xref: /illumos-gate/usr/src/cmd/devfsadm/disk_link.c (revision ff260c5b4bfdf290e38c0323160d5ec9d778a001)
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 /*
23  * Copyright 2016 Toomas Soome <tsoome@me.com>
24  * Copyright 2022 Tintri by DDN, Inc. All rights reserved.
25  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
26  * Use is subject to license terms.
27  *
28  * Copyright 2026 Oxide Computer Company
29  */
30 
31 #include <devfsadm.h>
32 #include <stdio.h>
33 #include <strings.h>
34 #include <stdlib.h>
35 #include <limits.h>
36 #include <ctype.h>
37 #include <unistd.h>
38 #include <sys/int_fmtio.h>
39 #include <sys/stat.h>
40 #include <bsm/devalloc.h>
41 #include <sys/scsi/scsi_address.h>
42 #include <sys/libdevid.h>
43 #include <sys/lofi.h>
44 
45 #define	DISK_SUBPATH_MAX 100
46 #define	RM_STALE 0x01
47 #define	DISK_LINK_RE	"^r?dsk/c[0-9]+(t[0-9A-F]+)?d[0-9]+(((s|p))[0-9]+)?$"
48 #define	DISK_LINK_TO_UPPER(ch)\
49 	(((ch) >= 'a' && (ch) <= 'z') ? (ch - 'a' + 'A') : ch)
50 
51 #define	SLICE_SMI	"s7"
52 #define	SLICE_EFI	""
53 
54 #define	MN_SMI		"h"
55 #define	MN_EFI		"wd"
56 #define	ASCIIWWNSIZE	255
57 #if defined(__i386) || defined(__amd64)
58 /*
59  * The number of minor nodes per LUN is defined by the disk drivers.
60  * Currently it is set to 64. Refer CMLBUNIT_SHIFT (cmlb_impl.h)
61  */
62 #define	NUM_MINORS_PER_INSTANCE	64
63 #endif
64 
65 
66 extern int system_labeled;
67 
68 static int disk_callback_chan(di_minor_t minor, di_node_t node);
69 static int disk_callback_nchan(di_minor_t minor, di_node_t node);
70 static int disk_callback_blkdev(di_minor_t minor, di_node_t node);
71 static int disk_callback_wwn(di_minor_t minor, di_node_t node);
72 static int disk_callback_xvmd(di_minor_t minor, di_node_t node);
73 static int disk_callback_fabric(di_minor_t minor, di_node_t node);
74 static int disk_callback_sas(di_minor_t minor, di_node_t node);
75 static void disk_common(di_minor_t minor, di_node_t node, char *disk,
76 				int flags);
77 static char *diskctrl(di_node_t node, di_minor_t minor);
78 static int reserved_links_exist(di_node_t node, di_minor_t minor, int nflags);
79 static void disk_rm_lofi_all(char *file);
80 
81 
82 static devfsadm_create_t disk_cbt[] = {
83 	{ "disk", DDI_NT_BLOCK, NULL,
84 	    TYPE_EXACT, ILEVEL_0, disk_callback_nchan
85 	},
86 	{ "disk", DDI_NT_BLOCK_CHAN, NULL,
87 	    TYPE_EXACT, ILEVEL_0, disk_callback_chan
88 	},
89 	{ "disk", DDI_NT_BLOCK_BLKDEV, NULL,
90 	    TYPE_EXACT, ILEVEL_0, disk_callback_blkdev
91 	},
92 	{ "disk", DDI_NT_BLOCK_FABRIC, NULL,
93 		TYPE_EXACT, ILEVEL_0, disk_callback_fabric
94 	},
95 	{ "disk", DDI_NT_BLOCK_WWN, NULL,
96 	    TYPE_EXACT, ILEVEL_0, disk_callback_wwn
97 	},
98 	{ "disk", DDI_NT_BLOCK_SAS, NULL,
99 	    TYPE_EXACT, ILEVEL_0, disk_callback_sas
100 	},
101 	{ "disk", DDI_NT_CD, NULL,
102 	    TYPE_EXACT, ILEVEL_0, disk_callback_nchan
103 	},
104 	{ "disk", DDI_NT_CD_CHAN, NULL,
105 	    TYPE_EXACT, ILEVEL_0, disk_callback_chan
106 	},
107 	{ "disk", DDI_NT_BLOCK_XVMD, NULL,
108 	    TYPE_EXACT, ILEVEL_0, disk_callback_xvmd
109 	},
110 	{ "disk", DDI_NT_CD_XVMD, NULL,
111 	    TYPE_EXACT, ILEVEL_0, disk_callback_xvmd
112 	},
113 };
114 
115 DEVFSADM_CREATE_INIT_V0(disk_cbt);
116 
117 /*
118  * HOT auto cleanup of disks is done for lofi devices only.
119  */
120 static devfsadm_remove_t disk_remove_cbt[] = {
121 	{ "disk", DISK_LINK_RE, RM_HOT | RM_POST | RM_ALWAYS,
122 		ILEVEL_0, disk_rm_lofi_all
123 	},
124 	{ "disk", DISK_LINK_RE, RM_POST,
125 		ILEVEL_0, devfsadm_rm_all
126 	}
127 };
128 
129 DEVFSADM_REMOVE_INIT_V0(disk_remove_cbt);
130 
131 static devlink_re_t disks_re_array[] = {
132 	{"^r?dsk/c([0-9]+)", 1},
133 	{"^cfg/c([0-9]+)$", 1},
134 	{"^scsi/.+/c([0-9]+)", 1},
135 	{NULL}
136 };
137 
138 static char *disk_mid = "disk_mid";
139 static char *modname = "disk_link";
140 
141 /*
142  * Check if link is from lofi by checking path from readlink().
143  */
144 static int
145 is_lofi_disk(char *file)
146 {
147 	char buf[PATH_MAX + 1];
148 	char filepath[PATH_MAX];
149 	char *ptr;
150 	ssize_t size;
151 
152 	size = snprintf(filepath, sizeof (filepath), "%s/dev/%s",
153 	    devfsadm_root_path(), file);
154 	if (size > sizeof (filepath))
155 		return (0);
156 
157 	size = readlink(filepath, buf, sizeof (buf) - 1);
158 	if (size == -1)
159 		return (0);
160 	buf[size] = '\0';
161 	ptr = strchr(buf, '@');
162 	if (ptr == NULL)
163 		return (0);
164 	ptr[1] = '\0';
165 	if (strcmp(buf, "../../devices/pseudo/lofi@") != 0)
166 		return (0);
167 	return (1);
168 }
169 
170 /*
171  * Wrapper around devfsadm_rm_link() for lofi devices.
172  */
173 static void disk_rm_lofi_all(char *file)
174 {
175 	if (is_lofi_disk(file))
176 		devfsadm_rm_link(file);
177 }
178 
179 int
180 minor_init()
181 {
182 	devfsadm_print(disk_mid,
183 	    "%s: minor_init(): Creating disks reserved ID cache\n",
184 	    modname);
185 	return (devfsadm_reserve_id_cache(disks_re_array, NULL));
186 }
187 
188 static int
189 disk_callback_chan(di_minor_t minor, di_node_t node)
190 {
191 	char *addr;
192 	char disk[23];
193 	char *driver;
194 	uint_t targ = 0;
195 	uint_t lun = 0;
196 
197 	driver = di_driver_name(node);
198 	if (strcmp(driver, LOFI_DRIVER_NAME) != 0) {
199 		addr = di_bus_addr(node);
200 		(void) sscanf(addr, "%X,%X", &targ, &lun);
201 	} else {
202 		targ = di_instance(node);
203 	}
204 
205 	(void) snprintf(disk, sizeof (disk), "t%dd%d", targ, lun);
206 	disk_common(minor, node, disk, 0);
207 	return (DEVFSADM_CONTINUE);
208 
209 }
210 
211 static int
212 disk_callback_nchan(di_minor_t minor, di_node_t node)
213 {
214 	char *addr;
215 	char disk[10];
216 	uint_t lun;
217 
218 	addr = di_bus_addr(node);
219 	(void) sscanf(addr, "%X", &lun);
220 	(void) sprintf(disk, "d%d", lun);
221 	disk_common(minor, node, disk, 0);
222 	return (DEVFSADM_CONTINUE);
223 
224 }
225 
226 static int
227 disk_callback_blkdev(di_minor_t minor, di_node_t node)
228 {
229 	char *addr;
230 	char disk[DISK_SUBPATH_MAX];
231 	char guid[50];
232 	uint_t lun = 0;
233 
234 	addr = di_bus_addr(node);
235 	(void) sscanf(addr, "w%49[0-9A-F],%X", &guid, &lun);
236 	(void) snprintf(disk, DISK_SUBPATH_MAX, "t%sd%d", guid, lun);
237 	disk_common(minor, node, disk, RM_STALE);
238 	return (DEVFSADM_CONTINUE);
239 }
240 
241 static int
242 disk_callback_wwn(di_minor_t minor, di_node_t node)
243 {
244 	char disk[10];
245 	int lun;
246 	int targ;
247 	int *intp;
248 
249 	if (di_prop_lookup_ints(DDI_DEV_T_ANY, node, SCSI_ADDR_PROP_TARGET,
250 	    &intp) <= 0) {
251 		return (DEVFSADM_CONTINUE);
252 	}
253 	targ = *intp;
254 	if (di_prop_lookup_ints(DDI_DEV_T_ANY, node, SCSI_ADDR_PROP_LUN,
255 	    &intp) <= 0) {
256 		lun = 0;
257 	} else {
258 		lun = *intp;
259 	}
260 	(void) sprintf(disk, "t%dd%d", targ, lun);
261 
262 	disk_common(minor, node, disk, RM_STALE);
263 
264 	return (DEVFSADM_CONTINUE);
265 }
266 
267 static int
268 disk_callback_fabric(di_minor_t minor, di_node_t node)
269 {
270 	char disk[DISK_SUBPATH_MAX];
271 	int lun;
272 	int count;
273 	int *intp;
274 	uchar_t *str;
275 	uchar_t *wwn;
276 	uchar_t ascii_wwn[ASCIIWWNSIZE];
277 
278 	if (di_prop_lookup_strings(DDI_DEV_T_ANY, node,
279 	    "client-guid", (char **)&wwn) > 0) {
280 		if (strlcpy((char *)ascii_wwn, (char *)wwn,
281 		    sizeof (ascii_wwn)) >= sizeof (ascii_wwn)) {
282 			devfsadm_errprint("SUNW_disk_link: GUID too long:%d",
283 			    strlen((char *)wwn));
284 			return (DEVFSADM_CONTINUE);
285 		}
286 		lun = 0;
287 	} else if (di_prop_lookup_bytes(DDI_DEV_T_ANY, node,
288 	    "port-wwn", &wwn) > 0) {
289 		if (di_prop_lookup_ints(DDI_DEV_T_ANY, node,
290 		    SCSI_ADDR_PROP_LUN, &intp) > 0) {
291 			lun = *intp;
292 		} else {
293 			lun = 0;
294 		}
295 
296 		for (count = 0, str = ascii_wwn; count < 8; count++, str += 2) {
297 			(void) sprintf((caddr_t)str, "%02x", wwn[count]);
298 		}
299 		*str = '\0';
300 	} else {
301 		return (DEVFSADM_CONTINUE);
302 	}
303 
304 	for (str = ascii_wwn; *str != '\0'; str++) {
305 		*str = DISK_LINK_TO_UPPER(*str);
306 	}
307 
308 	(void) snprintf(disk, DISK_SUBPATH_MAX, "t%sd%d", ascii_wwn, lun);
309 
310 	disk_common(minor, node, disk, RM_STALE);
311 
312 	return (DEVFSADM_CONTINUE);
313 }
314 
315 static int
316 disk_callback_sas(di_minor_t minor, di_node_t node)
317 {
318 	char disk[DISK_SUBPATH_MAX];
319 	boolean_t lun64_found = B_FALSE;
320 	scsi_lun64_t lun64, sl;
321 	scsi_lun_t lun;
322 	int64_t *lun64p;
323 	uint64_t wwn;
324 	int *intp;
325 	char *tgt_port;
326 	uchar_t addr_method;
327 
328 	/* Get lun property */
329 	if (di_prop_lookup_int64(DDI_DEV_T_ANY, node,
330 	    SCSI_ADDR_PROP_LUN64, &lun64p) > 0) {
331 		if (*lun64p != SCSI_LUN64_ILLEGAL) {
332 			lun64_found = B_TRUE;
333 			lun64 = (uint64_t)*lun64p;
334 		}
335 	}
336 	if (!lun64_found && di_prop_lookup_ints(DDI_DEV_T_ANY, node,
337 	    SCSI_ADDR_PROP_LUN, &intp) > 0) {
338 		lun64_found = B_TRUE;
339 		lun64 = (uint64_t)*intp;
340 	}
341 
342 	if (!lun64_found)
343 		return (DEVFSADM_CONTINUE);
344 
345 	lun = scsi_lun64_to_lun(lun64);
346 
347 	addr_method = (lun.sl_lun1_msb & SCSI_LUN_AM_MASK);
348 
349 	if (di_prop_lookup_strings(DDI_DEV_T_ANY, node,
350 	    SCSI_ADDR_PROP_TARGET_PORT, &tgt_port) > 0) {
351 		(void) scsi_wwnstr_to_wwn(tgt_port, &wwn);
352 		if ((addr_method == SCSI_LUN_AM_PDEV) &&
353 		    (lun.sl_lun2_msb == 0) && (lun.sl_lun2_lsb == 0) &&
354 		    (lun.sl_lun3_msb == 0) && (lun.sl_lun3_lsb == 0) &&
355 		    (lun.sl_lun4_msb == 0) && (lun.sl_lun4_lsb == 0)) {
356 			(void) snprintf(disk, DISK_SUBPATH_MAX,
357 			    "t%"PRIX64"d%"PRId64, wwn, lun64);
358 		} else if ((addr_method == SCSI_LUN_AM_FLAT) &&
359 		    (lun.sl_lun2_msb == 0) && (lun.sl_lun2_lsb == 0) &&
360 		    (lun.sl_lun3_msb == 0) && (lun.sl_lun3_lsb == 0) &&
361 		    (lun.sl_lun4_msb == 0) && (lun.sl_lun4_lsb == 0)) {
362 			sl = (lun.sl_lun1_msb << 8) | lun.sl_lun1_lsb;
363 			(void) snprintf(disk, DISK_SUBPATH_MAX,
364 			    "t%"PRIX64"d%"PRIX16, wwn, sl);
365 		} else {
366 			(void) snprintf(disk, DISK_SUBPATH_MAX,
367 			    "t%"PRIX64"d%"PRIX64, wwn, lun64);
368 		}
369 	} else if (di_prop_lookup_ints(DDI_DEV_T_ANY, node,
370 	    SCSI_ADDR_PROP_SATA_PHY, &intp) > 0) {
371 		/* Use phy format naming, for SATA devices without wwn */
372 		if ((addr_method == SCSI_LUN_AM_PDEV) &&
373 		    (lun.sl_lun2_msb == 0) && (lun.sl_lun2_lsb == 0) &&
374 		    (lun.sl_lun3_msb == 0) && (lun.sl_lun3_lsb == 0) &&
375 		    (lun.sl_lun4_msb == 0) && (lun.sl_lun4_lsb == 0)) {
376 			(void) snprintf(disk, DISK_SUBPATH_MAX,
377 			    "t%dd%"PRId64, *intp, lun64);
378 		} else if ((addr_method == SCSI_LUN_AM_FLAT) &&
379 		    (lun.sl_lun2_msb == 0) && (lun.sl_lun2_lsb == 0) &&
380 		    (lun.sl_lun3_msb == 0) && (lun.sl_lun3_lsb == 0) &&
381 		    (lun.sl_lun4_msb == 0) && (lun.sl_lun4_lsb == 0)) {
382 			sl = (lun.sl_lun1_msb << 8) | lun.sl_lun1_lsb;
383 			(void) snprintf(disk, DISK_SUBPATH_MAX,
384 			    "t%dd%"PRIX16, *intp, sl);
385 		} else {
386 			(void) snprintf(disk, DISK_SUBPATH_MAX,
387 			    "t%dd%"PRIX64, *intp, lun64);
388 		}
389 	} else {
390 		return (DEVFSADM_CONTINUE);
391 	}
392 
393 	disk_common(minor, node, disk, RM_STALE);
394 
395 	return (DEVFSADM_CONTINUE);
396 }
397 
398 /*
399  * xVM virtual block device
400  *
401  * Xen passes device number in the following format:
402  *
403  *    1 << 28 | disk << 8 | partition      xvd, disks or partitions 16 onwards
404  *  202 <<  8 | disk << 4 | partition      xvd, disks and partitions up to 15
405  *    8 <<  8 | disk << 4 | partition      sd, disks and partitions up to 15
406  *    3 <<  8 | disk << 6 | partition      hd, disks 0..1, partitions 0..63
407  *   22 <<  8 | (disk-2) << 6 | partition  hd, disks 2..3, partitions 0..63
408  *    2 << 28 onwards                      reserved for future use
409  *   other values less than 1 << 28        deprecated / reserved
410  *
411  * The corresponding /dev/dsk name can be:
412  *
413  *          c0tYdX
414  *
415  * where Y,X >= 0.
416  *
417  * For PV guests using the legacy naming (0, 1, 2, ...)
418  * the disk names created will be c0d[0..767].
419  */
420 
421 #define	HD_BASE		(3 << 8)
422 #define	XEN_EXT_SHIFT	(28)
423 
424 /*
425  * Return: Number of parsed and written parameters
426  */
427 static int
428 decode_xen_device(uint_t device, uint_t *disk, uint_t *plun)
429 {
430 	uint_t dsk, lun = 0;
431 	int ret = 1;
432 
433 	if ((device >> XEN_EXT_SHIFT) > 1)
434 		return (0);
435 
436 	if (device < HD_BASE) {
437 		/* legacy device address */
438 		dsk = device;
439 		goto end;
440 	}
441 
442 	ret = 2;
443 	if (device & (1 << XEN_EXT_SHIFT)) {
444 		/* extended */
445 		dsk = device & (~0xff);
446 		lun = device & 0xff;
447 		goto end;
448 	}
449 
450 	switch (device >> 8) {
451 	case 202:				/* xvd */
452 		dsk = (device >> 4) & 0xf;
453 		lun =  device & 0xf;
454 		break;
455 	case 8:					/* sd */
456 		dsk = device & (~0xf);
457 		lun = device & 0xf;
458 		break;
459 	case 3:					/* hd, disk 0..1 */
460 		dsk = (device >> 6) & 0x1;
461 		lun = device & 0x3f;
462 		break;
463 	case 22:				/* hd, disk 2..3 */
464 		dsk = ((device >> 6) & 0x1) + 2;
465 		lun = device & 0x3f;
466 		break;
467 	default:
468 		return (0);
469 	}
470 end:
471 	*disk = dsk;
472 	*plun = lun;
473 	return (ret);
474 }
475 
476 static int
477 disk_callback_xvmd(di_minor_t minor, di_node_t node)
478 {
479 	char *addr;
480 	char disk[16];
481 	uint_t targ;
482 	uint_t dsk, lun;
483 	int res;
484 
485 	addr = di_bus_addr(node);
486 	targ = strtol(addr, (char **)NULL, 10);
487 
488 	res = decode_xen_device(targ, &dsk, &lun);
489 
490 	/* HVM device names are generated using the standard generator */
491 
492 	if (res == 1)
493 		(void) snprintf(disk, sizeof (disk),  "d%d", dsk);
494 	else if (res == 2)
495 		(void) snprintf(disk, sizeof (disk), "t%dd%d", dsk, lun);
496 	else {
497 		devfsadm_errprint("%s: invalid disk device number (%s)\n",
498 		    modname, addr);
499 		return (DEVFSADM_CONTINUE);
500 	}
501 	disk_common(minor, node, disk, 0);
502 	return (DEVFSADM_CONTINUE);
503 }
504 
505 /*
506  * This function is called for every disk minor node.
507  * Calls enumerate to assign a logical controller number, and
508  * then devfsadm_mklink to make the link.
509  */
510 static void
511 disk_common(di_minor_t minor, di_node_t node, char *disk, int flags)
512 {
513 	char l_path[PATH_MAX + 1];
514 	char sec_path[PATH_MAX + 1];
515 	char stale_re[DISK_SUBPATH_MAX];
516 	char *dir;
517 	char slice[4];
518 	char *mn;
519 	char *ctrl;
520 	char *nt = NULL;
521 	int *int_prop;
522 	int  nflags = 0;
523 #if defined(__i386) || defined(__amd64)
524 	char mn_copy[4];
525 	char *part;
526 	int part_num;
527 #endif
528 
529 	mn = di_minor_name(minor);
530 	if (strstr(mn, ",raw")) {
531 		dir = "rdsk";
532 #if defined(__i386) || defined(__amd64)
533 		(void) strncpy(mn_copy, mn, 4);
534 		part = strtok(mn_copy, ",");
535 #endif
536 	} else {
537 		dir = "dsk";
538 #if defined(__i386) || defined(__amd64)
539 		part = mn;
540 #endif
541 	}
542 
543 #if defined(__i386) || defined(__amd64)
544 	/*
545 	 * The following is a table describing the allocation of
546 	 * minor numbers, minor names and /dev/dsk names for partitions
547 	 * and slices on x86 systems.
548 	 *
549 	 *	Minor Number	Minor Name	/dev/dsk name
550 	 *	---------------------------------------------
551 	 *	0 to 15		"a" to "p"	s0 to s15
552 	 *	16		"q"		p0
553 	 *	17 to 20	"r" to "u"	p1 to p4
554 	 *	21 to 52	"p5" to "p36"	p5 to p36
555 	 *
556 	 */
557 	part_num = atoi(part + 1);
558 
559 	if ((mn[0] == 'p') && (part_num >= 5)) {
560 		/* logical drive */
561 		(void) snprintf(slice, 4, "%s", part);
562 	} else {
563 #endif
564 	if (mn[0] < 'q') {
565 		(void) sprintf(slice, "s%d", mn[0] - 'a');
566 	} else if (strncmp(mn, MN_EFI, 2) != 0) {
567 		(void) sprintf(slice, "p%d", mn[0] - 'q');
568 	} else {
569 		/* For EFI label */
570 		(void) sprintf(slice, SLICE_EFI);
571 	}
572 #if defined(__i386) || defined(__amd64)
573 	}
574 #endif
575 
576 	nflags = 0;
577 	if (system_labeled) {
578 		nt = di_minor_nodetype(minor);
579 		if ((nt != NULL) &&
580 		    ((strcmp(nt, DDI_NT_CD) == 0) ||
581 		    (strcmp(nt, DDI_NT_CD_CHAN) == 0) ||
582 		    (strcmp(nt, DDI_NT_BLOCK_CHAN) == 0))) {
583 			nflags = DA_ADD|DA_CD;
584 		}
585 	}
586 
587 	if (reserved_links_exist(node, minor, nflags) == DEVFSADM_SUCCESS) {
588 		devfsadm_print(disk_mid, "Reserved link exists. Not "
589 		    "creating links for slice %s\n", slice);
590 		return;
591 	}
592 
593 	if (NULL == (ctrl = diskctrl(node, minor)))
594 		return;
595 
596 	(void) strcpy(l_path, dir);
597 	(void) strcat(l_path, "/c");
598 	(void) strcat(l_path, ctrl);
599 	(void) strcat(l_path, disk);
600 
601 	/*
602 	 * If switching between SMI and EFI label or vice versa
603 	 * cleanup the previous label's devlinks.
604 	 */
605 	if (*mn == *(MN_SMI) || (strncmp(mn, MN_EFI, 2) == 0)) {
606 		char *s, tpath[PATH_MAX + 1];
607 		struct stat sb;
608 
609 		s = l_path + strlen(l_path);
610 		(void) strcat(l_path, (*mn == *(MN_SMI))
611 		    ? SLICE_EFI : SLICE_SMI);
612 		/*
613 		 * Attempt the remove only if the stale link exists
614 		 */
615 		(void) snprintf(tpath, sizeof (tpath), "%s/dev/%s",
616 		    devfsadm_root_path(), l_path);
617 		if (lstat(tpath, &sb) != -1)
618 			devfsadm_rm_all(l_path);
619 		*s = '\0';
620 	}
621 	(void) strcat(l_path, slice);
622 
623 	(void) devfsadm_mklink(l_path, node, minor, nflags);
624 
625 	/* secondary links for removable and hotpluggable devices */
626 	if (di_prop_lookup_ints(DDI_DEV_T_ANY, node, "removable-media",
627 	    &int_prop) >= 0) {
628 		(void) strcpy(sec_path, "removable-media/");
629 		(void) strcat(sec_path, l_path);
630 		(void) devfsadm_secondary_link(sec_path, l_path, 0);
631 	}
632 	if (di_prop_lookup_ints(DDI_DEV_T_ANY, node, "hotpluggable",
633 	    &int_prop) >= 0) {
634 		(void) strcpy(sec_path, "hotpluggable/");
635 		(void) strcat(sec_path, l_path);
636 		(void) devfsadm_secondary_link(sec_path, l_path, 0);
637 	}
638 
639 	if ((flags & RM_STALE) == RM_STALE) {
640 		(void) strcpy(stale_re, "^");
641 		(void) strcat(stale_re, dir);
642 		(void) strcat(stale_re, "/c");
643 		(void) strcat(stale_re, ctrl);
644 		(void) strcat(stale_re, "t[0-9A-F]+d[0-9]+(s[0-9]+)?$");
645 		/*
646 		 * optimizations are made inside of devfsadm_rm_stale_links
647 		 * instead of before calling the function, as it always
648 		 * needs to add the valid link to the cache.
649 		 */
650 		devfsadm_rm_stale_links(stale_re, l_path, node, minor);
651 	}
652 
653 	free(ctrl);
654 }
655 
656 
657 /* index of enumeration rule applicable to this module */
658 #define	RULE_INDEX	0
659 
660 static char *
661 diskctrl(di_node_t node, di_minor_t minor)
662 {
663 	char path[PATH_MAX + 1];
664 	char *devfspath;
665 	char *buf, *mn;
666 	boolean_t is_vhci;
667 
668 	devfsadm_enumerate_t rules[3] = {
669 	    {"^r?dsk$/^c([0-9]+)", 1, MATCH_PARENT},
670 	    {"^cfg$/^c([0-9]+)$", 1, MATCH_ADDR},
671 	    {"^scsi$/^.+$/^c([0-9]+)", 1, MATCH_PARENT}
672 	};
673 
674 	mn = di_minor_name(minor);
675 
676 	if ((devfspath = di_devfs_path(node)) == NULL) {
677 		return (NULL);
678 	}
679 	(void) strcpy(path, devfspath);
680 	(void) strcat(path, ":");
681 	(void) strcat(path, mn);
682 	di_devfs_path_free(devfspath);
683 
684 	/*
685 	 * Use controller component of disk path
686 	 */
687 	is_vhci = (strncmp(path, "/scsi_vhci/", 11) == 0);
688 
689 	if (ctrl_enumerate_int(path, RULE_INDEX, &buf, rules, 3, 1, is_vhci) ==
690 	    DEVFSADM_MULTIPLE) {
691 		/*
692 		 * We failed because there are multiple logical controller
693 		 * numbers for a single physical controller.  If we use node
694 		 * name also in the match it should fix this and only find one
695 		 * logical controller. (See 4045879).
696 		 * NOTE: Rules for controllers are not changed, as there is
697 		 * no unique controller number for them in this case.
698 		 *
699 		 * MATCH_UNCACHED flag is private to the "disks" and "sgen"
700 		 * modules. NOT to be used by other modules.
701 		 */
702 
703 		rules[0].flags = MATCH_NODE | MATCH_UNCACHED; /* disks */
704 		rules[2].flags = MATCH_NODE | MATCH_UNCACHED; /* generic scsi */
705 		if (ctrl_enumerate_int(path, RULE_INDEX, &buf, rules, 3, 0,
706 		    is_vhci)) {
707 			return (NULL);
708 		}
709 	}
710 
711 	return (buf);
712 }
713 
714 typedef struct dvlist {
715 	char *dv_link;
716 	struct dvlist *dv_next;
717 } dvlist_t;
718 
719 static void
720 free_dvlist(dvlist_t **pp)
721 {
722 	dvlist_t *entry;
723 
724 	while (*pp) {
725 		entry = *pp;
726 		*pp = entry->dv_next;
727 		assert(entry->dv_link);
728 		free(entry->dv_link);
729 		free(entry);
730 	}
731 }
732 static int
733 dvlink_cb(di_devlink_t devlink, void *arg)
734 {
735 	char *path;
736 	char *can_path;
737 	dvlist_t **pp = (dvlist_t **)arg;
738 	dvlist_t *entry = NULL;
739 
740 	entry = calloc(1, sizeof (dvlist_t));
741 	if (entry == NULL) {
742 		devfsadm_errprint("%s: calloc failed\n", modname);
743 		goto error;
744 	}
745 
746 	path = (char *)di_devlink_path(devlink);
747 	assert(path);
748 	if (path == NULL) {
749 		devfsadm_errprint("%s: di_devlink_path() returned NULL\n",
750 		    modname);
751 		goto error;
752 	}
753 
754 	devfsadm_print(disk_mid, "%s: found link %s in reverse link cache\n",
755 	    modname, path);
756 
757 	/*
758 	 * Return linkname in canonical form i.e. without the
759 	 * "/dev/" prefix
760 	 */
761 	can_path = strstr(path, "/dev/");
762 	if (can_path == NULL) {
763 		devfsadm_errprint("%s: devlink path %s has no /dev/\n",
764 		    modname, path);
765 		goto error;
766 	}
767 
768 	entry->dv_link = s_strdup(can_path + strlen("/dev/"));
769 	entry->dv_next = *pp;
770 	*pp = entry;
771 
772 	return (DI_WALK_CONTINUE);
773 
774 error:
775 	free(entry);
776 	free_dvlist(pp);
777 	*pp = NULL;
778 	return (DI_WALK_TERMINATE);
779 }
780 
781 /*
782  * Returns success only if all goes well. If there is no matching reserved link
783  * or if there is an error, we assume no match. It is better to err on the side
784  * of caution by creating extra links than to miss out creating a required link.
785  */
786 static int
787 reserved_links_exist(di_node_t node, di_minor_t minor, int nflags)
788 {
789 	di_devlink_handle_t dvlink_cache = devfsadm_devlink_cache();
790 	char phys_path[PATH_MAX];
791 	char *minor_path;
792 	dvlist_t *head;
793 	dvlist_t *entry;
794 	char *s;
795 	char l[PATH_MAX];
796 	int switch_link = 0;
797 	char *mn = di_minor_name(minor);
798 
799 	if (dvlink_cache == NULL || mn == NULL) {
800 		devfsadm_errprint("%s: No minor or devlink cache\n", modname);
801 		return (DEVFSADM_FAILURE);
802 	}
803 
804 	if (!devfsadm_have_reserved()) {
805 		devfsadm_print(disk_mid, "%s: No reserved links\n", modname);
806 		return (DEVFSADM_FAILURE);
807 	}
808 
809 	minor_path = di_devfs_minor_path(minor);
810 	if (minor_path == NULL) {
811 		devfsadm_errprint("%s: di_devfs_minor_path failed\n", modname);
812 		return (DEVFSADM_FAILURE);
813 	}
814 
815 	(void) strlcpy(phys_path, minor_path, sizeof (phys_path));
816 
817 	di_devfs_path_free(minor_path);
818 
819 	head = NULL;
820 	(void) di_devlink_cache_walk(dvlink_cache, DISK_LINK_RE, phys_path,
821 	    DI_PRIMARY_LINK, &head, dvlink_cb);
822 
823 	/*
824 	 * We may be switching between EFI label and SMI label in which case
825 	 * we only have minors of the other type.
826 	 */
827 	if (head == NULL && (*mn == *(MN_SMI) ||
828 	    (strncmp(mn, MN_EFI, 2) == 0))) {
829 		devfsadm_print(disk_mid, "%s: No links for minor %s in /dev. "
830 		    "Trying another label\n", modname, mn);
831 		s = strrchr(phys_path, ':');
832 		if (s == NULL) {
833 			devfsadm_errprint("%s: invalid minor path: %s\n",
834 			    modname, phys_path);
835 			return (DEVFSADM_FAILURE);
836 		}
837 		(void) snprintf(s+1, sizeof (phys_path) - (s + 1 - phys_path),
838 		    "%s%s", *mn == *(MN_SMI) ? MN_EFI : MN_SMI,
839 		    strstr(s, ",raw") ? ",raw" : "");
840 		(void) di_devlink_cache_walk(dvlink_cache, DISK_LINK_RE,
841 		    phys_path, DI_PRIMARY_LINK, &head, dvlink_cb);
842 	}
843 
844 	if (head == NULL) {
845 		devfsadm_print(disk_mid, "%s: minor %s has no links in /dev\n",
846 		    modname, phys_path);
847 		/* no links on disk */
848 		return (DEVFSADM_FAILURE);
849 	}
850 
851 	/*
852 	 * It suffices to use 1 link to this minor, since
853 	 * we are matching with reserved IDs on the basis of
854 	 * the controller number which will be the same for
855 	 * all links to this minor.
856 	 */
857 	if (!devfsadm_is_reserved(disks_re_array, head->dv_link)) {
858 		/* not reserved links */
859 		devfsadm_print(disk_mid, "%s: devlink %s and its minor "
860 		    "are NOT reserved\n", modname, head->dv_link);
861 		free_dvlist(&head);
862 		return (DEVFSADM_FAILURE);
863 	}
864 
865 	devfsadm_print(disk_mid, "%s: devlink %s and its minor are on "
866 	    "reserved list\n", modname, head->dv_link);
867 
868 	/*
869 	 * Switch between SMI and EFI labels if required
870 	 */
871 	switch_link = 0;
872 	if (*mn == *(MN_SMI) || (strncmp(mn, MN_EFI, 2) == 0)) {
873 		for (entry = head; entry; entry = entry->dv_next) {
874 			s = strrchr(entry->dv_link, '/');
875 			assert(s);
876 			if (s == NULL) {
877 				devfsadm_errprint("%s: disk link %s has no "
878 				    "directory\n", modname, entry->dv_link);
879 				continue;
880 			}
881 			if (*mn == *(MN_SMI) && strchr(s, 's') == NULL) {
882 				(void) snprintf(l, sizeof (l), "%s%s",
883 				    entry->dv_link, SLICE_SMI);
884 				switch_link = 1;
885 				devfsadm_print(disk_mid, "%s: switching "
886 				    "reserved link from EFI to SMI label. "
887 				    "New link is %s\n", modname, l);
888 			} else if (strncmp(mn, MN_EFI, 2) == 0 &&
889 			    (s = strchr(s, 's'))) {
890 				*s = '\0';
891 				(void) snprintf(l, sizeof (l), "%s",
892 				    entry->dv_link);
893 				*s = 's';
894 				switch_link = 1;
895 				devfsadm_print(disk_mid, "%s: switching "
896 				    "reserved link from SMI to EFI label. "
897 				    "New link is %s\n", modname, l);
898 			}
899 			if (switch_link) {
900 				devfsadm_print(disk_mid, "%s: switching "
901 				    "link: deleting %s and creating %s\n",
902 				    modname, entry->dv_link, l);
903 				devfsadm_rm_link(entry->dv_link);
904 				(void) devfsadm_mklink(l, node, minor, nflags);
905 			}
906 		}
907 	}
908 	free_dvlist(&head);
909 
910 	/*
911 	 * return SUCCESS to indicate that new links to this minor should not
912 	 * be created so that only compatibility links to this minor remain.
913 	 */
914 	return (DEVFSADM_SUCCESS);
915 }
916