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      1 /*	$NetBSD: subr_disklabel.c,v 1.5 2026/01/04 03:16:53 riastradh Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1982, 1986, 1988 Regents of the University of California.
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. Neither the name of the University nor the names of its contributors
     16  *    may be used to endorse or promote products derived from this software
     17  *    without specific prior written permission.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     29  * SUCH DAMAGE.
     30  *
     31  *	@(#)ufs_disksubr.c	7.16 (Berkeley) 5/4/91
     32  */
     33 
     34 #include <sys/cdefs.h>
     35 __KERNEL_RCSID(0, "$NetBSD: subr_disklabel.c,v 1.5 2026/01/04 03:16:53 riastradh Exp $");
     36 
     37 #include <sys/param.h>
     38 #include <sys/types.h>
     39 
     40 #include <sys/disklabel.h>
     41 #include <sys/sdt.h>
     42 #include <sys/systm.h>
     43 
     44 #if !defined(__HAVE_SETDISKLABEL) || defined(_RUMPKERNEL)
     45 
     46 #ifdef DEBUG
     47 #define DPRINTF(a, ...) printf(a, ##__VA_ARGS__)
     48 #else
     49 #define DPRINTF(a, ...) __nothing
     50 #endif
     51 
     52 /*
     53  * Check new disk label for sensibility
     54  * before setting it.
     55  */
     56 int
     57 setdisklabel(struct disklabel *olp, struct disklabel *nlp, u_long openmask,
     58     struct cpu_disklabel *osdep)
     59 {
     60 	int i;
     61 	struct partition *opp, *npp;
     62 
     63 	/* sanity clause */
     64 	if (nlp->d_secpercyl == 0 || nlp->d_secsize == 0
     65 		|| (nlp->d_secsize % DEV_BSIZE) != 0) {
     66 		DPRINTF("%s: secpercyl/secsize %u/%u\n", __func__,
     67 		    nlp->d_secpercyl, nlp->d_secsize);
     68 		return SET_ERROR(EINVAL);
     69 	}
     70 
     71 	/* special case to allow disklabel to be invalidated */
     72 	if (nlp->d_magic == 0xffffffff) {
     73 		*olp = *nlp;
     74 		return 0;
     75 	}
     76 
     77 	if (nlp->d_magic != DISKMAGIC || nlp->d_magic2 != DISKMAGIC ||
     78 	    nlp->d_npartitions > MAXPARTITIONS || dkcksum(nlp) != 0) {
     79 		DPRINTF("%s: bad magic %#x/%#x != %#x, partitions %u != %u"
     80 		    ", bad sum=%#x\n", __func__,
     81 		    nlp->d_magic, nlp->d_magic2, DISKMAGIC,
     82 		    nlp->d_npartitions, MAXPARTITIONS, dkcksum(nlp));
     83 		return SET_ERROR(EINVAL);
     84 	}
     85 
     86 	while (openmask != 0) {
     87 		i = ffs(openmask) - 1;
     88 		openmask &= ~(1 << i);
     89 		if (i >= nlp->d_npartitions) {
     90 			DPRINTF("%s: partition not found\n", __func__);
     91 			return SET_ERROR(EBUSY);
     92 		}
     93 		opp = &olp->d_partitions[i];
     94 		npp = &nlp->d_partitions[i];
     95 		/*
     96 		 * Copy internally-set partition information
     97 		 * if new label doesn't include it.		XXX
     98 		 */
     99 		if (npp->p_fstype == FS_UNUSED && opp->p_fstype != FS_UNUSED) {
    100 			*npp = *opp;
    101 			continue;
    102 		}
    103 		if (npp->p_offset != opp->p_offset || npp->p_size < opp->p_size)
    104 		{
    105 			DPRINTF("%s: mismatched offset/size", __func__);
    106 			return SET_ERROR(EBUSY);
    107 		}
    108 	}
    109  	nlp->d_checksum = 0;
    110  	nlp->d_checksum = dkcksum(nlp);
    111 	*olp = *nlp;
    112 	return 0;
    113 }
    114 #endif
    115