xref: /netbsd-src/sys/dev/dm/device-mapper.c (revision 4e6df137e8e14049b5a701d249962c480449c141)
1 /*        $NetBSD: device-mapper.c,v 1.19 2010/02/27 00:31:57 jakllsch Exp $ */
2 
3 /*
4  * Copyright (c) 2010 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Adam Hamsik.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 /*
33  * I want to say thank you to all people who helped me with this project.
34  */
35 
36 #include <sys/types.h>
37 #include <sys/param.h>
38 
39 #include <sys/buf.h>
40 #include <sys/conf.h>
41 #include <sys/device.h>
42 #include <sys/dkio.h>
43 #include <sys/disk.h>
44 #include <sys/disklabel.h>
45 #include <sys/ioctl.h>
46 #include <sys/ioccom.h>
47 #include <sys/kmem.h>
48 #include <sys/module.h>
49 #include <sys/once.h>
50 
51 #include "netbsd-dm.h"
52 #include "dm.h"
53 
54 static dev_type_open(dmopen);
55 static dev_type_close(dmclose);
56 static dev_type_read(dmread);
57 static dev_type_write(dmwrite);
58 static dev_type_ioctl(dmioctl);
59 static dev_type_strategy(dmstrategy);
60 static dev_type_size(dmsize);
61 
62 /* attach and detach routines */
63 void dmattach(int);
64 int dmdestroy(void);
65 
66 static ONCE_DECL(doinit_control);
67 static int doinit(void);
68 
69 static int dm_cmd_to_fun(prop_dictionary_t);
70 static int disk_ioctl_switch(dev_t, u_long, void *);
71 static int dm_ioctl_switch(u_long);
72 static void dmminphys(struct buf *);
73 
74 /* CF attach/detach functions used for power management */
75 static int dm_detach(device_t, int);
76 static void dm_attach(device_t, device_t, void *);
77 static int dm_match(device_t, cfdata_t, void *);
78 
79 /* ***Variable-definitions*** */
80 const struct bdevsw dm_bdevsw = {
81 	.d_open = dmopen,
82 	.d_close = dmclose,
83 	.d_strategy = dmstrategy,
84 	.d_ioctl = dmioctl,
85 	.d_dump = nodump,
86 	.d_psize = dmsize,
87 	.d_flag = D_DISK | D_MPSAFE
88 };
89 
90 const struct cdevsw dm_cdevsw = {
91 	.d_open = dmopen,
92 	.d_close = dmclose,
93 	.d_read = dmread,
94 	.d_write = dmwrite,
95 	.d_ioctl = dmioctl,
96 	.d_stop = nostop,
97 	.d_tty = notty,
98 	.d_poll = nopoll,
99 	.d_mmap = nommap,
100 	.d_kqfilter = nokqfilter,
101 	.d_flag = D_DISK | D_MPSAFE
102 };
103 
104 const struct dkdriver dmdkdriver = {
105 	.d_strategy = dmstrategy
106 };
107 
108 #ifdef _MODULE
109 /* Autoconf defines */
110 CFDRIVER_DECL(dm, DV_DISK, NULL);
111 #endif
112 
113 CFATTACH_DECL3_NEW(dm, 0,
114      dm_match, dm_attach, dm_detach, NULL, NULL, NULL,
115      DVF_DETACH_SHUTDOWN);
116 
117 extern struct cfdriver dm_cd;
118 
119 extern uint64_t dm_dev_counter;
120 
121 /*
122  * This array is used to translate cmd to function pointer.
123  *
124  * Interface between libdevmapper and lvm2tools uses different
125  * names for one IOCTL call because libdevmapper do another thing
126  * then. When I run "info" or "mknodes" libdevmapper will send same
127  * ioctl to kernel but will do another things in userspace.
128  *
129  */
130 struct cmd_function cmd_fn[] = {
131 		{ .cmd = "version", .fn = dm_get_version_ioctl},
132 		{ .cmd = "targets", .fn = dm_list_versions_ioctl},
133 		{ .cmd = "create",  .fn = dm_dev_create_ioctl},
134 		{ .cmd = "info",    .fn = dm_dev_status_ioctl},
135 		{ .cmd = "mknodes", .fn = dm_dev_status_ioctl},
136 		{ .cmd = "names",   .fn = dm_dev_list_ioctl},
137 		{ .cmd = "suspend", .fn = dm_dev_suspend_ioctl},
138 		{ .cmd = "remove",  .fn = dm_dev_remove_ioctl},
139 		{ .cmd = "rename",  .fn = dm_dev_rename_ioctl},
140 		{ .cmd = "resume",  .fn = dm_dev_resume_ioctl},
141 		{ .cmd = "clear",   .fn = dm_table_clear_ioctl},
142 		{ .cmd = "deps",    .fn = dm_table_deps_ioctl},
143 		{ .cmd = "reload",  .fn = dm_table_load_ioctl},
144 		{ .cmd = "status",  .fn = dm_table_status_ioctl},
145 		{ .cmd = "table",   .fn = dm_table_status_ioctl},
146 		{NULL, NULL}
147 };
148 
149 MODULE(MODULE_CLASS_DRIVER, dm, NULL);
150 
151 /* New module handle routine */
152 static int
153 dm_modcmd(modcmd_t cmd, void *arg)
154 {
155 	int error, bmajor, cmajor;
156 
157 	error = 0;
158 	bmajor = -1;
159 	cmajor = -1;
160 
161 	switch (cmd) {
162 	case MODULE_CMD_INIT:
163 		error = config_cfdriver_attach(&dm_cd);
164 		if (error)
165 			break;
166 
167 		error = RUN_ONCE(&doinit_control, doinit);
168 		if (error) {
169 			config_cfdriver_detach(&dm_cd);
170 			break;
171 		}
172 
173 		error = devsw_attach(dm_cd.cd_name, &dm_bdevsw, &bmajor,
174 		    &dm_cdevsw, &cmajor);
175 		if (error) {
176 			config_cfattach_detach(dm_cd.cd_name, &dm_ca);
177 			config_cfdriver_detach(&dm_cd);
178 			break;
179 		}
180 		break;
181 
182 	case MODULE_CMD_FINI:
183 		/*
184 		 * Disable unloading of dm module if there are any devices
185 		 * defined in driver. This is probably too strong we need
186 		 * to disable auto-unload only if there is mounted dm device
187 		 * present.
188 		 */
189 		if (dm_dev_counter > 0)
190 			return EBUSY;
191 
192 		error = dmdestroy();
193 		if (error)
194 			break;
195 
196 		config_cfdriver_detach(&dm_cd);
197 
198 		devsw_detach(&dm_bdevsw, &dm_cdevsw);
199 		break;
200 	case MODULE_CMD_STAT:
201 		return ENOTTY;
202 
203 	default:
204 		return ENOTTY;
205 	}
206 
207 	return error;
208 }
209 
210 
211 /*
212  * dm_match:
213  *
214  *	Autoconfiguration match function for pseudo-device glue.
215  */
216 static int
217 dm_match(device_t parent, cfdata_t match,
218     void *aux)
219 {
220 
221 	/* Pseudo-device; always present. */
222 	return (1);
223 }
224 
225 /*
226  * dm_attach:
227  *
228  *	Autoconfiguration attach function for pseudo-device glue.
229  */
230 static void
231 dm_attach(device_t parent, device_t self,
232     void *aux)
233 {
234 	return;
235 }
236 
237 
238 /*
239  * dm_detach:
240  *
241  *	Autoconfiguration detach function for pseudo-device glue.
242  * This routine is called by dm_ioctl::dm_dev_remove_ioctl and by autoconf to
243  * remove devices created in device-mapper.
244  */
245 static int
246 dm_detach(device_t self, int flags)
247 {
248 	dm_dev_t *dmv;
249 
250 	/* Detach device from global device list */
251 	if ((dmv = dm_dev_detach(self)) == NULL)
252 		return ENOENT;
253 
254 	/* Destroy active table first.  */
255 	dm_table_destroy(&dmv->table_head, DM_TABLE_ACTIVE);
256 
257 	/* Destroy inactive table if exits, too. */
258 	dm_table_destroy(&dmv->table_head, DM_TABLE_INACTIVE);
259 
260 	dm_table_head_destroy(&dmv->table_head);
261 
262 	/* Destroy disk device structure */
263 	disk_detach(dmv->diskp);
264 	disk_destroy(dmv->diskp);
265 
266 	/* Destroy device */
267 	(void)dm_dev_free(dmv);
268 
269 	/* Decrement device counter After removing device */
270 	atomic_dec_64(&dm_dev_counter);
271 
272 	return 0;
273 }
274 
275 static int
276 doinit(void)
277 {
278 	int error;
279 
280 	error = config_cfattach_attach(dm_cd.cd_name, &dm_ca);
281 	if (error) {
282 		aprint_error("%s: unable to register cfattach\n",
283 		    dm_cd.cd_name);
284 		return error;
285 	}
286 
287 	dm_target_init();
288 	dm_dev_init();
289 	dm_pdev_init();
290 
291 	return 0;
292 }
293 
294 /* attach routine */
295 void
296 dmattach(int n)
297 {
298 	RUN_ONCE(&doinit_control, doinit);
299 }
300 
301 /* Destroy routine */
302 int
303 dmdestroy(void)
304 {
305 	int error;
306 
307 	error = config_cfattach_detach(dm_cd.cd_name, &dm_ca);
308 	if (error)
309 		return error;
310 
311 	dm_dev_destroy();
312 	dm_pdev_destroy();
313 	dm_target_destroy();
314 
315 	return 0;
316 }
317 
318 static int
319 dmopen(dev_t dev, int flags, int mode, struct lwp *l)
320 {
321 
322 	aprint_debug("dm open routine called %" PRIu32 "\n", minor(dev));
323 	return 0;
324 }
325 
326 static int
327 dmclose(dev_t dev, int flags, int mode, struct lwp *l)
328 {
329 
330 	aprint_debug("dm close routine called %" PRIu32 "\n", minor(dev));
331 	return 0;
332 }
333 
334 
335 static int
336 dmioctl(dev_t dev, const u_long cmd, void *data, int flag, struct lwp *l)
337 {
338 	int r;
339 	prop_dictionary_t dm_dict_in;
340 
341 	r = 0;
342 
343 	aprint_debug("dmioctl called\n");
344 
345 	KASSERT(data != NULL);
346 
347 	if (( r = disk_ioctl_switch(dev, cmd, data)) == ENOTTY) {
348 		struct plistref *pref = (struct plistref *) data;
349 
350 		/* Check if we were called with NETBSD_DM_IOCTL ioctl
351 		   otherwise quit. */
352 		if ((r = dm_ioctl_switch(cmd)) != 0)
353 			return r;
354 
355 		if((r = prop_dictionary_copyin_ioctl(pref, cmd, &dm_dict_in)) != 0)
356 			return r;
357 
358 		if ((r = dm_check_version(dm_dict_in)) != 0)
359 			goto cleanup_exit;
360 
361 		/* run ioctl routine */
362 		if ((r = dm_cmd_to_fun(dm_dict_in)) != 0)
363 			goto cleanup_exit;
364 
365 cleanup_exit:
366 		r = prop_dictionary_copyout_ioctl(pref, cmd, dm_dict_in);
367 		prop_object_release(dm_dict_in);
368 	}
369 
370 	return r;
371 }
372 
373 /*
374  * Translate command sent from libdevmapper to func.
375  */
376 static int
377 dm_cmd_to_fun(prop_dictionary_t dm_dict){
378 	int i, r;
379 	prop_string_t command;
380 
381 	r = 0;
382 
383 	if ((command = prop_dictionary_get(dm_dict, DM_IOCTL_COMMAND)) == NULL)
384 		return EINVAL;
385 
386 	for(i = 0; cmd_fn[i].cmd != NULL; i++)
387 		if (prop_string_equals_cstring(command, cmd_fn[i].cmd))
388 			break;
389 
390 	if (cmd_fn[i].cmd == NULL)
391 		return EINVAL;
392 
393 	aprint_debug("ioctl %s called\n", cmd_fn[i].cmd);
394 	r = cmd_fn[i].fn(dm_dict);
395 
396 	return r;
397 }
398 
399 /* Call apropriate ioctl handler function. */
400 static int
401 dm_ioctl_switch(u_long cmd)
402 {
403 
404 	switch(cmd) {
405 
406 	case NETBSD_DM_IOCTL:
407 		aprint_debug("dm NetBSD_DM_IOCTL called\n");
408 		break;
409 	default:
410 		 aprint_debug("dm unknown ioctl called\n");
411 		 return ENOTTY;
412 		 break; /* NOT REACHED */
413 	}
414 
415 	 return 0;
416 }
417 
418  /*
419   * Check for disk specific ioctls.
420   */
421 
422 static int
423 disk_ioctl_switch(dev_t dev, u_long cmd, void *data)
424 {
425 	dm_dev_t *dmv;
426 
427 	switch(cmd) {
428 	case DIOCGWEDGEINFO:
429 	{
430 		struct dkwedge_info *dkw = (void *) data;
431 
432 		if ((dmv = dm_dev_lookup(NULL, NULL, minor(dev))) == NULL)
433 			return ENODEV;
434 
435 		aprint_debug("DIOCGWEDGEINFO ioctl called\n");
436 
437 		strlcpy(dkw->dkw_devname, dmv->name, 16);
438 		strlcpy(dkw->dkw_wname, dmv->name, DM_NAME_LEN);
439 		strlcpy(dkw->dkw_parent, dmv->name, 16);
440 
441 		dkw->dkw_offset = 0;
442 		dkw->dkw_size = dm_table_size(&dmv->table_head);
443 		strcpy(dkw->dkw_ptype, DKW_PTYPE_FFS);
444 
445 		dm_dev_unbusy(dmv);
446 		break;
447 	}
448 
449 	case DIOCGDISKINFO:
450 	{
451 		struct plistref *pref = (struct plistref *) data;
452 
453 		if ((dmv = dm_dev_lookup(NULL, NULL, minor(dev))) == NULL)
454 			return ENODEV;
455 
456 		if (dmv->diskp->dk_info == NULL) {
457 			dm_dev_unbusy(dmv);
458 			return ENOTSUP;
459 		} else
460 			prop_dictionary_copyout_ioctl(pref, cmd,
461 			    dmv->diskp->dk_info);
462 
463 		dm_dev_unbusy(dmv);
464 		break;
465 	}
466 
467 	default:
468 		aprint_debug("unknown disk_ioctl called\n");
469 		return ENOTTY;
470 		break; /* NOT REACHED */
471 	}
472 
473 	return 0;
474 }
475 
476 /*
477  * Do all IO operations on dm logical devices.
478  */
479 static void
480 dmstrategy(struct buf *bp)
481 {
482 	dm_dev_t *dmv;
483 	dm_table_t  *tbl;
484 	dm_table_entry_t *table_en;
485 	struct buf *nestbuf;
486 
487 	uint32_t dev_type;
488 
489 	uint64_t buf_start, buf_len, issued_len;
490 	uint64_t table_start, table_end;
491 	uint64_t start, end;
492 
493 	buf_start = bp->b_blkno * DEV_BSIZE;
494 	buf_len = bp->b_bcount;
495 
496 	tbl = NULL;
497 
498 	table_end = 0;
499 	dev_type = 0;
500 	issued_len = 0;
501 
502 	if ((dmv = dm_dev_lookup(NULL, NULL, minor(bp->b_dev))) == NULL) {
503 		bp->b_error = EIO;
504 		bp->b_resid = bp->b_bcount;
505 		biodone(bp);
506 		return;
507 	}
508 
509 	if (bounds_check_with_mediasize(bp, DEV_BSIZE,
510 	    dm_table_size(&dmv->table_head)) <= 0) {
511 		dm_dev_unbusy(dmv);
512 		bp->b_resid = bp->b_bcount;
513 		biodone(bp);
514 		return;
515 	}
516 
517 	/*
518 	 * disk(9) is part of device structure and it can't be used without
519 	 * mutual exclusion, use diskp_mtx until it will be fixed.
520 	 */
521 	mutex_enter(&dmv->diskp_mtx);
522 	disk_busy(dmv->diskp);
523 	mutex_exit(&dmv->diskp_mtx);
524 
525 	/* Select active table */
526 	tbl = dm_table_get_entry(&dmv->table_head, DM_TABLE_ACTIVE);
527 
528 	 /* Nested buffers count down to zero therefore I have
529 	    to set bp->b_resid to maximal value. */
530 	bp->b_resid = bp->b_bcount;
531 
532 	/*
533 	 * Find out what tables I want to select.
534 	 */
535 	SLIST_FOREACH(table_en, tbl, next)
536 	{
537 		/* I need need number of bytes not blocks. */
538 		table_start = table_en->start * DEV_BSIZE;
539 		/*
540 		 * I have to sub 1 from table_en->length to prevent
541 		 * off by one error
542 		 */
543 		table_end = table_start + (table_en->length)* DEV_BSIZE;
544 
545 		start = MAX(table_start, buf_start);
546 
547 		end = MIN(table_end, buf_start + buf_len);
548 
549 		aprint_debug("----------------------------------------\n");
550 		aprint_debug("table_start %010" PRIu64", table_end %010"
551 		    PRIu64 "\n", table_start, table_end);
552 		aprint_debug("buf_start %010" PRIu64", buf_len %010"
553 		    PRIu64"\n", buf_start, buf_len);
554 		aprint_debug("start-buf_start %010"PRIu64", end %010"
555 		    PRIu64"\n", start - buf_start, end);
556 		aprint_debug("start %010" PRIu64" , end %010"
557                     PRIu64"\n", start, end);
558 		aprint_debug("\n----------------------------------------\n");
559 
560 		if (start < end) {
561 			/* create nested buffer  */
562 			nestbuf = getiobuf(NULL, true);
563 
564 			nestiobuf_setup(bp, nestbuf, start - buf_start,
565 			    (end - start));
566 
567 			issued_len += end - start;
568 
569 			/* I need number of blocks. */
570 			nestbuf->b_blkno = (start - table_start) / DEV_BSIZE;
571 
572 			table_en->target->strategy(table_en, nestbuf);
573 		}
574 	}
575 
576 	if (issued_len < buf_len)
577 		nestiobuf_done(bp, buf_len - issued_len, EINVAL);
578 
579 	mutex_enter(&dmv->diskp_mtx);
580 	disk_unbusy(dmv->diskp, buf_len, bp != NULL ? bp->b_flags & B_READ : 0);
581 	mutex_exit(&dmv->diskp_mtx);
582 
583 	dm_table_release(&dmv->table_head, DM_TABLE_ACTIVE);
584 	dm_dev_unbusy(dmv);
585 
586 	return;
587 }
588 
589 
590 static int
591 dmread(dev_t dev, struct uio *uio, int flag)
592 {
593 
594 	return (physio(dmstrategy, NULL, dev, B_READ, dmminphys, uio));
595 }
596 
597 static int
598 dmwrite(dev_t dev, struct uio *uio, int flag)
599 {
600 
601 	return (physio(dmstrategy, NULL, dev, B_WRITE, dmminphys, uio));
602 }
603 
604 static int
605 dmsize(dev_t dev)
606 {
607 	dm_dev_t *dmv;
608 	uint64_t size;
609 
610 	size = 0;
611 
612 	if ((dmv = dm_dev_lookup(NULL, NULL, minor(dev))) == NULL)
613 			return -ENOENT;
614 
615 	size = dm_table_size(&dmv->table_head);
616 	dm_dev_unbusy(dmv);
617 
618   	return size;
619 }
620 
621 static void
622 dmminphys(struct buf *bp)
623 {
624 
625 	bp->b_bcount = MIN(bp->b_bcount, MAXPHYS);
626 }
627 
628 void
629 dmgetproperties(struct disk *disk, dm_table_head_t *head)
630 {
631 	prop_dictionary_t disk_info, odisk_info, geom;
632 	int dmp_size;
633 
634 	dmp_size = dm_table_size(head);
635 	disk_info = prop_dictionary_create();
636 	geom = prop_dictionary_create();
637 
638 	prop_dictionary_set_cstring_nocopy(disk_info, "type", "ESDI");
639 	prop_dictionary_set_uint64(geom, "sectors-per-unit", dmp_size);
640 	prop_dictionary_set_uint32(geom, "sector-size",
641 	    DEV_BSIZE /* XXX 512? */);
642 	prop_dictionary_set_uint32(geom, "sectors-per-track", 32);
643 	prop_dictionary_set_uint32(geom, "tracks-per-cylinder", 64);
644 	prop_dictionary_set_uint32(geom, "cylinders-per-unit", dmp_size / 2048);
645 	prop_dictionary_set(disk_info, "geometry", geom);
646 	prop_object_release(geom);
647 
648 	odisk_info = disk->dk_info;
649 	disk->dk_info = disk_info;
650 
651 	if (odisk_info != NULL)
652 		prop_object_release(odisk_info);
653 }
654