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subr_disk.c revision 1.89.6.1
      1 /*	$NetBSD: subr_disk.c,v 1.89.6.1 2007/12/04 13:03:15 ad Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1996, 1997, 1999, 2000 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
      9  * NASA Ames Research Center.
     10  *
     11  * Redistribution and use in source and binary forms, with or without
     12  * modification, are permitted provided that the following conditions
     13  * are met:
     14  * 1. Redistributions of source code must retain the above copyright
     15  *    notice, this list of conditions and the following disclaimer.
     16  * 2. Redistributions in binary form must reproduce the above copyright
     17  *    notice, this list of conditions and the following disclaimer in the
     18  *    documentation and/or other materials provided with the distribution.
     19  * 3. All advertising materials mentioning features or use of this software
     20  *    must display the following acknowledgement:
     21  *	This product includes software developed by the NetBSD
     22  *	Foundation, Inc. and its contributors.
     23  * 4. Neither the name of The NetBSD Foundation nor the names of its
     24  *    contributors may be used to endorse or promote products derived
     25  *    from this software without specific prior written permission.
     26  *
     27  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     28  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     29  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     30  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     31  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     32  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     33  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     34  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     35  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     36  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     37  * POSSIBILITY OF SUCH DAMAGE.
     38  */
     39 
     40 /*
     41  * Copyright (c) 1982, 1986, 1988, 1993
     42  *	The Regents of the University of California.  All rights reserved.
     43  * (c) UNIX System Laboratories, Inc.
     44  * All or some portions of this file are derived from material licensed
     45  * to the University of California by American Telephone and Telegraph
     46  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
     47  * the permission of UNIX System Laboratories, Inc.
     48  *
     49  * Redistribution and use in source and binary forms, with or without
     50  * modification, are permitted provided that the following conditions
     51  * are met:
     52  * 1. Redistributions of source code must retain the above copyright
     53  *    notice, this list of conditions and the following disclaimer.
     54  * 2. Redistributions in binary form must reproduce the above copyright
     55  *    notice, this list of conditions and the following disclaimer in the
     56  *    documentation and/or other materials provided with the distribution.
     57  * 3. Neither the name of the University nor the names of its contributors
     58  *    may be used to endorse or promote products derived from this software
     59  *    without specific prior written permission.
     60  *
     61  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     62  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     63  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     64  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     65  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     66  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     67  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     68  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     69  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     70  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     71  * SUCH DAMAGE.
     72  *
     73  *	@(#)ufs_disksubr.c	8.5 (Berkeley) 1/21/94
     74  */
     75 
     76 #include <sys/cdefs.h>
     77 __KERNEL_RCSID(0, "$NetBSD: subr_disk.c,v 1.89.6.1 2007/12/04 13:03:15 ad Exp $");
     78 
     79 #include <sys/param.h>
     80 #include <sys/kernel.h>
     81 #include <sys/malloc.h>
     82 #include <sys/buf.h>
     83 #include <sys/syslog.h>
     84 #include <sys/disklabel.h>
     85 #include <sys/disk.h>
     86 #include <sys/sysctl.h>
     87 #include <lib/libkern/libkern.h>
     88 
     89 /*
     90  * Compute checksum for disk label.
     91  */
     92 u_int
     93 dkcksum(struct disklabel *lp)
     94 {
     95 	return dkcksum_sized(lp, lp->d_npartitions);
     96 }
     97 
     98 u_int
     99 dkcksum_sized(struct disklabel *lp, size_t npartitions)
    100 {
    101 	u_short *start, *end;
    102 	u_short sum = 0;
    103 
    104 	start = (u_short *)lp;
    105 	end = (u_short *)&lp->d_partitions[npartitions];
    106 	while (start < end)
    107 		sum ^= *start++;
    108 	return (sum);
    109 }
    110 
    111 /*
    112  * Disk error is the preface to plaintive error messages
    113  * about failing disk transfers.  It prints messages of the form
    114 
    115 hp0g: hard error reading fsbn 12345 of 12344-12347 (hp0 bn %d cn %d tn %d sn %d)
    116 
    117  * if the offset of the error in the transfer and a disk label
    118  * are both available.  blkdone should be -1 if the position of the error
    119  * is unknown; the disklabel pointer may be null from drivers that have not
    120  * been converted to use them.  The message is printed with printf
    121  * if pri is LOG_PRINTF, otherwise it uses log at the specified priority.
    122  * The message should be completed (with at least a newline) with printf
    123  * or addlog, respectively.  There is no trailing space.
    124  */
    125 #ifndef PRIdaddr
    126 #define PRIdaddr PRId64
    127 #endif
    128 void
    129 diskerr(const struct buf *bp, const char *dname, const char *what, int pri,
    130     int blkdone, const struct disklabel *lp)
    131 {
    132 	int unit = DISKUNIT(bp->b_dev), part = DISKPART(bp->b_dev);
    133 	void (*pr)(const char *, ...);
    134 	char partname = 'a' + part;
    135 	daddr_t sn;
    136 
    137 	if (/*CONSTCOND*/0)
    138 		/* Compiler will error this is the format is wrong... */
    139 		printf("%" PRIdaddr, bp->b_blkno);
    140 
    141 	if (pri != LOG_PRINTF) {
    142 		static const char fmt[] = "";
    143 		log(pri, fmt);
    144 		pr = addlog;
    145 	} else
    146 		pr = printf;
    147 	(*pr)("%s%d%c: %s %sing fsbn ", dname, unit, partname, what,
    148 	    bp->b_flags & B_READ ? "read" : "writ");
    149 	sn = bp->b_blkno;
    150 	if (bp->b_bcount <= DEV_BSIZE)
    151 		(*pr)("%" PRIdaddr, sn);
    152 	else {
    153 		if (blkdone >= 0) {
    154 			sn += blkdone;
    155 			(*pr)("%" PRIdaddr " of ", sn);
    156 		}
    157 		(*pr)("%" PRIdaddr "-%" PRIdaddr "", bp->b_blkno,
    158 		    bp->b_blkno + (bp->b_bcount - 1) / DEV_BSIZE);
    159 	}
    160 	if (lp && (blkdone >= 0 || bp->b_bcount <= lp->d_secsize)) {
    161 		sn += lp->d_partitions[part].p_offset;
    162 		(*pr)(" (%s%d bn %" PRIdaddr "; cn %" PRIdaddr "",
    163 		    dname, unit, sn, sn / lp->d_secpercyl);
    164 		sn %= lp->d_secpercyl;
    165 		(*pr)(" tn %" PRIdaddr " sn %" PRIdaddr ")",
    166 		    sn / lp->d_nsectors, sn % lp->d_nsectors);
    167 	}
    168 }
    169 
    170 /*
    171  * Searches the iostatlist for the disk corresponding to the
    172  * name provided.
    173  */
    174 struct disk *
    175 disk_find(const char *name)
    176 {
    177 	struct io_stats *stat;
    178 
    179 	stat = iostat_find(name);
    180 
    181 	if ((stat != NULL) && (stat->io_type == IOSTAT_DISK))
    182 		return stat->io_parent;
    183 
    184 	return (NULL);
    185 }
    186 
    187 void
    188 disk_init(struct disk *diskp, char *name, struct dkdriver *driver)
    189 {
    190 
    191 	/*
    192 	 * Initialize the wedge-related locks and other fields.
    193 	 */
    194 	mutex_init(&diskp->dk_rawlock, MUTEX_DEFAULT, IPL_NONE);
    195 	mutex_init(&diskp->dk_openlock, MUTEX_DEFAULT, IPL_NONE);
    196 	LIST_INIT(&diskp->dk_wedges);
    197 	diskp->dk_nwedges = 0;
    198 	diskp->dk_labelsector = LABELSECTOR;
    199 	disk_blocksize(diskp, DEV_BSIZE);
    200 	diskp->dk_name = name;
    201 	diskp->dk_driver = driver;
    202 }
    203 
    204 /*
    205  * Attach a disk.
    206  */
    207 void
    208 disk_attach(struct disk *diskp)
    209 {
    210 
    211 	/*
    212 	 * Allocate and initialize the disklabel structures.  Note that
    213 	 * it's not safe to sleep here, since we're probably going to be
    214 	 * called during autoconfiguration.
    215 	 */
    216 	diskp->dk_label = malloc(sizeof(struct disklabel), M_DEVBUF, M_NOWAIT);
    217 	diskp->dk_cpulabel = malloc(sizeof(struct cpu_disklabel), M_DEVBUF,
    218 	    M_NOWAIT);
    219 	if ((diskp->dk_label == NULL) || (diskp->dk_cpulabel == NULL))
    220 		panic("disk_attach: can't allocate storage for disklabel");
    221 
    222 	memset(diskp->dk_label, 0, sizeof(struct disklabel));
    223 	memset(diskp->dk_cpulabel, 0, sizeof(struct cpu_disklabel));
    224 
    225 	/*
    226 	 * Set up the stats collection.
    227 	 */
    228 	diskp->dk_stats = iostat_alloc(IOSTAT_DISK, diskp, diskp->dk_name);
    229 }
    230 
    231 /*
    232  * Detach a disk.
    233  */
    234 void
    235 disk_detach(struct disk *diskp)
    236 {
    237 
    238 	/*
    239 	 * Remove from the drivelist.
    240 	 */
    241 	iostat_free(diskp->dk_stats);
    242 
    243 	/*
    244 	 * Release the disk-info dictionary.
    245 	 */
    246 	if (diskp->dk_info) {
    247 		prop_object_release(diskp->dk_info);
    248 		diskp->dk_info = NULL;
    249 	}
    250 
    251 	/*
    252 	 * Free the space used by the disklabel structures.
    253 	 */
    254 	free(diskp->dk_label, M_DEVBUF);
    255 	free(diskp->dk_cpulabel, M_DEVBUF);
    256 }
    257 
    258 void
    259 disk_destroy(struct disk *diskp)
    260 {
    261 
    262 	mutex_destroy(&diskp->dk_openlock);
    263 	mutex_destroy(&diskp->dk_rawlock);
    264 }
    265 
    266 /*
    267  * Mark the disk as busy for metrics collection.
    268  */
    269 void
    270 disk_busy(struct disk *diskp)
    271 {
    272 
    273 	iostat_busy(diskp->dk_stats);
    274 }
    275 
    276 /*
    277  * Finished disk operations, gather metrics.
    278  */
    279 void
    280 disk_unbusy(struct disk *diskp, long bcount, int read)
    281 {
    282 
    283 	iostat_unbusy(diskp->dk_stats, bcount, read);
    284 }
    285 
    286 /*
    287  * Set the physical blocksize of a disk, in bytes.
    288  * Only necessary if blocksize != DEV_BSIZE.
    289  */
    290 void
    291 disk_blocksize(struct disk *diskp, int blocksize)
    292 {
    293 
    294 	diskp->dk_blkshift = DK_BSIZE2BLKSHIFT(blocksize);
    295 	diskp->dk_byteshift = DK_BSIZE2BYTESHIFT(blocksize);
    296 }
    297 
    298 /*
    299  * Bounds checking against the media size, used for the raw partition.
    300  * The sector size passed in should currently always be DEV_BSIZE,
    301  * and the media size the size of the device in DEV_BSIZE sectors.
    302  */
    303 int
    304 bounds_check_with_mediasize(struct buf *bp, int secsize, uint64_t mediasize)
    305 {
    306 	int64_t sz;
    307 
    308 	sz = howmany(bp->b_bcount, secsize);
    309 
    310 	if (bp->b_blkno + sz > mediasize) {
    311 		sz = mediasize - bp->b_blkno;
    312 		if (sz == 0) {
    313 			/* If exactly at end of disk, return EOF. */
    314 			bp->b_resid = bp->b_bcount;
    315 			return 0;
    316 		}
    317 		if (sz < 0) {
    318 			/* If past end of disk, return EINVAL. */
    319 			bp->b_error = EINVAL;
    320 			return 0;
    321 		}
    322 		/* Otherwise, truncate request. */
    323 		bp->b_bcount = sz << DEV_BSHIFT;
    324 	}
    325 
    326 	return 1;
    327 }
    328 
    329 /*
    330  * Determine the size of the transfer, and make sure it is
    331  * within the boundaries of the partition. Adjust transfer
    332  * if needed, and signal errors or early completion.
    333  */
    334 int
    335 bounds_check_with_label(struct disk *dk, struct buf *bp, int wlabel)
    336 {
    337 	struct disklabel *lp = dk->dk_label;
    338 	struct partition *p = lp->d_partitions + DISKPART(bp->b_dev);
    339 	uint64_t p_size, p_offset, labelsector;
    340 	int64_t sz;
    341 
    342 	/* Protect against division by zero. XXX: Should never happen?!?! */
    343 	if (lp->d_secpercyl == 0) {
    344 		bp->b_error = EINVAL;
    345 		return -1;
    346 	}
    347 
    348 	p_size = p->p_size << dk->dk_blkshift;
    349 	p_offset = p->p_offset << dk->dk_blkshift;
    350 #if RAW_PART == 3
    351 	labelsector = lp->d_partitions[2].p_offset;
    352 #else
    353 	labelsector = lp->d_partitions[RAW_PART].p_offset;
    354 #endif
    355 	labelsector = (labelsector + dk->dk_labelsector) << dk->dk_blkshift;
    356 
    357 	sz = howmany(bp->b_bcount, DEV_BSIZE);
    358 	if ((bp->b_blkno + sz) > p_size) {
    359 		sz = p_size - bp->b_blkno;
    360 		if (sz == 0) {
    361 			/* If exactly at end of disk, return EOF. */
    362 			bp->b_resid = bp->b_bcount;
    363 			return 0;
    364 		}
    365 		if (sz < 0) {
    366 			/* If past end of disk, return EINVAL. */
    367 			bp->b_error = EINVAL;
    368 			return -1;
    369 		}
    370 		/* Otherwise, truncate request. */
    371 		bp->b_bcount = sz << DEV_BSHIFT;
    372 	}
    373 
    374 	/* Overwriting disk label? */
    375 	if (bp->b_blkno + p_offset <= labelsector &&
    376 	    bp->b_blkno + p_offset + sz > labelsector &&
    377 	    (bp->b_flags & B_READ) == 0 && !wlabel) {
    378 		bp->b_error = EROFS;
    379 		return -1;
    380 	}
    381 
    382 	/* calculate cylinder for disksort to order transfers with */
    383 	bp->b_cylinder = (bp->b_blkno + p->p_offset) /
    384 	    (lp->d_secsize / DEV_BSIZE) / lp->d_secpercyl;
    385 	return 1;
    386 }
    387 
    388 int
    389 disk_read_sectors(void (*strat)(struct buf *), const struct disklabel *lp,
    390     struct buf *bp, unsigned int sector, int count)
    391 {
    392 	bp->b_blkno = sector;
    393 	bp->b_bcount = count * lp->d_secsize;
    394 	bp->b_flags = (bp->b_flags & ~B_WRITE) | B_READ;
    395 	bp->b_oflags &= ~BO_DONE;
    396 	bp->b_cylinder = sector / lp->d_secpercyl;
    397 	(*strat)(bp);
    398 	return biowait(bp);
    399 }
    400 
    401 const char *
    402 convertdisklabel(struct disklabel *lp, void (*strat)(struct buf *),
    403     struct buf *bp, uint32_t secperunit)
    404 {
    405 	struct partition rp, *altp, *p;
    406 	int geom_ok;
    407 
    408 	memset(&rp, 0, sizeof(rp));
    409 	rp.p_size = secperunit;
    410 	rp.p_fstype = FS_UNUSED;
    411 
    412 	/* If we can seek to d_secperunit - 1, believe the disk geometry. */
    413 	if (secperunit != 0 &&
    414 	    disk_read_sectors(strat, lp, bp, secperunit - 1, 1) == 0)
    415 		geom_ok = 1;
    416 	else
    417 		geom_ok = 0;
    418 
    419 #if 0
    420 	printf("%s: secperunit (%" PRIu32 ") %s\n", __func__,
    421 	    secperunit, geom_ok ? "ok" : "not ok");
    422 #endif
    423 
    424 	p = &lp->d_partitions[RAW_PART];
    425 	if (RAW_PART == 'c' - 'a')
    426 		altp = &lp->d_partitions['d' - 'a'];
    427 	else
    428 		altp = &lp->d_partitions['c' - 'a'];
    429 
    430 	if (lp->d_npartitions > RAW_PART && p->p_offset == 0 && p->p_size != 0)
    431 		;	/* already a raw partition */
    432 	else if (lp->d_npartitions > MAX('c', 'd') - 'a' &&
    433 		 altp->p_offset == 0 && altp->p_size != 0) {
    434 		/* alternate partition ('c' or 'd') is suitable for raw slot,
    435 		 * swap with 'd' or 'c'.
    436 		 */
    437 		rp = *p;
    438 		*p = *altp;
    439 		*altp = rp;
    440 	} else if (lp->d_npartitions <= RAW_PART &&
    441 	           lp->d_npartitions > 'c' - 'a') {
    442 		/* No raw partition is present, but the alternate is present.
    443 		 * Copy alternate to raw partition.
    444 		 */
    445 		lp->d_npartitions = RAW_PART + 1;
    446 		*p = *altp;
    447 	} else if (!geom_ok)
    448 		return "no raw partition and disk reports bad geometry";
    449 	else if (lp->d_npartitions <= RAW_PART) {
    450 		memset(&lp->d_partitions[lp->d_npartitions], 0,
    451 		    sizeof(struct partition) * (RAW_PART - lp->d_npartitions));
    452 		*p = rp;
    453 		lp->d_npartitions = RAW_PART + 1;
    454 	} else if (lp->d_npartitions < MAXPARTITIONS) {
    455 		memmove(p + 1, p,
    456 		    sizeof(struct partition) * (lp->d_npartitions - RAW_PART));
    457 		*p = rp;
    458 		lp->d_npartitions++;
    459 	} else
    460 		return "no raw partition and partition table is full";
    461 	return NULL;
    462 }
    463 
    464 /*
    465  * disk_ioctl --
    466  *	Generic disk ioctl handling.
    467  */
    468 int
    469 disk_ioctl(struct disk *diskp, u_long cmd, void *data, int flag,
    470 	   struct lwp *l)
    471 {
    472 	int error;
    473 
    474 	switch (cmd) {
    475 	case DIOCGDISKINFO:
    476 	    {
    477 		struct plistref *pref = (struct plistref *) data;
    478 
    479 		if (diskp->dk_info == NULL)
    480 			error = ENOTSUP;
    481 		else
    482 			error = prop_dictionary_copyout_ioctl(pref, cmd,
    483 							diskp->dk_info);
    484 		break;
    485 	    }
    486 
    487 	default:
    488 		error = EPASSTHROUGH;
    489 	}
    490 
    491 	return (error);
    492 }
    493