xref: /minix3/sys/ufs/ffs/ffs_subr.c (revision 84d9c625bfea59e274550651111ae9edfdc40fbd)
1*84d9c625SLionel Sambuc /*	$NetBSD: ffs_subr.c,v 1.48 2013/10/20 00:29:10 htodd Exp $	*/
2d65f6f70SBen Gras 
3d65f6f70SBen Gras /*
4d65f6f70SBen Gras  * Copyright (c) 1982, 1986, 1989, 1993
5d65f6f70SBen Gras  *	The Regents of the University of California.  All rights reserved.
6d65f6f70SBen Gras  *
7d65f6f70SBen Gras  * Redistribution and use in source and binary forms, with or without
8d65f6f70SBen Gras  * modification, are permitted provided that the following conditions
9d65f6f70SBen Gras  * are met:
10d65f6f70SBen Gras  * 1. Redistributions of source code must retain the above copyright
11d65f6f70SBen Gras  *    notice, this list of conditions and the following disclaimer.
12d65f6f70SBen Gras  * 2. Redistributions in binary form must reproduce the above copyright
13d65f6f70SBen Gras  *    notice, this list of conditions and the following disclaimer in the
14d65f6f70SBen Gras  *    documentation and/or other materials provided with the distribution.
15d65f6f70SBen Gras  * 3. Neither the name of the University nor the names of its contributors
16d65f6f70SBen Gras  *    may be used to endorse or promote products derived from this software
17d65f6f70SBen Gras  *    without specific prior written permission.
18d65f6f70SBen Gras  *
19d65f6f70SBen Gras  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20d65f6f70SBen Gras  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21d65f6f70SBen Gras  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22d65f6f70SBen Gras  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23d65f6f70SBen Gras  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24d65f6f70SBen Gras  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25d65f6f70SBen Gras  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26d65f6f70SBen Gras  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27d65f6f70SBen Gras  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28d65f6f70SBen Gras  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29d65f6f70SBen Gras  * SUCH DAMAGE.
30d65f6f70SBen Gras  *
31d65f6f70SBen Gras  *	@(#)ffs_subr.c	8.5 (Berkeley) 3/21/95
32d65f6f70SBen Gras  */
33d65f6f70SBen Gras 
34d65f6f70SBen Gras #if HAVE_NBTOOL_CONFIG_H
35d65f6f70SBen Gras #include "nbtool_config.h"
36d65f6f70SBen Gras #endif
37d65f6f70SBen Gras 
38d65f6f70SBen Gras #include <sys/cdefs.h>
39*84d9c625SLionel Sambuc __KERNEL_RCSID(0, "$NetBSD: ffs_subr.c,v 1.48 2013/10/20 00:29:10 htodd Exp $");
40d65f6f70SBen Gras 
41d65f6f70SBen Gras #include <sys/param.h>
42d65f6f70SBen Gras 
43d65f6f70SBen Gras /* in ffs_tables.c */
44d65f6f70SBen Gras extern const int inside[], around[];
45d65f6f70SBen Gras extern const u_char * const fragtbl[];
46d65f6f70SBen Gras 
47d65f6f70SBen Gras #ifndef _KERNEL
48d65f6f70SBen Gras #define FFS_EI /* always include byteswapped filesystems support */
49d65f6f70SBen Gras #endif
50d65f6f70SBen Gras #include <ufs/ffs/fs.h>
51d65f6f70SBen Gras #include <ufs/ffs/ffs_extern.h>
52d65f6f70SBen Gras #include <ufs/ufs/ufs_bswap.h>
53d65f6f70SBen Gras 
54d65f6f70SBen Gras #ifndef _KERNEL
55d65f6f70SBen Gras #include <ufs/ufs/dinode.h>
56d65f6f70SBen Gras void    panic(const char *, ...)
57d65f6f70SBen Gras     __attribute__((__noreturn__,__format__(__printf__,1,2)));
58d65f6f70SBen Gras 
59d65f6f70SBen Gras #else	/* _KERNEL */
60d65f6f70SBen Gras #include <sys/systm.h>
61d65f6f70SBen Gras #include <sys/vnode.h>
62d65f6f70SBen Gras #include <sys/mount.h>
63d65f6f70SBen Gras #include <sys/buf.h>
64d65f6f70SBen Gras #include <sys/inttypes.h>
65d65f6f70SBen Gras #include <sys/pool.h>
66d65f6f70SBen Gras #include <sys/fstrans.h>
67d65f6f70SBen Gras #include <ufs/ufs/inode.h>
68d65f6f70SBen Gras #include <ufs/ufs/ufsmount.h>
69d65f6f70SBen Gras #include <ufs/ufs/ufs_extern.h>
70d65f6f70SBen Gras 
71d65f6f70SBen Gras /*
72d65f6f70SBen Gras  * Load up the contents of an inode and copy the appropriate pieces
73d65f6f70SBen Gras  * to the incore copy.
74d65f6f70SBen Gras  */
75d65f6f70SBen Gras void
ffs_load_inode(struct buf * bp,struct inode * ip,struct fs * fs,ino_t ino)76d65f6f70SBen Gras ffs_load_inode(struct buf *bp, struct inode *ip, struct fs *fs, ino_t ino)
77d65f6f70SBen Gras {
78d65f6f70SBen Gras 	struct ufs1_dinode *dp1;
79d65f6f70SBen Gras 	struct ufs2_dinode *dp2;
80d65f6f70SBen Gras 
81d65f6f70SBen Gras 	if (ip->i_ump->um_fstype == UFS1) {
82d65f6f70SBen Gras 		dp1 = (struct ufs1_dinode *)bp->b_data + ino_to_fsbo(fs, ino);
83d65f6f70SBen Gras #ifdef FFS_EI
84d65f6f70SBen Gras 		if (UFS_FSNEEDSWAP(fs))
85d65f6f70SBen Gras 			ffs_dinode1_swap(dp1, ip->i_din.ffs1_din);
86d65f6f70SBen Gras 		else
87d65f6f70SBen Gras #endif
88d65f6f70SBen Gras 		*ip->i_din.ffs1_din = *dp1;
89d65f6f70SBen Gras 
90d65f6f70SBen Gras 		ip->i_mode = ip->i_ffs1_mode;
91d65f6f70SBen Gras 		ip->i_nlink = ip->i_ffs1_nlink;
92d65f6f70SBen Gras 		ip->i_size = ip->i_ffs1_size;
93d65f6f70SBen Gras 		ip->i_flags = ip->i_ffs1_flags;
94d65f6f70SBen Gras 		ip->i_gen = ip->i_ffs1_gen;
95d65f6f70SBen Gras 		ip->i_uid = ip->i_ffs1_uid;
96d65f6f70SBen Gras 		ip->i_gid = ip->i_ffs1_gid;
97d65f6f70SBen Gras 	} else {
98d65f6f70SBen Gras 		dp2 = (struct ufs2_dinode *)bp->b_data + ino_to_fsbo(fs, ino);
99d65f6f70SBen Gras #ifdef FFS_EI
100d65f6f70SBen Gras 		if (UFS_FSNEEDSWAP(fs))
101d65f6f70SBen Gras 			ffs_dinode2_swap(dp2, ip->i_din.ffs2_din);
102d65f6f70SBen Gras 		else
103d65f6f70SBen Gras #endif
104d65f6f70SBen Gras 		*ip->i_din.ffs2_din = *dp2;
105d65f6f70SBen Gras 
106d65f6f70SBen Gras 		ip->i_mode = ip->i_ffs2_mode;
107d65f6f70SBen Gras 		ip->i_nlink = ip->i_ffs2_nlink;
108d65f6f70SBen Gras 		ip->i_size = ip->i_ffs2_size;
109d65f6f70SBen Gras 		ip->i_flags = ip->i_ffs2_flags;
110d65f6f70SBen Gras 		ip->i_gen = ip->i_ffs2_gen;
111d65f6f70SBen Gras 		ip->i_uid = ip->i_ffs2_uid;
112d65f6f70SBen Gras 		ip->i_gid = ip->i_ffs2_gid;
113d65f6f70SBen Gras 	}
114d65f6f70SBen Gras }
115d65f6f70SBen Gras 
116d65f6f70SBen Gras int
ffs_getblk(struct vnode * vp,daddr_t lblkno,daddr_t blkno,int size,bool clearbuf,buf_t ** bpp)117d65f6f70SBen Gras ffs_getblk(struct vnode *vp, daddr_t lblkno, daddr_t blkno, int size,
118d65f6f70SBen Gras     bool clearbuf, buf_t **bpp)
119d65f6f70SBen Gras {
120d65f6f70SBen Gras 	int error = 0;
121d65f6f70SBen Gras 
122d65f6f70SBen Gras 	KASSERT(blkno >= 0 || blkno == FFS_NOBLK);
123d65f6f70SBen Gras 
124d65f6f70SBen Gras 	if ((*bpp = getblk(vp, lblkno, size, 0, 0)) == NULL)
125d65f6f70SBen Gras 		return ENOMEM;
126d65f6f70SBen Gras 	if (blkno != FFS_NOBLK)
127d65f6f70SBen Gras 		(*bpp)->b_blkno = blkno;
128d65f6f70SBen Gras 	if (clearbuf)
129d65f6f70SBen Gras 		clrbuf(*bpp);
130d65f6f70SBen Gras 	if ((*bpp)->b_blkno >= 0 && (error = fscow_run(*bpp, false)) != 0)
131d65f6f70SBen Gras 		brelse(*bpp, BC_INVAL);
132d65f6f70SBen Gras 	return error;
133d65f6f70SBen Gras }
134d65f6f70SBen Gras 
135d65f6f70SBen Gras #endif	/* _KERNEL */
136d65f6f70SBen Gras 
137d65f6f70SBen Gras /*
138d65f6f70SBen Gras  * Update the frsum fields to reflect addition or deletion
139d65f6f70SBen Gras  * of some frags.
140d65f6f70SBen Gras  */
141d65f6f70SBen Gras void
ffs_fragacct(struct fs * fs,int fragmap,int32_t fraglist[],int cnt,int needswap)142d65f6f70SBen Gras ffs_fragacct(struct fs *fs, int fragmap, int32_t fraglist[], int cnt,
143d65f6f70SBen Gras     int needswap)
144d65f6f70SBen Gras {
145d65f6f70SBen Gras 	int inblk;
146d65f6f70SBen Gras 	int field, subfield;
147d65f6f70SBen Gras 	int siz, pos;
148d65f6f70SBen Gras 
149d65f6f70SBen Gras 	inblk = (int)(fragtbl[fs->fs_frag][fragmap]) << 1;
150d65f6f70SBen Gras 	fragmap <<= 1;
151d65f6f70SBen Gras 	for (siz = 1; siz < fs->fs_frag; siz++) {
152d65f6f70SBen Gras 		if ((inblk & (1 << (siz + (fs->fs_frag & (NBBY - 1))))) == 0)
153d65f6f70SBen Gras 			continue;
154d65f6f70SBen Gras 		field = around[siz];
155d65f6f70SBen Gras 		subfield = inside[siz];
156d65f6f70SBen Gras 		for (pos = siz; pos <= fs->fs_frag; pos++) {
157d65f6f70SBen Gras 			if ((fragmap & field) == subfield) {
158d65f6f70SBen Gras 				fraglist[siz] = ufs_rw32(
159d65f6f70SBen Gras 				    ufs_rw32(fraglist[siz], needswap) + cnt,
160d65f6f70SBen Gras 				    needswap);
161d65f6f70SBen Gras 				pos += siz;
162d65f6f70SBen Gras 				field <<= siz;
163d65f6f70SBen Gras 				subfield <<= siz;
164d65f6f70SBen Gras 			}
165d65f6f70SBen Gras 			field <<= 1;
166d65f6f70SBen Gras 			subfield <<= 1;
167d65f6f70SBen Gras 		}
168d65f6f70SBen Gras 	}
169d65f6f70SBen Gras }
170d65f6f70SBen Gras 
171d65f6f70SBen Gras /*
172d65f6f70SBen Gras  * block operations
173d65f6f70SBen Gras  *
174d65f6f70SBen Gras  * check if a block is available
175d65f6f70SBen Gras  *  returns true if all the correponding bits in the free map are 1
176d65f6f70SBen Gras  *  returns false if any corresponding bit in the free map is 0
177d65f6f70SBen Gras  */
178d65f6f70SBen Gras int
ffs_isblock(struct fs * fs,u_char * cp,int32_t h)179d65f6f70SBen Gras ffs_isblock(struct fs *fs, u_char *cp, int32_t h)
180d65f6f70SBen Gras {
181d65f6f70SBen Gras 	u_char mask;
182d65f6f70SBen Gras 
183d65f6f70SBen Gras 	switch ((int)fs->fs_fragshift) {
184d65f6f70SBen Gras 	case 3:
185d65f6f70SBen Gras 		return (cp[h] == 0xff);
186d65f6f70SBen Gras 	case 2:
187d65f6f70SBen Gras 		mask = 0x0f << ((h & 0x1) << 2);
188d65f6f70SBen Gras 		return ((cp[h >> 1] & mask) == mask);
189d65f6f70SBen Gras 	case 1:
190d65f6f70SBen Gras 		mask = 0x03 << ((h & 0x3) << 1);
191d65f6f70SBen Gras 		return ((cp[h >> 2] & mask) == mask);
192d65f6f70SBen Gras 	case 0:
193d65f6f70SBen Gras 		mask = 0x01 << (h & 0x7);
194d65f6f70SBen Gras 		return ((cp[h >> 3] & mask) == mask);
195d65f6f70SBen Gras 	default:
196d65f6f70SBen Gras 		panic("ffs_isblock: unknown fs_fragshift %d",
197d65f6f70SBen Gras 		    (int)fs->fs_fragshift);
198d65f6f70SBen Gras 	}
199d65f6f70SBen Gras }
200d65f6f70SBen Gras 
201d65f6f70SBen Gras /*
202d65f6f70SBen Gras  * check if a block is completely allocated
203d65f6f70SBen Gras  *  returns true if all the corresponding bits in the free map are 0
204d65f6f70SBen Gras  *  returns false if any corresponding bit in the free map is 1
205d65f6f70SBen Gras  */
206d65f6f70SBen Gras int
ffs_isfreeblock(struct fs * fs,u_char * cp,int32_t h)207d65f6f70SBen Gras ffs_isfreeblock(struct fs *fs, u_char *cp, int32_t h)
208d65f6f70SBen Gras {
209d65f6f70SBen Gras 
210d65f6f70SBen Gras 	switch ((int)fs->fs_fragshift) {
211d65f6f70SBen Gras 	case 3:
212d65f6f70SBen Gras 		return (cp[h] == 0);
213d65f6f70SBen Gras 	case 2:
214d65f6f70SBen Gras 		return ((cp[h >> 1] & (0x0f << ((h & 0x1) << 2))) == 0);
215d65f6f70SBen Gras 	case 1:
216d65f6f70SBen Gras 		return ((cp[h >> 2] & (0x03 << ((h & 0x3) << 1))) == 0);
217d65f6f70SBen Gras 	case 0:
218d65f6f70SBen Gras 		return ((cp[h >> 3] & (0x01 << (h & 0x7))) == 0);
219d65f6f70SBen Gras 	default:
220d65f6f70SBen Gras 		panic("ffs_isfreeblock: unknown fs_fragshift %d",
221d65f6f70SBen Gras 		    (int)fs->fs_fragshift);
222d65f6f70SBen Gras 	}
223d65f6f70SBen Gras }
224d65f6f70SBen Gras 
225d65f6f70SBen Gras /*
226d65f6f70SBen Gras  * take a block out of the map
227d65f6f70SBen Gras  */
228d65f6f70SBen Gras void
ffs_clrblock(struct fs * fs,u_char * cp,int32_t h)229d65f6f70SBen Gras ffs_clrblock(struct fs *fs, u_char *cp, int32_t h)
230d65f6f70SBen Gras {
231d65f6f70SBen Gras 
232d65f6f70SBen Gras 	switch ((int)fs->fs_fragshift) {
233d65f6f70SBen Gras 	case 3:
234d65f6f70SBen Gras 		cp[h] = 0;
235d65f6f70SBen Gras 		return;
236d65f6f70SBen Gras 	case 2:
237d65f6f70SBen Gras 		cp[h >> 1] &= ~(0x0f << ((h & 0x1) << 2));
238d65f6f70SBen Gras 		return;
239d65f6f70SBen Gras 	case 1:
240d65f6f70SBen Gras 		cp[h >> 2] &= ~(0x03 << ((h & 0x3) << 1));
241d65f6f70SBen Gras 		return;
242d65f6f70SBen Gras 	case 0:
243d65f6f70SBen Gras 		cp[h >> 3] &= ~(0x01 << (h & 0x7));
244d65f6f70SBen Gras 		return;
245d65f6f70SBen Gras 	default:
246d65f6f70SBen Gras 		panic("ffs_clrblock: unknown fs_fragshift %d",
247d65f6f70SBen Gras 		    (int)fs->fs_fragshift);
248d65f6f70SBen Gras 	}
249d65f6f70SBen Gras }
250d65f6f70SBen Gras 
251d65f6f70SBen Gras /*
252d65f6f70SBen Gras  * put a block into the map
253d65f6f70SBen Gras  */
254d65f6f70SBen Gras void
ffs_setblock(struct fs * fs,u_char * cp,int32_t h)255d65f6f70SBen Gras ffs_setblock(struct fs *fs, u_char *cp, int32_t h)
256d65f6f70SBen Gras {
257d65f6f70SBen Gras 
258d65f6f70SBen Gras 	switch ((int)fs->fs_fragshift) {
259d65f6f70SBen Gras 	case 3:
260d65f6f70SBen Gras 		cp[h] = 0xff;
261d65f6f70SBen Gras 		return;
262d65f6f70SBen Gras 	case 2:
263d65f6f70SBen Gras 		cp[h >> 1] |= (0x0f << ((h & 0x1) << 2));
264d65f6f70SBen Gras 		return;
265d65f6f70SBen Gras 	case 1:
266d65f6f70SBen Gras 		cp[h >> 2] |= (0x03 << ((h & 0x3) << 1));
267d65f6f70SBen Gras 		return;
268d65f6f70SBen Gras 	case 0:
269d65f6f70SBen Gras 		cp[h >> 3] |= (0x01 << (h & 0x7));
270d65f6f70SBen Gras 		return;
271d65f6f70SBen Gras 	default:
272d65f6f70SBen Gras 		panic("ffs_setblock: unknown fs_fragshift %d",
273d65f6f70SBen Gras 		    (int)fs->fs_fragshift);
274d65f6f70SBen Gras 	}
275d65f6f70SBen Gras }
276d65f6f70SBen Gras 
277d65f6f70SBen Gras /*
278d65f6f70SBen Gras  * Update the cluster map because of an allocation or free.
279d65f6f70SBen Gras  *
280d65f6f70SBen Gras  * Cnt == 1 means free; cnt == -1 means allocating.
281d65f6f70SBen Gras  */
282d65f6f70SBen Gras void
ffs_clusteracct(struct fs * fs,struct cg * cgp,int32_t blkno,int cnt)283d65f6f70SBen Gras ffs_clusteracct(struct fs *fs, struct cg *cgp, int32_t blkno, int cnt)
284d65f6f70SBen Gras {
285d65f6f70SBen Gras 	int32_t *sump;
286d65f6f70SBen Gras 	int32_t *lp;
287d65f6f70SBen Gras 	u_char *freemapp, *mapp;
288d65f6f70SBen Gras 	int i, start, end, forw, back, map, bit;
289d65f6f70SBen Gras 	const int needswap = UFS_FSNEEDSWAP(fs);
290d65f6f70SBen Gras 
291d65f6f70SBen Gras 	/* KASSERT(mutex_owned(&ump->um_lock)); */
292d65f6f70SBen Gras 
293d65f6f70SBen Gras 	if (fs->fs_contigsumsize <= 0)
294d65f6f70SBen Gras 		return;
295d65f6f70SBen Gras 	freemapp = cg_clustersfree(cgp, needswap);
296d65f6f70SBen Gras 	sump = cg_clustersum(cgp, needswap);
297d65f6f70SBen Gras 	/*
298d65f6f70SBen Gras 	 * Allocate or clear the actual block.
299d65f6f70SBen Gras 	 */
300d65f6f70SBen Gras 	if (cnt > 0)
301d65f6f70SBen Gras 		setbit(freemapp, blkno);
302d65f6f70SBen Gras 	else
303d65f6f70SBen Gras 		clrbit(freemapp, blkno);
304d65f6f70SBen Gras 	/*
305d65f6f70SBen Gras 	 * Find the size of the cluster going forward.
306d65f6f70SBen Gras 	 */
307d65f6f70SBen Gras 	start = blkno + 1;
308d65f6f70SBen Gras 	end = start + fs->fs_contigsumsize;
309d65f6f70SBen Gras 	if ((uint32_t)end >= ufs_rw32(cgp->cg_nclusterblks, needswap))
310d65f6f70SBen Gras 		end = ufs_rw32(cgp->cg_nclusterblks, needswap);
311d65f6f70SBen Gras 	mapp = &freemapp[start / NBBY];
312d65f6f70SBen Gras 	map = *mapp++;
313d65f6f70SBen Gras 	bit = 1 << (start % NBBY);
314d65f6f70SBen Gras 	for (i = start; i < end; i++) {
315d65f6f70SBen Gras 		if ((map & bit) == 0)
316d65f6f70SBen Gras 			break;
317d65f6f70SBen Gras 		if ((i & (NBBY - 1)) != (NBBY - 1)) {
318d65f6f70SBen Gras 			bit <<= 1;
319d65f6f70SBen Gras 		} else {
320d65f6f70SBen Gras 			map = *mapp++;
321d65f6f70SBen Gras 			bit = 1;
322d65f6f70SBen Gras 		}
323d65f6f70SBen Gras 	}
324d65f6f70SBen Gras 	forw = i - start;
325d65f6f70SBen Gras 	/*
326d65f6f70SBen Gras 	 * Find the size of the cluster going backward.
327d65f6f70SBen Gras 	 */
328d65f6f70SBen Gras 	start = blkno - 1;
329d65f6f70SBen Gras 	end = start - fs->fs_contigsumsize;
330d65f6f70SBen Gras 	if (end < 0)
331d65f6f70SBen Gras 		end = -1;
332d65f6f70SBen Gras 	mapp = &freemapp[start / NBBY];
333d65f6f70SBen Gras 	map = *mapp--;
334d65f6f70SBen Gras 	bit = 1 << (start % NBBY);
335d65f6f70SBen Gras 	for (i = start; i > end; i--) {
336d65f6f70SBen Gras 		if ((map & bit) == 0)
337d65f6f70SBen Gras 			break;
338d65f6f70SBen Gras 		if ((i & (NBBY - 1)) != 0) {
339d65f6f70SBen Gras 			bit >>= 1;
340d65f6f70SBen Gras 		} else {
341d65f6f70SBen Gras 			map = *mapp--;
342d65f6f70SBen Gras 			bit = 1 << (NBBY - 1);
343d65f6f70SBen Gras 		}
344d65f6f70SBen Gras 	}
345d65f6f70SBen Gras 	back = start - i;
346d65f6f70SBen Gras 	/*
347d65f6f70SBen Gras 	 * Account for old cluster and the possibly new forward and
348d65f6f70SBen Gras 	 * back clusters.
349d65f6f70SBen Gras 	 */
350d65f6f70SBen Gras 	i = back + forw + 1;
351d65f6f70SBen Gras 	if (i > fs->fs_contigsumsize)
352d65f6f70SBen Gras 		i = fs->fs_contigsumsize;
353d65f6f70SBen Gras 	ufs_add32(sump[i], cnt, needswap);
354d65f6f70SBen Gras 	if (back > 0)
355d65f6f70SBen Gras 		ufs_add32(sump[back], -cnt, needswap);
356d65f6f70SBen Gras 	if (forw > 0)
357d65f6f70SBen Gras 		ufs_add32(sump[forw], -cnt, needswap);
358d65f6f70SBen Gras 
359d65f6f70SBen Gras 	/*
360d65f6f70SBen Gras 	 * Update cluster summary information.
361d65f6f70SBen Gras 	 */
362d65f6f70SBen Gras 	lp = &sump[fs->fs_contigsumsize];
363d65f6f70SBen Gras 	for (i = fs->fs_contigsumsize; i > 0; i--)
364d65f6f70SBen Gras 		if (ufs_rw32(*lp--, needswap) > 0)
365d65f6f70SBen Gras 			break;
366d65f6f70SBen Gras #if defined(_KERNEL)
367d65f6f70SBen Gras 	fs->fs_maxcluster[ufs_rw32(cgp->cg_cgx, needswap)] = i;
368d65f6f70SBen Gras #endif
369d65f6f70SBen Gras }
370