xref: /illumos-gate/usr/src/cmd/devfsadm/disk_link.c (revision c26dc428cee0f025b14a5ad03a7722f2a52f8383)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 #include <devfsadm.h>
27 #include <stdio.h>
28 #include <strings.h>
29 #include <stdlib.h>
30 #include <limits.h>
31 #include <ctype.h>
32 #include <sys/stat.h>
33 #include <bsm/devalloc.h>
34 
35 #define	DISK_SUBPATH_MAX 100
36 #define	RM_STALE 0x01
37 #define	DISK_LINK_RE	"^r?dsk/c[0-9]+(t[0-9A-F]+)?d[0-9]+(((s|p))[0-9]+)?$"
38 #define	DISK_LINK_TO_UPPER(ch)\
39 	(((ch) >= 'a' && (ch) <= 'z') ? (ch - 'a' + 'A') : ch)
40 
41 #define	SLICE_SMI	"s7"
42 #define	SLICE_EFI	""
43 
44 #define	MN_SMI		"h"
45 #define	MN_EFI		"wd"
46 #define	ASCIIWWNSIZE	255
47 #if defined(__i386) || defined(__amd64)
48 /*
49  * The number of minor nodes per LUN is defined by the disk drivers.
50  * Currently it is set to 64. Refer CMLBUNIT_SHIFT (cmlb_impl.h)
51  */
52 #define	NUM_MINORS_PER_INSTANCE	64
53 #endif
54 
55 
56 extern int system_labeled;
57 
58 static int disk_callback_chan(di_minor_t minor, di_node_t node);
59 static int disk_callback_nchan(di_minor_t minor, di_node_t node);
60 static int disk_callback_wwn(di_minor_t minor, di_node_t node);
61 static int disk_callback_xvmd(di_minor_t minor, di_node_t node);
62 static int disk_callback_fabric(di_minor_t minor, di_node_t node);
63 static void disk_common(di_minor_t minor, di_node_t node, char *disk,
64 				int flags);
65 static char *diskctrl(di_node_t node, di_minor_t minor);
66 static int reserved_links_exist(di_node_t node, di_minor_t minor, int nflags);
67 
68 
69 static devfsadm_create_t disk_cbt[] = {
70 	{ "disk", "ddi_block", NULL,
71 	    TYPE_EXACT, ILEVEL_0, disk_callback_nchan
72 	},
73 	{ "disk", "ddi_block:channel", NULL,
74 	    TYPE_EXACT, ILEVEL_0, disk_callback_chan
75 	},
76 	{ "disk", "ddi_block:fabric", NULL,
77 		TYPE_EXACT, ILEVEL_0, disk_callback_fabric
78 	},
79 	{ "disk", "ddi_block:wwn", NULL,
80 	    TYPE_EXACT, ILEVEL_0, disk_callback_wwn
81 	},
82 	{ "disk", "ddi_block:cdrom", NULL,
83 	    TYPE_EXACT, ILEVEL_0, disk_callback_nchan
84 	},
85 	{ "disk", "ddi_block:cdrom:channel", NULL,
86 	    TYPE_EXACT, ILEVEL_0, disk_callback_chan
87 	},
88 	{ "disk", "ddi_block:xvmd", NULL,
89 	    TYPE_EXACT, ILEVEL_0, disk_callback_xvmd
90 	},
91 	{ "disk", "ddi_block:cdrom:xvmd", NULL,
92 	    TYPE_EXACT, ILEVEL_0, disk_callback_xvmd
93 	},
94 };
95 
96 DEVFSADM_CREATE_INIT_V0(disk_cbt);
97 
98 /*
99  * HOT auto cleanup of disks not desired.
100  */
101 static devfsadm_remove_t disk_remove_cbt[] = {
102 	{ "disk", DISK_LINK_RE, RM_POST,
103 		ILEVEL_0, devfsadm_rm_all
104 	}
105 };
106 
107 DEVFSADM_REMOVE_INIT_V0(disk_remove_cbt);
108 
109 static devlink_re_t disks_re_array[] = {
110 	{"^r?dsk/c([0-9]+)", 1},
111 	{"^cfg/c([0-9]+)$", 1},
112 	{"^scsi/.+/c([0-9]+)", 1},
113 	{NULL}
114 };
115 
116 static char *disk_mid = "disk_mid";
117 static char *modname = "disk_link";
118 
119 int
120 minor_init()
121 {
122 	devfsadm_print(disk_mid,
123 	    "%s: minor_init(): Creating disks reserved ID cache\n",
124 	    modname);
125 	return (devfsadm_reserve_id_cache(disks_re_array, NULL));
126 }
127 
128 static int
129 disk_callback_chan(di_minor_t minor, di_node_t node)
130 {
131 	char *addr;
132 	char disk[20];
133 	uint_t targ;
134 	uint_t lun;
135 
136 	addr = di_bus_addr(node);
137 	(void) sscanf(addr, "%X,%X", &targ, &lun);
138 	(void) sprintf(disk, "t%dd%d", targ, lun);
139 	disk_common(minor, node, disk, 0);
140 	return (DEVFSADM_CONTINUE);
141 
142 }
143 
144 static int
145 disk_callback_nchan(di_minor_t minor, di_node_t node)
146 {
147 	char *addr;
148 	char disk[10];
149 	uint_t lun;
150 
151 	addr = di_bus_addr(node);
152 	(void) sscanf(addr, "%X", &lun);
153 	(void) sprintf(disk, "d%d", lun);
154 	disk_common(minor, node, disk, 0);
155 	return (DEVFSADM_CONTINUE);
156 
157 }
158 
159 static int
160 disk_callback_wwn(di_minor_t minor, di_node_t node)
161 {
162 	char disk[10];
163 	int lun;
164 	int targ;
165 	int *intp;
166 
167 	if (di_prop_lookup_ints(DDI_DEV_T_ANY, node, "target", &intp) <= 0) {
168 		return (DEVFSADM_CONTINUE);
169 	}
170 	targ = *intp;
171 	if (di_prop_lookup_ints(DDI_DEV_T_ANY, node, "lun", &intp) <= 0) {
172 		lun = 0;
173 	} else {
174 		lun = *intp;
175 	}
176 	(void) sprintf(disk, "t%dd%d", targ, lun);
177 
178 	disk_common(minor, node, disk, RM_STALE);
179 
180 	return (DEVFSADM_CONTINUE);
181 }
182 
183 static int
184 disk_callback_fabric(di_minor_t minor, di_node_t node)
185 {
186 	char disk[DISK_SUBPATH_MAX];
187 	int lun;
188 	int count;
189 	int *intp;
190 	uchar_t *str;
191 	uchar_t *wwn;
192 	uchar_t ascii_wwn[ASCIIWWNSIZE];
193 
194 	if (di_prop_lookup_strings(DDI_DEV_T_ANY, node,
195 	    "client-guid", (char **)&wwn) > 0) {
196 		if (strlcpy((char *)ascii_wwn, (char *)wwn,
197 		    sizeof (ascii_wwn)) >= sizeof (ascii_wwn)) {
198 			devfsadm_errprint("SUNW_disk_link: GUID too long:%d",
199 			    strlen((char *)wwn));
200 			return (DEVFSADM_CONTINUE);
201 		}
202 		lun = 0;
203 	} else if (di_prop_lookup_bytes(DDI_DEV_T_ANY, node,
204 	    "port-wwn", &wwn) > 0) {
205 		if (di_prop_lookup_ints(DDI_DEV_T_ANY, node,
206 		    "lun", &intp) > 0) {
207 			lun = *intp;
208 		} else {
209 			lun = 0;
210 		}
211 
212 		for (count = 0, str = ascii_wwn; count < 8; count++, str += 2) {
213 			(void) sprintf((caddr_t)str, "%02x", wwn[count]);
214 		}
215 		*str = '\0';
216 	} else {
217 		return (DEVFSADM_CONTINUE);
218 	}
219 
220 	for (str = ascii_wwn; *str != '\0'; str++) {
221 		*str = DISK_LINK_TO_UPPER(*str);
222 	}
223 
224 	(void) snprintf(disk, DISK_SUBPATH_MAX, "t%sd%d", ascii_wwn, lun);
225 
226 	disk_common(minor, node, disk, RM_STALE);
227 
228 	return (DEVFSADM_CONTINUE);
229 }
230 
231 /*
232  * xVM virtual block device
233  *
234  * VBDs are enumerated into xenstore by xend and named using
235  * the linux dev_t values for 'hd' and 'xvd' devices.  Linux
236  * dev_t's are 16-bit values.  The upper 8 bits identify the major #
237  * of the device (hd, xvd) and the lower 8 bits the instance and partition
238  *
239  * For PV guests, VBDs are named by the virt-tools using
240  * the form xvd[a-p][1-15].  The corresponding Solaris /dev/dsk name
241  * created by this generator will be c0t[0-15]d[0-15]sN,
242  * were the target (t) value represents [a-p] and the
243  * disk (d) value is either 0 (e.g. xvda) or contains the partition
244  * information if it has been specified [1-15] (e.g. xvda1)
245  *
246  * For PV guests using the legacy naming (0, 1, 2, ...)
247  * the Solaris disk names created will be c0d[0..767]sN
248  * The Solaris version of virt-install based on virtinst.101
249  * named PV disks as sequential integers.  With virtinst.300_1 and
250  * beyond, the virt-* tools will no longer create legacy disk
251  * names.
252  */
253 static int
254 disk_callback_xvmd(di_minor_t minor, di_node_t node)
255 {
256 #define	HD_BASE (3 << 8)
257 #define	XVBDMAJ 202
258 
259 	char *addr;
260 	char disk[16];
261 	uint_t targ;
262 	uint_t lun = 0;
263 	uint_t fmaj;
264 
265 	addr = di_bus_addr(node);
266 	targ = strtol(addr, (char **)NULL, 10);
267 	fmaj = targ >> 8;
268 
269 	/* legacy device address */
270 	if (targ < HD_BASE)
271 		(void) snprintf(disk, sizeof (disk),  "d%d", targ);
272 	/* PV VBD */
273 	else if (fmaj == XVBDMAJ) {
274 		lun = targ & 0xf;
275 		targ = (targ & 0xff) >> 4;
276 		(void) snprintf(disk, sizeof (disk), "t%dd%d", targ, lun);
277 	/* HVM device names are generated using the standard generator */
278 	} else {
279 		devfsadm_errprint("%s: invalid disk device number (%s)\n",
280 		    modname, addr);
281 		return (DEVFSADM_CONTINUE);
282 	}
283 	disk_common(minor, node, disk, 0);
284 	return (DEVFSADM_CONTINUE);
285 
286 }
287 
288 /*
289  * This function is called for every disk minor node.
290  * Calls enumerate to assign a logical controller number, and
291  * then devfsadm_mklink to make the link.
292  */
293 static void
294 disk_common(di_minor_t minor, di_node_t node, char *disk, int flags)
295 {
296 	char l_path[PATH_MAX + 1];
297 	char sec_path[PATH_MAX + 1];
298 	char stale_re[DISK_SUBPATH_MAX];
299 	char *dir;
300 	char slice[4];
301 	char *mn;
302 	char *ctrl;
303 	char *nt = NULL;
304 	int *int_prop;
305 	int  nflags = 0;
306 #if defined(__i386) || defined(__amd64)
307 	char mn_copy[4];
308 	char *part;
309 	int part_num;
310 #endif
311 
312 	mn = di_minor_name(minor);
313 	if (strstr(mn, ",raw")) {
314 		dir = "rdsk";
315 #if defined(__i386) || defined(__amd64)
316 		(void) strncpy(mn_copy, mn, 4);
317 		part = strtok(mn_copy, ",");
318 #endif
319 	} else {
320 		dir = "dsk";
321 #if defined(__i386) || defined(__amd64)
322 		part = mn;
323 #endif
324 	}
325 
326 #if defined(__i386) || defined(__amd64)
327 	/*
328 	 * The following is a table describing the allocation of
329 	 * minor numbers, minor names and /dev/dsk names for partitions
330 	 * and slices on x86 systems.
331 	 *
332 	 *	Minor Number	Minor Name	/dev/dsk name
333 	 *	---------------------------------------------
334 	 *	0 to 15		"a" to "p"	s0 to s15
335 	 *	16		"q"		p0
336 	 *	17 to 20	"r" to "u"	p1 to p4
337 	 *	21 to 52	"p5" to "p36"	p5 to p36
338 	 *
339 	 */
340 	part_num = atoi(part + 1);
341 
342 	if ((mn[0] == 'p') && (part_num >= 5)) {
343 		/* logical drive */
344 		(void) snprintf(slice, 4, "%s", part);
345 	} else {
346 #endif
347 	if (mn[0] < 'q') {
348 		(void) sprintf(slice, "s%d", mn[0] - 'a');
349 	} else if (strncmp(mn, MN_EFI, 2) != 0) {
350 		(void) sprintf(slice, "p%d", mn[0] - 'q');
351 	} else {
352 		/* For EFI label */
353 		(void) sprintf(slice, SLICE_EFI);
354 	}
355 #if defined(__i386) || defined(__amd64)
356 	}
357 #endif
358 
359 	nflags = 0;
360 	if (system_labeled) {
361 		nt = di_minor_nodetype(minor);
362 		if ((nt != NULL) &&
363 		    ((strcmp(nt, DDI_NT_CD) == 0) ||
364 		    (strcmp(nt, DDI_NT_CD_CHAN) == 0) ||
365 		    (strcmp(nt, DDI_NT_BLOCK_CHAN) == 0))) {
366 			nflags = DA_ADD|DA_CD;
367 		}
368 	}
369 
370 	if (reserved_links_exist(node, minor, nflags) == DEVFSADM_SUCCESS) {
371 		devfsadm_print(disk_mid, "Reserved link exists. Not "
372 		    "creating links for slice %s\n", slice);
373 		return;
374 	}
375 
376 	if (NULL == (ctrl = diskctrl(node, minor)))
377 		return;
378 
379 	(void) strcpy(l_path, dir);
380 	(void) strcat(l_path, "/c");
381 	(void) strcat(l_path, ctrl);
382 	(void) strcat(l_path, disk);
383 
384 	/*
385 	 * If switching between SMI and EFI label or vice versa
386 	 * cleanup the previous label's devlinks.
387 	 */
388 	if (*mn == *(MN_SMI) || (strncmp(mn, MN_EFI, 2) == 0)) {
389 		char *s, tpath[PATH_MAX + 1];
390 		struct stat sb;
391 
392 		s = l_path + strlen(l_path);
393 		(void) strcat(l_path, (*mn == *(MN_SMI))
394 		    ? SLICE_EFI : SLICE_SMI);
395 		/*
396 		 * Attempt the remove only if the stale link exists
397 		 */
398 		(void) snprintf(tpath, sizeof (tpath), "%s/dev/%s",
399 		    devfsadm_root_path(), l_path);
400 		if (lstat(tpath, &sb) != -1)
401 			devfsadm_rm_all(l_path);
402 		*s = '\0';
403 	}
404 	(void) strcat(l_path, slice);
405 
406 	(void) devfsadm_mklink(l_path, node, minor, nflags);
407 
408 	/* secondary links for removable and hotpluggable devices */
409 	if (di_prop_lookup_ints(DDI_DEV_T_ANY, node, "removable-media",
410 	    &int_prop) >= 0) {
411 		(void) strcpy(sec_path, "removable-media/");
412 		(void) strcat(sec_path, l_path);
413 		(void) devfsadm_secondary_link(sec_path, l_path, 0);
414 	}
415 	if (di_prop_lookup_ints(DDI_DEV_T_ANY, node, "hotpluggable",
416 	    &int_prop) >= 0) {
417 		(void) strcpy(sec_path, "hotpluggable/");
418 		(void) strcat(sec_path, l_path);
419 		(void) devfsadm_secondary_link(sec_path, l_path, 0);
420 	}
421 
422 	if ((flags & RM_STALE) == RM_STALE) {
423 		(void) strcpy(stale_re, "^");
424 		(void) strcat(stale_re, dir);
425 		(void) strcat(stale_re, "/c");
426 		(void) strcat(stale_re, ctrl);
427 		(void) strcat(stale_re, "t[0-9A-F]+d[0-9]+(s[0-9]+)?$");
428 		/*
429 		 * optimizations are made inside of devfsadm_rm_stale_links
430 		 * instead of before calling the function, as it always
431 		 * needs to add the valid link to the cache.
432 		 */
433 		devfsadm_rm_stale_links(stale_re, l_path, node, minor);
434 	}
435 
436 	free(ctrl);
437 }
438 
439 
440 /* index of enumeration rule applicable to this module */
441 #define	RULE_INDEX	0
442 
443 static char *
444 diskctrl(di_node_t node, di_minor_t minor)
445 {
446 	char path[PATH_MAX + 1];
447 	char *devfspath;
448 	char *buf, *mn;
449 
450 	devfsadm_enumerate_t rules[3] = {
451 	    {"^r?dsk$/^c([0-9]+)", 1, MATCH_PARENT},
452 	    {"^cfg$/^c([0-9]+)$", 1, MATCH_ADDR},
453 	    {"^scsi$/^.+$/^c([0-9]+)", 1, MATCH_PARENT}
454 	};
455 
456 	mn = di_minor_name(minor);
457 
458 	if ((devfspath = di_devfs_path(node)) == NULL) {
459 		return (NULL);
460 	}
461 	(void) strcpy(path, devfspath);
462 	(void) strcat(path, ":");
463 	(void) strcat(path, mn);
464 	di_devfs_path_free(devfspath);
465 
466 	/*
467 	 * Use controller component of disk path
468 	 */
469 	if (disk_enumerate_int(path, RULE_INDEX, &buf, rules, 3) ==
470 	    DEVFSADM_MULTIPLE) {
471 
472 		/*
473 		 * We failed because there are multiple logical controller
474 		 * numbers for a single physical controller.  If we use node
475 		 * name also in the match it should fix this and only find one
476 		 * logical controller. (See 4045879).
477 		 * NOTE: Rules for controllers are not changed, as there is
478 		 * no unique controller number for them in this case.
479 		 *
480 		 * MATCH_UNCACHED flag is private to the "disks" and "sgen"
481 		 * modules. NOT to be used by other modules.
482 		 */
483 
484 		rules[0].flags = MATCH_NODE | MATCH_UNCACHED; /* disks */
485 		rules[2].flags = MATCH_NODE | MATCH_UNCACHED; /* generic scsi */
486 		if (devfsadm_enumerate_int(path, RULE_INDEX, &buf, rules, 3)) {
487 			return (NULL);
488 		}
489 	}
490 
491 	return (buf);
492 }
493 
494 typedef struct dvlist {
495 	char *dv_link;
496 	struct dvlist *dv_next;
497 } dvlist_t;
498 
499 static void
500 free_dvlist(dvlist_t **pp)
501 {
502 	dvlist_t *entry;
503 
504 	while (*pp) {
505 		entry = *pp;
506 		*pp = entry->dv_next;
507 		assert(entry->dv_link);
508 		free(entry->dv_link);
509 		free(entry);
510 	}
511 }
512 static int
513 dvlink_cb(di_devlink_t devlink, void *arg)
514 {
515 	char *path;
516 	char *can_path;
517 	dvlist_t **pp = (dvlist_t **)arg;
518 	dvlist_t *entry = NULL;
519 
520 	entry = calloc(1, sizeof (dvlist_t));
521 	if (entry == NULL) {
522 		devfsadm_errprint("%s: calloc failed\n", modname);
523 		goto error;
524 	}
525 
526 	path = (char *)di_devlink_path(devlink);
527 	assert(path);
528 	if (path == NULL) {
529 		devfsadm_errprint("%s: di_devlink_path() returned NULL\n",
530 		    modname);
531 		goto error;
532 	}
533 
534 	devfsadm_print(disk_mid, "%s: found link %s in reverse link cache\n",
535 	    modname, path);
536 
537 	/*
538 	 * Return linkname in canonical form i.e. without the
539 	 * "/dev/" prefix
540 	 */
541 	can_path = strstr(path, "/dev/");
542 	if (can_path == NULL) {
543 		devfsadm_errprint("%s: devlink path %s has no /dev/\n",
544 		    modname, path);
545 		goto error;
546 	}
547 
548 	entry->dv_link = s_strdup(can_path + strlen("/dev/"));
549 	entry->dv_next = *pp;
550 	*pp = entry;
551 
552 	return (DI_WALK_CONTINUE);
553 
554 error:
555 	free(entry);
556 	free_dvlist(pp);
557 	*pp = NULL;
558 	return (DI_WALK_TERMINATE);
559 }
560 
561 /*
562  * Returns success only if all goes well. If there is no matching reserved link
563  * or if there is an error, we assume no match. It is better to err on the side
564  * of caution by creating extra links than to miss out creating a required link.
565  */
566 static int
567 reserved_links_exist(di_node_t node, di_minor_t minor, int nflags)
568 {
569 	di_devlink_handle_t dvlink_cache = devfsadm_devlink_cache();
570 	char phys_path[PATH_MAX];
571 	char *minor_path;
572 	dvlist_t *head;
573 	dvlist_t *entry;
574 	char *s;
575 	char l[PATH_MAX];
576 	int switch_link = 0;
577 	char *mn = di_minor_name(minor);
578 
579 	if (dvlink_cache == NULL || mn == NULL) {
580 		devfsadm_errprint("%s: No minor or devlink cache\n", modname);
581 		return (DEVFSADM_FAILURE);
582 	}
583 
584 	if (!devfsadm_have_reserved()) {
585 		devfsadm_print(disk_mid, "%s: No reserved links\n", modname);
586 		return (DEVFSADM_FAILURE);
587 	}
588 
589 	minor_path = di_devfs_minor_path(minor);
590 	if (minor_path == NULL) {
591 		devfsadm_errprint("%s: di_devfs_minor_path failed\n", modname);
592 		return (DEVFSADM_FAILURE);
593 	}
594 
595 	(void) strlcpy(phys_path, minor_path, sizeof (phys_path));
596 
597 	di_devfs_path_free(minor_path);
598 
599 	head = NULL;
600 	(void) di_devlink_cache_walk(dvlink_cache, DISK_LINK_RE, phys_path,
601 	    DI_PRIMARY_LINK, &head, dvlink_cb);
602 
603 	/*
604 	 * We may be switching between EFI label and SMI label in which case
605 	 * we only have minors of the other type.
606 	 */
607 	if (head == NULL && (*mn == *(MN_SMI) ||
608 	    (strncmp(mn, MN_EFI, 2) == 0))) {
609 		devfsadm_print(disk_mid, "%s: No links for minor %s in /dev. "
610 		    "Trying another label\n", modname, mn);
611 		s = strrchr(phys_path, ':');
612 		if (s == NULL) {
613 			devfsadm_errprint("%s: invalid minor path: %s\n",
614 			    modname, phys_path);
615 			return (DEVFSADM_FAILURE);
616 		}
617 		(void) snprintf(s+1, sizeof (phys_path) - (s + 1 - phys_path),
618 		    "%s%s", *mn == *(MN_SMI) ? MN_EFI : MN_SMI,
619 		    strstr(s, ",raw") ? ",raw" : "");
620 		(void) di_devlink_cache_walk(dvlink_cache, DISK_LINK_RE,
621 		    phys_path, DI_PRIMARY_LINK, &head, dvlink_cb);
622 	}
623 
624 	if (head == NULL) {
625 		devfsadm_print(disk_mid, "%s: minor %s has no links in /dev\n",
626 		    modname, phys_path);
627 		/* no links on disk */
628 		return (DEVFSADM_FAILURE);
629 	}
630 
631 	/*
632 	 * It suffices to use 1 link to this minor, since
633 	 * we are matching with reserved IDs on the basis of
634 	 * the controller number which will be the same for
635 	 * all links to this minor.
636 	 */
637 	if (!devfsadm_is_reserved(disks_re_array, head->dv_link)) {
638 		/* not reserved links */
639 		devfsadm_print(disk_mid, "%s: devlink %s and its minor "
640 		    "are NOT reserved\n", modname, head->dv_link);
641 		free_dvlist(&head);
642 		return (DEVFSADM_FAILURE);
643 	}
644 
645 	devfsadm_print(disk_mid, "%s: devlink %s and its minor are on "
646 	    "reserved list\n", modname, head->dv_link);
647 
648 	/*
649 	 * Switch between SMI and EFI labels if required
650 	 */
651 	switch_link = 0;
652 	if (*mn == *(MN_SMI) || (strncmp(mn, MN_EFI, 2) == 0)) {
653 		for (entry = head; entry; entry = entry->dv_next) {
654 			s = strrchr(entry->dv_link, '/');
655 			assert(s);
656 			if (s == NULL) {
657 				devfsadm_errprint("%s: disk link %s has no "
658 				    "directory\n", modname, entry->dv_link);
659 				continue;
660 			}
661 			if (*mn == *(MN_SMI) && strchr(s, 's') == NULL) {
662 				(void) snprintf(l, sizeof (l), "%s%s",
663 				    entry->dv_link, SLICE_SMI);
664 				switch_link = 1;
665 				devfsadm_print(disk_mid, "%s: switching "
666 				    "reserved link from EFI to SMI label. "
667 				    "New link is %s\n", modname, l);
668 			} else if (strncmp(mn, MN_EFI, 2) == 0 &&
669 			    (s = strchr(s, 's'))) {
670 				*s = '\0';
671 				(void) snprintf(l, sizeof (l), "%s",
672 				    entry->dv_link);
673 				*s = 's';
674 				switch_link = 1;
675 				devfsadm_print(disk_mid, "%s: switching "
676 				    "reserved link from SMI to EFI label. "
677 				    "New link is %s\n", modname, l);
678 			}
679 			if (switch_link) {
680 				devfsadm_print(disk_mid, "%s: switching "
681 				    "link: deleting %s and creating %s\n",
682 				    modname, entry->dv_link, l);
683 				devfsadm_rm_link(entry->dv_link);
684 				(void) devfsadm_mklink(l, node, minor, nflags);
685 			}
686 		}
687 	}
688 	free_dvlist(&head);
689 
690 	/*
691 	 * return SUCCESS to indicate that new links to this minor should not
692 	 * be created so that only compatibility links to this minor remain.
693 	 */
694 	return (DEVFSADM_SUCCESS);
695 }
696