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subr_disk.c revision 1.83.4.1
      1 /*	$NetBSD: subr_disk.c,v 1.83.4.1 2007/03/12 05:58:39 rmind 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 1.83.4.1 2007/03/12 05:58:39 rmind 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 static void
    188 disk_init0(struct disk *diskp)
    189 {
    190 
    191 	/*
    192 	 * Initialize the wedge-related locks and other fields.
    193 	 */
    194 	lockinit(&diskp->dk_rawlock, PRIBIO, "dkrawlk", 0, 0);
    195 	lockinit(&diskp->dk_openlock, PRIBIO, "dkoplk", 0, 0);
    196 	LIST_INIT(&diskp->dk_wedges);
    197 	diskp->dk_nwedges = 0;
    198 	diskp->dk_labelsector = LABELSECTOR;
    199 	disk_blocksize(diskp, DEV_BSIZE);
    200 }
    201 
    202 static void
    203 disk_attach0(struct disk *diskp)
    204 {
    205 
    206 	/*
    207 	 * Allocate and initialize the disklabel structures.  Note that
    208 	 * it's not safe to sleep here, since we're probably going to be
    209 	 * called during autoconfiguration.
    210 	 */
    211 	diskp->dk_label = malloc(sizeof(struct disklabel), M_DEVBUF, M_NOWAIT);
    212 	diskp->dk_cpulabel = malloc(sizeof(struct cpu_disklabel), M_DEVBUF,
    213 	    M_NOWAIT);
    214 	if ((diskp->dk_label == NULL) || (diskp->dk_cpulabel == NULL))
    215 		panic("disk_attach: can't allocate storage for disklabel");
    216 
    217 	memset(diskp->dk_label, 0, sizeof(struct disklabel));
    218 	memset(diskp->dk_cpulabel, 0, sizeof(struct cpu_disklabel));
    219 
    220 	/*
    221 	 * Set up the stats collection.
    222 	 */
    223 	diskp->dk_stats = iostat_alloc(IOSTAT_DISK, diskp, diskp->dk_name);
    224 }
    225 
    226 static void
    227 disk_detach0(struct disk *diskp)
    228 {
    229 
    230 	/*
    231 	 * Remove from the drivelist.
    232 	 */
    233 	iostat_free(diskp->dk_stats);
    234 
    235 	/*
    236 	 * Release the disk-info dictionary.
    237 	 */
    238 	if (diskp->dk_info) {
    239 		prop_object_release(diskp->dk_info);
    240 		diskp->dk_info = NULL;
    241 	}
    242 
    243 	/*
    244 	 * Free the space used by the disklabel structures.
    245 	 */
    246 	free(diskp->dk_label, M_DEVBUF);
    247 	free(diskp->dk_cpulabel, M_DEVBUF);
    248 }
    249 
    250 /*
    251  * Attach a disk.
    252  */
    253 void
    254 disk_attach(struct disk *diskp)
    255 {
    256 
    257 	disk_init0(diskp);
    258 	disk_attach0(diskp);
    259 }
    260 
    261 /*
    262  * Detach a disk.
    263  */
    264 void
    265 disk_detach(struct disk *diskp)
    266 {
    267 
    268 	(void) lockmgr(&diskp->dk_openlock, LK_DRAIN, NULL);
    269 	disk_detach0(diskp);
    270 }
    271 
    272 /*
    273  * Initialize a pseudo disk.
    274  */
    275 void
    276 pseudo_disk_init(struct disk *diskp)
    277 {
    278 
    279 	disk_init0(diskp);
    280 }
    281 
    282 /*
    283  * Attach a pseudo disk.
    284  */
    285 void
    286 pseudo_disk_attach(struct disk *diskp)
    287 {
    288 
    289 	disk_attach0(diskp);
    290 }
    291 
    292 /*
    293  * Detach a pseudo disk.
    294  */
    295 void
    296 pseudo_disk_detach(struct disk *diskp)
    297 {
    298 
    299 	disk_detach0(diskp);
    300 }
    301 
    302 /*
    303  * Mark the disk as busy for metrics collection.
    304  */
    305 void
    306 disk_busy(struct disk *diskp)
    307 {
    308 
    309 	iostat_busy(diskp->dk_stats);
    310 }
    311 
    312 /*
    313  * Finished disk operations, gather metrics.
    314  */
    315 void
    316 disk_unbusy(struct disk *diskp, long bcount, int read)
    317 {
    318 
    319 	iostat_unbusy(diskp->dk_stats, bcount, read);
    320 }
    321 
    322 /*
    323  * Set the physical blocksize of a disk, in bytes.
    324  * Only necessary if blocksize != DEV_BSIZE.
    325  */
    326 void
    327 disk_blocksize(struct disk *diskp, int blocksize)
    328 {
    329 
    330 	diskp->dk_blkshift = DK_BSIZE2BLKSHIFT(blocksize);
    331 	diskp->dk_byteshift = DK_BSIZE2BYTESHIFT(blocksize);
    332 }
    333 
    334 /*
    335  * Bounds checking against the media size, used for the raw partition.
    336  * The sector size passed in should currently always be DEV_BSIZE,
    337  * and the media size the size of the device in DEV_BSIZE sectors.
    338  */
    339 int
    340 bounds_check_with_mediasize(struct buf *bp, int secsize, uint64_t mediasize)
    341 {
    342 	int64_t sz;
    343 
    344 	sz = howmany(bp->b_bcount, secsize);
    345 
    346 	if (bp->b_blkno + sz > mediasize) {
    347 		sz = mediasize - bp->b_blkno;
    348 		if (sz == 0) {
    349 			/* If exactly at end of disk, return EOF. */
    350 			bp->b_resid = bp->b_bcount;
    351 			goto done;
    352 		}
    353 		if (sz < 0) {
    354 			/* If past end of disk, return EINVAL. */
    355 			bp->b_error = EINVAL;
    356 			goto bad;
    357 		}
    358 		/* Otherwise, truncate request. */
    359 		bp->b_bcount = sz << DEV_BSHIFT;
    360 	}
    361 
    362 	return 1;
    363 
    364 bad:
    365 	bp->b_flags |= B_ERROR;
    366 done:
    367 	return 0;
    368 }
    369 
    370 /*
    371  * Determine the size of the transfer, and make sure it is
    372  * within the boundaries of the partition. Adjust transfer
    373  * if needed, and signal errors or early completion.
    374  */
    375 int
    376 bounds_check_with_label(struct disk *dk, struct buf *bp, int wlabel)
    377 {
    378 	struct disklabel *lp = dk->dk_label;
    379 	struct partition *p = lp->d_partitions + DISKPART(bp->b_dev);
    380 	uint64_t p_size, p_offset, labelsector;
    381 	int64_t sz;
    382 
    383 	/* Protect against division by zero. XXX: Should never happen?!?! */
    384 	if (lp->d_secpercyl == 0) {
    385 		bp->b_error = EINVAL;
    386 		goto bad;
    387 	}
    388 
    389 	p_size = p->p_size << dk->dk_blkshift;
    390 	p_offset = p->p_offset << dk->dk_blkshift;
    391 #if RAW_PART == 3
    392 	labelsector = lp->d_partitions[2].p_offset;
    393 #else
    394 	labelsector = lp->d_partitions[RAW_PART].p_offset;
    395 #endif
    396 	labelsector = (labelsector + dk->dk_labelsector) << dk->dk_blkshift;
    397 
    398 	sz = howmany(bp->b_bcount, DEV_BSIZE);
    399 	if ((bp->b_blkno + sz) > p_size) {
    400 		sz = p_size - bp->b_blkno;
    401 		if (sz == 0) {
    402 			/* If exactly at end of disk, return EOF. */
    403 			bp->b_resid = bp->b_bcount;
    404 			return (0);
    405 		}
    406 		if (sz < 0) {
    407 			/* If past end of disk, return EINVAL. */
    408 			bp->b_error = EINVAL;
    409 			goto bad;
    410 		}
    411 		/* Otherwise, truncate request. */
    412 		bp->b_bcount = sz << DEV_BSHIFT;
    413 	}
    414 
    415 	/* Overwriting disk label? */
    416 	if (bp->b_blkno + p_offset <= labelsector &&
    417 	    bp->b_blkno + p_offset + sz > labelsector &&
    418 	    (bp->b_flags & B_READ) == 0 && !wlabel) {
    419 		bp->b_error = EROFS;
    420 		goto bad;
    421 	}
    422 
    423 	/* calculate cylinder for disksort to order transfers with */
    424 	bp->b_cylinder = (bp->b_blkno + p->p_offset) /
    425 	    (lp->d_secsize / DEV_BSIZE) / lp->d_secpercyl;
    426 	return (1);
    427 
    428 bad:
    429 	bp->b_flags |= B_ERROR;
    430 	return (-1);
    431 }
    432 
    433 /*
    434  * disk_ioctl --
    435  *	Generic disk ioctl handling.
    436  */
    437 int
    438 disk_ioctl(struct disk *diskp, u_long cmd, void *data, int flag,
    439 	   struct lwp *l)
    440 {
    441 	int error;
    442 
    443 	switch (cmd) {
    444 	case DIOCGDISKINFO:
    445 	    {
    446 		struct plistref *pref = (struct plistref *) data;
    447 
    448 		if (diskp->dk_info == NULL)
    449 			error = ENOTSUP;
    450 		else
    451 			error = prop_dictionary_copyout_ioctl(pref, cmd,
    452 							diskp->dk_info);
    453 		break;
    454 	    }
    455 
    456 	default:
    457 		error = EPASSTHROUGH;
    458 	}
    459 
    460 	return (error);
    461 }
    462