Пример #1
0
void
quot(char *name, char *mp)
{
	int i, fd;
	struct fs *fs;

	get_inode(-1, NULL, 0);		/* flush cache */
	inituser();
	initfsizes();
	/*
	 * XXX this is completely broken.  Of course you can't read a
	 * directory, well, not anymore.  How to fix this, though...
	 */
	if ((fd = open(name, 0)) < 0) {
		warn("%s", name);
		return;
	}
	for (i = 0; sblock_try[i] != -1; i++) {
		if (lseek(fd, sblock_try[i], 0) != sblock_try[i]) {
			close(fd);
			return;
		}
		if (read(fd, superblock, SBLOCKSIZE) != SBLOCKSIZE) {
			close(fd);
			return;
		}
		fs = (struct fs *)superblock;
		if ((fs->fs_magic == FS_UFS1_MAGIC ||
		    (fs->fs_magic == FS_UFS2_MAGIC &&
		    fs->fs_sblockloc == sblock_try[i])) &&
		    fs->fs_bsize <= MAXBSIZE &&
		    fs->fs_bsize >= sizeof(struct fs))
			break;
	}
	if (sblock_try[i] == -1) {
		warnx("%s: not a BSD filesystem", name);
		close(fd);
		return;
	}
	ffs_oldfscompat(fs);
	printf("%s:", name);
	if (mp)
		printf(" (%s)", mp);
	putchar('\n');
	(*func)(fd, fs, name);
	close(fd);
}
Пример #2
0
/*
 * Open a file.
 */
__compactcall int
ufs_open(const char *path, struct open_file *f)
{
#ifndef LIBSA_FS_SINGLECOMPONENT
	const char *cp, *ncp;
	int c;
#endif
	ino32_t inumber;
	struct file *fp;
	struct fs *fs;
	int rc;
#ifndef LIBSA_NO_FS_SYMLINK
	ino32_t parent_inumber;
	int nlinks = 0;
	char namebuf[MAXPATHLEN+1];
	char *buf;
#endif

	/* allocate file system specific data structure */
	fp = alloc(sizeof(struct file));
	memset(fp, 0, sizeof(struct file));
	f->f_fsdata = (void *)fp;

	/* allocate space and read super block */
	fs = alloc(SBLOCKSIZE);
	fp->f_fs = fs;
	twiddle();

#ifdef LIBSA_FFSv2
	rc = ffs_find_superblock(f, fs);
	if (rc)
		goto out;
#else
	{
		size_t buf_size;
		rc = DEV_STRATEGY(f->f_dev)(f->f_devdata, F_READ,
			SBLOCKOFFSET / DEV_BSIZE, SBLOCKSIZE, fs, &buf_size);
		if (rc)
			goto out;
		if (buf_size != SBLOCKSIZE ||
#ifdef LIBSA_FFS
		    fs->lfs_version != REQUIRED_LFS_VERSION ||
#endif
		    fs->fs_magic != FS_MAGIC) {
			rc = EINVAL;
			goto out;
		}
	}
#if defined(LIBSA_LFS) && REQUIRED_LFS_VERSION == 2
	/*
	 * XXX	We should check the second superblock and use the eldest
	 *	of the two.  See comments near the top of lfs_mountfs()
	 *	in sys/ufs/lfs/lfs_vfsops.c.
	 *      This may need a LIBSA_LFS_SMALL check as well.
	 */
#endif
#endif

#ifdef LIBSA_FFSv1
	ffs_oldfscompat(fs);
#endif

	if (fs->fs_bsize > MAXBSIZE ||
	    (size_t)fs->fs_bsize < sizeof(struct fs)) {
		rc = EINVAL;
		goto out;
	}

	/*
	 * Calculate indirect block levels.
	 */
	{
		indp_t mult;
		int ln2;

		/*
		 * We note that the number of indirect blocks is always
		 * a power of 2.  This lets us use shifts and masks instead
		 * of divide and remainder and avoinds pulling in the
		 * 64bit division routine into the boot code.
		 */
		mult = UFS_NINDIR(fs);
#ifdef DEBUG
		if (mult & (mult - 1)) {
			/* Hummm was't a power of 2 */
			rc = EINVAL;
			goto out;
		}
#endif
		for (ln2 = 0; mult != 1; ln2++)
			mult >>= 1;

		fp->f_nishift = ln2;
	}

	/* alloc a block sized buffer used for all fs transfers */
	fp->f_buf = alloc(fs->fs_bsize);
	inumber = UFS_ROOTINO;
	if ((rc = read_inode(inumber, f)) != 0)
		goto out;

#ifndef LIBSA_FS_SINGLECOMPONENT
	cp = path;
	while (*cp) {

		/*
		 * Remove extra separators
		 */
		while (*cp == '/')
			cp++;
		if (*cp == '\0')
			break;

		/*
		 * Check that current node is a directory.
		 */
		if ((fp->f_di.di_mode & IFMT) != IFDIR) {
			rc = ENOTDIR;
			goto out;
		}

		/*
		 * Get next component of path name.
		 */
		ncp = cp;
		while ((c = *cp) != '\0' && c != '/')
			cp++;

		/*
		 * Look up component in current directory.
		 * Save directory inumber in case we find a
		 * symbolic link.
		 */
#ifndef LIBSA_NO_FS_SYMLINK
		parent_inumber = inumber;
#endif
		rc = search_directory(ncp, cp - ncp, f, &inumber);
		if (rc)
			goto out;

		/*
		 * Open next component.
		 */
		if ((rc = read_inode(inumber, f)) != 0)
			goto out;

#ifndef LIBSA_NO_FS_SYMLINK
		/*
		 * Check for symbolic link.
		 */
		if ((fp->f_di.di_mode & IFMT) == IFLNK) {
			int link_len = fp->f_di.di_size;
			int len;

			len = strlen(cp);

			if (link_len + len > MAXPATHLEN ||
			    ++nlinks > MAXSYMLINKS) {
				rc = ENOENT;
				goto out;
			}

			memmove(&namebuf[link_len], cp, len + 1);

			if (link_len < fs->fs_maxsymlinklen) {
				memcpy(namebuf, fp->f_di.di_db, link_len);
			} else {
				/*
				 * Read file for symbolic link
				 */
				size_t buf_size;
				indp_t	disk_block;

				buf = fp->f_buf;
				rc = block_map(f, (indp_t)0, &disk_block);
				if (rc)
					goto out;

				twiddle();
				rc = DEV_STRATEGY(f->f_dev)(f->f_devdata,
					F_READ, FSBTODB(fs, disk_block),
					fs->fs_bsize, buf, &buf_size);
				if (rc)
					goto out;

				memcpy(namebuf, buf, link_len);
			}

			/*
			 * If relative pathname, restart at parent directory.
			 * If absolute pathname, restart at root.
			 */
			cp = namebuf;
			if (*cp != '/')
				inumber = parent_inumber;
			else
				inumber = (ino32_t)UFS_ROOTINO;

			if ((rc = read_inode(inumber, f)) != 0)
				goto out;
		}
#endif	/* !LIBSA_NO_FS_SYMLINK */
	}

	/*
	 * Found terminal component.
	 */
	rc = 0;

#else /* !LIBSA_FS_SINGLECOMPONENT */

	/* look up component in the current (root) directory */
	rc = search_directory(path, strlen(path), f, &inumber);
	if (rc)
		goto out;

	/* open it */
	rc = read_inode(inumber, f);

#endif /* !LIBSA_FS_SINGLECOMPONENT */

	fp->f_seekp = 0;		/* reset seek pointer */

out:
	if (rc)
		ufs_close(f);
#ifdef FSMOD		/* Only defined for lfs */
	else
		fsmod = FSMOD;
#endif
	return rc;
}
Пример #3
0
/*
 * Reload all incore data for a filesystem (used after running fsck on
 * the root filesystem and finding things to fix). The filesystem must
 * be mounted read-only.
 *
 * Things to do to update the mount:
 *	1) invalidate all cached meta-data.
 *	2) re-read superblock from disk.
 *	3) re-read summary information from disk.
 *	4) invalidate all inactive vnodes.
 *	5) invalidate all cached file data.
 *	6) re-read inode data for all active vnodes.
 */
int
ffs_reload(struct mount *mountp, struct ucred *cred, struct proc *p)
{
	struct vnode *devvp;
	caddr_t space;
	struct fs *fs, *newfs;
	struct partinfo dpart;
	int i, blks, size, error;
	int32_t *lp;
	struct buf *bp = NULL;
	struct ffs_reload_args fra;

	if ((mountp->mnt_flag & MNT_RDONLY) == 0)
		return (EINVAL);
	/*
	 * Step 1: invalidate all cached meta-data.
	 */
	devvp = VFSTOUFS(mountp)->um_devvp;
	vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY, p);
	error = vinvalbuf(devvp, 0, cred, p, 0, 0);
	VOP_UNLOCK(devvp, 0, p);
	if (error)
		panic("ffs_reload: dirty1");

	/*
	 * Step 2: re-read superblock from disk.
	 */
	if (VOP_IOCTL(devvp, DIOCGPART, (caddr_t)&dpart, FREAD, NOCRED, p) != 0)
		size = DEV_BSIZE;
	else
		size = dpart.disklab->d_secsize;

	error = bread(devvp, (daddr_t)(SBOFF / size), SBSIZE, NOCRED, &bp);
	if (error) {
		brelse(bp);
		return (error);
	}

	newfs = (struct fs *)bp->b_data;
	if (ffs_validate(newfs) == 0) {
		brelse(bp);
		return (EINVAL);
	}
	fs = VFSTOUFS(mountp)->um_fs;
	/*
	 * Copy pointer fields back into superblock before copying in	XXX
	 * new superblock. These should really be in the ufsmount.	XXX
	 * Note that important parameters (eg fs_ncg) are unchanged.
	 */
	newfs->fs_csp = fs->fs_csp;
	newfs->fs_maxcluster = fs->fs_maxcluster;
	newfs->fs_ronly = fs->fs_ronly;
	bcopy(newfs, fs, (u_int)fs->fs_sbsize);
	if (fs->fs_sbsize < SBSIZE)
		bp->b_flags |= B_INVAL;
	brelse(bp);
	mountp->mnt_maxsymlinklen = fs->fs_maxsymlinklen;
	ffs1_compat_read(fs, VFSTOUFS(mountp), SBOFF);
	ffs_oldfscompat(fs);
	(void)ffs_statfs(mountp, &mountp->mnt_stat, p);
	/*
	 * Step 3: re-read summary information from disk.
	 */
	blks = howmany(fs->fs_cssize, fs->fs_fsize);
	space = (caddr_t)fs->fs_csp;
	for (i = 0; i < blks; i += fs->fs_frag) {
		size = fs->fs_bsize;
		if (i + fs->fs_frag > blks)
			size = (blks - i) * fs->fs_fsize;
		error = bread(devvp, fsbtodb(fs, fs->fs_csaddr + i), size,
			      NOCRED, &bp);
		if (error) {
			brelse(bp);
			return (error);
		}
		bcopy(bp->b_data, space, (u_int)size);
		space += size;
		brelse(bp);
	}
	if ((fs->fs_flags & FS_DOSOFTDEP))
		(void) softdep_mount(devvp, mountp, fs, cred);
	/*
	 * We no longer know anything about clusters per cylinder group.
	 */
	if (fs->fs_contigsumsize > 0) {
		lp = fs->fs_maxcluster;
		for (i = 0; i < fs->fs_ncg; i++)
			*lp++ = fs->fs_contigsumsize;
	}

	fra.p = p;
	fra.cred = cred;
	fra.fs = fs;
	fra.devvp = devvp;

	error = vfs_mount_foreach_vnode(mountp, ffs_reload_vnode, &fra);

	return (error);
}
Пример #4
0
/*
 * Common code for mount and mountroot
 */
int
ffs_mountfs(struct vnode *devvp, struct mount *mp, struct proc *p)
{
	struct ufsmount *ump;
	struct buf *bp;
	struct fs *fs;
	dev_t dev;
	struct partinfo dpart;
	caddr_t space;
	ufs2_daddr_t sbloc;
	int error, i, blks, size, ronly;
	int32_t *lp;
	size_t strsize;
	struct ucred *cred;
	u_int64_t maxfilesize;					/* XXX */

	dev = devvp->v_rdev;
	cred = p ? p->p_ucred : NOCRED;
	/*
	 * Disallow multiple mounts of the same device.
	 * Disallow mounting of a device that is currently in use
	 * (except for root, which might share swap device for miniroot).
	 * Flush out any old buffers remaining from a previous use.
	 */
	if ((error = vfs_mountedon(devvp)) != 0)
		return (error);
	if (vcount(devvp) > 1 && devvp != rootvp)
		return (EBUSY);
	vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY, p);
	error = vinvalbuf(devvp, V_SAVE, cred, p, 0, 0);
	VOP_UNLOCK(devvp, 0, p);
	if (error)
		return (error);

	ronly = (mp->mnt_flag & MNT_RDONLY) != 0;
	error = VOP_OPEN(devvp, ronly ? FREAD : FREAD|FWRITE, FSCRED, p);
	if (error)
		return (error);
	if (VOP_IOCTL(devvp, DIOCGPART, (caddr_t)&dpart, FREAD, cred, p) != 0)
		size = DEV_BSIZE;
	else
		size = dpart.disklab->d_secsize;

	bp = NULL;
	ump = NULL;

	/*
	 * Try reading the super-block in each of its possible locations.
	 */
	for (i = 0; sbtry[i] != -1; i++) {
		if (bp != NULL) {
			bp->b_flags |= B_NOCACHE;
			brelse(bp);
			bp = NULL;
		}

		error = bread(devvp, sbtry[i] / size, SBSIZE, cred, &bp);
		if (error)
			goto out;

		fs = (struct fs *) bp->b_data;
		sbloc = sbtry[i];

#if 0
		if (fs->fs_magic == FS_UFS2_MAGIC) {
			printf("ffs_mountfs(): Sorry, no UFS2 support (yet)\n");
			error = EFTYPE;
			goto out;
		}
#endif

		/*
		 * Do not look for an FFS1 file system at SBLOCK_UFS2. Doing so
		 * will find the wrong super-block for file systems with 64k
		 * block size.
		 */
		if (fs->fs_magic == FS_UFS1_MAGIC && sbloc == SBLOCK_UFS2)
			continue;

		if (ffs_validate(fs))
			break; /* Super block validated */
	}

	if (sbtry[i] == -1) {
		error = EINVAL;
		goto out;
	}

	fs->fs_fmod = 0;
	fs->fs_flags &= ~FS_UNCLEAN;
	if (fs->fs_clean == 0) {
		fs->fs_flags |= FS_UNCLEAN;
#if 0
		/*
		 * It is safe mount unclean file system
		 * if it was previously mounted with softdep
		 * but we may loss space and must
		 * sometimes run fsck manually.
		 */
		if (fs->fs_flags & FS_DOSOFTDEP)
			printf(
"WARNING: %s was not properly unmounted\n",
			    fs->fs_fsmnt);
		else
#endif
		if (ronly || (mp->mnt_flag & MNT_FORCE)) {
			printf(
"WARNING: %s was not properly unmounted\n",
			    fs->fs_fsmnt);
		} else {
			printf(
"WARNING: R/W mount of %s denied.  Filesystem is not clean - run fsck\n",
			    fs->fs_fsmnt);
			error = EROFS;
			goto out;
		}
	}

	if (fs->fs_postblformat == FS_42POSTBLFMT && !ronly) {
#ifndef SMALL_KERNEL
		printf("ffs_mountfs(): obsolete rotational table format, "
		    "please use fsck_ffs(8) -c 1\n");
#endif
		error = EFTYPE;
		goto out;
	}

	ump = malloc(sizeof *ump, M_UFSMNT, M_WAITOK);
	bzero(ump, sizeof *ump);
	ump->um_fs = malloc((u_long)fs->fs_sbsize, M_UFSMNT,
	    M_WAITOK);

	if (fs->fs_magic == FS_UFS1_MAGIC)
		ump->um_fstype = UM_UFS1;
#ifdef FFS2
	else
		ump->um_fstype = UM_UFS2;
#endif

	bcopy(bp->b_data, ump->um_fs, (u_int)fs->fs_sbsize);
	if (fs->fs_sbsize < SBSIZE)
		bp->b_flags |= B_INVAL;
	brelse(bp);
	bp = NULL;
	fs = ump->um_fs;

	ffs1_compat_read(fs, ump, sbloc);

	fs->fs_ronly = ronly;
	size = fs->fs_cssize;
	blks = howmany(size, fs->fs_fsize);
	if (fs->fs_contigsumsize > 0)
		size += fs->fs_ncg * sizeof(int32_t);
	space = malloc((u_long)size, M_UFSMNT, M_WAITOK);
	fs->fs_csp = (struct csum *)space;
	for (i = 0; i < blks; i += fs->fs_frag) {
		size = fs->fs_bsize;
		if (i + fs->fs_frag > blks)
			size = (blks - i) * fs->fs_fsize;
		error = bread(devvp, fsbtodb(fs, fs->fs_csaddr + i), size,
			      cred, &bp);
		if (error) {
			free(fs->fs_csp, M_UFSMNT);
			goto out;
		}
		bcopy(bp->b_data, space, (u_int)size);
		space += size;
		brelse(bp);
		bp = NULL;
	}
	if (fs->fs_contigsumsize > 0) {
		fs->fs_maxcluster = lp = (int32_t *)space;
		for (i = 0; i < fs->fs_ncg; i++)
			*lp++ = fs->fs_contigsumsize;
	}
	mp->mnt_data = (qaddr_t)ump;
	mp->mnt_stat.f_fsid.val[0] = (long)dev;
	/* Use on-disk fsid if it exists, else fake it */
	if (fs->fs_id[0] != 0 && fs->fs_id[1] != 0)
		mp->mnt_stat.f_fsid.val[1] = fs->fs_id[1];
	else
		mp->mnt_stat.f_fsid.val[1] = mp->mnt_vfc->vfc_typenum;
	mp->mnt_maxsymlinklen = fs->fs_maxsymlinklen;
	mp->mnt_flag |= MNT_LOCAL;
	ump->um_mountp = mp;
	ump->um_dev = dev;
	ump->um_devvp = devvp;
	ump->um_nindir = fs->fs_nindir;
	ump->um_bptrtodb = fs->fs_fsbtodb;
	ump->um_seqinc = fs->fs_frag;
	for (i = 0; i < MAXQUOTAS; i++)
		ump->um_quotas[i] = NULLVP;

	devvp->v_specmountpoint = mp;
	ffs_oldfscompat(fs);

	if (ronly)
		fs->fs_contigdirs = NULL;
	else {
		fs->fs_contigdirs = (u_int8_t*)malloc((u_long)fs->fs_ncg,
						      M_UFSMNT, M_WAITOK);
		bzero(fs->fs_contigdirs, fs->fs_ncg);
	}

	/*
	 * Set FS local "last mounted on" information (NULL pad)
	 */
	copystr(mp->mnt_stat.f_mntonname,	/* mount point*/
		fs->fs_fsmnt,			/* copy area*/
		sizeof(fs->fs_fsmnt) - 1,	/* max size*/
		&strsize);			/* real size*/
	bzero(fs->fs_fsmnt + strsize, sizeof(fs->fs_fsmnt) - strsize);

#if 0
	if( mp->mnt_flag & MNT_ROOTFS) {
		/*
		 * Root mount; update timestamp in mount structure.
		 * this will be used by the common root mount code
		 * to update the system clock.
		 */
		mp->mnt_time = fs->fs_time;
	}
#endif

	/*
	 * XXX
	 * Limit max file size.  Even though ffs can handle files up to 16TB,
	 * we do limit the max file to 2^31 pages to prevent overflow of
	 * a 32-bit unsigned int.  The buffer cache has its own checks but
	 * a little added paranoia never hurts.
	 */
	ump->um_savedmaxfilesize = fs->fs_maxfilesize;		/* XXX */
	maxfilesize = (u_int64_t)0x80000000 * MIN(PAGE_SIZE, fs->fs_bsize) - 1;
	if (fs->fs_maxfilesize > maxfilesize)			/* XXX */
		fs->fs_maxfilesize = maxfilesize;		/* XXX */
	if (ronly == 0) {
		if ((fs->fs_flags & FS_DOSOFTDEP) &&
		    (error = softdep_mount(devvp, mp, fs, cred)) != 0) {
			free(fs->fs_csp, M_UFSMNT);
			free(fs->fs_contigdirs, M_UFSMNT);
			goto out;
		}
		fs->fs_fmod = 1;
		fs->fs_clean = 0;
		if (mp->mnt_flag & MNT_SOFTDEP)
			fs->fs_flags |= FS_DOSOFTDEP;
		else
			fs->fs_flags &= ~FS_DOSOFTDEP;
		(void) ffs_sbupdate(ump, MNT_WAIT);
	}
	return (0);
out:
	devvp->v_specmountpoint = NULL;
	if (bp)
		brelse(bp);
	vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY, p);
	(void)VOP_CLOSE(devvp, ronly ? FREAD : FREAD|FWRITE, cred, p);
	VOP_UNLOCK(devvp, 0, p);
	if (ump) {
		free(ump->um_fs, M_UFSMNT);
		free(ump, M_UFSMNT);
		mp->mnt_data = (qaddr_t)0;
	}
	return (error);
}
Пример #5
0
/*
 * Open a file.
 */
static int
ufs_open(const char *upath, struct open_file *f)
{
	char *cp, *ncp;
	int c;
	ino_t inumber, parent_inumber;
	struct file *fp;
	struct fs *fs;
	int rc;
	size_t buf_size;
	int nlinks = 0;
	char namebuf[MAXPATHLEN+1];
	char *buf = NULL;
	char *path = NULL;

	/* allocate file system specific data structure */
	fp = malloc(sizeof(struct file));
	bzero(fp, sizeof(struct file));
	f->f_fsdata = (void *)fp;

	/* allocate space and read super block */
	fs = malloc(SBSIZE);
	fp->f_fs = fs;
	twiddle();
	rc = (f->f_dev->dv_strategy)(f->f_devdata, F_READ,
		SBOFF / DEV_BSIZE, SBSIZE, (char *)fs, &buf_size);
	if (rc)
		goto out;

	if (buf_size != SBSIZE || fs->fs_magic != FS_MAGIC ||
	    fs->fs_bsize > MAXBSIZE || fs->fs_bsize < sizeof(struct fs)) {
		rc = EINVAL;
		goto out;
	}
#ifdef COMPAT_UFS
	ffs_oldfscompat(fs);
#endif

	/*
	 * Calculate indirect block levels.
	 */
	{
		int omult;
		int mult;
		int level;

		omult = 0;
		mult = 1;
		for (level = 0; level < NIADDR; level++) {
			mult *= NINDIR(fs);
			if (mult < omult)
				mult = 0x7FFFFFFF;
			fp->f_nindir[level] = mult;
			omult = mult;
		}
	}

	inumber = ROOTINO;
	if ((rc = read_inode(inumber, f)) != 0)
		goto out;

	cp = path = strdup(upath);
	if (path == NULL) {
	    rc = ENOMEM;
	    goto out;
	}
	while (*cp) {

		/*
		 * Remove extra separators
		 */
		while (*cp == '/')
			cp++;
		if (*cp == '\0')
			break;

		/*
		 * Check that current node is a directory.
		 */
		if ((fp->f_di.di_mode & IFMT) != IFDIR) {
			rc = ENOTDIR;
			goto out;
		}

		/*
		 * Get next component of path name.
		 */
		{
			int len = 0;

			ncp = cp;
			while ((c = *cp) != '\0' && c != '/') {
				if (++len > MAXNAMLEN) {
					rc = ENOENT;
					goto out;
				}
				cp++;
			}
			*cp = '\0';
		}

		/*
		 * Look up component in current directory.
		 * Save directory inumber in case we find a
		 * symbolic link.
		 */
		parent_inumber = inumber;
		rc = search_directory(ncp, f, &inumber);
		*cp = c;
		if (rc)
			goto out;

		/*
		 * Open next component.
		 */
		if ((rc = read_inode(inumber, f)) != 0)
			goto out;

		/*
		 * Check for symbolic link.
		 */
		if ((fp->f_di.di_mode & IFMT) == IFLNK) {
			int link_len = fp->f_di.di_size;
			int len;

			len = strlen(cp);

			if (link_len + len > MAXPATHLEN ||
			    ++nlinks > MAXSYMLINKS) {
				rc = ENOENT;
				goto out;
			}

			bcopy(cp, &namebuf[link_len], len + 1);

			if (link_len < fs->fs_maxsymlinklen) {
				bcopy(fp->f_di.di_shortlink, namebuf,
				      (unsigned) link_len);
			} else {
				/*
				 * Read file for symbolic link
				 */
				size_t buf_size;
				daddr_t	disk_block;
				struct fs *fs = fp->f_fs;

				if (!buf)
					buf = malloc(fs->fs_bsize);
				rc = block_map(f, (daddr_t)0, &disk_block);
				if (rc)
					goto out;
				
				twiddle();
				rc = (f->f_dev->dv_strategy)(f->f_devdata,
					F_READ, fsbtodb(fs, disk_block),
					fs->fs_bsize, buf, &buf_size);
				if (rc)
					goto out;

				bcopy((char *)buf, namebuf, (unsigned)link_len);
			}

			/*
			 * If relative pathname, restart at parent directory.
			 * If absolute pathname, restart at root.
			 */
			cp = namebuf;
			if (*cp != '/')
				inumber = parent_inumber;
			else
				inumber = (ino_t)ROOTINO;

			if ((rc = read_inode(inumber, f)) != 0)
				goto out;
		}
	}

	/*
	 * Found terminal component.
	 */
	fp->f_seekp = 0;
	rc = 0;
out:
	if (buf)
		free(buf);
	if (path)
		free(path);
	if (rc) {
		f->f_fsdata = NULL;
		if (fp->f_buf)
			free(fp->f_buf);
		free(fp->f_fs);
		free(fp);
	}
	return (rc);
}