xref: /src/sys/ufs/lfs/lfs.h

/*	$NetBSD: lfs.h,v 1.23 2000/05/27 00:19:52 perseant Exp $	*/

/*-
 * Copyright (c) 1999 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Konrad E. Schroder <perseant (at) hhhh.org>.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the NetBSD
 *      Foundation, Inc. and its contributors.
 * 4. Neither the name of The NetBSD Foundation nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */
/*-
 * Copyright (c) 1991, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	@(#)lfs.h	8.9 (Berkeley) 5/8/95
 */

/*
 * Compile-time options for LFS.
 */
#define LFS_EAGAIN_FAIL          /* markv fail with EAGAIN if ino is locked */
#define LFS_TRACK_IOS            /* attempt to avoid cleaning segments not yet fully written to disk */
#define LFS_CANNOT_ROLLFW       /* No roll-forward agent exists */

/* #define DEBUG_LFS */              /* Intensive debugging of LFS subsystem */

/* #define LFS_ATIME_IFILE */         /* Store atime in Ifile, don't push */

/*
 * Parameters and generic definitions
 */
#define BW_CLEAN	1
#define MIN_FREE_SEGS	4
#define LFS_MAX_ACTIVE	10
#define LFS_MAXDIROP	(desiredvnodes>>2)

#ifndef LFS_ATIME_IFILE
# define LFS_ITIMES(ip, acc, mod, cre) FFS_ITIMES((ip),(acc),(mod),(cre))
#else
# define LFS_ITIMES(ip, acc, mod, cre) {                                \
	struct buf *ibp;						\
	IFILE *ifp;							\
									\
        if ((ip)->i_flag & IN_ACCESS) {                         	\
	LFS_IENTRY(ifp, ip->i_lfs, ip->i_number, ibp);			\
       		ifp->if_atime = (mod);					\
       		VOP_BWRITE(bp);						\
		(ip)->i_flag &= ~IN_ACCESS;				\
        }                                                       	\
        if ((ip)->i_flag & (IN_CHANGE | IN_UPDATE)) {       		\
                (ip)->i_flag |= IN_MODIFIED;                            \
                if ((ip)->i_flag & IN_UPDATE) {                         \
                        (ip)->i_ffs_mtime = (mod)->tv_sec;		\
                        (ip)->i_ffs_mtimensec = (mod)->tv_nsec;         \
                        (ip)->i_modrev++;                               \
                }                                                       \
                if ((ip)->i_flag & IN_CHANGE) {                         \
                        (ip)->i_ffs_ctime = (cre)->tv_sec;		\
                        (ip)->i_ffs_ctimensec = (cre)->tv_nsec;         \
                }                                                       \
                (ip)->i_flag &= ~(IN_CHANGE | IN_UPDATE);   		\
        }                                                               \
}
#endif

#define WRITEINPROG(vp) (vp->v_dirtyblkhd.lh_first && !(VTOI(vp)->i_flag & (IN_MODIFIED|IN_CLEANING)))

/* Here begins the berkeley code */

#define	LFS_LABELPAD	8192		/* LFS label size */
#define	LFS_SBPAD	8192		/* LFS superblock size */

/* On-disk and in-memory checkpoint segment usage structure. */
typedef struct segusage SEGUSE;
struct segusage {
	u_int32_t su_nbytes;		/* number of live bytes */
	u_int32_t su_lastmod;		/* SEGUSE last modified timestamp */
	u_int16_t su_nsums;		/* number of summaries in segment */
	u_int16_t su_ninos;		/* number of inode blocks in seg */

#define	SEGUSE_ACTIVE		0x01	/* segment is currently being written */
#define	SEGUSE_DIRTY		0x02	/* segment has data in it */
#define	SEGUSE_SUPERBLOCK	0x04	/* segment contains a superblock */
	u_int32_t su_flags;
};

#define	SEGUPB(fs)	(1 << (fs)->lfs_sushift)
#define	SEGTABSIZE_SU(fs)						\
	(((fs)->lfs_nseg + SEGUPB(fs) - 1) >> (fs)->lfs_sushift)

/* On-disk file information.  One per file with data blocks in the segment. */
typedef struct finfo FINFO;
struct finfo {
	u_int32_t fi_nblocks;		/* number of blocks */
	u_int32_t fi_version;		/* version number */
	u_int32_t fi_ino;		/* inode number */
	u_int32_t fi_lastlength;	/* length of last block in array */
	ufs_daddr_t	  fi_blocks[1];		/* array of logical block numbers */
};

/* On-disk super block. */
struct dlfs {
#define	LFS_MAGIC	0x070162
        u_int32_t dlfs_magic;     /* 0: magic number */
#define	LFS_VERSION	1
        u_int32_t dlfs_version;   /* 4: version number */

        u_int32_t dlfs_size;      /* 8: number of blocks in fs */
        u_int32_t dlfs_ssize;     /* 12: number of blocks per segment */
        u_int32_t dlfs_dsize;     /* 16: number of disk blocks in fs */
        u_int32_t dlfs_bsize;     /* 20: file system block size */
        u_int32_t dlfs_fsize;     /* 24: size of frag blocks in fs */
        u_int32_t dlfs_frag;      /* 28: number of frags in a block in fs */

/* Checkpoint region. */
        u_int32_t dlfs_free;      /* 32: start of the free list */
        u_int32_t dlfs_bfree;     /* 36: number of free disk blocks */
        u_int32_t dlfs_nfiles;    /* 40: number of allocated inodes */
        int32_t   dlfs_avail;     /* 44: blocks available for writing */
        u_int32_t dlfs_uinodes;   /* 48: inodes in cache not yet on disk */
        ufs_daddr_t  dlfs_idaddr; /* 52: inode file disk address */
        u_int32_t dlfs_ifile;     /* 56: inode file inode number */
        ufs_daddr_t  dlfs_lastseg; /* 60: address of last segment written */
        ufs_daddr_t  dlfs_nextseg; /* 64: address of next segment to write */
        ufs_daddr_t  dlfs_curseg; /* 68: current segment being written */
        ufs_daddr_t  dlfs_offset; /* 72: offset in curseg for next partial */
        ufs_daddr_t  dlfs_lastpseg; /* 76: address of last partial written */
        u_int32_t dlfs_tstamp;    /* 80: time stamp */

/* These are configuration parameters. */
        u_int32_t dlfs_minfree;   /* 84: minimum percentage of free blocks */

/* These fields can be computed from the others. */
        u_int64_t dlfs_maxfilesize; /* 88: maximum representable file size */
        u_int32_t dlfs_dbpseg;    /* 96: disk blocks per segment */
        u_int32_t dlfs_inopb;     /* 100: inodes per block */
        u_int32_t dlfs_ifpb;      /* 104: IFILE entries per block */
        u_int32_t dlfs_sepb;      /* 108: SEGUSE entries per block */
        u_int32_t dlfs_nindir;    /* 112: indirect pointers per block */
        u_int32_t dlfs_nseg;      /* 116: number of segments */
        u_int32_t dlfs_nspf;      /* 120: number of sectors per fragment */
        u_int32_t dlfs_cleansz;   /* 124: cleaner info size in blocks */
        u_int32_t dlfs_segtabsz;  /* 128: segment table size in blocks */
        u_int32_t dlfs_segmask;   /* 132: calculate offset within a segment */
        u_int32_t dlfs_segshift;  /* 136: fast mult/div for segments */
        u_int32_t dlfs_bshift;    /* 140: calc block number from file offset */
        u_int32_t dlfs_ffshift;   /* 144: fast mult/div for frag from file */
        u_int32_t dlfs_fbshift;   /* 148: fast mult/div for frag from block */
        u_int64_t dlfs_bmask;     /* 152: calc block offset from file offset */
        u_int64_t dlfs_ffmask;    /* 160: calc frag offset from file offset */
        u_int64_t dlfs_fbmask;    /* 168: calc frag offset from block offset */
        u_int32_t dlfs_fsbtodb;   /* 176: fsbtodb and dbtofsb shift constant */
        u_int32_t dlfs_sushift;   /* 180: fast mult/div for segusage table */

        int32_t   dlfs_maxsymlinklen; /* 184: max length of an internal symlink */

#define	LFS_MIN_SBINTERVAL	5  /* minimum superblock segment spacing */
#define LFS_MAXNUMSB            10 /* 188: superblock disk offsets */
        ufs_daddr_t       dlfs_sboffs[LFS_MAXNUMSB];

	u_int32_t dlfs_nclean;    /* 228: Number of clean segments */
	u_char	  dlfs_fsmnt[MNAMELEN];	 /* 232: name mounted on */
	/* XXX this is 2 bytes only to pad to a quad boundary */
	u_int16_t dlfs_clean;     /* 322: file system is clean flag */
        int8_t    dlfs_pad[184];  /* 324: round to 512 bytes */
/* Checksum -- last valid disk field. */
        u_int32_t dlfs_cksum;     /* 328: checksum for superblock checking */
};

/* Maximum number of io's we can have pending at once */
#define LFS_THROTTLE  16 /* XXX should be better paramtrized - ? */

/* In-memory super block. */
struct lfs {
        struct dlfs lfs_dlfs;           /* on-disk parameters */
#define lfs_magic lfs_dlfs.dlfs_magic
#define lfs_version lfs_dlfs.dlfs_version
#define lfs_size lfs_dlfs.dlfs_size
#define lfs_ssize lfs_dlfs.dlfs_ssize
#define lfs_dsize lfs_dlfs.dlfs_dsize
#define lfs_bsize lfs_dlfs.dlfs_bsize
#define lfs_fsize lfs_dlfs.dlfs_fsize
#define lfs_frag lfs_dlfs.dlfs_frag
#define lfs_free lfs_dlfs.dlfs_free
#define lfs_bfree lfs_dlfs.dlfs_bfree
#define lfs_nfiles lfs_dlfs.dlfs_nfiles
#define lfs_avail lfs_dlfs.dlfs_avail
#define lfs_uinodes lfs_dlfs.dlfs_uinodes
#define lfs_idaddr lfs_dlfs.dlfs_idaddr
#define lfs_ifile lfs_dlfs.dlfs_ifile
#define lfs_lastseg lfs_dlfs.dlfs_lastseg
#define lfs_nextseg lfs_dlfs.dlfs_nextseg
#define lfs_curseg lfs_dlfs.dlfs_curseg
#define lfs_offset lfs_dlfs.dlfs_offset
#define lfs_lastpseg lfs_dlfs.dlfs_lastpseg
#define lfs_tstamp lfs_dlfs.dlfs_tstamp
#define lfs_minfree lfs_dlfs.dlfs_minfree
#define lfs_maxfilesize lfs_dlfs.dlfs_maxfilesize
#define lfs_dbpseg lfs_dlfs.dlfs_dbpseg
#define lfs_inopb lfs_dlfs.dlfs_inopb
#define lfs_ifpb lfs_dlfs.dlfs_ifpb
#define lfs_sepb lfs_dlfs.dlfs_sepb
#define lfs_nindir lfs_dlfs.dlfs_nindir
#define lfs_nseg lfs_dlfs.dlfs_nseg
#define lfs_nspf lfs_dlfs.dlfs_nspf
#define lfs_cleansz lfs_dlfs.dlfs_cleansz
#define lfs_segtabsz lfs_dlfs.dlfs_segtabsz
#define lfs_segmask lfs_dlfs.dlfs_segmask
#define lfs_segshift lfs_dlfs.dlfs_segshift
#define lfs_bmask lfs_dlfs.dlfs_bmask
#define lfs_bshift lfs_dlfs.dlfs_bshift
#define lfs_ffmask lfs_dlfs.dlfs_ffmask
#define lfs_ffshift lfs_dlfs.dlfs_ffshift
#define lfs_fbmask lfs_dlfs.dlfs_fbmask
#define lfs_fbshift lfs_dlfs.dlfs_fbshift
#define lfs_fsbtodb lfs_dlfs.dlfs_fsbtodb
#define lfs_sushift lfs_dlfs.dlfs_sushift
#define lfs_maxsymlinklen lfs_dlfs.dlfs_maxsymlinklen
#define lfs_sboffs lfs_dlfs.dlfs_sboffs
#define lfs_cksum lfs_dlfs.dlfs_cksum
#define lfs_clean lfs_dlfs.dlfs_clean
#define lfs_fsmnt lfs_dlfs.dlfs_fsmnt
#define lfs_nclean lfs_dlfs.dlfs_nclean
/* These fields are set at mount time and are meaningless on disk. */
	struct segment *lfs_sp;		/* current segment being written */
	struct vnode *lfs_ivnode;	/* vnode for the ifile */
	u_int32_t  lfs_seglock;		/* single-thread the segment writer */
	pid_t	  lfs_lockpid;		/* pid of lock holder */
	u_int32_t lfs_iocount;		/* number of ios pending */
	u_int32_t lfs_writer;		/* don't allow any dirops to start */
	u_int32_t lfs_dirops;		/* count of active directory ops */
	u_int32_t lfs_doifile;		/* Write ifile blocks on next write */
	u_int32_t lfs_nactive;		/* Number of segments since last ckp */
	int8_t	  lfs_fmod;		/* super block modified flag */
	int8_t	  lfs_ronly;		/* mounted read-only flag */
	int8_t	  lfs_flags;		/* currently unused flag */
	u_int16_t lfs_activesb;         /* toggle between superblocks */
#ifdef LFS_TRACK_IOS
	daddr_t   lfs_pending[LFS_THROTTLE]; /* daddrs of pending writes */
#endif /* LFS_TRACK_IOS */
#ifdef LFS_CANNOT_ROLLFW
	daddr_t   lfs_sbactive;         /* disk address of in-progress sb write */
#endif
	struct vnode *lfs_flushvp;      /* vnode being flushed */
	struct vnode *lfs_unlockvp;     /* being inactivated in lfs_segunlock */
	u_int32_t lfs_diropwait;	/* # procs waiting on dirop flush */
	struct lock lfs_freelock;
	int       lfs_nadirop;		/* number of active dirop nodes */
};

/*
 * Inode 0:	out-of-band inode number
 * Inode 1:	IFILE inode number
 * Inode 2:	root inode
 * Inode 3:	lost+found inode number
 */
#define	LFS_UNUSED_INUM	0		/* out of band inode number */
#define	LFS_IFILE_INUM	1		/* IFILE inode number */
#define	LOSTFOUNDINO	3		/* lost+found inode number */
#define	LFS_FIRST_INUM	4		/* first free inode number */

/* Address calculations for metadata located in the inode */
#define	S_INDIR(fs)	-NDADDR
#define	D_INDIR(fs)	(S_INDIR(fs) - NINDIR(fs) - 1)
#define	T_INDIR(fs)	(D_INDIR(fs) - NINDIR(fs) * NINDIR(fs) - 1)

/* Unassigned disk addresses. */
#define	UNASSIGNED	-1
#define UNWRITTEN       -2

/* Unused logical block number */
#define LFS_UNUSED_LBN	-1

typedef struct ifile IFILE;
struct ifile {
	u_int32_t if_version;		/* inode version number */
#define	LFS_UNUSED_DADDR	0	/* out-of-band daddr */
	ufs_daddr_t if_daddr;		/* inode disk address */
	ino_t	  if_nextfree;		/* next-unallocated inode */
#ifdef LFS_ATIME_IFILE
	struct timespec if_atime;	/* Last access time */
#endif
};

/*
 * Cleaner information structure.  This resides in the ifile and is used
 * to pass information between the cleaner and the kernel.
 */
typedef struct _cleanerinfo {
	u_int32_t clean;		/* K: number of clean segments */
	u_int32_t dirty;		/* K: number of dirty segments */
} CLEANERINFO;

#define	CLEANSIZE_SU(fs)						\
	((sizeof(CLEANERINFO) + (fs)->lfs_bsize - 1) >> (fs)->lfs_bshift)

/*
 * All summary blocks are the same size, so we can always read a summary
 * block easily from a segment.
 */
#define	LFS_SUMMARY_SIZE	512

/* On-disk segment summary information */
typedef struct segsum SEGSUM;
struct segsum {
	u_int32_t ss_sumsum;		/* check sum of summary block */
	u_int32_t ss_datasum;		/* check sum of data */
	u_int32_t ss_magic;		/* segment summary magic number */
#define SS_MAGIC	0x061561
	ufs_daddr_t ss_next;		/* next segment */
	u_int32_t ss_create;		/* creation time stamp */
	u_int16_t ss_nfinfo;		/* number of file info structures */
	u_int16_t ss_ninos;		/* number of inodes in summary */

#define	SS_DIROP	0x01		/* segment begins a dirop */
#define	SS_CONT		0x02		/* more partials to finish this write*/
	u_int16_t ss_flags;		/* used for directory operations */
	u_int16_t ss_pad;		/* extra space */
	/* FINFO's and inode daddr's... */
};

/* NINDIR is the number of indirects in a file system block. */
#define	NINDIR(fs)	((fs)->lfs_nindir)

/* INOPB is the number of inodes in a secondary storage block. */
#define	INOPB(fs)	((fs)->lfs_inopb)

#define	blksize(fs, ip, lbn) \
	(((lbn) >= NDADDR || (ip)->i_ffs_size >= ((lbn) + 1) << (fs)->lfs_bshift) \
	    ? (fs)->lfs_bsize \
	    : (fragroundup(fs, blkoff(fs, (ip)->i_ffs_size))))
#define	blkoff(fs, loc)		((int)(loc) & (fs)->lfs_bmask)
#define fragoff(fs, loc)    /* calculates (loc % fs->lfs_fsize) */ \
    ((int)((loc) & (fs)->lfs_ffmask))
#define	fsbtodb(fs, b)		((b) << (fs)->lfs_fsbtodb)
#define	dbtofsb(fs, b)		((b) >> (fs)->lfs_fsbtodb)
#define fragstodb(fs, b)	((b) << ((fs)->lfs_fsbtodb - (fs)->lfs_fbshift))
#define dbtofrags(fs, b)	((b) >> ((fs)->lfs_fsbtodb - (fs)->lfs_fbshift))
#define	lblkno(fs, loc)		((loc) >> (fs)->lfs_bshift)
#define	lblktosize(fs, blk)	((blk) << (fs)->lfs_bshift)
#define numfrags(fs, loc)	/* calculates (loc / fs->lfs_fsize) */	\
	((loc) >> (fs)->lfs_ffshift)
#define blkroundup(fs, size)	/* calculates roundup(size, fs->lfs_bsize) */ \
	((int)(((size) + (fs)->lfs_bmask) & (~(fs)->lfs_bmask)))
#define fragroundup(fs, size)	/* calculates roundup(size, fs->lfs_fsize) */ \
	((int)(((size) + (fs)->lfs_ffmask) & (~(fs)->lfs_ffmask)))
#define fragstoblks(fs, frags)	/* calculates (frags / fs->lfs_frag) */ \
	((frags) >> (fs)->lfs_fbshift)
#define blkstofrags(fs, blks)	/* calculates (blks * fs->lfs_frag) */ \
	((blks) << (fs)->lfs_fbshift)
#define fragnum(fs, fsb)	/* calculates (fsb % fs->lfs_frag) */ \
	((fsb) & ((fs)->lfs_frag - 1))
#define blknum(fs, fsb)		/* calculates rounddown(fsb, fs->lfs_frag) */ \
	((fsb) &~ ((fs)->lfs_frag - 1))
#define dblksize(fs, dip, lbn) \
	(((lbn) >= NDADDR || (dip)->di_size >= ((lbn) + 1) << (fs)->lfs_bshift)\
	    ? (fs)->lfs_bsize \
	    : (fragroundup(fs, blkoff(fs, (dip)->di_size))))
#define	datosn(fs, daddr)	/* disk address to segment number */	\
	(((daddr) - (fs)->lfs_sboffs[0]) / fsbtodb((fs), (fs)->lfs_ssize))
#define sntoda(fs, sn) 		/* segment number to disk address */	\
	((ufs_daddr_t)((sn) * ((fs)->lfs_ssize << (fs)->lfs_fsbtodb) +	\
	    (fs)->lfs_sboffs[0]))

/* Read in the block with the cleaner info from the ifile. */
#define LFS_CLEANERINFO(CP, F, BP) {					\
	VTOI((F)->lfs_ivnode)->i_flag |= IN_ACCESS;			\
	if (bread((F)->lfs_ivnode,					\
	    (ufs_daddr_t)0, (F)->lfs_bsize, NOCRED, &(BP)))		\
		panic("lfs: ifile read");				\
	(CP) = (CLEANERINFO *)(BP)->b_data;				\
}

/* Read in the block with a specific inode from the ifile. */
#define	LFS_IENTRY(IP, F, IN, BP) {					\
	int _e;								\
	VTOI((F)->lfs_ivnode)->i_flag |= IN_ACCESS;			\
	if ((_e = bread((F)->lfs_ivnode,				\
	    (IN) / (F)->lfs_ifpb + (F)->lfs_cleansz + (F)->lfs_segtabsz,\
	    (F)->lfs_bsize, NOCRED, &(BP))) != 0)			\
		panic("lfs: ifile read %d", _e);			\
	(IP) = (IFILE *)(BP)->b_data + (IN) % (F)->lfs_ifpb;		\
}

/* Read in the block with a specific segment usage entry from the ifile. */
#define	LFS_SEGENTRY(SP, F, IN, BP) {					\
	int _e;								\
	VTOI((F)->lfs_ivnode)->i_flag |= IN_ACCESS;			\
	if ((_e = bread((F)->lfs_ivnode,				\
	    ((IN) >> (F)->lfs_sushift) + (F)->lfs_cleansz,		\
	    (F)->lfs_bsize, NOCRED, &(BP))) != 0)			\
		panic("lfs: ifile read: %d", _e);			\
	(SP) = (SEGUSE *)(BP)->b_data + ((IN) & ((F)->lfs_sepb - 1));	\
}

/* Determine if a buffer belongs to the ifile */
#define IS_IFILE(bp)	(VTOI(bp->b_vp)->i_number == LFS_IFILE_INUM)

/*
 * Structures used by lfs_bmapv and lfs_markv to communicate information
 * about inodes and data blocks.
 */
typedef struct block_info {
	ino_t	bi_inode;		/* inode # */
	ufs_daddr_t bi_lbn;		/* logical block w/in file */
	ufs_daddr_t bi_daddr;		/* disk address of block */
	time_t	bi_segcreate;		/* origin segment create time */
	int	bi_version;		/* file version number */
	void	*bi_bp;			/* data buffer */
	int     bi_size;		/* size of the block (if fragment) */
} BLOCK_INFO;

/* In-memory description of a segment about to be written. */
struct segment {
	struct lfs	 *fs;		/* file system pointer */
	struct buf	**bpp;		/* pointer to buffer array */
	struct buf	**cbpp;		/* pointer to next available bp */
	struct buf	**start_bpp;	/* pointer to first bp in this set */
	struct buf	 *ibp;		/* buffer pointer to inode page */
	struct dinode    *idp;          /* pointer to ifile dinode */
	struct finfo	 *fip;		/* current fileinfo pointer */
	struct vnode	 *vp;		/* vnode being gathered */
	void	 *segsum;		/* segment summary info */
	u_int32_t ninodes;		/* number of inodes in this segment */
	u_int32_t seg_bytes_left;	/* bytes left in segment */
	u_int32_t sum_bytes_left;	/* bytes left in summary block */
	u_int32_t seg_number;		/* number of this segment */
	ufs_daddr_t *start_lbp;		/* beginning lbn for this set */

#define	SEGM_CKP	0x01		/* doing a checkpoint */
#define	SEGM_CLEAN	0x02		/* cleaner call; don't sort */
#define	SEGM_SYNC	0x04		/* wait for segment */
	u_int16_t seg_flags;		/* run-time flags for this segment */
};

#define ISSPACE(F, BB, C)						\
	(((C)->cr_uid == 0 && (F)->lfs_bfree >= (BB)) ||		\
	((C)->cr_uid != 0 && IS_FREESPACE(F, BB)))

#define IS_FREESPACE(F, BB)						\
	((F)->lfs_bfree > ((F)->lfs_dsize * (F)->lfs_minfree / 100 + (BB)))

#define ISSPACE_XXX(F, BB)						\
	((F)->lfs_bfree >= (BB))

/* Statistics Counters */
struct lfs_stats {
	u_int	segsused;
	u_int	psegwrites;
	u_int	psyncwrites;
	u_int	pcleanwrites;
	u_int	blocktot;
	u_int	cleanblocks;
	u_int	ncheckpoints;
	u_int	nwrites;
	u_int	nsync_writes;
	u_int	wait_exceeded;
	u_int	write_exceeded;
	u_int	flush_invoked;
	u_int	vflush_invoked;
};
extern struct lfs_stats lfs_stats;