config root man

/*-
 * Copyright (c) 1982, 1986, 1989, 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.
 * 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.
 *
 *	@(#)ffs_subr.c	8.5 (Berkeley) 3/21/95
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD: release/9.1.0/sys/ufs/ffs/ffs_subr.c 207141 2010-04-24 07:05:35Z jeff $");

#include <sys/param.h>

#ifndef _KERNEL
#include <ufs/ufs/dinode.h>
#include <ufs/ffs/fs.h>
#else
#include <sys/systm.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/vnode.h>
#include <sys/bio.h>
#include <sys/buf.h>
#include <sys/ucred.h>

#include <ufs/ufs/quota.h>
#include <ufs/ufs/inode.h>
#include <ufs/ufs/extattr.h>
#include <ufs/ufs/ufsmount.h>
#include <ufs/ufs/ufs_extern.h>
#include <ufs/ffs/ffs_extern.h>
#include <ufs/ffs/fs.h>

#ifdef KDB
void	ffs_checkoverlap(struct buf *, struct inode *);
#endif

/*
 * Return buffer with the contents of block "offset" from the beginning of
 * directory "ip".  If "res" is non-zero, fill it in with a pointer to the
 * remaining space in the directory.
 */
int
ffs_blkatoff(vp, offset, res, bpp)
	struct vnode *vp;
	off_t offset;
	char **res;
	struct buf **bpp;
{
	struct inode *ip;
	struct fs *fs;
	struct buf *bp;
	ufs_lbn_t lbn;
	int bsize, error;

	ip = VTOI(vp);
	fs = ip->i_fs;
	lbn = lblkno(fs, offset);
	bsize = blksize(fs, ip, lbn);

	*bpp = NULL;
	error = bread(vp, lbn, bsize, NOCRED, &bp);
	if (error) {
		brelse(bp);
		return (error);
	}
	if (res)
		*res = (char *)bp->b_data + blkoff(fs, offset);
	*bpp = bp;
	return (0);
}

/*
 * Load up the contents of an inode and copy the appropriate pieces
 * to the incore copy.
 */
void
ffs_load_inode(bp, ip, fs, ino)
	struct buf *bp;
	struct inode *ip;
	struct fs *fs;
	ino_t ino;
{

	if (ip->i_ump->um_fstype == UFS1) {
		*ip->i_din1 =
		    *((struct ufs1_dinode *)bp->b_data + ino_to_fsbo(fs, ino));
		ip->i_mode = ip->i_din1->di_mode;
		ip->i_nlink = ip->i_din1->di_nlink;
		ip->i_size = ip->i_din1->di_size;
		ip->i_flags = ip->i_din1->di_flags;
		ip->i_gen = ip->i_din1->di_gen;
		ip->i_uid = ip->i_din1->di_uid;
		ip->i_gid = ip->i_din1->di_gid;
	} else {
		*ip->i_din2 =
		    *((struct ufs2_dinode *)bp->b_data + ino_to_fsbo(fs, ino));
		ip->i_mode = ip->i_din2->di_mode;
		ip->i_nlink = ip->i_din2->di_nlink;
		ip->i_size = ip->i_din2->di_size;
		ip->i_flags = ip->i_din2->di_flags;
		ip->i_gen = ip->i_din2->di_gen;
		ip->i_uid = ip->i_din2->di_uid;
		ip->i_gid = ip->i_din2->di_gid;
	}
}
#endif /* KERNEL */

/*
 * Update the frsum fields to reflect addition or deletion
 * of some frags.
 */
void
ffs_fragacct(fs, fragmap, fraglist, cnt)
	struct fs *fs;
	int fragmap;
	int32_t fraglist[];
	int cnt;
{
	int inblk;
	int field, subfield;
	int siz, pos;

	inblk = (int)(fragtbl[fs->fs_frag][fragmap]) << 1;
	fragmap <<= 1;
	for (siz = 1; siz < fs->fs_frag; siz++) {
		if ((inblk & (1 << (siz + (fs->fs_frag % NBBY)))) == 0)
			continue;
		field = around[siz];
		subfield = inside[siz];
		for (pos = siz; pos <= fs->fs_frag; pos++) {
			if ((fragmap & field) == subfield) {
				fraglist[siz] += cnt;
				pos += siz;
				field <<= siz;
				subfield <<= siz;
			}
			field <<= 1;
			subfield <<= 1;
		}
	}
}

#ifdef KDB
void
ffs_checkoverlap(bp, ip)
	struct buf *bp;
	struct inode *ip;
{
	struct buf *ebp, *ep;
	ufs2_daddr_t start, last;
	struct vnode *vp;

	ebp = &buf[nbuf];
	start = bp->b_blkno;
	last = start + btodb(bp->b_bcount) - 1;
	for (ep = buf; ep < ebp; ep++) {
		if (ep == bp || (ep->b_flags & B_INVAL) ||
		    ep->b_vp == NULLVP)
			continue;
		vp = ip->i_devvp;
		/* look for overlap */
		if (ep->b_bcount == 0 || ep->b_blkno > last ||
		    ep->b_blkno + btodb(ep->b_bcount) <= start)
			continue;
		vprint("Disk overlap", vp);
		printf("\tstart %jd, end %jd overlap start %jd, end %jd\n",
		    (intmax_t)start, (intmax_t)last, (intmax_t)ep->b_blkno,
		    (intmax_t)(ep->b_blkno + btodb(ep->b_bcount) - 1));
		panic("ffs_checkoverlap: Disk buffer overlap");
	}
}
#endif /* KDB */

/*
 * block operations
 *
 * check if a block is available
 */
int
ffs_isblock(fs, cp, h)
	struct fs *fs;
	unsigned char *cp;
	ufs1_daddr_t h;
{
	unsigned char mask;

	switch ((int)fs->fs_frag) {
	case 8:
		return (cp[h] == 0xff);
	case 4:
		mask = 0x0f << ((h & 0x1) << 2);
		return ((cp[h >> 1] & mask) == mask);
	case 2:
		mask = 0x03 << ((h & 0x3) << 1);
		return ((cp[h >> 2] & mask) == mask);
	case 1:
		mask = 0x01 << (h & 0x7);
		return ((cp[h >> 3] & mask) == mask);
	default:
#ifdef _KERNEL
		panic("ffs_isblock");
#endif
		break;
	}
	return (0);
}

/*
 * check if a block is free
 */
int
ffs_isfreeblock(fs, cp, h)
	struct fs *fs;
	u_char *cp;
	ufs1_daddr_t h;
{
 
	switch ((int)fs->fs_frag) {
	case 8:
		return (cp[h] == 0);
	case 4:
		return ((cp[h >> 1] & (0x0f << ((h & 0x1) << 2))) == 0);
	case 2:
		return ((cp[h >> 2] & (0x03 << ((h & 0x3) << 1))) == 0);
	case 1:
		return ((cp[h >> 3] & (0x01 << (h & 0x7))) == 0);
	default:
#ifdef _KERNEL
		panic("ffs_isfreeblock");
#endif
		break;
	}
	return (0);
}

/*
 * take a block out of the map
 */
void
ffs_clrblock(fs, cp, h)
	struct fs *fs;
	u_char *cp;
	ufs1_daddr_t h;
{

	switch ((int)fs->fs_frag) {
	case 8:
		cp[h] = 0;
		return;
	case 4:
		cp[h >> 1] &= ~(0x0f << ((h & 0x1) << 2));
		return;
	case 2:
		cp[h >> 2] &= ~(0x03 << ((h & 0x3) << 1));
		return;
	case 1:
		cp[h >> 3] &= ~(0x01 << (h & 0x7));
		return;
	default:
#ifdef _KERNEL
		panic("ffs_clrblock");
#endif
		break;
	}
}

/*
 * put a block into the map
 */
void
ffs_setblock(fs, cp, h)
	struct fs *fs;
	unsigned char *cp;
	ufs1_daddr_t h;
{

	switch ((int)fs->fs_frag) {

	case 8:
		cp[h] = 0xff;
		return;
	case 4:
		cp[h >> 1] |= (0x0f << ((h & 0x1) << 2));
		return;
	case 2:
		cp[h >> 2] |= (0x03 << ((h & 0x3) << 1));
		return;
	case 1:
		cp[h >> 3] |= (0x01 << (h & 0x7));
		return;
	default:
#ifdef _KERNEL
		panic("ffs_setblock");
#endif
		break;
	}
}

/*
 * Update the cluster map because of an allocation or free.
 *
 * Cnt == 1 means free; cnt == -1 means allocating.
 */
void
ffs_clusteracct(fs, cgp, blkno, cnt)
	struct fs *fs;
	struct cg *cgp;
	ufs1_daddr_t blkno;
	int cnt;
{
	int32_t *sump;
	int32_t *lp;
	u_char *freemapp, *mapp;
	int i, start, end, forw, back, map, bit;

	if (fs->fs_contigsumsize <= 0)
		return;
	freemapp = cg_clustersfree(cgp);
	sump = cg_clustersum(cgp);
	/*
	 * Allocate or clear the actual block.
	 */
	if (cnt > 0)
		setbit(freemapp, blkno);
	else
		clrbit(freemapp, blkno);
	/*
	 * Find the size of the cluster going forward.
	 */
	start = blkno + 1;
	end = start + fs->fs_contigsumsize;
	if (end >= cgp->cg_nclusterblks)
		end = cgp->cg_nclusterblks;
	mapp = &freemapp[start / NBBY];
	map = *mapp++;
	bit = 1 << (start % NBBY);
	for (i = start; i < end; i++) {
		if ((map & bit) == 0)
			break;
		if ((i & (NBBY - 1)) != (NBBY - 1)) {
			bit <<= 1;
		} else {
			map = *mapp++;
			bit = 1;
		}
	}
	forw = i - start;
	/*
	 * Find the size of the cluster going backward.
	 */
	start = blkno - 1;
	end = start - fs->fs_contigsumsize;
	if (end < 0)
		end = -1;
	mapp = &freemapp[start / NBBY];
	map = *mapp--;
	bit = 1 << (start % NBBY);
	for (i = start; i > end; i--) {
		if ((map & bit) == 0)
			break;
		if ((i & (NBBY - 1)) != 0) {
			bit >>= 1;
		} else {
			map = *mapp--;
			bit = 1 << (NBBY - 1);
		}
	}
	back = start - i;
	/*
	 * Account for old cluster and the possibly new forward and
	 * back clusters.
	 */
	i = back + forw + 1;
	if (i > fs->fs_contigsumsize)
		i = fs->fs_contigsumsize;
	sump[i] += cnt;
	if (back > 0)
		sump[back] -= cnt;
	if (forw > 0)
		sump[forw] -= cnt;
	/*
	 * Update cluster summary information.
	 */
	lp = &sump[fs->fs_contigsumsize];
	for (i = fs->fs_contigsumsize; i > 0; i--)
		if (*lp-- > 0)
			break;
	fs->fs_maxcluster[cgp->cg_cgx] = i;
}