lfs.c

早期freebsd实现

/*-
 * 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.
 */

#ifndef lint
static char sccsid[] = "@(#)lfs.c	8.1 (Berkeley) 6/5/93";
#endif /* not lint */

#include <sys/param.h>
#include <sys/disklabel.h>
#include <sys/time.h>
#include <sys/mount.h>

#include <ufs/ufs/dir.h>
#include <ufs/ufs/quota.h>
#include <ufs/ufs/dinode.h>
#include <ufs/lfs/lfs.h>

#include <unistd.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include "config.h"
#include "extern.h"

/*
 * This table is indexed by the log base 2 of the block size.
 * It returns the maximum file size allowed in a file system
 * with the specified block size.  For block sizes smaller than
 * 8K, the size is limited by tha maximum number of blocks that
 * can be reached by triply indirect blocks:
 *	NDADDR + INOPB(bsize) + INOPB(bsize)^2 + INOPB(bsize)^3
 * For block size of 8K or larger, the file size is limited by the
 * number of blocks that can be represented in the file system.  Since
 * we use negative block numbers to represent indirect blocks, we can
 * have a maximum of 2^31 blocks.
 */

u_quad_t maxtable[] = {
	/*    1 */ -1,
	/*    2 */ -1,
	/*    4 */ -1,
	/*    8 */ -1,
	/*   16 */ -1,
	/*   32 */ -1,
	/*   64 */ -1,
	/*  128 */ -1,
	/*  256 */ -1,
	/*  512 */ NDADDR + 128 + 128 * 128 + 128 * 128 * 128,
	/* 1024 */ NDADDR + 256 + 256 * 256 + 256 * 256 * 256,
	/* 2048 */ NDADDR + 512 + 512 * 512 + 512 * 512 * 512,
	/* 4096 */ NDADDR + 1024 + 1024 * 1024 + 1024 * 1024 * 1024,
	/* 8192 */ 1 << 31,
	/* 16 K */ 1 << 31,
	/* 32 K */ 1 << 31,
};

static struct lfs lfs_default =  {
	/* lfs_magic */		LFS_MAGIC,
	/* lfs_version */	LFS_VERSION,
	/* lfs_size */		0,
	/* lfs_ssize */		DFL_LFSSEG/DFL_LFSBLOCK,
	/* lfs_dsize */		0,
	/* lfs_bsize */		DFL_LFSBLOCK,
	/* lfs_fsize */		DFL_LFSBLOCK,
	/* lfs_frag */		1,
	/* lfs_free */		LFS_FIRST_INUM,
	/* lfs_bfree */		0,
	/* lfs_nfiles */	0,
	/* lfs_avail */		0,
	/* lfs_uinodes */	0,
	/* lfs_idaddr */	0,
	/* lfs_ifile */		LFS_IFILE_INUM,
	/* lfs_lastseg */	0,
	/* lfs_nextseg */	0,
	/* lfs_curseg */	0,
	/* lfs_offset */	0,
	/* lfs_lastpseg */	0,
	/* lfs_tstamp */	0,
	/* lfs_minfree */	MINFREE,
	/* lfs_maxfilesize */	0,
	/* lfs_dbpseg */	DFL_LFSSEG/DEV_BSIZE,
	/* lfs_inopb */		DFL_LFSBLOCK/sizeof(struct dinode),
	/* lfs_ifpb */		DFL_LFSBLOCK/sizeof(IFILE),
	/* lfs_sepb */		DFL_LFSBLOCK/sizeof(SEGUSE),
	/* lfs_nindir */	DFL_LFSBLOCK/sizeof(daddr_t),
	/* lfs_nseg */		0,
	/* lfs_nspf */		0,
	/* lfs_cleansz */	0,
	/* lfs_segtabsz */	0,
	/* lfs_segmask */	DFL_LFSSEG_MASK,
	/* lfs_segshift */	DFL_LFSSEG_SHIFT,
	/* lfs_bmask */		DFL_LFSBLOCK_MASK,
	/* lfs_bshift */	DFL_LFSBLOCK_SHIFT,
	/* lfs_ffmask */	0,
	/* lfs_ffshift */	0,
	/* lfs_fbmask */	0,
	/* lfs_fbshift */	0,
	/* lfs_fsbtodb */	0,
	/* lfs_sushift */	0,
	/* lfs_sboffs */	{ 0 },
	/* lfs_sp */		NULL,
	/* lfs_ivnode */	NULL,
	/* lfs_seglock */	0,
	/* lfs_lockpid */	0,
	/* lfs_iocount */	0,
	/* lfs_writer */	0,
	/* lfs_dirops */	0,
	/* lfs_doifile */	0,
	/* lfs_nactive */	0,
	/* lfs_fmod */		0,
	/* lfs_clean */		0,
	/* lfs_ronly */		0,
	/* lfs_flags */		0,
	/* lfs_fsmnt */		{ 0 },
	/* lfs_pad */		{ 0 },
	/* lfs_cksum */		0
};


struct direct lfs_root_dir[] = {
	{ ROOTINO, sizeof(struct direct), DT_DIR, 1, "."},
	{ ROOTINO, sizeof(struct direct), DT_DIR, 2, ".."},
	{ LFS_IFILE_INUM, sizeof(struct direct), DT_REG, 5, "ifile"},
	{ LOSTFOUNDINO, sizeof(struct direct), DT_DIR, 10, "lost+found"},
};

struct direct lfs_lf_dir[] = {
        { LOSTFOUNDINO, sizeof(struct direct), DT_DIR, 1, "." },
        { ROOTINO, sizeof(struct direct), DT_DIR, 2, ".." },
};

static daddr_t make_dinode 
	__P((ino_t, struct dinode *, int, daddr_t, struct lfs *));
static void make_dir __P(( void *, struct direct *, int));
static void put __P((int, off_t, void *, size_t));

int
make_lfs(fd, lp, partp, minfree, block_size, seg_size)
	int fd;
	struct disklabel *lp;
	struct partition *partp;
	int minfree;
	int block_size;
	int seg_size;
{
	struct dinode *dip;	/* Pointer to a disk inode */
	struct dinode *dpagep;	/* Pointer to page of disk inodes */
	CLEANERINFO *cleaninfo;	/* Segment cleaner information table */
	FINFO file_info;	/* File info structure in summary blocks */
	IFILE *ifile;		/* Pointer to array of ifile structures */
	IFILE *ip;		/* Pointer to array of ifile structures */
	struct lfs *lfsp;	/* Superblock */
	SEGUSE *segp;		/* Segment usage table */
	SEGUSE *segtable;	/* Segment usage table */
	SEGSUM summary;		/* Segment summary structure */
	SEGSUM *sp;		/* Segment summary pointer */
	daddr_t	last_sb_addr;	/* Address of superblocks */
	daddr_t last_addr;	/* Previous segment address */
	daddr_t	sb_addr;	/* Address of superblocks */
	daddr_t	seg_addr;	/* Address of current segment */
	void *ipagep;		/* Pointer to the page we use to write stuff */
	void *sump;		/* Used to copy stuff into segment buffer */
	u_long *block_array;	/* Array of logical block nos to put in sum */
	u_long blocks_used;	/* Number of blocks in first segment */
	u_long *dp;		/* Used to computed checksum on data */
	u_long *datasump;	/* Used to computed checksum on data */
	int block_array_size;	/* How many entries in block array */
	int bsize;		/* Block size */
	int db_per_fb;		/* Disk blocks per file block */
	int i, j;
	int off;		/* Offset at which to write */
	int sb_interval;	/* number of segs between super blocks */
	int seg_seek;		/* Seek offset for a segment */
	int ssize;		/* Segment size */
	int sum_size;		/* Size of the summary block */

	lfsp = &lfs_default;

	if (!(bsize = block_size))
		bsize = DFL_LFSBLOCK;
	if (!(ssize = seg_size))
		ssize = DFL_LFSSEG;

	/* Modify parts of superblock overridden by command line arguments */
	if (bsize != DFL_LFSBLOCK) {
		lfsp->lfs_bshift = log2(bsize);
		if (1 << lfsp->lfs_bshift != bsize)
			fatal("%d: block size not a power of 2", bsize);
		lfsp->lfs_bsize = bsize;
		lfsp->lfs_fsize = bsize;
		lfsp->lfs_bmask = bsize - 1;
		lfsp->lfs_inopb = bsize / sizeof(struct dinode);
/* MIS -- should I round to power of 2 */
		lfsp->lfs_ifpb = bsize / sizeof(IFILE);
		lfsp->lfs_sepb = bsize / sizeof(SEGUSE);
		lfsp->lfs_nindir = bsize / sizeof(daddr_t);
	}

	if (ssize != DFL_LFSSEG) {
		lfsp->lfs_segshift = log2(ssize);
		if (1 << lfsp->lfs_segshift != ssize)
			fatal("%d: segment size not power of 2", ssize);
		lfsp->lfs_ssize = ssize;
		lfsp->lfs_segmask = ssize - 1;
		lfsp->lfs_dbpseg = ssize / DEV_BSIZE;
	}
	lfsp->lfs_ssize = ssize >> lfsp->lfs_bshift;

	if (minfree)
		lfsp->lfs_minfree = minfree;

	/*
	 * Fill in parts of superblock that can be computed from file system
	 * size, disk geometry and current time.
	 */
	db_per_fb = bsize/lp->d_secsize;
	lfsp->lfs_fsbtodb = log2(db_per_fb);
	lfsp->lfs_sushift = log2(lfsp->lfs_sepb);
	lfsp->lfs_size = partp->p_size >> lfsp->lfs_fsbtodb;
	lfsp->lfs_dsize = lfsp->lfs_size - (LFS_LABELPAD >> lfsp->lfs_bshift);
	lfsp->lfs_nseg = lfsp->lfs_dsize / lfsp->lfs_ssize;
	lfsp->lfs_maxfilesize = maxtable[lfsp->lfs_bshift] << lfsp->lfs_bshift;

	/* 
	 * The number of free blocks is set from the number of segments times
	 * the segment size - 2 (that we never write because we need to make
	 * sure the cleaner can run).  Then we'll subtract off the room for the
	 * superblocks ifile entries and segment usage table.
	 */
	lfsp->lfs_dsize = fsbtodb(lfsp, (lfsp->lfs_nseg - 2) * lfsp->lfs_ssize);
	lfsp->lfs_bfree = lfsp->lfs_dsize;
	lfsp->lfs_segtabsz = SEGTABSIZE_SU(lfsp);
	lfsp->lfs_cleansz = CLEANSIZE_SU(lfsp);
	if ((lfsp->lfs_tstamp = time(NULL)) == -1)
		fatal("time: %s", strerror(errno));
	if ((sb_interval = lfsp->lfs_nseg / LFS_MAXNUMSB) < LFS_MIN_SBINTERVAL)
		sb_interval = LFS_MIN_SBINTERVAL;

	/*
	 * Now, lay out the file system.  We need to figure out where
	 * the superblocks go, initialize the checkpoint information
	 * for the first two superblocks, initialize the segment usage
	 * information, put the segusage information in the ifile, create
	 * the first block of IFILE structures, and link all the IFILE
	 * structures into a free list.
	 */

	/* Figure out where the superblocks are going to live */
	lfsp->lfs_sboffs[0] = LFS_LABELPAD/lp->d_secsize;
	for (i = 1; i < LFS_MAXNUMSB; i++) {
		sb_addr = ((i * sb_interval) << 
		    (lfsp->lfs_segshift - lfsp->lfs_bshift + lfsp->lfs_fsbtodb))
		    + lfsp->lfs_sboffs[0];
		if (sb_addr > partp->p_size)
			break;
		lfsp->lfs_sboffs[i] = sb_addr;
	}
	last_sb_addr = lfsp->lfs_sboffs[i - 1];
	lfsp->lfs_lastseg = lfsp->lfs_sboffs[0];
	lfsp->lfs_nextseg = 
	    lfsp->lfs_sboffs[1] ? lfsp->lfs_sboffs[1] : lfsp->lfs_sboffs[0];
	lfsp->lfs_curseg = lfsp->lfs_lastseg;

	/*
	 * Initialize the segment usage table.  The first segment will
	 * contain the superblock, the cleanerinfo (cleansz), the segusage 
	 * table * (segtabsz), 1 block's worth of IFILE entries, the root 
	 * directory, the lost+found directory and one block's worth of 
	 * inodes (containing the ifile, root, and l+f inodes).
	 */
	if (!(cleaninfo = malloc(lfsp->lfs_cleansz << lfsp->lfs_bshift)))
		fatal("%s", strerror(errno));
	cleaninfo->clean = lfsp->lfs_nseg - 1;
	cleaninfo->dirty = 1;

	if (!(segtable = malloc(lfsp->lfs_segtabsz << lfsp->lfs_bshift)))
		fatal("%s", strerror(errno));
	segp = segtable;
	blocks_used = lfsp->lfs_segtabsz + lfsp->lfs_cleansz + 4;
	segp->su_nbytes = ((blocks_used - 1) << lfsp->lfs_bshift) +
	    3 * sizeof(struct dinode) + LFS_SUMMARY_SIZE;
	segp->su_lastmod = lfsp->lfs_tstamp;
	segp->su_nsums = 1;	/* 1 summary blocks */
	segp->su_ninos = 1;	/* 1 inode block */
	segp->su_flags = SEGUSE_SUPERBLOCK | SEGUSE_DIRTY;
	lfsp->lfs_bfree -= LFS_SUMMARY_SIZE / lp->d_secsize;
	lfsp->lfs_bfree -=
	     fsbtodb(lfsp, lfsp->lfs_cleansz + lfsp->lfs_segtabsz + 4);

	/* 
	 * Now figure out the address of the ifile inode. The inode block
	 * appears immediately after the segment summary.
	 */
	lfsp->lfs_idaddr = (LFS_LABELPAD + LFS_SBPAD + LFS_SUMMARY_SIZE) /
	    lp->d_secsize;

	for (segp = segtable + 1, i = 1; i < lfsp->lfs_nseg; i++, segp++) {
		if ((i % sb_interval) == 0) {
			segp->su_flags = SEGUSE_SUPERBLOCK;
			lfsp->lfs_bfree -= (LFS_SBPAD / lp->d_secsize);
		} else
			segp->su_flags = 0;
		segp->su_lastmod = 0;
		segp->su_nbytes = 0;
		segp->su_ninos = 0;
		segp->su_nsums = 0;
	}