usr/src/boot/sys/boot/common/ufsread.c - illumos-gate - Gitiles

 /*-
  * Copyright (c) 2002 McAfee, Inc.
  * All rights reserved.
  *
  * This software was developed for the FreeBSD Project by Marshall
  * Kirk McKusick and McAfee Research,, the Security Research Division of
  * McAfee, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as
  * part of the DARPA CHATS research program
  *
  * 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.
  *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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) 1998 Robert Nordier
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms are freely
  * permitted provided that the above copyright notice and this
  * paragraph and the following disclaimer are duplicated in all
  * such forms.
  *
  * 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.
  */

 #include <sys/cdefs.h>
 __FBSDID("$FreeBSD$");

 #include <ufs/ufs/dinode.h>
 #include <ufs/ufs/dir.h>
 #include <ufs/ffs/fs.h>

 #ifdef UFS_SMALL_CGBASE
 /* XXX: Revert to old (broken for over 1.5Tb filesystems) version of cgbase
    (see sys/ufs/ffs/fs.h rev 1.39) so that small boot loaders (e.g. boot2) can
    support both UFS1 and UFS2. */
 #undef cgbase
 #define cgbase(fs, c)   ((ufs2_daddr_t)((fs)->fs_fpg * (c)))
 #endif

 typedef	uint32_t	ufs_ino_t;

 /*
  * We use 4k `virtual' blocks for filesystem data, whatever the actual
  * filesystem block size. FFS blocks are always a multiple of 4k.
  */
 #define VBLKSHIFT	12
 #define VBLKSIZE	(1 << VBLKSHIFT)
 #define VBLKMASK	(VBLKSIZE - 1)
 #define DBPERVBLK	(VBLKSIZE / DEV_BSIZE)
 #define INDIRPERVBLK(fs) (NINDIR(fs) / ((fs)->fs_bsize >> VBLKSHIFT))
 #define IPERVBLK(fs)	(INOPB(fs) / ((fs)->fs_bsize >> VBLKSHIFT))
 #define INO_TO_VBA(fs, ipervblk, x) \
     (fsbtodb(fs, cgimin(fs, ino_to_cg(fs, x))) + \
     (((x) % (fs)->fs_ipg) / (ipervblk) * DBPERVBLK))
 #define INO_TO_VBO(ipervblk, x) ((x) % ipervblk)
 #define FS_TO_VBA(fs, fsb, off) (fsbtodb(fs, fsb) + \
     ((off) / VBLKSIZE) * DBPERVBLK)
 #define FS_TO_VBO(fs, fsb, off) ((off) & VBLKMASK)

 /* Buffers that must not span a 64k boundary. */
 struct dmadat {
 	char blkbuf[VBLKSIZE];	/* filesystem blocks */
 	char indbuf[VBLKSIZE];	/* indir blocks */
 	char sbbuf[SBLOCKSIZE];	/* superblock */
 	char secbuf[DEV_BSIZE];	/* for MBR/disklabel */
 };
 static struct dmadat *dmadat;

 static ufs_ino_t lookup(const char *);
 static ssize_t fsread(ufs_ino_t, void *, size_t);
 static uint8_t inode_type(ufs_ino_t inode);

 static uint8_t ls, dsk_meta;
 static uint32_t fs_off;

 #ifndef UFS2_ONLY
 static struct ufs1_dinode dp1;
 ufs1_daddr_t addr1;
 #endif
 #ifndef UFS1_ONLY
 static struct ufs2_dinode dp2;
 #endif
 static struct fs fs;
 static ufs_ino_t inomap;
 static ufs2_daddr_t blkmap, indmap;

 static __inline uint8_t
 fsfind(const char *name, ufs_ino_t * ino)
 {
 	static char buf[DEV_BSIZE];
 	struct direct *d;
 	char *s;
 	ssize_t n;

 	fs_off = 0;
 	while ((n = fsread(*ino, buf, DEV_BSIZE)) > 0)
 		for (s = buf; s < buf + DEV_BSIZE;) {
 			d = (void *)s;
 			if (ls)
 				printf("%s ", d->d_name);
 			else if (!strcmp(name, d->d_name)) {
 				*ino = d->d_ino;
 				return inode_type(*ino);
 			}
 			s += d->d_reclen;
 		}
 	if (n != -1 && ls)
 		printf("\n");
 	return 0;
 }

 static ufs_ino_t
 lookup(const char *path)
 {
 	static char name[MAXNAMLEN + 1];
 	const char *s;
 	ufs_ino_t ino;
 	ssize_t n;
 	uint8_t dt;

 	ino = ROOTINO;
 	dt = DT_DIR;
 	for (;;) {
 		if (*path == '/')
 			path++;
 		if (!*path)
 			break;
 		for (s = path; *s && *s != '/'; s++);
 		if ((n = s - path) > MAXNAMLEN)
 			return 0;
 		ls = *path == '?' && n == 1 && !*s;
 		memcpy(name, path, n);
 		name[n] = 0;
 		if (dt != DT_DIR) {
 			printf("%s: not a directory.\n", name);
 			return (0);
 		}
 		if ((dt = fsfind(name, &ino)) <= 0)
 			break;
 		path = s;
 	}
 	return dt == DT_REG ? ino : 0;
 }

 /*
  * Possible superblock locations ordered from most to least likely.
  */
 static int sblock_try[] = SBLOCKSEARCH;

 #if defined(UFS2_ONLY)
 #define DIP(field) dp2.field
 #elif defined(UFS1_ONLY)
 #define DIP(field) dp1.field
 #else
 #define DIP(field) fs.fs_magic == FS_UFS1_MAGIC ? dp1.field : dp2.field
 #endif

 static uint8_t
 inode_type(ufs_ino_t inode)
 {
 	char *blkbuf;
 	void *indbuf;
 	size_t n;

 	blkbuf = dmadat->blkbuf;
 	indbuf = dmadat->indbuf;

 	if (!inode)
 		return (0);
 	if (inomap != inode) {
 		n = IPERVBLK(&fs);
 		if (dskread(blkbuf, INO_TO_VBA(&fs, n, inode), DBPERVBLK))
 			return (-1);
 		n = INO_TO_VBO(n, inode);
 #if defined(UFS1_ONLY)
 		memcpy(&dp1, (struct ufs1_dinode *)blkbuf + n,
 		    sizeof(struct ufs1_dinode));
 #elif defined(UFS2_ONLY)
 		memcpy(&dp2, (struct ufs2_dinode *)blkbuf + n,
 		    sizeof(struct ufs2_dinode));
 #else
 		if (fs.fs_magic == FS_UFS1_MAGIC)
 			memcpy(&dp1, (struct ufs1_dinode *)blkbuf + n,
 			    sizeof(struct ufs1_dinode));
 		else
 			memcpy(&dp2, (struct ufs2_dinode *)blkbuf + n,
 			    sizeof(struct ufs2_dinode));
 #endif
 		inomap = inode;
 		fs_off = 0;
 		blkmap = indmap = 0;
 	}
 	return (IFTODT(DIP(di_mode)));
 }

 static ssize_t
 fsread_size(ufs_ino_t inode, void *buf, size_t nbyte, size_t *fsizep)
 {
 	char *blkbuf;
 	void *indbuf;
 	char *s;
 	size_t n, nb, size, off, vboff;
 	ufs_lbn_t lbn;
 	ufs2_daddr_t addr2, vbaddr;
 	u_int u;

 	/* Basic parameter validation. */
 	if ((buf == NULL && nbyte != 0) || dmadat == NULL)
 		return (-1);

 	blkbuf = dmadat->blkbuf;
 	indbuf = dmadat->indbuf;

 	/*
 	 * Force probe if inode is zero to ensure we have a valid fs, otherwise
 	 * when probing multiple paritions, reads from subsequent parititions
 	 * will incorrectly succeed.
 	 */
 	if (!dsk_meta || inode == 0) {
 		inomap = 0;
 		dsk_meta = 0;
 		for (n = 0; sblock_try[n] != -1; n++) {
 			if (dskread(dmadat->sbbuf, sblock_try[n] / DEV_BSIZE,
 			    SBLOCKSIZE / DEV_BSIZE))
 				return -1;
 			memcpy(&fs, dmadat->sbbuf, sizeof(struct fs));
 			if ((
 #if defined(UFS1_ONLY)
 			    fs.fs_magic == FS_UFS1_MAGIC
 #elif defined(UFS2_ONLY)
 			    (fs.fs_magic == FS_UFS2_MAGIC &&
 			    fs.fs_sblockloc == sblock_try[n])
 #else
 			    fs.fs_magic == FS_UFS1_MAGIC ||
 			    (fs.fs_magic == FS_UFS2_MAGIC &&
 			    fs.fs_sblockloc == sblock_try[n])
 #endif
 			    ) &&
 			    fs.fs_bsize <= MAXBSIZE &&
 			    fs.fs_bsize >= (int32_t)sizeof(struct fs))
 				break;
 		}
 		if (sblock_try[n] == -1) {
 			return -1;
 		}
 		dsk_meta++;
 	} else
 		memcpy(&fs, dmadat->sbbuf, sizeof(struct fs));
 	if (!inode)
 		return 0;
 	if (inomap != inode) {
 		n = IPERVBLK(&fs);
 		if (dskread(blkbuf, INO_TO_VBA(&fs, n, inode), DBPERVBLK))
 			return -1;
 		n = INO_TO_VBO(n, inode);
 #if defined(UFS1_ONLY)
 		memcpy(&dp1, (struct ufs1_dinode *)(void *)blkbuf + n,
 		    sizeof(dp1));
 #elif defined(UFS2_ONLY)
 		memcpy(&dp2, (struct ufs2_dinode *)(void *)blkbuf + n,
 		    sizeof(dp2));
 #else
 		if (fs.fs_magic == FS_UFS1_MAGIC)
 			memcpy(&dp1, (struct ufs1_dinode *)(void *)blkbuf + n,
 			    sizeof(dp1));
 		else
 			memcpy(&dp2, (struct ufs2_dinode *)(void *)blkbuf + n,
 			    sizeof(dp2));
 #endif
 		inomap = inode;
 		fs_off = 0;
 		blkmap = indmap = 0;
 	}
 	s = buf;
 	size = DIP(di_size);
 	n = size - fs_off;
 	if (nbyte > n)
 		nbyte = n;
 	nb = nbyte;
 	while (nb) {
 		lbn = lblkno(&fs, fs_off);
 		off = blkoff(&fs, fs_off);
 		if (lbn < NDADDR) {
 			addr2 = DIP(di_db[lbn]);
 		} else if (lbn < NDADDR + NINDIR(&fs)) {
 			n = INDIRPERVBLK(&fs);
 			addr2 = DIP(di_ib[0]);
 			u = (u_int)(lbn - NDADDR) / n * DBPERVBLK;
 			vbaddr = fsbtodb(&fs, addr2) + u;
 			if (indmap != vbaddr) {
 				if (dskread(indbuf, vbaddr, DBPERVBLK))
 					return -1;
 				indmap = vbaddr;
 			}
 			n = (lbn - NDADDR) & (n - 1);
 #if defined(UFS1_ONLY)
 			memcpy(&addr1, (ufs1_daddr_t *)indbuf + n,
 			    sizeof(ufs1_daddr_t));
 			addr2 = addr1;
 #elif defined(UFS2_ONLY)
 			memcpy(&addr2, (ufs2_daddr_t *)indbuf + n,
 			    sizeof(ufs2_daddr_t));
 #else
 			if (fs.fs_magic == FS_UFS1_MAGIC) {
 				memcpy(&addr1, (ufs1_daddr_t *)indbuf + n,
 				    sizeof(ufs1_daddr_t));
 				addr2 = addr1;
 			} else
 				memcpy(&addr2, (ufs2_daddr_t *)indbuf + n,
 				    sizeof(ufs2_daddr_t));
 #endif
 		} else
 			return -1;
 		vbaddr = fsbtodb(&fs, addr2) + (off >> VBLKSHIFT) * DBPERVBLK;
 		vboff = off & VBLKMASK;
 		n = sblksize(&fs, (off_t)size, lbn) - (off & ~VBLKMASK);
 		if (n > VBLKSIZE)
 			n = VBLKSIZE;
 		if (blkmap != vbaddr) {
 			if (dskread(blkbuf, vbaddr, n >> DEV_BSHIFT))
 				return -1;
 			blkmap = vbaddr;
 		}
 		n -= vboff;
 		if (n > nb)
 			n = nb;
 		memcpy(s, blkbuf + vboff, n);
 		s += n;
 		fs_off += n;
 		nb -= n;
 	}

 	if (fsizep != NULL)
 		*fsizep = size;

 	return nbyte;
 }

 static ssize_t
 fsread(ufs_ino_t inode, void *buf, size_t nbyte)
 {

 	return fsread_size(inode, buf, nbyte, NULL);
 }
	/*-
	* Copyright (c) 2002 McAfee, Inc.
	* All rights reserved.
	*
	* This software was developed for the FreeBSD Project by Marshall
	* Kirk McKusick and McAfee Research,, the Security Research Division of
	* McAfee, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as
	* part of the DARPA CHATS research program
	*
	* 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.
	*
	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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) 1998 Robert Nordier
	* All rights reserved.
	*
	* Redistribution and use in source and binary forms are freely
	* permitted provided that the above copyright notice and this
	* paragraph and the following disclaimer are duplicated in all
	* such forms.
	*
	* 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.
	*/

	#include <sys/cdefs.h>
	__FBSDID("$FreeBSD$");

	#include <ufs/ufs/dinode.h>
	#include <ufs/ufs/dir.h>
	#include <ufs/ffs/fs.h>

	#ifdef UFS_SMALL_CGBASE
	/* XXX: Revert to old (broken for over 1.5Tb filesystems) version of cgbase
	(see sys/ufs/ffs/fs.h rev 1.39) so that small boot loaders (e.g. boot2) can
	support both UFS1 and UFS2. */
	#undef cgbase
	#define cgbase(fs, c) ((ufs2_daddr_t)((fs)->fs_fpg * (c)))
	#endif

	typedef uint32_t ufs_ino_t;

	/*
	* We use 4k `virtual' blocks for filesystem data, whatever the actual
	* filesystem block size. FFS blocks are always a multiple of 4k.
	*/
	#define VBLKSHIFT 12
	#define VBLKSIZE (1 << VBLKSHIFT)
	#define VBLKMASK (VBLKSIZE - 1)
	#define DBPERVBLK (VBLKSIZE / DEV_BSIZE)
	#define INDIRPERVBLK(fs) (NINDIR(fs) / ((fs)->fs_bsize >> VBLKSHIFT))
	#define IPERVBLK(fs) (INOPB(fs) / ((fs)->fs_bsize >> VBLKSHIFT))
	#define INO_TO_VBA(fs, ipervblk, x) \
	(fsbtodb(fs, cgimin(fs, ino_to_cg(fs, x))) + \
	(((x) % (fs)->fs_ipg) / (ipervblk) * DBPERVBLK))
	#define INO_TO_VBO(ipervblk, x) ((x) % ipervblk)
	#define FS_TO_VBA(fs, fsb, off) (fsbtodb(fs, fsb) + \
	((off) / VBLKSIZE) * DBPERVBLK)
	#define FS_TO_VBO(fs, fsb, off) ((off) & VBLKMASK)

	/* Buffers that must not span a 64k boundary. */
	struct dmadat {
	char blkbuf[VBLKSIZE]; /* filesystem blocks */
	char indbuf[VBLKSIZE]; /* indir blocks */
	char sbbuf[SBLOCKSIZE]; /* superblock */
	char secbuf[DEV_BSIZE]; /* for MBR/disklabel */
	};
	static struct dmadat *dmadat;

	static ufs_ino_t lookup(const char *);
	static ssize_t fsread(ufs_ino_t, void *, size_t);
	static uint8_t inode_type(ufs_ino_t inode);

	static uint8_t ls, dsk_meta;
	static uint32_t fs_off;

	#ifndef UFS2_ONLY
	static struct ufs1_dinode dp1;
	ufs1_daddr_t addr1;
	#endif
	#ifndef UFS1_ONLY
	static struct ufs2_dinode dp2;
	#endif
	static struct fs fs;
	static ufs_ino_t inomap;
	static ufs2_daddr_t blkmap, indmap;

	static __inline uint8_t
	fsfind(const char name, ufs_ino_t ino)
	{
	static char buf[DEV_BSIZE];
	struct direct *d;
	char *s;
	ssize_t n;

	fs_off = 0;
	while ((n = fsread(*ino, buf, DEV_BSIZE)) > 0)
	for (s = buf; s < buf + DEV_BSIZE;) {
	d = (void *)s;
	if (ls)
	printf("%s ", d->d_name);
	else if (!strcmp(name, d->d_name)) {
	*ino = d->d_ino;
	return inode_type(*ino);
	}
	s += d->d_reclen;
	}
	if (n != -1 && ls)
	printf("\n");
	return 0;
	}

	static ufs_ino_t
	lookup(const char *path)
	{
	static char name[MAXNAMLEN + 1];
	const char *s;
	ufs_ino_t ino;
	ssize_t n;
	uint8_t dt;

	ino = ROOTINO;
	dt = DT_DIR;
	for (;;) {
	if (*path == '/')
	path++;
	if (!*path)
	break;
	for (s = path; s && s != '/'; s++);
	if ((n = s - path) > MAXNAMLEN)
	return 0;
	ls = path == '?' && n == 1 && !s;
	memcpy(name, path, n);
	name[n] = 0;
	if (dt != DT_DIR) {
	printf("%s: not a directory.\n", name);
	return (0);
	}
	if ((dt = fsfind(name, &ino)) <= 0)
	break;
	path = s;
	}
	return dt == DT_REG ? ino : 0;
	}

	/*
	* Possible superblock locations ordered from most to least likely.
	*/
	static int sblock_try[] = SBLOCKSEARCH;

	#if defined(UFS2_ONLY)
	#define DIP(field) dp2.field
	#elif defined(UFS1_ONLY)
	#define DIP(field) dp1.field
	#else
	#define DIP(field) fs.fs_magic == FS_UFS1_MAGIC ? dp1.field : dp2.field
	#endif

	static uint8_t
	inode_type(ufs_ino_t inode)
	{
	char *blkbuf;
	void *indbuf;
	size_t n;

	blkbuf = dmadat->blkbuf;
	indbuf = dmadat->indbuf;

	if (!inode)
	return (0);
	if (inomap != inode) {
	n = IPERVBLK(&fs);
	if (dskread(blkbuf, INO_TO_VBA(&fs, n, inode), DBPERVBLK))
	return (-1);
	n = INO_TO_VBO(n, inode);
	#if defined(UFS1_ONLY)
	memcpy(&dp1, (struct ufs1_dinode *)blkbuf + n,
	sizeof(struct ufs1_dinode));
	#elif defined(UFS2_ONLY)
	memcpy(&dp2, (struct ufs2_dinode *)blkbuf + n,
	sizeof(struct ufs2_dinode));
	#else
	if (fs.fs_magic == FS_UFS1_MAGIC)
	memcpy(&dp1, (struct ufs1_dinode *)blkbuf + n,
	sizeof(struct ufs1_dinode));
	else
	memcpy(&dp2, (struct ufs2_dinode *)blkbuf + n,
	sizeof(struct ufs2_dinode));
	#endif
	inomap = inode;
	fs_off = 0;
	blkmap = indmap = 0;
	}
	return (IFTODT(DIP(di_mode)));
	}

	static ssize_t
	fsread_size(ufs_ino_t inode, void buf, size_t nbyte, size_t fsizep)
	{
	char *blkbuf;
	void *indbuf;
	char *s;
	size_t n, nb, size, off, vboff;
	ufs_lbn_t lbn;
	ufs2_daddr_t addr2, vbaddr;
	u_int u;

	/* Basic parameter validation. */
	if ((buf == NULL && nbyte != 0) \|\| dmadat == NULL)
	return (-1);

	blkbuf = dmadat->blkbuf;
	indbuf = dmadat->indbuf;

	/*
	* Force probe if inode is zero to ensure we have a valid fs, otherwise
	* when probing multiple paritions, reads from subsequent parititions
	* will incorrectly succeed.
	*/
	if (!dsk_meta \|\| inode == 0) {
	inomap = 0;
	dsk_meta = 0;
	for (n = 0; sblock_try[n] != -1; n++) {
	if (dskread(dmadat->sbbuf, sblock_try[n] / DEV_BSIZE,
	SBLOCKSIZE / DEV_BSIZE))
	return -1;
	memcpy(&fs, dmadat->sbbuf, sizeof(struct fs));
	if ((
	#if defined(UFS1_ONLY)
	fs.fs_magic == FS_UFS1_MAGIC
	#elif defined(UFS2_ONLY)
	(fs.fs_magic == FS_UFS2_MAGIC &&
	fs.fs_sblockloc == sblock_try[n])
	#else
	fs.fs_magic == FS_UFS1_MAGIC \|\|
	(fs.fs_magic == FS_UFS2_MAGIC &&
	fs.fs_sblockloc == sblock_try[n])
	#endif
	) &&
	fs.fs_bsize <= MAXBSIZE &&
	fs.fs_bsize >= (int32_t)sizeof(struct fs))
	break;
	}
	if (sblock_try[n] == -1) {
	return -1;
	}
	dsk_meta++;
	} else
	memcpy(&fs, dmadat->sbbuf, sizeof(struct fs));
	if (!inode)
	return 0;
	if (inomap != inode) {
	n = IPERVBLK(&fs);
	if (dskread(blkbuf, INO_TO_VBA(&fs, n, inode), DBPERVBLK))
	return -1;
	n = INO_TO_VBO(n, inode);
	#if defined(UFS1_ONLY)
	memcpy(&dp1, (struct ufs1_dinode )(void )blkbuf + n,
	sizeof(dp1));
	#elif defined(UFS2_ONLY)
	memcpy(&dp2, (struct ufs2_dinode )(void )blkbuf + n,
	sizeof(dp2));
	#else
	if (fs.fs_magic == FS_UFS1_MAGIC)
	memcpy(&dp1, (struct ufs1_dinode )(void )blkbuf + n,
	sizeof(dp1));
	else
	memcpy(&dp2, (struct ufs2_dinode )(void )blkbuf + n,
	sizeof(dp2));
	#endif
	inomap = inode;
	fs_off = 0;
	blkmap = indmap = 0;
	}
	s = buf;
	size = DIP(di_size);
	n = size - fs_off;
	if (nbyte > n)
	nbyte = n;
	nb = nbyte;
	while (nb) {
	lbn = lblkno(&fs, fs_off);
	off = blkoff(&fs, fs_off);
	if (lbn < NDADDR) {
	addr2 = DIP(di_db[lbn]);
	} else if (lbn < NDADDR + NINDIR(&fs)) {
	n = INDIRPERVBLK(&fs);
	addr2 = DIP(di_ib[0]);
	u = (u_int)(lbn - NDADDR) / n * DBPERVBLK;
	vbaddr = fsbtodb(&fs, addr2) + u;
	if (indmap != vbaddr) {
	if (dskread(indbuf, vbaddr, DBPERVBLK))
	return -1;
	indmap = vbaddr;
	}
	n = (lbn - NDADDR) & (n - 1);
	#if defined(UFS1_ONLY)
	memcpy(&addr1, (ufs1_daddr_t *)indbuf + n,
	sizeof(ufs1_daddr_t));
	addr2 = addr1;
	#elif defined(UFS2_ONLY)
	memcpy(&addr2, (ufs2_daddr_t *)indbuf + n,
	sizeof(ufs2_daddr_t));
	#else
	if (fs.fs_magic == FS_UFS1_MAGIC) {
	memcpy(&addr1, (ufs1_daddr_t *)indbuf + n,
	sizeof(ufs1_daddr_t));
	addr2 = addr1;
	} else
	memcpy(&addr2, (ufs2_daddr_t *)indbuf + n,
	sizeof(ufs2_daddr_t));
	#endif
	} else
	return -1;
	vbaddr = fsbtodb(&fs, addr2) + (off >> VBLKSHIFT) * DBPERVBLK;
	vboff = off & VBLKMASK;
	n = sblksize(&fs, (off_t)size, lbn) - (off & ~VBLKMASK);
	if (n > VBLKSIZE)
	n = VBLKSIZE;
	if (blkmap != vbaddr) {
	if (dskread(blkbuf, vbaddr, n >> DEV_BSHIFT))
	return -1;
	blkmap = vbaddr;
	}
	n -= vboff;
	if (n > nb)
	n = nb;
	memcpy(s, blkbuf + vboff, n);
	s += n;
	fs_off += n;
	nb -= n;
	}

	if (fsizep != NULL)
	*fsizep = size;

	return nbyte;
	}

	static ssize_t
	fsread(ufs_ino_t inode, void *buf, size_t nbyte)
	{

	return fsread_size(inode, buf, nbyte, NULL);
	}