xref: /dflybsd-src/sys/kern/subr_disklabel64.c (revision fb8e1c0c0541c89d2a73956362ee4eb015a16101)
1 /*
2  * Copyright (c) 2007 The DragonFly Project.  All rights reserved.
3  *
4  * This code is derived from software contributed to The DragonFly Project
5  * by Matthew Dillon <dillon@backplane.com>
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  *
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in
15  *    the documentation and/or other materials provided with the
16  *    distribution.
17  * 3. Neither the name of The DragonFly Project nor the names of its
18  *    contributors may be used to endorse or promote products derived
19  *    from this software without specific, prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  * $DragonFly: src/sys/kern/subr_disklabel64.c,v 1.4 2007/06/19 06:39:06 dillon Exp $
35  */
36 
37 #include <sys/param.h>
38 #include <sys/systm.h>
39 #include <sys/kernel.h>
40 #include <sys/conf.h>
41 #include <sys/disklabel.h>
42 #include <sys/disklabel64.h>
43 #include <sys/diskslice.h>
44 #include <sys/disk.h>
45 #include <sys/kern_syscall.h>
46 #include <sys/buf2.h>
47 
48 /*
49  * Retrieve the partition start and extent, in blocks.  Return 0 on success,
50  * EINVAL on error.
51  */
52 static int
53 l64_getpartbounds(struct diskslices *ssp, disklabel_t lp, u_int32_t part,
54 		  u_int64_t *start, u_int64_t *blocks)
55 {
56 	struct partition64 *pp;
57 
58 	if (part >= lp.lab64->d_npartitions)
59 		return (EINVAL);
60 
61 	pp = &lp.lab64->d_partitions[part];
62 
63 	if ((pp->p_boffset & (ssp->dss_secsize - 1)) ||
64 	    (pp->p_bsize & (ssp->dss_secsize - 1))) {
65 		return (EINVAL);
66 	}
67 	*start = pp->p_boffset / ssp->dss_secsize;
68 	*blocks = pp->p_bsize / ssp->dss_secsize;
69 	return(0);
70 }
71 
72 /*
73  * Get the filesystem type XXX - diskslices code needs to use uuids
74  */
75 static void
76 l64_loadpartinfo(disklabel_t lp, u_int32_t part, struct partinfo *dpart)
77 {
78 	struct partition64 *pp;
79 	const size_t uuid_size = sizeof(struct uuid);
80 
81 	if (part < lp.lab64->d_npartitions) {
82 		pp = &lp.lab64->d_partitions[part];
83 		dpart->fstype_uuid = pp->p_type_uuid;
84 		dpart->storage_uuid = pp->p_stor_uuid;
85 		dpart->fstype = pp->p_fstype;
86 	} else {
87 		bzero(&dpart->fstype_uuid, uuid_size);
88 		bzero(&dpart->storage_uuid, uuid_size);
89 		dpart->fstype = 0;
90 	}
91 }
92 
93 /*
94  * Get the number of partitions
95  */
96 static u_int32_t
97 l64_getnumparts(disklabel_t lp)
98 {
99 	return(lp.lab64->d_npartitions);
100 }
101 
102 /*
103  * Attempt to read a disk label from a device.  64 bit disklabels are
104  * sector-agnostic and begin at offset 0 on the device.  64 bit disklabels
105  * may only be used with GPT partitioning schemes.
106  *
107  * Returns NULL on sucess, and an error string on failure.
108  */
109 static const char *
110 l64_readdisklabel(cdev_t dev, struct diskslice *sp, disklabel_t *lpp,
111 		  struct disk_info *info)
112 {
113 	struct buf *bp;
114 	struct disklabel64 *dlp;
115 	const char *msg;
116 	uint32_t savecrc;
117 	size_t dlpcrcsize;
118 	size_t bpsize;
119 	int secsize;
120 
121 	secsize = info->d_media_blksize;
122 	bpsize = (sizeof(*dlp) + secsize - 1) & ~(secsize - 1);
123 
124 	bp = geteblk(bpsize);
125 	bp->b_bio1.bio_offset = 0;
126 	bp->b_bcount = bpsize;
127 	bp->b_flags &= ~B_INVAL;
128 	bp->b_cmd = BUF_CMD_READ;
129 	dev_dstrategy(dev, &bp->b_bio1);
130 
131 	if (biowait(bp)) {
132 		msg = "I/O error";
133 	} else {
134 		dlp = (struct disklabel64 *)bp->b_data;
135 		dlpcrcsize = offsetof(struct disklabel64,
136 				      d_partitions[dlp->d_npartitions]) -
137 			     offsetof(struct disklabel64, d_magic);
138 		savecrc = dlp->d_crc;
139 		dlp->d_crc = 0;
140 		if (dlp->d_magic != DISKMAGIC64) {
141 			msg = "no disk label";
142 		} else if (dlp->d_npartitions > MAXPARTITIONS64) {
143 			msg = "disklabel64 corrupted, too many partitions";
144 		} else if (savecrc != crc32(&dlp->d_magic, dlpcrcsize)) {
145 			msg = "disklabel64 corrupted, bad CRC";
146 		} else {
147 			dlp->d_crc = savecrc;
148 			(*lpp).lab64 = kmalloc(sizeof(*dlp),
149 					       M_DEVBUF, M_WAITOK|M_ZERO);
150 			*(*lpp).lab64 = *dlp;
151 			msg = NULL;
152 		}
153 	}
154 	bp->b_flags |= B_INVAL | B_AGE;
155 	brelse(bp);
156 	return (msg);
157 }
158 
159 /*
160  * If everything is good, copy olpx to nlpx.  Check to see if any
161  * open partitions would change.
162  */
163 static int
164 l64_setdisklabel(disklabel_t olpx, disklabel_t nlpx, struct diskslices *ssp,
165 		 struct diskslice *sp, u_int32_t *openmask)
166 {
167 	struct disklabel64 *olp, *nlp;
168 	struct partition64 *opp, *npp;
169 	uint32_t savecrc;
170 	uint64_t slicebsize;
171 	size_t nlpcrcsize;
172 	int part;
173 	int i;
174 
175 	olp = olpx.lab64;
176 	nlp = nlpx.lab64;
177 
178 	slicebsize = (uint64_t)sp->ds_size * ssp->dss_secsize;
179 
180 	if (nlp->d_magic != DISKMAGIC64)
181 		return (EINVAL);
182 	if (nlp->d_npartitions > MAXPARTITIONS64)
183 		return (EINVAL);
184 	savecrc = nlp->d_crc;
185 	nlp->d_crc = 0;
186 	nlpcrcsize = offsetof(struct disklabel64,
187 			      d_partitions[nlp->d_npartitions]) -
188 		     offsetof(struct disklabel64, d_magic);
189 	if (crc32(&nlp->d_magic, nlpcrcsize) != savecrc) {
190 		nlp->d_crc = savecrc;
191 		return (EINVAL);
192 	}
193 	nlp->d_crc = savecrc;
194 
195 	/*
196 	 * Check if open partitions have changed
197 	 */
198 	i = 0;
199 	while (i < 128) {
200 		if (openmask[i >> 5] == 0) {
201 			i += 32;
202 			continue;
203 		}
204 		if ((openmask[i >> 5] & (1 << (i & 31))) == 0) {
205 			++i;
206 			continue;
207 		}
208 		if (nlp->d_npartitions <= i)
209 			return (EBUSY);
210 		opp = &olp->d_partitions[i];
211 		npp = &nlp->d_partitions[i];
212 		if (npp->p_boffset != opp->p_boffset ||
213 		    npp->p_bsize < opp->p_bsize) {
214 			return (EBUSY);
215 		}
216 
217 		/*
218 		 * Do not allow p_type_uuid or p_stor_uuid to change if
219 		 * the partition is currently open.
220 		 */
221 		if (bcmp(&npp->p_type_uuid, &opp->p_type_uuid,
222 		     sizeof(npp->p_type_uuid)) != 0) {
223 			return (EBUSY);
224 		}
225 		if (bcmp(&npp->p_stor_uuid, &opp->p_stor_uuid,
226 		     sizeof(npp->p_stor_uuid)) != 0) {
227 			return (EBUSY);
228 		}
229 		++i;
230 	}
231 
232 	/*
233 	 * Make sure the label and partition offsets and sizes are sane.
234 	 */
235 	if (nlp->d_total_size > slicebsize)
236 		return (ENOSPC);
237 	if (nlp->d_total_size & (ssp->dss_secsize - 1))
238 		return (EINVAL);
239 	if (nlp->d_bbase & (ssp->dss_secsize - 1))
240 		return (EINVAL);
241 	if (nlp->d_pbase & (ssp->dss_secsize - 1))
242 		return (EINVAL);
243 	if (nlp->d_pstop & (ssp->dss_secsize - 1))
244 		return (EINVAL);
245 	if (nlp->d_abase & (ssp->dss_secsize - 1))
246 		return (EINVAL);
247 
248 	for (part = 0; part < nlp->d_npartitions; ++part) {
249 		npp = &nlp->d_partitions[i];
250 		if (npp->p_bsize == 0) {
251 			if (npp->p_boffset != 0)
252 				return (EINVAL);
253 			continue;
254 		}
255 		if (npp->p_boffset & (ssp->dss_secsize - 1))
256 			return (EINVAL);
257 		if (npp->p_bsize & (ssp->dss_secsize - 1))
258 			return (EINVAL);
259 		if (npp->p_boffset < nlp->d_pbase)
260 			return (ENOSPC);
261 		if (npp->p_boffset + npp->p_bsize > nlp->d_total_size)
262 			return (ENOSPC);
263 	}
264 
265 	/*
266 	 * Structurally we may add code to make modifications above in the
267 	 * future, so regenerate the crc anyway.
268 	 */
269 	nlp->d_crc = 0;
270 	nlp->d_crc = crc32(&nlp->d_magic, nlpcrcsize);
271 	*olp = *nlp;
272 
273 	return (0);
274 }
275 
276 /*
277  * Write disk label back to device after modification.
278  */
279 static int
280 l64_writedisklabel(cdev_t dev, struct diskslices *ssp,
281 		   struct diskslice *sp, disklabel_t lpx)
282 {
283 	struct disklabel64 *lp;
284 	struct disklabel64 *dlp;
285 	struct buf *bp;
286 	int error = 0;
287 	size_t bpsize;
288 	int secsize;
289 
290 	lp = lpx.lab64;
291 
292 	secsize = ssp->dss_secsize;
293 	bpsize = (sizeof(*lp) + secsize - 1) & ~(secsize - 1);
294 
295 	bp = geteblk(bpsize);
296 	bp->b_bio1.bio_offset = 0;
297 	bp->b_bcount = bpsize;
298 
299 	/*
300 	 * Because our I/O is larger then the label, and because we do not
301 	 * write the d_reserved0[] area, do a read-modify-write.
302 	 */
303 	bp->b_flags &= ~B_INVAL;
304 	bp->b_cmd = BUF_CMD_READ;
305 	dev_dstrategy(dkmodpart(dev, WHOLE_SLICE_PART), &bp->b_bio1);
306 	error = biowait(bp);
307 	if (error)
308 		goto done;
309 
310 	dlp = (void *)bp->b_data;
311 	bcopy(&lp->d_magic, &dlp->d_magic,
312 	      sizeof(*lp) - offsetof(struct disklabel64, d_magic));
313 	bp->b_cmd = BUF_CMD_WRITE;
314 	dev_dstrategy(dkmodpart(dev, WHOLE_SLICE_PART), &bp->b_bio1);
315 	error = biowait(bp);
316 done:
317 	bp->b_flags |= B_INVAL | B_AGE;
318 	brelse(bp);
319 	return (error);
320 }
321 
322 /*
323  * Create a disklabel based on a disk_info structure for the purposes of
324  * DSO_COMPATLABEL - cases where no real label exists on the storage medium.
325  *
326  * If a diskslice is passed, the label is truncated to the slice.
327  *
328  * NOTE!  This is not a legal label because d_bbase and d_pbase are both
329  * set to 0.
330  */
331 static disklabel_t
332 l64_clone_label(struct disk_info *info, struct diskslice *sp)
333 {
334 	struct disklabel64 *lp;
335 	disklabel_t res;
336 	uint32_t blksize = info->d_media_blksize;
337 	size_t lpcrcsize;
338 
339 	lp = kmalloc(sizeof *lp, M_DEVBUF, M_WAITOK | M_ZERO);
340 
341 	if (sp)
342 		lp->d_total_size = (uint64_t)sp->ds_size * blksize;
343 	else
344 		lp->d_total_size = info->d_media_blocks * blksize;
345 
346 	lp->d_magic = DISKMAGIC64;
347 	lp->d_align = blksize;
348 	lp->d_npartitions = MAXPARTITIONS64;
349 	lp->d_pstop = lp->d_total_size;
350 
351 	/*
352 	 * Create a dummy 'c' part and a dummy 'a' part (if requested).
353 	 * Note that the 'c' part is really a hack.  64 bit disklabels
354 	 * do not use 'c' to mean the raw partition.
355 	 */
356 
357 	lp->d_partitions[2].p_boffset = 0;
358 	lp->d_partitions[2].p_bsize = lp->d_total_size;
359 	/* XXX SET FS TYPE */
360 
361 	if (info->d_dsflags & DSO_COMPATPARTA) {
362 		lp->d_partitions[0].p_boffset = 0;
363 		lp->d_partitions[0].p_bsize = lp->d_total_size;
364 		/* XXX SET FS TYPE */
365 	}
366 
367 	lpcrcsize = offsetof(struct disklabel64,
368 			     d_partitions[lp->d_npartitions]) -
369 		    offsetof(struct disklabel64, d_magic);
370 
371 	lp->d_crc = crc32(&lp->d_magic, lpcrcsize);
372 	res.lab64 = lp;
373 	return (res);
374 }
375 
376 /*
377  * Create a virgin disklabel64 suitable for writing to the media.
378  *
379  * disklabel64 always reserves 32KB for a boot area and leaves room
380  * for up to RESPARTITIONS64 partitions.
381  */
382 static void
383 l64_makevirginlabel(disklabel_t lpx, struct diskslices *ssp,
384 		    struct diskslice *sp, struct disk_info *info)
385 {
386 	struct disklabel64 *lp = lpx.lab64;
387 	struct partition64 *pp;
388 	uint32_t blksize;
389 	uint32_t ressize;
390 	uint64_t blkmask;	/* 64 bits so we can ~ */
391 	size_t lpcrcsize;
392 
393 	/*
394 	 * Setup the initial label.  Use of a block size of at least 4KB
395 	 * for calculating the initial reserved areas to allow some degree
396 	 * of portability between media with different sector sizes.
397 	 *
398 	 * Note that the modified blksize is stored in d_align as a hint
399 	 * to the disklabeling program.
400 	 */
401 	bzero(lp, sizeof(*lp));
402 	if ((blksize = info->d_media_blksize) < 4096)
403 		blksize = 4096;
404 	blkmask = blksize - 1;
405 
406 	if (sp)
407 		lp->d_total_size = (uint64_t)sp->ds_size * ssp->dss_secsize;
408 	else
409 		lp->d_total_size = info->d_media_blocks * info->d_media_blksize;
410 
411 	lp->d_magic = DISKMAGIC64;
412 	lp->d_align = blksize;
413 	lp->d_npartitions = MAXPARTITIONS64;
414 	kern_uuidgen(&lp->d_stor_uuid, 1);
415 
416 	ressize = offsetof(struct disklabel64, d_partitions[RESPARTITIONS64]);
417 	ressize = (ressize + (uint32_t)blkmask) & ~blkmask;
418 
419 	lp->d_bbase = ressize;
420 	lp->d_pbase = lp->d_bbase + ((32768 + blkmask) & ~blkmask);
421 	lp->d_pstop = (lp->d_total_size - lp->d_bbase) & ~blkmask;
422 	lp->d_abase = lp->d_pstop;
423 
424 	/*
425 	 * All partitions are left empty unless DSO_COMPATPARTA is set
426 	 */
427 
428 	if (info->d_dsflags & DSO_COMPATPARTA) {
429 		pp = &lp->d_partitions[0];
430 		pp->p_boffset = lp->d_pbase;
431 		pp->p_bsize = lp->d_pstop - lp->d_pbase;
432 		/* XXX SET FS TYPE */
433 	}
434 
435 	lpcrcsize = offsetof(struct disklabel64,
436 			     d_partitions[lp->d_npartitions]) -
437 		    offsetof(struct disklabel64, d_magic);
438 	lp->d_crc = crc32(&lp->d_magic, lpcrcsize);
439 }
440 
441 /*
442  * Set the number of blocks at the beginning of the slice which have
443  * been reserved for label operations.  This area will be write-protected
444  * when accessed via the slice.
445  *
446  * For now just protect the label area proper.  Do not protect the
447  * boot area.  Note partitions in 64 bit disklabels do not overlap
448  * the disklabel or boot area.
449  */
450 static void
451 l64_adjust_label_reserved(struct diskslices *ssp, int slice,
452 			  struct diskslice *sp)
453 {
454 	struct disklabel64 *lp = sp->ds_label.lab64;
455 
456 	sp->ds_reserved = lp->d_bbase / ssp->dss_secsize;
457 }
458 
459 struct disklabel_ops disklabel64_ops = {
460 	.labelsize = sizeof(struct disklabel64),
461 	.op_readdisklabel = l64_readdisklabel,
462 	.op_setdisklabel = l64_setdisklabel,
463 	.op_writedisklabel = l64_writedisklabel,
464 	.op_clone_label = l64_clone_label,
465 	.op_adjust_label_reserved = l64_adjust_label_reserved,
466 	.op_getpartbounds = l64_getpartbounds,
467 	.op_loadpartinfo = l64_loadpartinfo,
468 	.op_getnumparts = l64_getnumparts,
469 	.op_makevirginlabel = l64_makevirginlabel
470 };
471 
472