zero out usec fields (from Rick Macklem)

[unix-history] / usr / src / sys / ufs / ffs / ffs_subr.c

/*
 * Copyright (c) 1982, 1986, 1989 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by the University of California, Berkeley.  The name of the
 * University may not be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 *
 *	@(#)ffs_subr.c	7.8 (Berkeley) %G%
 */

#ifdef KERNEL
#include "param.h"
#include "systm.h"
#include "buf.h"
#include "time.h"
#include "kernel.h"
#include "file.h"
#include "mount.h"
#include "vnode.h"
#include "../ufs/inode.h"
#include "../ufs/ufsmount.h"
#include "../ufs/fs.h"
#include "../ufs/quota.h"
#else
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/buf.h>
#include <sys/time.h>
#include <sys/file.h>
#include <sys/mount.h>
#include <sys/vnode.h>
#include <ufs/inode.h>
#include <ufs/ufsmount.h>
#include <ufs/fs.h>
#include <ufs/quota.h>
#endif

#ifdef KERNEL
/*
 * Flush all the blocks associated with an inode.
 * There are two strategies based on the size of the file;
 * large files are those with more than (nbuf / 2) blocks.
 * Large files
 * 	Walk through the buffer pool and push any dirty pages
 *	associated with the device on which the file resides.
 * Small files
 *	Look up each block in the file to see if it is in the 
 *	buffer pool writing any that are found to disk.
 *	Note that we make a more stringent check of
 *	writing out any block in the buffer pool that may
 *	overlap the inode. This brings the inode up to
 *	date with recent mods to the cooked device.
 */
syncip(ip)
	register struct inode *ip;
{
	register struct fs *fs;
	register struct buf *bp;
	struct buf *lastbufp;
	long lbn, lastlbn;
	int s, error, allerror = 0;
	daddr_t blkno;

	fs = ip->i_fs;
	lastlbn = howmany(ip->i_size, fs->fs_bsize);
	if (lastlbn < nbuf / 2) {
#ifdef SECSIZE
		lastlbn--;
		s = fsbtodb(fs, fs->fs_frag);
		for (lbn = 0; lbn < lastlbn; lbn++) {
			error = bmap(ip, lbn, &blkno, (daddr_t *)0, (int *)0);
			if (error)
				allerror = error;
			if (error = blkflush(ip->i_devvp, blkno,
			    blksize(fs, ip, lbn)))
				allerror = error;
		}
#endif SECSIZE
	} else {
		lastbufp = &buf[nbuf];
		for (bp = buf; bp < lastbufp; bp++) {
			if (bp->b_dev != ip->i_dev ||
			    (bp->b_flags & B_DELWRI) == 0)
				continue;
			s = splbio();
			if (bp->b_flags & B_BUSY) {
				bp->b_flags |= B_WANTED;
				sleep((caddr_t)bp, PRIBIO+1);
				splx(s);
				bp--;
				continue;
			}
			splx(s);
			notavail(bp);
			if (error = bwrite(bp))
				allerror = error;
		}
	}
	if (error = iupdat(ip, &time, &time, 1))
		allerror = error;
	return (allerror);
}
#endif KERNEL

extern	int around[9];
extern	int inside[9];
extern	u_char *fragtbl[];

/*
 * Update the frsum fields to reflect addition or deletion 
 * of some frags.
 */
fragacct(fs, fragmap, fraglist, cnt)
	struct fs *fs;
	int fragmap;
	long fraglist[];
	int cnt;
{
	int inblk;
	register int field, subfield;
	register 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 KERNEL
/*
 * Check that a specified block number is in range.
 */
badblock(fs, bn)
	register struct fs *fs;
	daddr_t bn;
{

	if ((unsigned)bn >= fs->fs_size) {
		printf("bad block %d, ", bn);
		fserr(fs, "bad block");
		return (1);
	}
	return (0);
}
#endif

/*
 * block operations
 *
 * check if a block is available
 */
isblock(fs, cp, h)
	struct fs *fs;
	unsigned char *cp;
	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:
		panic("isblock");
		return (NULL);
	}
}

/*
 * take a block out of the map
 */
clrblock(fs, cp, h)
	struct fs *fs;
	u_char *cp;
	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:
		panic("clrblock");
	}
}

/*
 * put a block into the map
 */
setblock(fs, cp, h)
	struct fs *fs;
	unsigned char *cp;
	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:
		panic("setblock");
	}
}

#ifdef KERNEL
/*
 * Getfs maps a device number into a pointer to the incore super block.
 *
 * The algorithm is a linear search through the mount table. A
 * consistency check of the super block magic number is performed.
 * Filesystems still working on a mount are skipped.
 *
 * panic: no fs -- the device is not mounted.
 *	this "cannot happen"
 */
struct fs *
getfs(dev)
	dev_t dev;
{
	register struct ufsmount *mp;
	register struct fs *fs;

	for (mp = &mounttab[0]; mp < &mounttab[NMOUNT]; mp++) {
		if (mp->um_fs == NULL || mp->um_dev != dev ||
		    mp->um_fs == (struct fs *)1)		/* XXX */
			continue;
		fs = mp->um_fs;
		if (fs->fs_magic != FS_MAGIC) {
			printf("dev = 0x%x, fs = %s\n", dev, fs->fs_fsmnt);
			panic("getfs: bad magic");
		}
		return (fs);
	}
	printf("dev = 0x%x\n", dev);
	panic("getfs: no fs");
	return (NULL);
}

/*
 * Getfsx returns the index in the file system
 * table of the specified device.  The swap device
 * is also assigned a pseudo-index.  The index may
 * be used as a compressed indication of the location
 * of a block, recording
 *	<getfsx(dev),blkno>
 * rather than
 *	<dev, blkno>
 * provided the information need remain valid only
 * as long as the file system is mounted.
 */
getfsx(dev)
	dev_t dev;
{
	register struct ufsmount *mp;

	if (dev == swapdev)
		return (MSWAPX);
	for(mp = &mounttab[0]; mp < &mounttab[NMOUNT]; mp++)
		if (mp->um_dev == dev)
			return (mp - &mounttab[0]);
	return (-1);
}
#endif

#if (!defined(vax) && !defined(tahoe)) || defined(VAX630) || defined(VAX650)
/*
 * C definitions of special instructions.
 * Normally expanded with inline.
 */
scanc(size, cp, table, mask)
	u_int size;
	register u_char *cp, table[];
	register u_char mask;
{
	register u_char *end = &cp[size];

	while (cp < end && (table[*cp] & mask) == 0)
		cp++;
	return (end - cp);
}
#endif

#if !defined(vax) && !defined(tahoe)
skpc(mask, size, cp)
	register u_char mask;
	u_int size;
	register u_char *cp;
{
	register u_char *end = &cp[size];

	while (cp < end && *cp == mask)
		cp++;
	return (end - cp);
}

locc(mask, size, cp)
	register u_char mask;
	u_int size;
	register u_char *cp;
{
	register u_char *end = &cp[size];

	while (cp < end && *cp != mask)
		cp++;
	return (end - cp);
}
#endif