ec888383cf
check hash to the superblock. If a check hash fails when an attempt is made to mount a filesystem, the mount fails with EINVAL (Invalid argument). This avoids a class of filesystem panics related to corrupted superblocks. The hash is done using crc32c. Check hases are added only to UFS2 and not to UFS1 as UFS1 is primarily used in embedded systems with small memories and low-powered processors which need as light-weight a filesystem as possible. Reviewed by: kib Tested by: Peter Holm Sponsored by: Netflix
612 lines
15 KiB
C
612 lines
15 KiB
C
/*-
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* SPDX-License-Identifier: BSD-3-Clause
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*
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* Copyright (c) 1982, 1986, 1989, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* @(#)ffs_subr.c 8.5 (Berkeley) 3/21/95
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include <sys/param.h>
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#ifndef _KERNEL
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#include <stdio.h>
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#include <string.h>
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#include <stdlib.h>
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#include <time.h>
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#include <sys/errno.h>
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#include <ufs/ufs/dinode.h>
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#include <ufs/ffs/fs.h>
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uint32_t calculate_crc32c(uint32_t, const void *, size_t);
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struct malloc_type;
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#define UFS_MALLOC(size, type, flags) malloc(size)
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#define UFS_FREE(ptr, type) free(ptr)
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#define UFS_TIME time(NULL)
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#else /* _KERNEL */
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#include <sys/systm.h>
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#include <sys/lock.h>
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#include <sys/malloc.h>
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#include <sys/mount.h>
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#include <sys/vnode.h>
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#include <sys/bio.h>
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#include <sys/buf.h>
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#include <sys/ucred.h>
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#include <ufs/ufs/quota.h>
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#include <ufs/ufs/inode.h>
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#include <ufs/ufs/extattr.h>
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#include <ufs/ufs/ufsmount.h>
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#include <ufs/ufs/ufs_extern.h>
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#include <ufs/ffs/ffs_extern.h>
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#include <ufs/ffs/fs.h>
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#define UFS_MALLOC(size, type, flags) malloc(size, type, flags)
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#define UFS_FREE(ptr, type) free(ptr, type)
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#define UFS_TIME time_second
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/*
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* Return buffer with the contents of block "offset" from the beginning of
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* directory "ip". If "res" is non-zero, fill it in with a pointer to the
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* remaining space in the directory.
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*/
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int
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ffs_blkatoff(struct vnode *vp, off_t offset, char **res, struct buf **bpp)
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{
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struct inode *ip;
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struct fs *fs;
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struct buf *bp;
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ufs_lbn_t lbn;
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int bsize, error;
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ip = VTOI(vp);
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fs = ITOFS(ip);
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lbn = lblkno(fs, offset);
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bsize = blksize(fs, ip, lbn);
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*bpp = NULL;
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error = bread(vp, lbn, bsize, NOCRED, &bp);
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if (error) {
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brelse(bp);
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return (error);
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}
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if (res)
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*res = (char *)bp->b_data + blkoff(fs, offset);
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*bpp = bp;
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return (0);
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}
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/*
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* Load up the contents of an inode and copy the appropriate pieces
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* to the incore copy.
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*/
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void
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ffs_load_inode(struct buf *bp, struct inode *ip, struct fs *fs, ino_t ino)
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{
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if (I_IS_UFS1(ip)) {
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*ip->i_din1 =
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*((struct ufs1_dinode *)bp->b_data + ino_to_fsbo(fs, ino));
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ip->i_mode = ip->i_din1->di_mode;
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ip->i_nlink = ip->i_din1->di_nlink;
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ip->i_size = ip->i_din1->di_size;
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ip->i_flags = ip->i_din1->di_flags;
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ip->i_gen = ip->i_din1->di_gen;
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ip->i_uid = ip->i_din1->di_uid;
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ip->i_gid = ip->i_din1->di_gid;
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} else {
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*ip->i_din2 =
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*((struct ufs2_dinode *)bp->b_data + ino_to_fsbo(fs, ino));
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ip->i_mode = ip->i_din2->di_mode;
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ip->i_nlink = ip->i_din2->di_nlink;
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ip->i_size = ip->i_din2->di_size;
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ip->i_flags = ip->i_din2->di_flags;
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ip->i_gen = ip->i_din2->di_gen;
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ip->i_uid = ip->i_din2->di_uid;
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ip->i_gid = ip->i_din2->di_gid;
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}
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}
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#endif /* KERNEL */
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/*
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* These are the low-level functions that actually read and write
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* the superblock and its associated data.
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*/
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static off_t sblock_try[] = SBLOCKSEARCH;
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static int readsuper(void *, struct fs **, off_t, int,
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int (*)(void *, off_t, void **, int));
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static uint32_t calc_sbhash(struct fs *);
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/*
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* Read a superblock from the devfd device.
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*
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* If an alternate superblock is specified, it is read. Otherwise the
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* set of locations given in the SBLOCKSEARCH list is searched for a
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* superblock. Memory is allocated for the superblock by the readfunc and
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* is returned. If filltype is non-NULL, additional memory is allocated
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* of type filltype and filled in with the superblock summary information.
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* All memory is freed when any error is returned.
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*
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* If a superblock is found, zero is returned. Otherwise one of the
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* following error values is returned:
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* EIO: non-existent or truncated superblock.
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* EIO: error reading summary information.
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* ENOENT: no usable known superblock found.
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* ENOSPC: failed to allocate space for the superblock.
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* EINVAL: The previous newfs operation on this volume did not complete.
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* The administrator must complete newfs before using this volume.
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*/
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int
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ffs_sbget(void *devfd, struct fs **fsp, off_t altsblock,
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struct malloc_type *filltype,
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int (*readfunc)(void *devfd, off_t loc, void **bufp, int size))
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{
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struct fs *fs;
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int i, error, size, blks;
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uint8_t *space;
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int32_t *lp;
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char *buf;
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fs = NULL;
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*fsp = NULL;
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if (altsblock != -1) {
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if ((error = readsuper(devfd, &fs, altsblock, 1,
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readfunc)) != 0) {
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if (fs != NULL)
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UFS_FREE(fs, filltype);
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return (error);
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}
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} else {
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for (i = 0; sblock_try[i] != -1; i++) {
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if ((error = readsuper(devfd, &fs, sblock_try[i], 0,
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readfunc)) == 0)
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break;
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if (fs != NULL) {
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UFS_FREE(fs, filltype);
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fs = NULL;
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}
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if (error == ENOENT)
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continue;
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return (error);
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}
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if (sblock_try[i] == -1)
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return (ENOENT);
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}
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/*
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* Read in the superblock summary information.
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*/
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size = fs->fs_cssize;
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blks = howmany(size, fs->fs_fsize);
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if (fs->fs_contigsumsize > 0)
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size += fs->fs_ncg * sizeof(int32_t);
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size += fs->fs_ncg * sizeof(u_int8_t);
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/* When running in libufs or libsa, UFS_MALLOC may fail */
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if ((space = UFS_MALLOC(size, filltype, M_WAITOK)) == NULL) {
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UFS_FREE(fs, filltype);
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return (ENOSPC);
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}
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fs->fs_csp = (struct csum *)space;
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for (i = 0; i < blks; i += fs->fs_frag) {
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size = fs->fs_bsize;
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if (i + fs->fs_frag > blks)
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size = (blks - i) * fs->fs_fsize;
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buf = NULL;
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error = (*readfunc)(devfd,
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dbtob(fsbtodb(fs, fs->fs_csaddr + i)), (void **)&buf, size);
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if (error) {
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if (buf != NULL)
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UFS_FREE(buf, filltype);
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UFS_FREE(fs->fs_csp, filltype);
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UFS_FREE(fs, filltype);
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return (error);
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}
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memcpy(space, buf, size);
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UFS_FREE(buf, filltype);
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space += size;
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}
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if (fs->fs_contigsumsize > 0) {
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fs->fs_maxcluster = lp = (int32_t *)space;
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for (i = 0; i < fs->fs_ncg; i++)
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*lp++ = fs->fs_contigsumsize;
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space = (uint8_t *)lp;
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}
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size = fs->fs_ncg * sizeof(u_int8_t);
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fs->fs_contigdirs = (u_int8_t *)space;
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bzero(fs->fs_contigdirs, size);
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*fsp = fs;
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return (0);
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}
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/*
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* Try to read a superblock from the location specified by sblockloc.
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* Return zero on success or an errno on failure.
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*/
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static int
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readsuper(void *devfd, struct fs **fsp, off_t sblockloc, int isaltsblk,
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int (*readfunc)(void *devfd, off_t loc, void **bufp, int size))
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{
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struct fs *fs;
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int error, res;
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uint32_t ckhash;
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error = (*readfunc)(devfd, sblockloc, (void **)fsp, SBLOCKSIZE);
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if (error != 0)
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return (error);
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fs = *fsp;
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if (fs->fs_magic == FS_BAD_MAGIC)
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return (EINVAL);
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if (((fs->fs_magic == FS_UFS1_MAGIC && (isaltsblk ||
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sblockloc <= SBLOCK_UFS1)) ||
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(fs->fs_magic == FS_UFS2_MAGIC && (isaltsblk ||
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sblockloc == fs->fs_sblockloc))) &&
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fs->fs_ncg >= 1 &&
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fs->fs_bsize >= MINBSIZE &&
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fs->fs_bsize <= MAXBSIZE &&
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fs->fs_bsize >= roundup(sizeof(struct fs), DEV_BSIZE) &&
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fs->fs_sbsize <= SBLOCKSIZE) {
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if (fs->fs_ckhash != (ckhash = calc_sbhash(fs))) {
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#ifdef _KERNEL
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res = uprintf("Superblock check-hash failed: recorded "
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"check-hash 0x%x != computed check-hash 0x%x\n",
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fs->fs_ckhash, ckhash);
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#else
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res = 0;
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#endif
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/*
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* Print check-hash failure if no controlling terminal
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* in kernel or always if in user-mode (libufs).
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*/
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if (res == 0)
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printf("Superblock check-hash failed: recorded "
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"check-hash 0x%x != computed check-hash "
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"0x%x\n", fs->fs_ckhash, ckhash);
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return (EINVAL);
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}
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/* Have to set for old filesystems that predate this field */
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fs->fs_sblockactualloc = sblockloc;
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/* Not yet any summary information */
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fs->fs_csp = NULL;
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return (0);
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}
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return (ENOENT);
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}
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/*
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* Write a superblock to the devfd device from the memory pointed to by fs.
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* Write out the superblock summary information if it is present.
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*
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* If the write is successful, zero is returned. Otherwise one of the
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* following error values is returned:
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* EIO: failed to write superblock.
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* EIO: failed to write superblock summary information.
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*/
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int
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ffs_sbput(void *devfd, struct fs *fs, off_t loc,
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int (*writefunc)(void *devfd, off_t loc, void *buf, int size))
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{
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int i, error, blks, size;
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uint8_t *space;
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/*
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* If there is summary information, write it first, so if there
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* is an error, the superblock will not be marked as clean.
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*/
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if (fs->fs_csp != NULL) {
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blks = howmany(fs->fs_cssize, fs->fs_fsize);
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space = (uint8_t *)fs->fs_csp;
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for (i = 0; i < blks; i += fs->fs_frag) {
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size = fs->fs_bsize;
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if (i + fs->fs_frag > blks)
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size = (blks - i) * fs->fs_fsize;
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if ((error = (*writefunc)(devfd,
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dbtob(fsbtodb(fs, fs->fs_csaddr + i)),
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space, size)) != 0)
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return (error);
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space += size;
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}
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}
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fs->fs_fmod = 0;
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fs->fs_time = UFS_TIME;
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fs->fs_ckhash = calc_sbhash(fs);
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if ((error = (*writefunc)(devfd, loc, fs, fs->fs_sbsize)) != 0)
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return (error);
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return (0);
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}
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/*
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* Calculate the check-hash for a superblock.
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*/
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static uint32_t
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calc_sbhash(struct fs *fs)
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{
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uint32_t ckhash, save_ckhash;
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/*
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* A filesystem that was using a superblock ckhash may be moved
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* to an older kernel that does not support ckhashes. The
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* older kernel will clear the FS_METACKHASH flag indicating
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* that it does not update hashes. When the disk is moved back
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* to a kernel capable of ckhashes it disables them on mount:
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*
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* if ((fs->fs_flags & FS_METACKHASH) == 0)
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* fs->fs_metackhash = 0;
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*
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* This leaves (fs->fs_metackhash & CK_SUPERBLOCK) == 0) with an
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* old stale value in the fs->fs_ckhash field. Thus the need to
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* just accept what is there.
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*/
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if ((fs->fs_metackhash & CK_SUPERBLOCK) == 0)
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return (fs->fs_ckhash);
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save_ckhash = fs->fs_ckhash;
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fs->fs_ckhash = 0;
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/*
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* If newly read from disk, the caller is responsible for
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* verifying that fs->fs_sbsize <= SBLOCKSIZE.
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*/
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ckhash = calculate_crc32c(~0L, (void *)fs, fs->fs_sbsize);
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fs->fs_ckhash = save_ckhash;
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return (ckhash);
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}
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/*
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* Update the frsum fields to reflect addition or deletion
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* of some frags.
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*/
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void
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ffs_fragacct(struct fs *fs, int fragmap, int32_t fraglist[], int cnt)
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{
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int inblk;
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int field, subfield;
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int siz, pos;
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inblk = (int)(fragtbl[fs->fs_frag][fragmap]) << 1;
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fragmap <<= 1;
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for (siz = 1; siz < fs->fs_frag; siz++) {
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if ((inblk & (1 << (siz + (fs->fs_frag % NBBY)))) == 0)
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continue;
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field = around[siz];
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subfield = inside[siz];
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for (pos = siz; pos <= fs->fs_frag; pos++) {
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if ((fragmap & field) == subfield) {
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fraglist[siz] += cnt;
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pos += siz;
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field <<= siz;
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subfield <<= siz;
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}
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field <<= 1;
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subfield <<= 1;
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}
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}
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}
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/*
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* block operations
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*
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* check if a block is available
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*/
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int
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ffs_isblock(struct fs *fs, unsigned char *cp, ufs1_daddr_t h)
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{
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unsigned char mask;
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switch ((int)fs->fs_frag) {
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case 8:
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return (cp[h] == 0xff);
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case 4:
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mask = 0x0f << ((h & 0x1) << 2);
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return ((cp[h >> 1] & mask) == mask);
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case 2:
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mask = 0x03 << ((h & 0x3) << 1);
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return ((cp[h >> 2] & mask) == mask);
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case 1:
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mask = 0x01 << (h & 0x7);
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return ((cp[h >> 3] & mask) == mask);
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default:
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#ifdef _KERNEL
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panic("ffs_isblock");
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#endif
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break;
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}
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return (0);
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}
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/*
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* check if a block is free
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*/
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int
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ffs_isfreeblock(struct fs *fs, u_char *cp, ufs1_daddr_t h)
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{
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switch ((int)fs->fs_frag) {
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case 8:
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return (cp[h] == 0);
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case 4:
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return ((cp[h >> 1] & (0x0f << ((h & 0x1) << 2))) == 0);
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case 2:
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return ((cp[h >> 2] & (0x03 << ((h & 0x3) << 1))) == 0);
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case 1:
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return ((cp[h >> 3] & (0x01 << (h & 0x7))) == 0);
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default:
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#ifdef _KERNEL
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panic("ffs_isfreeblock");
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#endif
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break;
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}
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return (0);
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}
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/*
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* take a block out of the map
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*/
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void
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ffs_clrblock(struct fs *fs, u_char *cp, ufs1_daddr_t h)
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{
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switch ((int)fs->fs_frag) {
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case 8:
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cp[h] = 0;
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return;
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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:
|
|
#ifdef _KERNEL
|
|
panic("ffs_clrblock");
|
|
#endif
|
|
break;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* put a block into the map
|
|
*/
|
|
void
|
|
ffs_setblock(struct fs *fs, unsigned char *cp, ufs1_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:
|
|
#ifdef _KERNEL
|
|
panic("ffs_setblock");
|
|
#endif
|
|
break;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Update the cluster map because of an allocation or free.
|
|
*
|
|
* Cnt == 1 means free; cnt == -1 means allocating.
|
|
*/
|
|
void
|
|
ffs_clusteracct(struct fs *fs, struct cg *cgp, ufs1_daddr_t blkno, int cnt)
|
|
{
|
|
int32_t *sump;
|
|
int32_t *lp;
|
|
u_char *freemapp, *mapp;
|
|
int i, start, end, forw, back, map;
|
|
u_int bit;
|
|
|
|
if (fs->fs_contigsumsize <= 0)
|
|
return;
|
|
freemapp = cg_clustersfree(cgp);
|
|
sump = cg_clustersum(cgp);
|
|
/*
|
|
* Allocate or clear the actual block.
|
|
*/
|
|
if (cnt > 0)
|
|
setbit(freemapp, blkno);
|
|
else
|
|
clrbit(freemapp, blkno);
|
|
/*
|
|
* Find the size of the cluster going forward.
|
|
*/
|
|
start = blkno + 1;
|
|
end = start + fs->fs_contigsumsize;
|
|
if (end >= cgp->cg_nclusterblks)
|
|
end = cgp->cg_nclusterblks;
|
|
mapp = &freemapp[start / NBBY];
|
|
map = *mapp++;
|
|
bit = 1U << (start % NBBY);
|
|
for (i = start; i < end; i++) {
|
|
if ((map & bit) == 0)
|
|
break;
|
|
if ((i & (NBBY - 1)) != (NBBY - 1)) {
|
|
bit <<= 1;
|
|
} else {
|
|
map = *mapp++;
|
|
bit = 1;
|
|
}
|
|
}
|
|
forw = i - start;
|
|
/*
|
|
* Find the size of the cluster going backward.
|
|
*/
|
|
start = blkno - 1;
|
|
end = start - fs->fs_contigsumsize;
|
|
if (end < 0)
|
|
end = -1;
|
|
mapp = &freemapp[start / NBBY];
|
|
map = *mapp--;
|
|
bit = 1U << (start % NBBY);
|
|
for (i = start; i > end; i--) {
|
|
if ((map & bit) == 0)
|
|
break;
|
|
if ((i & (NBBY - 1)) != 0) {
|
|
bit >>= 1;
|
|
} else {
|
|
map = *mapp--;
|
|
bit = 1U << (NBBY - 1);
|
|
}
|
|
}
|
|
back = start - i;
|
|
/*
|
|
* Account for old cluster and the possibly new forward and
|
|
* back clusters.
|
|
*/
|
|
i = back + forw + 1;
|
|
if (i > fs->fs_contigsumsize)
|
|
i = fs->fs_contigsumsize;
|
|
sump[i] += cnt;
|
|
if (back > 0)
|
|
sump[back] -= cnt;
|
|
if (forw > 0)
|
|
sump[forw] -= cnt;
|
|
/*
|
|
* Update cluster summary information.
|
|
*/
|
|
lp = &sump[fs->fs_contigsumsize];
|
|
for (i = fs->fs_contigsumsize; i > 0; i--)
|
|
if (*lp-- > 0)
|
|
break;
|
|
fs->fs_maxcluster[cgp->cg_cgx] = i;
|
|
}
|