xref: /illumos-gate/usr/src/cmd/devfsadm/disk_link.c (revision f85c7842adab30da40b7225f83b02f9df9fbb1f0)
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 #pragma ident	"%Z%%M%	%I%	%E% SMI"
27 
28 #include <devfsadm.h>
29 #include <stdio.h>
30 #include <strings.h>
31 #include <stdlib.h>
32 #include <limits.h>
33 #include <ctype.h>
34 #include <sys/stat.h>
35 #include <bsm/devalloc.h>
36 
37 #define	DISK_SUBPATH_MAX 100
38 #define	RM_STALE 0x01
39 #define	DISK_LINK_RE	"^r?dsk/c[0-9]+(t[0-9A-F]+)?d[0-9]+(((s|p))[0-9]+)?$"
40 #define	DISK_LINK_TO_UPPER(ch)\
41 	(((ch) >= 'a' && (ch) <= 'z') ? (ch - 'a' + 'A') : ch)
42 
43 #define	SLICE_SMI	"s7"
44 #define	SLICE_EFI	""
45 
46 #define	MN_SMI		"h"
47 #define	MN_EFI		"wd"
48 #define	ASCIIWWNSIZE	255
49 
50 extern int system_labeled;
51 
52 static int disk_callback_chan(di_minor_t minor, di_node_t node);
53 static int disk_callback_nchan(di_minor_t minor, di_node_t node);
54 static int disk_callback_wwn(di_minor_t minor, di_node_t node);
55 static int disk_callback_xvmd(di_minor_t minor, di_node_t node);
56 static int disk_callback_fabric(di_minor_t minor, di_node_t node);
57 static void disk_common(di_minor_t minor, di_node_t node, char *disk,
58 				int flags);
59 static char *diskctrl(di_node_t node, di_minor_t minor);
60 static int reserved_links_exist(di_node_t node, di_minor_t minor, int nflags);
61 
62 
63 static devfsadm_create_t disk_cbt[] = {
64 	{ "disk", "ddi_block", NULL,
65 	    TYPE_EXACT, ILEVEL_0, disk_callback_nchan
66 	},
67 	{ "disk", "ddi_block:channel", NULL,
68 	    TYPE_EXACT, ILEVEL_0, disk_callback_chan
69 	},
70 	{ "disk", "ddi_block:fabric", NULL,
71 		TYPE_EXACT, ILEVEL_0, disk_callback_fabric
72 	},
73 	{ "disk", "ddi_block:wwn", NULL,
74 	    TYPE_EXACT, ILEVEL_0, disk_callback_wwn
75 	},
76 	{ "disk", "ddi_block:cdrom", NULL,
77 	    TYPE_EXACT, ILEVEL_0, disk_callback_nchan
78 	},
79 	{ "disk", "ddi_block:cdrom:channel", NULL,
80 	    TYPE_EXACT, ILEVEL_0, disk_callback_chan
81 	},
82 	{ "disk", "ddi_block:xvmd", NULL,
83 	    TYPE_EXACT, ILEVEL_0, disk_callback_xvmd
84 	},
85 	{ "disk", "ddi_block:cdrom:xvmd", NULL,
86 	    TYPE_EXACT, ILEVEL_0, disk_callback_xvmd
87 	},
88 };
89 
90 DEVFSADM_CREATE_INIT_V0(disk_cbt);
91 
92 /*
93  * HOT auto cleanup of disks not desired.
94  */
95 static devfsadm_remove_t disk_remove_cbt[] = {
96 	{ "disk", DISK_LINK_RE, RM_POST,
97 		ILEVEL_0, devfsadm_rm_all
98 	}
99 };
100 
101 DEVFSADM_REMOVE_INIT_V0(disk_remove_cbt);
102 
103 static devlink_re_t disks_re_array[] = {
104 	{"^r?dsk/c([0-9]+)", 1},
105 	{"^cfg/c([0-9]+)$", 1},
106 	{"^scsi/.+/c([0-9]+)", 1},
107 	{NULL}
108 };
109 
110 static char *disk_mid = "disk_mid";
111 static char *modname = "disk_link";
112 
113 int
114 minor_init()
115 {
116 	devfsadm_print(disk_mid,
117 	    "%s: minor_init(): Creating disks reserved ID cache\n",
118 	    modname);
119 	return (devfsadm_reserve_id_cache(disks_re_array, NULL));
120 }
121 
122 static int
123 disk_callback_chan(di_minor_t minor, di_node_t node)
124 {
125 	char *addr;
126 	char disk[20];
127 	uint_t targ;
128 	uint_t lun;
129 
130 	addr = di_bus_addr(node);
131 	(void) sscanf(addr, "%X,%X", &targ, &lun);
132 	(void) sprintf(disk, "t%dd%d", targ, lun);
133 	disk_common(minor, node, disk, 0);
134 	return (DEVFSADM_CONTINUE);
135 
136 }
137 
138 static int
139 disk_callback_nchan(di_minor_t minor, di_node_t node)
140 {
141 	char *addr;
142 	char disk[10];
143 	uint_t lun;
144 
145 	addr = di_bus_addr(node);
146 	(void) sscanf(addr, "%X", &lun);
147 	(void) sprintf(disk, "d%d", lun);
148 	disk_common(minor, node, disk, 0);
149 	return (DEVFSADM_CONTINUE);
150 
151 }
152 
153 static int
154 disk_callback_wwn(di_minor_t minor, di_node_t node)
155 {
156 	char disk[10];
157 	int lun;
158 	int targ;
159 	int *intp;
160 
161 	if (di_prop_lookup_ints(DDI_DEV_T_ANY, node, "target", &intp) <= 0) {
162 		return (DEVFSADM_CONTINUE);
163 	}
164 	targ = *intp;
165 	if (di_prop_lookup_ints(DDI_DEV_T_ANY, node, "lun", &intp) <= 0) {
166 		lun = 0;
167 	} else {
168 		lun = *intp;
169 	}
170 	(void) sprintf(disk, "t%dd%d", targ, lun);
171 
172 	disk_common(minor, node, disk, RM_STALE);
173 
174 	return (DEVFSADM_CONTINUE);
175 }
176 
177 static int
178 disk_callback_fabric(di_minor_t minor, di_node_t node)
179 {
180 	char disk[DISK_SUBPATH_MAX];
181 	int lun;
182 	int count;
183 	int *intp;
184 	uchar_t *str;
185 	uchar_t *wwn;
186 	uchar_t ascii_wwn[ASCIIWWNSIZE];
187 
188 	if (di_prop_lookup_strings(DDI_DEV_T_ANY, node,
189 	    "client-guid", (char **)&wwn) > 0) {
190 		if (strlcpy((char *)ascii_wwn, (char *)wwn,
191 		    sizeof (ascii_wwn)) >= sizeof (ascii_wwn)) {
192 			devfsadm_errprint("SUNW_disk_link: GUID too long:%d",
193 			    strlen((char *)wwn));
194 			return (DEVFSADM_CONTINUE);
195 		}
196 		lun = 0;
197 	} else if (di_prop_lookup_bytes(DDI_DEV_T_ANY, node,
198 	    "port-wwn", &wwn) > 0) {
199 		if (di_prop_lookup_ints(DDI_DEV_T_ANY, node,
200 		    "lun", &intp) > 0) {
201 			lun = *intp;
202 		} else {
203 			lun = 0;
204 		}
205 
206 		for (count = 0, str = ascii_wwn; count < 8; count++, str += 2) {
207 			(void) sprintf((caddr_t)str, "%02x", wwn[count]);
208 		}
209 		*str = '\0';
210 	} else {
211 		return (DEVFSADM_CONTINUE);
212 	}
213 
214 	for (str = ascii_wwn; *str != '\0'; str++) {
215 		*str = DISK_LINK_TO_UPPER(*str);
216 	}
217 
218 	(void) snprintf(disk, DISK_SUBPATH_MAX, "t%sd%d", ascii_wwn, lun);
219 
220 	disk_common(minor, node, disk, RM_STALE);
221 
222 	return (DEVFSADM_CONTINUE);
223 }
224 
225 /*
226  * xVM virtual block device
227  *
228  * VBDs are enumerated into xenstore by xend and named using
229  * the linux dev_t values for 'hd' and 'xvd' devices.  Linux
230  * dev_t's are 16-bit values.  The upper 8 bits identify the major #
231  * of the device (hd, xvd) and the lower 8 bits the instance and partition
232  *
233  * For PV guests, VBDs are named by the virt-tools using
234  * the form xvd[a-p][1-15].  The corresponding Solaris /dev/dsk name
235  * created by this generator will be c0t[0-15]d[0-15]sN,
236  * were the target (t) value represents [a-p] and the
237  * disk (d) value is either 0 (e.g. xvda) or contains the partition
238  * information if it has been specified [1-15] (e.g. xvda1)
239  *
240  * For PV guests using the legacy naming (0, 1, 2, ...)
241  * the Solaris disk names created will be c0d[0..767]sN
242  * The Solaris version of virt-install based on virtinst.101
243  * named PV disks as sequential integers.  With virtinst.300_1 and
244  * beyond, the virt-* tools will no longer create legacy disk
245  * names.
246  */
247 static int
248 disk_callback_xvmd(di_minor_t minor, di_node_t node)
249 {
250 #define	HD_BASE (3 << 8)
251 #define	XVBDMAJ 202
252 
253 	char *addr;
254 	char disk[16];
255 	uint_t targ;
256 	uint_t lun = 0;
257 	uint_t fmaj;
258 
259 	addr = di_bus_addr(node);
260 	targ = strtol(addr, (char **)NULL, 10);
261 	fmaj = targ >> 8;
262 
263 	/* legacy device address */
264 	if (targ < HD_BASE)
265 		(void) snprintf(disk, sizeof (disk),  "d%d", targ);
266 	/* PV VBD */
267 	else if (fmaj == XVBDMAJ) {
268 		lun = targ & 0xf;
269 		targ = (targ & 0xff) >> 4;
270 		(void) snprintf(disk, sizeof (disk), "t%dd%d", targ, lun);
271 	/* HVM device names are generated using the standard generator */
272 	} else {
273 		devfsadm_errprint("%s: invalid disk device number (%s)\n",
274 		    modname, addr);
275 		return (DEVFSADM_CONTINUE);
276 	}
277 	disk_common(minor, node, disk, 0);
278 	return (DEVFSADM_CONTINUE);
279 
280 }
281 
282 /*
283  * This function is called for every disk minor node.
284  * Calls enumerate to assign a logical controller number, and
285  * then devfsadm_mklink to make the link.
286  */
287 static void
288 disk_common(di_minor_t minor, di_node_t node, char *disk, int flags)
289 {
290 	char l_path[PATH_MAX + 1];
291 	char sec_path[PATH_MAX + 1];
292 	char stale_re[DISK_SUBPATH_MAX];
293 	char *dir;
294 	char slice[4];
295 	char *mn;
296 	char *ctrl;
297 	char *nt = NULL;
298 	int *int_prop;
299 	int  nflags = 0;
300 
301 	if (strstr(mn = di_minor_name(minor), ",raw")) {
302 		dir = "rdsk";
303 	} else {
304 		dir = "dsk";
305 	}
306 
307 	if (mn[0] < 113) {
308 		(void) sprintf(slice, "s%d", mn[0] - 'a');
309 	} else if (strncmp(mn, MN_EFI, 2) != 0) {
310 		(void) sprintf(slice, "p%d", mn[0] - 'q');
311 	} else {
312 		/* For EFI label */
313 		(void) sprintf(slice, SLICE_EFI);
314 	}
315 
316 	nflags = 0;
317 	if (system_labeled) {
318 		nt = di_minor_nodetype(minor);
319 		if ((nt != NULL) &&
320 		    ((strcmp(nt, DDI_NT_CD) == 0) ||
321 		    (strcmp(nt, DDI_NT_CD_CHAN) == 0) ||
322 		    (strcmp(nt, DDI_NT_BLOCK_CHAN) == 0))) {
323 			nflags = DA_ADD|DA_CD;
324 		}
325 	}
326 
327 	if (reserved_links_exist(node, minor, nflags) == DEVFSADM_SUCCESS) {
328 		devfsadm_print(disk_mid, "Reserved link exists. Not "
329 		    "creating links for slice %s\n", slice);
330 		return;
331 	}
332 
333 	if (NULL == (ctrl = diskctrl(node, minor)))
334 		return;
335 
336 	(void) strcpy(l_path, dir);
337 	(void) strcat(l_path, "/c");
338 	(void) strcat(l_path, ctrl);
339 	(void) strcat(l_path, disk);
340 
341 	/*
342 	 * If switching between SMI and EFI label or vice versa
343 	 * cleanup the previous label's devlinks.
344 	 */
345 	if (*mn == *(MN_SMI) || (strncmp(mn, MN_EFI, 2) == 0)) {
346 		char *s, tpath[PATH_MAX + 1];
347 		struct stat sb;
348 
349 		s = l_path + strlen(l_path);
350 		(void) strcat(l_path, (*mn == *(MN_SMI))
351 		    ? SLICE_EFI : SLICE_SMI);
352 		/*
353 		 * Attempt the remove only if the stale link exists
354 		 */
355 		(void) snprintf(tpath, sizeof (tpath), "%s/dev/%s",
356 		    devfsadm_root_path(), l_path);
357 		if (lstat(tpath, &sb) != -1)
358 			devfsadm_rm_all(l_path);
359 		*s = '\0';
360 	}
361 	(void) strcat(l_path, slice);
362 
363 	(void) devfsadm_mklink(l_path, node, minor, nflags);
364 
365 	/* secondary links for removable and hotpluggable devices */
366 	if (di_prop_lookup_ints(DDI_DEV_T_ANY, node, "removable-media",
367 	    &int_prop) >= 0) {
368 		(void) strcpy(sec_path, "removable-media/");
369 		(void) strcat(sec_path, l_path);
370 		(void) devfsadm_secondary_link(sec_path, l_path, 0);
371 	}
372 	if (di_prop_lookup_ints(DDI_DEV_T_ANY, node, "hotpluggable",
373 	    &int_prop) >= 0) {
374 		(void) strcpy(sec_path, "hotpluggable/");
375 		(void) strcat(sec_path, l_path);
376 		(void) devfsadm_secondary_link(sec_path, l_path, 0);
377 	}
378 
379 	if ((flags & RM_STALE) == RM_STALE) {
380 		(void) strcpy(stale_re, "^");
381 		(void) strcat(stale_re, dir);
382 		(void) strcat(stale_re, "/c");
383 		(void) strcat(stale_re, ctrl);
384 		(void) strcat(stale_re, "t[0-9A-F]+d[0-9]+(s[0-9]+)?$");
385 		/*
386 		 * optimizations are made inside of devfsadm_rm_stale_links
387 		 * instead of before calling the function, as it always
388 		 * needs to add the valid link to the cache.
389 		 */
390 		devfsadm_rm_stale_links(stale_re, l_path, node, minor);
391 	}
392 
393 	free(ctrl);
394 }
395 
396 
397 /* index of enumeration rule applicable to this module */
398 #define	RULE_INDEX	0
399 
400 static char *
401 diskctrl(di_node_t node, di_minor_t minor)
402 {
403 	char path[PATH_MAX + 1];
404 	char *devfspath;
405 	char *buf, *mn;
406 
407 	devfsadm_enumerate_t rules[3] = {
408 	    {"^r?dsk$/^c([0-9]+)", 1, MATCH_PARENT},
409 	    {"^cfg$/^c([0-9]+)$", 1, MATCH_ADDR},
410 	    {"^scsi$/^.+$/^c([0-9]+)", 1, MATCH_PARENT}
411 	};
412 
413 	mn = di_minor_name(minor);
414 
415 	if ((devfspath = di_devfs_path(node)) == NULL) {
416 		return (NULL);
417 	}
418 	(void) strcpy(path, devfspath);
419 	(void) strcat(path, ":");
420 	(void) strcat(path, mn);
421 	di_devfs_path_free(devfspath);
422 
423 	/*
424 	 * Use controller component of disk path
425 	 */
426 	if (disk_enumerate_int(path, RULE_INDEX, &buf, rules, 3) ==
427 	    DEVFSADM_MULTIPLE) {
428 
429 		/*
430 		 * We failed because there are multiple logical controller
431 		 * numbers for a single physical controller.  If we use node
432 		 * name also in the match it should fix this and only find one
433 		 * logical controller. (See 4045879).
434 		 * NOTE: Rules for controllers are not changed, as there is
435 		 * no unique controller number for them in this case.
436 		 *
437 		 * MATCH_UNCACHED flag is private to the "disks" and "sgen"
438 		 * modules. NOT to be used by other modules.
439 		 */
440 
441 		rules[0].flags = MATCH_NODE | MATCH_UNCACHED; /* disks */
442 		rules[2].flags = MATCH_NODE | MATCH_UNCACHED; /* generic scsi */
443 		if (devfsadm_enumerate_int(path, RULE_INDEX, &buf, rules, 3)) {
444 			return (NULL);
445 		}
446 	}
447 
448 	return (buf);
449 }
450 
451 typedef struct dvlist {
452 	char *dv_link;
453 	struct dvlist *dv_next;
454 } dvlist_t;
455 
456 static void
457 free_dvlist(dvlist_t **pp)
458 {
459 	dvlist_t *entry;
460 
461 	while (*pp) {
462 		entry = *pp;
463 		*pp = entry->dv_next;
464 		assert(entry->dv_link);
465 		free(entry->dv_link);
466 		free(entry);
467 	}
468 }
469 static int
470 dvlink_cb(di_devlink_t devlink, void *arg)
471 {
472 	char *path;
473 	char *can_path;
474 	dvlist_t **pp = (dvlist_t **)arg;
475 	dvlist_t *entry = NULL;
476 
477 	entry = calloc(1, sizeof (dvlist_t));
478 	if (entry == NULL) {
479 		devfsadm_errprint("%s: calloc failed\n", modname);
480 		goto error;
481 	}
482 
483 	path = (char *)di_devlink_path(devlink);
484 	assert(path);
485 	if (path == NULL) {
486 		devfsadm_errprint("%s: di_devlink_path() returned NULL\n",
487 		    modname);
488 		goto error;
489 	}
490 
491 	devfsadm_print(disk_mid, "%s: found link %s in reverse link cache\n",
492 	    modname, path);
493 
494 	/*
495 	 * Return linkname in canonical form i.e. without the
496 	 * "/dev/" prefix
497 	 */
498 	can_path = strstr(path, "/dev/");
499 	if (can_path == NULL) {
500 		devfsadm_errprint("%s: devlink path %s has no /dev/\n",
501 		    modname, path);
502 		goto error;
503 	}
504 
505 	entry->dv_link = s_strdup(can_path + strlen("/dev/"));
506 	entry->dv_next = *pp;
507 	*pp = entry;
508 
509 	return (DI_WALK_CONTINUE);
510 
511 error:
512 	free(entry);
513 	free_dvlist(pp);
514 	*pp = NULL;
515 	return (DI_WALK_TERMINATE);
516 }
517 
518 /*
519  * Returns success only if all goes well. If there is no matching reserved link
520  * or if there is an error, we assume no match. It is better to err on the side
521  * of caution by creating extra links than to miss out creating a required link.
522  */
523 static int
524 reserved_links_exist(di_node_t node, di_minor_t minor, int nflags)
525 {
526 	di_devlink_handle_t dvlink_cache = devfsadm_devlink_cache();
527 	char phys_path[PATH_MAX];
528 	char *minor_path;
529 	dvlist_t *head;
530 	dvlist_t *entry;
531 	char *s;
532 	char l[PATH_MAX];
533 	int switch_link = 0;
534 	char *mn = di_minor_name(minor);
535 
536 	if (dvlink_cache == NULL || mn == NULL) {
537 		devfsadm_errprint("%s: No minor or devlink cache\n", modname);
538 		return (DEVFSADM_FAILURE);
539 	}
540 
541 	if (!devfsadm_have_reserved()) {
542 		devfsadm_print(disk_mid, "%s: No reserved links\n", modname);
543 		return (DEVFSADM_FAILURE);
544 	}
545 
546 	minor_path = di_devfs_minor_path(minor);
547 	if (minor_path == NULL) {
548 		devfsadm_errprint("%s: di_devfs_minor_path failed\n", modname);
549 		return (DEVFSADM_FAILURE);
550 	}
551 
552 	(void) strlcpy(phys_path, minor_path, sizeof (phys_path));
553 
554 	di_devfs_path_free(minor_path);
555 
556 	head = NULL;
557 	(void) di_devlink_cache_walk(dvlink_cache, DISK_LINK_RE, phys_path,
558 	    DI_PRIMARY_LINK, &head, dvlink_cb);
559 
560 	/*
561 	 * We may be switching between EFI label and SMI label in which case
562 	 * we only have minors of the other type.
563 	 */
564 	if (head == NULL && (*mn == *(MN_SMI) ||
565 	    (strncmp(mn, MN_EFI, 2) == 0))) {
566 		devfsadm_print(disk_mid, "%s: No links for minor %s in /dev. "
567 		    "Trying another label\n", modname, mn);
568 		s = strrchr(phys_path, ':');
569 		if (s == NULL) {
570 			devfsadm_errprint("%s: invalid minor path: %s\n",
571 			    modname, phys_path);
572 			return (DEVFSADM_FAILURE);
573 		}
574 		(void) snprintf(s+1, sizeof (phys_path) - (s + 1 - phys_path),
575 		    "%s%s", *mn == *(MN_SMI) ? MN_EFI : MN_SMI,
576 		    strstr(s, ",raw") ? ",raw" : "");
577 		(void) di_devlink_cache_walk(dvlink_cache, DISK_LINK_RE,
578 		    phys_path, DI_PRIMARY_LINK, &head, dvlink_cb);
579 	}
580 
581 	if (head == NULL) {
582 		devfsadm_print(disk_mid, "%s: minor %s has no links in /dev\n",
583 		    modname, phys_path);
584 		/* no links on disk */
585 		return (DEVFSADM_FAILURE);
586 	}
587 
588 	/*
589 	 * It suffices to use 1 link to this minor, since
590 	 * we are matching with reserved IDs on the basis of
591 	 * the controller number which will be the same for
592 	 * all links to this minor.
593 	 */
594 	if (!devfsadm_is_reserved(disks_re_array, head->dv_link)) {
595 		/* not reserved links */
596 		devfsadm_print(disk_mid, "%s: devlink %s and its minor "
597 		    "are NOT reserved\n", modname, head->dv_link);
598 		free_dvlist(&head);
599 		return (DEVFSADM_FAILURE);
600 	}
601 
602 	devfsadm_print(disk_mid, "%s: devlink %s and its minor are on "
603 	    "reserved list\n", modname, head->dv_link);
604 
605 	/*
606 	 * Switch between SMI and EFI labels if required
607 	 */
608 	switch_link = 0;
609 	if (*mn == *(MN_SMI) || (strncmp(mn, MN_EFI, 2) == 0)) {
610 		for (entry = head; entry; entry = entry->dv_next) {
611 			s = strrchr(entry->dv_link, '/');
612 			assert(s);
613 			if (s == NULL) {
614 				devfsadm_errprint("%s: disk link %s has no "
615 				    "directory\n", modname, entry->dv_link);
616 				continue;
617 			}
618 			if (*mn == *(MN_SMI) && strchr(s, 's') == NULL) {
619 				(void) snprintf(l, sizeof (l), "%s%s",
620 				    entry->dv_link, SLICE_SMI);
621 				switch_link = 1;
622 				devfsadm_print(disk_mid, "%s: switching "
623 				    "reserved link from EFI to SMI label. "
624 				    "New link is %s\n", modname, l);
625 			} else if (strncmp(mn, MN_EFI, 2) == 0 &&
626 			    (s = strchr(s, 's'))) {
627 				*s = '\0';
628 				(void) snprintf(l, sizeof (l), "%s",
629 				    entry->dv_link);
630 				*s = 's';
631 				switch_link = 1;
632 				devfsadm_print(disk_mid, "%s: switching "
633 				    "reserved link from SMI to EFI label. "
634 				    "New link is %s\n", modname, l);
635 			}
636 			if (switch_link) {
637 				devfsadm_print(disk_mid, "%s: switching "
638 				    "link: deleting %s and creating %s\n",
639 				    modname, entry->dv_link, l);
640 				devfsadm_rm_link(entry->dv_link);
641 				(void) devfsadm_mklink(l, node, minor, nflags);
642 			}
643 		}
644 	}
645 	free_dvlist(&head);
646 
647 	/*
648 	 * return SUCCESS to indicate that new links to this minor should not
649 	 * be created so that only compatibility links to this minor remain.
650 	 */
651 	return (DEVFSADM_SUCCESS);
652 }
653