAST, "FLLAST" }, \
	{ XFS_AGF_FLCOUNT, "FLCOUNT" }, \
	{ XFS_AGF_FREEBLKS, "FREEBLKS" }, \
	{ XFS_AGF_LONGEST, "LONGEST" }, \
	{ XFS_AGF_BTREEBLKS, "BTREEBLKS" }

	/* 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))

	extern int xfs_read_agf(struct xfs_mount mp, struct xfs_trans tp,
	xfs_agnumber_t agno, int flags, struct xfs_buf **bpp);

	/*
	* 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))

	extern int xfs_read_agi(struct xfs_mount mp, struct xfs_trans tp,
	xfs_agnumber_t agno, struct xfs_buf **bpp);

	/*
	* 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. Indexed by a rbtree in perag to mark blocks that
	* have been freed but whose transactions aren't committed to disk yet.
	*
	* Note that we use the transaction ID to record the transaction, not the
	* transaction structure itself. See xfs_alloc_busy_insert() for details.
	*/
	struct xfs_busy_extent {
	struct rb_node rb_node; /* ag by-bno indexed search tree */
	struct list_head list; /* transaction busy extent list */
	xfs_agnumber_t agno;
	xfs_agblock_t bno;
	xfs_extlen_t length;
	};

	/*
	* Per-ag incore structure, copies of information in agf and agi,
	* to improve the performance of allocation group selection.
	*/
	#define XFS_PAGB_NUM_SLOTS 128

	typedef struct xfs_perag {
	struct xfs_mount pag_mount; / owner filesystem */
	xfs_agnumber_t pag_agno; /* AG this structure belongs to */
	atomic_t pag_ref; /* perag reference count */
	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 */
	__uint32_t pagf_btreeblks; /* # of blocks held in AGF btrees */
	xfs_agino_t pagi_freecount; /* number of free inodes */
	xfs_agino_t pagi_count; /* number of allocated inodes */

	/*
	* Inode allocation search lookup optimisation.
	* If the pagino matches, the search for new inodes
	* doesn't need to search the near ones again straight away
	*/
	xfs_agino_t pagl_pagino;
	xfs_agino_t pagl_leftrec;
	xfs_agino_t pagl_rightrec;
	#ifdef __KERNEL__
	spinlock_t pagb_lock; /* lock for pagb_tree */
	struct rb_root pagb_tree; /* ordered tree of busy extents */

	atomic_t pagf_fstrms; /* # of filestreams active in this AG */

	spinlock_t pag_ici_lock; /* incore inode cache lock */
	struct radix_tree_root pag_ici_root; /* incore inode cache root */
	int pag_ici_reclaimable; /* reclaimable inodes */
	struct mutex pag_ici_reclaim_lock; /* serialisation point */
	unsigned long pag_ici_reclaim_cursor; /* reclaim restart point */

	/* buffer cache index */
	spinlock_t pag_buf_lock; /* lock for pag_buf_tree */
	struct rb_root pag_buf_tree; /* ordered tree of active buffers */

	/* for rcu-safe freeing */
	struct rcu_head rcu_head;
	#endif
	int pagb_count; /* pagb slots in use */
	} xfs_perag_t;

	/*
	* tags for inode radix tree
	*/
	#define XFS_ICI_NO_TAG (-1) /* special flag for an untagged lookup
	in xfs_inode_ag_iterator */
	#define XFS_ICI_RECLAIM_TAG 0 /* inode is to be reclaimed */

	#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( \
	(unsigned int)(pag)->pagf_levels[XFS_BTNUM_BNOi], \
	(unsigned int)(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__ */