xref: /netbsd-src/sys/kern/subr_disk.c (revision 6a9b3088d8d2341ca1454531d365c15fe9c1c589)
1 /*	$NetBSD: subr_disk.c,v 1.100 2010/10/14 00:47:16 mrg Exp $	*/
2 
3 /*-
4  * Copyright (c) 1996, 1997, 1999, 2000, 2009 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  *
20  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
24  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30  * POSSIBILITY OF SUCH DAMAGE.
31  */
32 
33 /*
34  * Copyright (c) 1982, 1986, 1988, 1993
35  *	The Regents of the University of California.  All rights reserved.
36  * (c) UNIX System Laboratories, Inc.
37  * All or some portions of this file are derived from material licensed
38  * to the University of California by American Telephone and Telegraph
39  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
40  * the permission of UNIX System Laboratories, Inc.
41  *
42  * Redistribution and use in source and binary forms, with or without
43  * modification, are permitted provided that the following conditions
44  * are met:
45  * 1. Redistributions of source code must retain the above copyright
46  *    notice, this list of conditions and the following disclaimer.
47  * 2. Redistributions in binary form must reproduce the above copyright
48  *    notice, this list of conditions and the following disclaimer in the
49  *    documentation and/or other materials provided with the distribution.
50  * 3. Neither the name of the University nor the names of its contributors
51  *    may be used to endorse or promote products derived from this software
52  *    without specific prior written permission.
53  *
54  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
55  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
56  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
57  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
58  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
59  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
60  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
61  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
62  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
63  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
64  * SUCH DAMAGE.
65  *
66  *	@(#)ufs_disksubr.c	8.5 (Berkeley) 1/21/94
67  */
68 
69 #include <sys/cdefs.h>
70 __KERNEL_RCSID(0, "$NetBSD: subr_disk.c,v 1.100 2010/10/14 00:47:16 mrg Exp $");
71 
72 #include <sys/param.h>
73 #include <sys/kernel.h>
74 #include <sys/kmem.h>
75 #include <sys/buf.h>
76 #include <sys/syslog.h>
77 #include <sys/disklabel.h>
78 #include <sys/disk.h>
79 #include <sys/sysctl.h>
80 #include <lib/libkern/libkern.h>
81 
82 /*
83  * Compute checksum for disk label.
84  */
85 u_int
86 dkcksum(struct disklabel *lp)
87 {
88 
89 	return dkcksum_sized(lp, lp->d_npartitions);
90 }
91 
92 u_int
93 dkcksum_sized(struct disklabel *lp, size_t npartitions)
94 {
95 	uint16_t *start, *end;
96 	uint16_t sum = 0;
97 
98 	start = (uint16_t *)lp;
99 	end = (uint16_t *)&lp->d_partitions[npartitions];
100 	while (start < end)
101 		sum ^= *start++;
102 	return sum;
103 }
104 
105 /*
106  * Disk error is the preface to plaintive error messages
107  * about failing disk transfers.  It prints messages of the form
108 
109 hp0g: hard error reading fsbn 12345 of 12344-12347 (hp0 bn %d cn %d tn %d sn %d)
110 
111  * if the offset of the error in the transfer and a disk label
112  * are both available.  blkdone should be -1 if the position of the error
113  * is unknown; the disklabel pointer may be null from drivers that have not
114  * been converted to use them.  The message is printed with printf
115  * if pri is LOG_PRINTF, otherwise it uses log at the specified priority.
116  * The message should be completed (with at least a newline) with printf
117  * or addlog, respectively.  There is no trailing space.
118  */
119 #ifndef PRIdaddr
120 #define PRIdaddr PRId64
121 #endif
122 void
123 diskerr(const struct buf *bp, const char *dname, const char *what, int pri,
124     int blkdone, const struct disklabel *lp)
125 {
126 	int unit = DISKUNIT(bp->b_dev), part = DISKPART(bp->b_dev);
127 	void (*pr)(const char *, ...);
128 	char partname = 'a' + part;
129 	daddr_t sn;
130 
131 	if (/*CONSTCOND*/0)
132 		/* Compiler will error this is the format is wrong... */
133 		printf("%" PRIdaddr, bp->b_blkno);
134 
135 	if (pri != LOG_PRINTF) {
136 		static const char fmt[] = "";
137 		log(pri, fmt);
138 		pr = addlog;
139 	} else
140 		pr = printf;
141 	(*pr)("%s%d%c: %s %sing fsbn ", dname, unit, partname, what,
142 	    bp->b_flags & B_READ ? "read" : "writ");
143 	sn = bp->b_blkno;
144 	if (bp->b_bcount <= DEV_BSIZE)
145 		(*pr)("%" PRIdaddr, sn);
146 	else {
147 		if (blkdone >= 0) {
148 			sn += blkdone;
149 			(*pr)("%" PRIdaddr " of ", sn);
150 		}
151 		(*pr)("%" PRIdaddr "-%" PRIdaddr "", bp->b_blkno,
152 		    bp->b_blkno + (bp->b_bcount - 1) / DEV_BSIZE);
153 	}
154 	if (lp && (blkdone >= 0 || bp->b_bcount <= lp->d_secsize)) {
155 		sn += lp->d_partitions[part].p_offset;
156 		(*pr)(" (%s%d bn %" PRIdaddr "; cn %" PRIdaddr "",
157 		    dname, unit, sn, sn / lp->d_secpercyl);
158 		sn %= lp->d_secpercyl;
159 		(*pr)(" tn %" PRIdaddr " sn %" PRIdaddr ")",
160 		    sn / lp->d_nsectors, sn % lp->d_nsectors);
161 	}
162 }
163 
164 /*
165  * Searches the iostatlist for the disk corresponding to the
166  * name provided.
167  */
168 struct disk *
169 disk_find(const char *name)
170 {
171 	struct io_stats *stat;
172 
173 	stat = iostat_find(name);
174 
175 	if ((stat != NULL) && (stat->io_type == IOSTAT_DISK))
176 		return stat->io_parent;
177 
178 	return (NULL);
179 }
180 
181 void
182 disk_init(struct disk *diskp, const char *name, const struct dkdriver *driver)
183 {
184 
185 	/*
186 	 * Initialize the wedge-related locks and other fields.
187 	 */
188 	mutex_init(&diskp->dk_rawlock, MUTEX_DEFAULT, IPL_NONE);
189 	mutex_init(&diskp->dk_openlock, MUTEX_DEFAULT, IPL_NONE);
190 	LIST_INIT(&diskp->dk_wedges);
191 	diskp->dk_nwedges = 0;
192 	diskp->dk_labelsector = LABELSECTOR;
193 	disk_blocksize(diskp, DEV_BSIZE);
194 	diskp->dk_name = name;
195 	diskp->dk_driver = driver;
196 }
197 
198 /*
199  * Attach a disk.
200  */
201 void
202 disk_attach(struct disk *diskp)
203 {
204 
205 	/*
206 	 * Allocate and initialize the disklabel structures.
207 	 */
208 	diskp->dk_label = kmem_zalloc(sizeof(struct disklabel), KM_SLEEP);
209 	diskp->dk_cpulabel = kmem_zalloc(sizeof(struct cpu_disklabel),
210 	    KM_SLEEP);
211 	if ((diskp->dk_label == NULL) || (diskp->dk_cpulabel == NULL))
212 		panic("disk_attach: can't allocate storage for disklabel");
213 
214 	/*
215 	 * Set up the stats collection.
216 	 */
217 	diskp->dk_stats = iostat_alloc(IOSTAT_DISK, diskp, diskp->dk_name);
218 }
219 
220 int
221 disk_begindetach(struct disk *dk, int (*lastclose)(device_t),
222     device_t self, int flags)
223 {
224 	int rc;
225 
226 	rc = 0;
227 	mutex_enter(&dk->dk_openlock);
228 	if (dk->dk_openmask == 0)
229 		;	/* nothing to do */
230 	else if ((flags & DETACH_FORCE) == 0)
231 		rc = EBUSY;
232 	else if (lastclose != NULL)
233 		rc = (*lastclose)(self);
234 	mutex_exit(&dk->dk_openlock);
235 
236 	return rc;
237 }
238 
239 /*
240  * Detach a disk.
241  */
242 void
243 disk_detach(struct disk *diskp)
244 {
245 
246 	/*
247 	 * Remove from the drivelist.
248 	 */
249 	iostat_free(diskp->dk_stats);
250 
251 	/*
252 	 * Release the disk-info dictionary.
253 	 */
254 	if (diskp->dk_info) {
255 		prop_object_release(diskp->dk_info);
256 		diskp->dk_info = NULL;
257 	}
258 
259 	/*
260 	 * Free the space used by the disklabel structures.
261 	 */
262 	kmem_free(diskp->dk_label, sizeof(*diskp->dk_label));
263 	kmem_free(diskp->dk_cpulabel, sizeof(*diskp->dk_cpulabel));
264 }
265 
266 void
267 disk_destroy(struct disk *diskp)
268 {
269 
270 	mutex_destroy(&diskp->dk_openlock);
271 	mutex_destroy(&diskp->dk_rawlock);
272 }
273 
274 /*
275  * Mark the disk as busy for metrics collection.
276  */
277 void
278 disk_busy(struct disk *diskp)
279 {
280 
281 	iostat_busy(diskp->dk_stats);
282 }
283 
284 /*
285  * Finished disk operations, gather metrics.
286  */
287 void
288 disk_unbusy(struct disk *diskp, long bcount, int read)
289 {
290 
291 	iostat_unbusy(diskp->dk_stats, bcount, read);
292 }
293 
294 /*
295  * Return true if disk has an I/O operation in flight.
296  */
297 bool
298 disk_isbusy(struct disk *diskp)
299 {
300 
301 	return iostat_isbusy(diskp->dk_stats);
302 }
303 
304 /*
305  * Set the physical blocksize of a disk, in bytes.
306  * Only necessary if blocksize != DEV_BSIZE.
307  */
308 void
309 disk_blocksize(struct disk *diskp, int blocksize)
310 {
311 
312 	diskp->dk_blkshift = DK_BSIZE2BLKSHIFT(blocksize);
313 	diskp->dk_byteshift = DK_BSIZE2BYTESHIFT(blocksize);
314 }
315 
316 /*
317  * Bounds checking against the media size, used for the raw partition.
318  * secsize, mediasize and b_blkno must all be the same units.
319  * Possibly this has to be DEV_BSIZE (512).
320  */
321 int
322 bounds_check_with_mediasize(struct buf *bp, int secsize, uint64_t mediasize)
323 {
324 	int64_t sz;
325 
326 	sz = howmany(bp->b_bcount, secsize);
327 
328 	if (bp->b_blkno + sz > mediasize) {
329 		sz = mediasize - bp->b_blkno;
330 		if (sz == 0) {
331 			/* If exactly at end of disk, return EOF. */
332 			bp->b_resid = bp->b_bcount;
333 			return 0;
334 		}
335 		if (sz < 0) {
336 			/* If past end of disk, return EINVAL. */
337 			bp->b_error = EINVAL;
338 			return 0;
339 		}
340 		/* Otherwise, truncate request. */
341 		bp->b_bcount = sz * secsize;
342 	}
343 
344 	return 1;
345 }
346 
347 /*
348  * Determine the size of the transfer, and make sure it is
349  * within the boundaries of the partition. Adjust transfer
350  * if needed, and signal errors or early completion.
351  */
352 int
353 bounds_check_with_label(struct disk *dk, struct buf *bp, int wlabel)
354 {
355 	struct disklabel *lp = dk->dk_label;
356 	struct partition *p = lp->d_partitions + DISKPART(bp->b_dev);
357 	uint64_t p_size, p_offset, labelsector;
358 	int64_t sz;
359 
360 	/* Protect against division by zero. XXX: Should never happen?!?! */
361 	if (lp->d_secpercyl == 0) {
362 		bp->b_error = EINVAL;
363 		return -1;
364 	}
365 
366 	p_size = (uint64_t)p->p_size << dk->dk_blkshift;
367 	p_offset = (uint64_t)p->p_offset << dk->dk_blkshift;
368 #if RAW_PART == 3
369 	labelsector = lp->d_partitions[2].p_offset;
370 #else
371 	labelsector = lp->d_partitions[RAW_PART].p_offset;
372 #endif
373 	labelsector = (labelsector + dk->dk_labelsector) << dk->dk_blkshift;
374 
375 	sz = howmany(bp->b_bcount, DEV_BSIZE);
376 	if ((bp->b_blkno + sz) > p_size) {
377 		sz = p_size - bp->b_blkno;
378 		if (sz == 0) {
379 			/* If exactly at end of disk, return EOF. */
380 			bp->b_resid = bp->b_bcount;
381 			return 0;
382 		}
383 		if (sz < 0) {
384 			/* If past end of disk, return EINVAL. */
385 			bp->b_error = EINVAL;
386 			return -1;
387 		}
388 		/* Otherwise, truncate request. */
389 		bp->b_bcount = sz << DEV_BSHIFT;
390 	}
391 
392 	/* Overwriting disk label? */
393 	if (bp->b_blkno + p_offset <= labelsector &&
394 	    bp->b_blkno + p_offset + sz > labelsector &&
395 	    (bp->b_flags & B_READ) == 0 && !wlabel) {
396 		bp->b_error = EROFS;
397 		return -1;
398 	}
399 
400 	/* calculate cylinder for disksort to order transfers with */
401 	bp->b_cylinder = (bp->b_blkno + p->p_offset) /
402 	    (lp->d_secsize / DEV_BSIZE) / lp->d_secpercyl;
403 	return 1;
404 }
405 
406 int
407 disk_read_sectors(void (*strat)(struct buf *), const struct disklabel *lp,
408     struct buf *bp, unsigned int sector, int count)
409 {
410 	bp->b_blkno = sector;
411 	bp->b_bcount = count * lp->d_secsize;
412 	bp->b_flags = (bp->b_flags & ~B_WRITE) | B_READ;
413 	bp->b_oflags &= ~BO_DONE;
414 	bp->b_cylinder = sector / lp->d_secpercyl;
415 	(*strat)(bp);
416 	return biowait(bp);
417 }
418 
419 const char *
420 convertdisklabel(struct disklabel *lp, void (*strat)(struct buf *),
421     struct buf *bp, uint32_t secperunit)
422 {
423 	struct partition rp, *altp, *p;
424 	int geom_ok;
425 
426 	memset(&rp, 0, sizeof(rp));
427 	rp.p_size = secperunit;
428 	rp.p_fstype = FS_UNUSED;
429 
430 	/* If we can seek to d_secperunit - 1, believe the disk geometry. */
431 	if (secperunit != 0 &&
432 	    disk_read_sectors(strat, lp, bp, secperunit - 1, 1) == 0)
433 		geom_ok = 1;
434 	else
435 		geom_ok = 0;
436 
437 #if 0
438 	printf("%s: secperunit (%" PRIu32 ") %s\n", __func__,
439 	    secperunit, geom_ok ? "ok" : "not ok");
440 #endif
441 
442 	p = &lp->d_partitions[RAW_PART];
443 	if (RAW_PART == 'c' - 'a')
444 		altp = &lp->d_partitions['d' - 'a'];
445 	else
446 		altp = &lp->d_partitions['c' - 'a'];
447 
448 	if (lp->d_npartitions > RAW_PART && p->p_offset == 0 && p->p_size != 0)
449 		;	/* already a raw partition */
450 	else if (lp->d_npartitions > MAX('c', 'd') - 'a' &&
451 		 altp->p_offset == 0 && altp->p_size != 0) {
452 		/* alternate partition ('c' or 'd') is suitable for raw slot,
453 		 * swap with 'd' or 'c'.
454 		 */
455 		rp = *p;
456 		*p = *altp;
457 		*altp = rp;
458 	} else if (lp->d_npartitions <= RAW_PART &&
459 	           lp->d_npartitions > 'c' - 'a') {
460 		/* No raw partition is present, but the alternate is present.
461 		 * Copy alternate to raw partition.
462 		 */
463 		lp->d_npartitions = RAW_PART + 1;
464 		*p = *altp;
465 	} else if (!geom_ok)
466 		return "no raw partition and disk reports bad geometry";
467 	else if (lp->d_npartitions <= RAW_PART) {
468 		memset(&lp->d_partitions[lp->d_npartitions], 0,
469 		    sizeof(struct partition) * (RAW_PART - lp->d_npartitions));
470 		*p = rp;
471 		lp->d_npartitions = RAW_PART + 1;
472 	} else if (lp->d_npartitions < MAXPARTITIONS) {
473 		memmove(p + 1, p,
474 		    sizeof(struct partition) * (lp->d_npartitions - RAW_PART));
475 		*p = rp;
476 		lp->d_npartitions++;
477 	} else
478 		return "no raw partition and partition table is full";
479 	return NULL;
480 }
481 
482 /*
483  * disk_ioctl --
484  *	Generic disk ioctl handling.
485  */
486 int
487 disk_ioctl(struct disk *diskp, u_long cmd, void *data, int flag,
488 	   struct lwp *l)
489 {
490 	int error;
491 
492 	switch (cmd) {
493 	case DIOCGDISKINFO:
494 	    {
495 		struct plistref *pref = (struct plistref *) data;
496 
497 		if (diskp->dk_info == NULL)
498 			error = ENOTSUP;
499 		else
500 			error = prop_dictionary_copyout_ioctl(pref, cmd,
501 							diskp->dk_info);
502 		break;
503 	    }
504 
505 	default:
506 		error = EPASSTHROUGH;
507 	}
508 
509 	return (error);
510 }
511