du_u.c

/*	$NetBSD: du.c,v 1.33 2008/07/30 22:03:40 dsl Exp $	*/

/*
 * Copyright (c) 1989, 1993, 1994
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Chris Newcomb.
 *
 * 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. 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.
 */

#include <sys/cdefs.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <dirent.h>
#include <err.h>
#include <errno.h>
#include <fts.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <limits.h>
#include <stdint.h>

int	linkchk(dev_t, ino_t);
void	prstat(const char *, int64_t);
void	usage(void);

long blocksize;

#ifndef howmany
#define howmany(x, y) (((x)+((y)-1))/(y))
#endif

int
du_main(int argc, char *argv[])
{
	FTS *fts;
	FTSENT *p;
	int64_t totalblocks;
	int ftsoptions, listfiles;
	int depth;
	int Hflag, Lflag, aflag, ch, cflag, dflag, gkmflag, rval, sflag;
	char *noargv[2];

	Hflag = Lflag = aflag = cflag = dflag = gkmflag = sflag = 0;
	totalblocks = 0;
	ftsoptions = FTS_PHYSICAL;
	depth = INT_MAX;
	while((ch = getopt(argc, argv, "HLPacd:ghkmnrsx")) != -1)
		switch(ch) {
			case 'H':
				Hflag = 1;
				Lflag = 0;
				break;
			case 'L':
				Lflag = 1;
				Hflag = 0;
				break;
			case 'P':
				Hflag = Lflag = 0;
				break;
			case 'a':
				aflag = 1;
				break;
			case 'c':
				cflag = 1;
				break;
			case 'd':
				dflag = 1;
				depth = atoi(optarg);
				if (depth < 0 || depth > SHRT_MAX) {
					warnx("invalid argument to option d: %s", optarg);
					usage();
				}
				break;
			case 'g':
				blocksize = 1024 * 1024 * 1024;
				gkmflag = 1;
				break;
			case 'k':
				blocksize = 1024;
				gkmflag = 1;
				break;
			case 'm':
				blocksize = 1024 * 1024;
				gkmflag = 1;
				break; 
			case 'r':
				break;
			case 's':
				sflag = 1;
				break;
			case 'x':
				ftsoptions |= FTS_XDEV;
				break;
			case '?':
			default:
				usage();
		}
	argc -= optind;
	argv += optind;

	/*
	 * XXX
	 * Because of the way that fts(3) works, logical walks will not count
	 * the blocks actually used by symbolic links.  We rationalize this by
	 * noting that users computing logical sizes are likely to do logical
	 * copies, so not counting the links is correct.  The real reason is
	 * that we'd have to re-implement the kernel's symbolic link traversing
	 * algorithm to get this right.  If, for example, you have relative
	 * symbolic links referencing other relative symbolic links, it gets
	 * very nasty, very fast.  The bottom line is that it's documented in
	 * the man page, so it's a feature.
	 */
	if(Hflag) ftsoptions |= FTS_COMFOLLOW;
	if(Lflag) {
		ftsoptions &= ~FTS_PHYSICAL;
		ftsoptions |= FTS_LOGICAL;
	}

	listfiles = 0;
	if(aflag) {
		if (sflag || dflag)
			usage();
		listfiles = 1;
	} else if(sflag) {
		if(dflag) usage();
		depth = 0;
	}

	if(!*argv) {
		noargv[0] = ".";
		noargv[1] = NULL;
		argv = noargv;
	}

	if(!gkmflag) blocksize = 512;
	blocksize /= 512;

	if(!(fts = fts_open(argv, ftsoptions, NULL))) err(1, "fts_open `%s'", *argv);

	for(rval = 0; (p = fts_read(fts));) {
		switch (p->fts_info) {
		case FTS_D:			/* Ignore. */
			break;
		case FTS_DP:
			p->fts_parent->fts_number += 
			    p->fts_number += p->fts_statp->st_blocks;
			if (cflag)
				totalblocks += p->fts_statp->st_blocks;
			/*
			 * If listing each directory, or not listing files
			 * or directories and this is post-order of the
			 * root of a traversal, display the total.
			 */
			if (p->fts_level <= depth
			    || (!listfiles && !p->fts_level))
				prstat(p->fts_path, p->fts_number);
			break;
		case FTS_DC:			/* Ignore. */
			break;
		case FTS_DNR:			/* Warn, continue. */
		case FTS_ERR:
		case FTS_NS:
			warnx("%s: %s", p->fts_path, strerror(p->fts_errno));
			rval = 1;
			break;
		default:
			if (p->fts_statp->st_nlink > 1 && linkchk(p->fts_statp->st_dev, p->fts_statp->st_ino)) {
				break;
			}
			/*
			 * If listing each file, or a non-directory file was
			 * the root of a traversal, display the total.
			 */
			if(listfiles || !p->fts_level) prstat(p->fts_path, p->fts_statp->st_blocks);
			p->fts_parent->fts_number += p->fts_statp->st_blocks;
			if(cflag) totalblocks += p->fts_statp->st_blocks;
		}
	}
	if(errno) err(1, "fts_read");
	if(cflag) prstat("total", totalblocks);
	exit(rval);
}

void
prstat(const char *fname, int64_t blocks)
{
	printf("%lld\t%s\n", (long long)howmany(blocks, (int64_t)blocksize), fname);
}

int
linkchk(dev_t dev, ino_t ino)
{
	static struct entry {
		dev_t	dev;
		ino_t	ino;
	} *htable;
	static int htshift;  /* log(allocated size) */
	static int htmask;   /* allocated size - 1 */
	static int htused;   /* 2*number of insertions */
	static int sawzero;  /* Whether zero is in table or not */
	int h, h2;
	uint64_t tmp;
	/* this constant is (1<<64)/((1+sqrt(5))/2)
	 * aka (word size)/(golden ratio)
	 */
	const uint64_t HTCONST = 11400714819323198485ULL;
	const int HTBITS = CHAR_BIT * sizeof(tmp);

	/* Never store zero in hashtable */
	if(dev == 0 && ino == 0) {
		h = sawzero;
		sawzero = 1;
		return h;
	}

	/* Extend hash table if necessary, keep load under 0.5 */
	if(htused<<1 >= htmask) {
		struct entry *ohtable;

		if(!htable) htshift = 10;   /* starting hashtable size */
		else htshift++;   /* exponential hashtable growth */

		htmask = (1 << htshift) - 1;
		htused = 0;

		ohtable = htable;
		htable = calloc(htmask+1, sizeof(*htable));
		if(!htable) err(1, "calloc");

		/* populate newly allocated hashtable */
		if(ohtable) {
			int i;
			for(i = 0; i <= htmask>>1; i++) {
				if(ohtable[i].ino || ohtable[i].dev) linkchk(ohtable[i].dev, ohtable[i].ino);
			}
			free(ohtable);
		}
	}

	/* multiplicative hashing */
	tmp = dev;
	tmp <<= HTBITS>>1;
	tmp |=  ino;
	tmp *= HTCONST;
	h  = tmp >> (HTBITS - htshift);
	h2 = 1 | ( tmp >> (HTBITS - (htshift<<1) - 1));		/* must be odd */

	/* open address hashtable search with double hash probing */
	while(htable[h].ino || htable[h].dev) {
		if(htable[h].ino == ino && htable[h].dev == dev) return 1;
		h = (h + h2) & htmask;
	}

	/* Insert the current entry into hashtable */
	htable[h].dev = dev;
	htable[h].ino = ino;
	htused++;
	return 0;
}

void
usage(void)
{
	fprintf(stderr, "Usage: du [-H | -L | -P] [-a | -d depth | -s] [-cgkmrx] [file ...]\n");
	exit(1);
}