1 /*-
2  * Copyright (c) 1998 Michael Smith <msmith@freebsd.org>
3  * Copyright (c) 2012 Andrey V. Elsukov <ae@FreeBSD.org>
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  */
27 
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD: stable/9/sys/boot/common/disk.c 243243 2012-11-18 17:09:29Z ae $");
30 
31 #include <sys/disk.h>
32 #include <sys/queue.h>
33 #include <stand.h>
34 #include <stdarg.h>
35 #include <bootstrap.h>
36 #include <part.h>
37 
38 #include "disk.h"
39 
40 #ifdef DISK_DEBUG
41 # define DEBUG(fmt, args...)	printf("%s: " fmt "\n" , __func__ , ## args)
42 #else
43 # define DEBUG(fmt, args...)
44 #endif
45 
46 struct open_disk {
47 	struct ptable		*table;
48 	off_t			mediasize;
49 	u_int			sectorsize;
50 	u_int			flags;
51 	int			rcnt;
52 };
53 
54 struct print_args {
55 	struct disk_devdesc	*dev;
56 	const char		*prefix;
57 	int			verbose;
58 };
59 
60 struct dentry {
61 	const struct devsw	*d_dev;
62 	int			d_unit;
63 	int			d_slice;
64 	int			d_partition;
65 
66 	struct open_disk	*od;
67 	off_t			d_offset;
68 	STAILQ_ENTRY(dentry)	entry;
69 #ifdef DISK_DEBUG
70 	uint32_t		count;
71 #endif
72 };
73 
74 static STAILQ_HEAD(, dentry) opened_disks =
75     STAILQ_HEAD_INITIALIZER(opened_disks);
76 
77 static int
disk_lookup(struct disk_devdesc * dev)78 disk_lookup(struct disk_devdesc *dev)
79 {
80 	struct dentry *entry;
81 	int rc;
82 
83 	rc = ENOENT;
84 	STAILQ_FOREACH(entry, &opened_disks, entry) {
85 		if (entry->d_dev != dev->d_dev ||
86 		    entry->d_unit != dev->d_unit)
87 			continue;
88 		dev->d_opendata = entry->od;
89 		if (entry->d_slice == dev->d_slice &&
90 		    entry->d_partition == dev->d_partition) {
91 			dev->d_offset = entry->d_offset;
92 			DEBUG("%s offset %lld", disk_fmtdev(dev),
93 			    dev->d_offset);
94 #ifdef DISK_DEBUG
95 			entry->count++;
96 #endif
97 			return (0);
98 		}
99 		rc = EAGAIN;
100 	}
101 	return (rc);
102 }
103 
104 static void
disk_insert(struct disk_devdesc * dev)105 disk_insert(struct disk_devdesc *dev)
106 {
107 	struct dentry *entry;
108 
109 	entry = (struct dentry *)malloc(sizeof(struct dentry));
110 	if (entry == NULL) {
111 		DEBUG("no memory");
112 		return;
113 	}
114 	entry->d_dev = dev->d_dev;
115 	entry->d_unit = dev->d_unit;
116 	entry->d_slice = dev->d_slice;
117 	entry->d_partition = dev->d_partition;
118 	entry->od = (struct open_disk *)dev->d_opendata;
119 	entry->od->rcnt++;
120 	entry->d_offset = dev->d_offset;
121 #ifdef DISK_DEBUG
122 	entry->count = 1;
123 #endif
124 	STAILQ_INSERT_TAIL(&opened_disks, entry, entry);
125 	DEBUG("%s cached", disk_fmtdev(dev));
126 }
127 
128 #ifdef DISK_DEBUG
129 COMMAND_SET(dcachestat, "dcachestat", "get disk cache stats",
130     command_dcachestat);
131 
132 static int
command_dcachestat(int argc,char * argv[])133 command_dcachestat(int argc, char *argv[])
134 {
135 	struct disk_devdesc dev;
136 	struct dentry *entry;
137 
138 	STAILQ_FOREACH(entry, &opened_disks, entry) {
139 		dev.d_dev = (struct devsw *)entry->d_dev;
140 		dev.d_unit = entry->d_unit;
141 		dev.d_slice = entry->d_slice;
142 		dev.d_partition = entry->d_partition;
143 		printf("%s %d => %p [%d]\n", disk_fmtdev(&dev), entry->count,
144 		    entry->od, entry->od->rcnt);
145 	}
146 	return (CMD_OK);
147 }
148 #endif /* DISK_DEBUG */
149 
150 /* Convert size to a human-readable number. */
151 static char *
display_size(uint64_t size,u_int sectorsize)152 display_size(uint64_t size, u_int sectorsize)
153 {
154 	static char buf[80];
155 	char unit;
156 
157 	size = size * sectorsize / 1024;
158 	unit = 'K';
159 	if (size >= 10485760000LL) {
160 		size /= 1073741824;
161 		unit = 'T';
162 	} else if (size >= 10240000) {
163 		size /= 1048576;
164 		unit = 'G';
165 	} else if (size >= 10000) {
166 		size /= 1024;
167 		unit = 'M';
168 	}
169 	sprintf(buf, "%ld%cB", (long)size, unit);
170 	return (buf);
171 }
172 
173 static int
ptblread(void * d,void * buf,size_t blocks,off_t offset)174 ptblread(void *d, void *buf, size_t blocks, off_t offset)
175 {
176 	struct disk_devdesc *dev;
177 	struct open_disk *od;
178 
179 	dev = (struct disk_devdesc *)d;
180 	od = (struct open_disk *)dev->d_opendata;
181 	return (dev->d_dev->dv_strategy(dev, F_READ, offset,
182 	    blocks * od->sectorsize, (char *)buf, NULL));
183 }
184 
185 #define	PWIDTH	35
186 static void
ptable_print(void * arg,const char * pname,const struct ptable_entry * part)187 ptable_print(void *arg, const char *pname, const struct ptable_entry *part)
188 {
189 	struct print_args *pa, bsd;
190 	struct open_disk *od;
191 	struct ptable *table;
192 	char line[80];
193 
194 	pa = (struct print_args *)arg;
195 	od = (struct open_disk *)pa->dev->d_opendata;
196 	sprintf(line, "  %s%s: %s", pa->prefix, pname,
197 	    parttype2str(part->type));
198 	if (pa->verbose)
199 		sprintf(line, "%-*s%s", PWIDTH, line,
200 		    display_size(part->end - part->start + 1,
201 		    od->sectorsize));
202 	strcat(line, "\n");
203 	pager_output(line);
204 	if (part->type == PART_FREEBSD) {
205 		/* Open slice with BSD label */
206 		pa->dev->d_offset = part->start;
207 		table = ptable_open(pa->dev, part->end - part->start + 1,
208 		    od->sectorsize, ptblread);
209 		if (table == NULL)
210 			return;
211 		sprintf(line, "  %s%s", pa->prefix, pname);
212 		bsd.dev = pa->dev;
213 		bsd.prefix = line;
214 		bsd.verbose = pa->verbose;
215 		ptable_iterate(table, &bsd, ptable_print);
216 		ptable_close(table);
217 	}
218 }
219 #undef PWIDTH
220 
221 void
disk_print(struct disk_devdesc * dev,char * prefix,int verbose)222 disk_print(struct disk_devdesc *dev, char *prefix, int verbose)
223 {
224 	struct open_disk *od;
225 	struct print_args pa;
226 
227 	/* Disk should be opened */
228 	od = (struct open_disk *)dev->d_opendata;
229 	pa.dev = dev;
230 	pa.prefix = prefix;
231 	pa.verbose = verbose;
232 	ptable_iterate(od->table, &pa, ptable_print);
233 }
234 
235 int
disk_open(struct disk_devdesc * dev,off_t mediasize,u_int sectorsize,u_int flags)236 disk_open(struct disk_devdesc *dev, off_t mediasize, u_int sectorsize,
237     u_int flags)
238 {
239 	struct open_disk *od;
240 	struct ptable *table;
241 	struct ptable_entry part;
242 	int rc, slice, partition;
243 
244 	rc = 0;
245 	if ((flags & DISK_F_NOCACHE) == 0) {
246 		rc = disk_lookup(dev);
247 		if (rc == 0)
248 			return (0);
249 	}
250 	/*
251 	 * While we are reading disk metadata, make sure we do it relative
252 	 * to the start of the disk
253 	 */
254 	dev->d_offset = 0;
255 	table = NULL;
256 	slice = dev->d_slice;
257 	partition = dev->d_partition;
258 	if (rc == EAGAIN) {
259 		/*
260 		 * This entire disk was already opened and there is no
261 		 * need to allocate new open_disk structure and open the
262 		 * main partition table.
263 		 */
264 		od = (struct open_disk *)dev->d_opendata;
265 		DEBUG("%s unit %d, slice %d, partition %d => %p (cached)",
266 		    disk_fmtdev(dev), dev->d_unit, dev->d_slice,
267 		    dev->d_partition, od);
268 		goto opened;
269 	} else {
270 		od = (struct open_disk *)malloc(sizeof(struct open_disk));
271 		if (od == NULL) {
272 			DEBUG("no memory");
273 			return (ENOMEM);
274 		}
275 		dev->d_opendata = od;
276 		od->rcnt = 0;
277 	}
278 	od->mediasize = mediasize;
279 	od->sectorsize = sectorsize;
280 	od->flags = flags;
281 	DEBUG("%s unit %d, slice %d, partition %d => %p",
282 	    disk_fmtdev(dev), dev->d_unit, dev->d_slice, dev->d_partition, od);
283 
284 	/* Determine disk layout. */
285 	od->table = ptable_open(dev, mediasize / sectorsize, sectorsize,
286 	    ptblread);
287 	if (od->table == NULL) {
288 		DEBUG("Can't read partition table");
289 		rc = ENXIO;
290 		goto out;
291 	}
292 opened:
293 	rc = 0;
294 	if (ptable_gettype(od->table) == PTABLE_BSD &&
295 	    partition >= 0) {
296 		/* It doesn't matter what value has d_slice */
297 		rc = ptable_getpart(od->table, &part, partition);
298 		if (rc == 0)
299 			dev->d_offset = part.start;
300 	} else if (slice >= 0) {
301 		/* Try to get information about partition */
302 		if (slice == 0)
303 			rc = ptable_getbestpart(od->table, &part);
304 		else
305 			rc = ptable_getpart(od->table, &part, slice);
306 		if (rc != 0) /* Partition doesn't exist */
307 			goto out;
308 		dev->d_offset = part.start;
309 		slice = part.index;
310 		if (ptable_gettype(od->table) == PTABLE_GPT) {
311 			partition = 255;
312 			goto out; /* Nothing more to do */
313 		} else if (partition == 255) {
314 			/*
315 			 * When we try to open GPT partition, but partition
316 			 * table isn't GPT, reset d_partition value to -1
317 			 * and try to autodetect appropriate value.
318 			 */
319 			partition = -1;
320 		}
321 		/*
322 		 * If d_partition < 0 and we are looking at a BSD slice,
323 		 * then try to read BSD label, otherwise return the
324 		 * whole MBR slice.
325 		 */
326 		if (partition == -1 &&
327 		    part.type != PART_FREEBSD)
328 			goto out;
329 		/* Try to read BSD label */
330 		table = ptable_open(dev, part.end - part.start + 1,
331 		    od->sectorsize, ptblread);
332 		if (table == NULL) {
333 			DEBUG("Can't read BSD label");
334 			rc = ENXIO;
335 			goto out;
336 		}
337 		/*
338 		 * If slice contains BSD label and d_partition < 0, then
339 		 * assume the 'a' partition. Otherwise just return the
340 		 * whole MBR slice, because it can contain ZFS.
341 		 */
342 		if (partition < 0) {
343 			if (ptable_gettype(table) != PTABLE_BSD)
344 				goto out;
345 			partition = 0;
346 		}
347 		rc = ptable_getpart(table, &part, partition);
348 		if (rc != 0)
349 			goto out;
350 		dev->d_offset += part.start;
351 	}
352 out:
353 	if (table != NULL)
354 		ptable_close(table);
355 
356 	if (rc != 0) {
357 		if (od->rcnt < 1) {
358 			if (od->table != NULL)
359 				ptable_close(od->table);
360 			free(od);
361 		}
362 		DEBUG("%s could not open", disk_fmtdev(dev));
363 	} else {
364 		if ((flags & DISK_F_NOCACHE) == 0)
365 			disk_insert(dev);
366 		/* Save the slice and partition number to the dev */
367 		dev->d_slice = slice;
368 		dev->d_partition = partition;
369 		DEBUG("%s offset %lld => %p", disk_fmtdev(dev),
370 		    dev->d_offset, od);
371 	}
372 	return (rc);
373 }
374 
375 int
disk_close(struct disk_devdesc * dev)376 disk_close(struct disk_devdesc *dev)
377 {
378 	struct open_disk *od;
379 
380 	od = (struct open_disk *)dev->d_opendata;
381 	DEBUG("%s closed => %p [%d]", disk_fmtdev(dev), od, od->rcnt);
382 	if (od->flags & DISK_F_NOCACHE) {
383 		ptable_close(od->table);
384 		free(od);
385 	}
386 	return (0);
387 }
388 
389 void
disk_cleanup(const struct devsw * d_dev)390 disk_cleanup(const struct devsw *d_dev)
391 {
392 #ifdef DISK_DEBUG
393 	struct disk_devdesc dev;
394 #endif
395 	struct dentry *entry, *tmp;
396 
397 	STAILQ_FOREACH_SAFE(entry, &opened_disks, entry, tmp) {
398 		if (entry->d_dev != d_dev)
399 			continue;
400 		entry->od->rcnt--;
401 #ifdef DISK_DEBUG
402 		dev.d_dev = (struct devsw *)entry->d_dev;
403 		dev.d_unit = entry->d_unit;
404 		dev.d_slice = entry->d_slice;
405 		dev.d_partition = entry->d_partition;
406 		DEBUG("%s was freed => %p [%d]", disk_fmtdev(&dev),
407 		    entry->od, entry->od->rcnt);
408 #endif
409 		STAILQ_REMOVE(&opened_disks, entry, dentry, entry);
410 		if (entry->od->rcnt < 1) {
411 			if (entry->od->table != NULL)
412 				ptable_close(entry->od->table);
413 			free(entry->od);
414 		}
415 		free(entry);
416 	}
417 }
418 
419 char*
disk_fmtdev(struct disk_devdesc * dev)420 disk_fmtdev(struct disk_devdesc *dev)
421 {
422 	static char buf[128];
423 	char *cp;
424 
425 	cp = buf + sprintf(buf, "%s%d", dev->d_dev->dv_name, dev->d_unit);
426 	if (dev->d_slice >= 0) {
427 #ifdef LOADER_GPT_SUPPORT
428 		if (dev->d_partition == 255) {
429 			sprintf(cp, "p%d:", dev->d_slice);
430 			return (buf);
431 		} else
432 #endif
433 #ifdef LOADER_MBR_SUPPORT
434 			cp += sprintf(cp, "s%d", dev->d_slice);
435 #endif
436 	}
437 	if (dev->d_partition >= 0)
438 		cp += sprintf(cp, "%c", dev->d_partition + 'a');
439 	strcat(cp, ":");
440 	return (buf);
441 }
442 
443 int
disk_parsedev(struct disk_devdesc * dev,const char * devspec,const char ** path)444 disk_parsedev(struct disk_devdesc *dev, const char *devspec, const char **path)
445 {
446 	int unit, slice, partition;
447 	const char *np;
448 	char *cp;
449 
450 	np = devspec;
451 	unit = slice = partition = -1;
452 	if (*np != '\0' && *np != ':') {
453 		unit = strtol(np, &cp, 10);
454 		if (cp == np)
455 			return (EUNIT);
456 #ifdef LOADER_GPT_SUPPORT
457 		if (*cp == 'p') {
458 			np = cp + 1;
459 			slice = strtol(np, &cp, 10);
460 			if (np == cp)
461 				return (ESLICE);
462 			/* we don't support nested partitions on GPT */
463 			if (*cp != '\0' && *cp != ':')
464 				return (EINVAL);
465 			partition = 255;
466 		} else
467 #endif
468 #ifdef LOADER_MBR_SUPPORT
469 		if (*cp == 's') {
470 			np = cp + 1;
471 			slice = strtol(np, &cp, 10);
472 			if (np == cp)
473 				return (ESLICE);
474 		}
475 #endif
476 		if (*cp != '\0' && *cp != ':') {
477 			partition = *cp - 'a';
478 			if (partition < 0)
479 				return (EPART);
480 			cp++;
481 		}
482 	} else
483 		return (EINVAL);
484 
485 	if (*cp != '\0' && *cp != ':')
486 		return (EINVAL);
487 	dev->d_unit = unit;
488 	dev->d_slice = slice;
489 	dev->d_partition = partition;
490 	if (path != NULL)
491 		*path = (*cp == '\0') ? cp: cp + 1;
492 	return (0);
493 }
494