xref: /illumos-gate/usr/src/uts/common/fs/zfs/vdev_disk.c (revision 8b26092d)
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 (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
23  * Copyright (c) 2012, 2018 by Delphix. All rights reserved.
24  * Copyright 2016 Nexenta Systems, Inc.  All rights reserved.
25  * Copyright 2020 Joyent, Inc.
26  * Copyright 2020 Joshua M. Clulow <josh@sysmgr.org>
27  * Copyright 2022 Tintri by DDN, Inc. All rights reserved.
28  */
29 
30 #include <sys/zfs_context.h>
31 #include <sys/spa_impl.h>
32 #include <sys/refcount.h>
33 #include <sys/vdev_impl.h>
34 #include <sys/vdev_trim.h>
35 #include <sys/abd.h>
36 #include <sys/fs/zfs.h>
37 #include <sys/zio.h>
38 #include <sys/sunldi.h>
39 #include <sys/efi_partition.h>
40 #include <sys/fm/fs/zfs.h>
41 #include <sys/ddi.h>
42 
43 /*
44  * Tunable to disable TRIM in case we're using a problematic SSD.
45  */
46 uint_t zfs_no_trim = 0;
47 
48 /*
49  * Tunable parameter for debugging or performance analysis. Setting this
50  * will cause pool corruption on power loss if a volatile out-of-order
51  * write cache is enabled.
52  */
53 boolean_t zfs_nocacheflush = B_FALSE;
54 
55 /*
56  * Virtual device vector for disks.
57  */
58 
59 extern ldi_ident_t zfs_li;
60 
61 static void vdev_disk_close(vdev_t *);
62 
63 typedef struct vdev_disk {
64 	ddi_devid_t	vd_devid;
65 	char		*vd_minor;
66 	ldi_handle_t	vd_lh;
67 	list_t		vd_ldi_cbs;
68 	boolean_t	vd_ldi_offline;
69 } vdev_disk_t;
70 
71 typedef struct vdev_disk_buf {
72 	buf_t	vdb_buf;
73 	zio_t	*vdb_io;
74 } vdev_disk_buf_t;
75 
76 typedef struct vdev_disk_ldi_cb {
77 	list_node_t		lcb_next;
78 	ldi_callback_id_t	lcb_id;
79 } vdev_disk_ldi_cb_t;
80 
81 /*
82  * Bypass the devid when opening a disk vdev.
83  * There have been issues where the devids of several devices were shuffled,
84  * causing pool open failures. Note, that this flag is intended to be used
85  * for pool recovery only.
86  *
87  * Note that if a pool is imported with the devids bypassed, all its vdevs will
88  * cease storing devid information permanently. In practice, the devid is rarely
89  * useful as vdev paths do not tend to change unless the hardware is
90  * reconfigured. That said, if the paths do change and a pool fails to open
91  * automatically at boot, a simple zpool import should re-scan the paths and fix
92  * the issue.
93  */
94 boolean_t vdev_disk_bypass_devid = B_FALSE;
95 
96 static void
vdev_disk_alloc(vdev_t * vd)97 vdev_disk_alloc(vdev_t *vd)
98 {
99 	vdev_disk_t *dvd;
100 
101 	dvd = vd->vdev_tsd = kmem_zalloc(sizeof (vdev_disk_t), KM_SLEEP);
102 	/*
103 	 * Create the LDI event callback list.
104 	 */
105 	list_create(&dvd->vd_ldi_cbs, sizeof (vdev_disk_ldi_cb_t),
106 	    offsetof(vdev_disk_ldi_cb_t, lcb_next));
107 }
108 
109 static void
vdev_disk_free(vdev_t * vd)110 vdev_disk_free(vdev_t *vd)
111 {
112 	vdev_disk_t *dvd = vd->vdev_tsd;
113 	vdev_disk_ldi_cb_t *lcb;
114 
115 	if (dvd == NULL)
116 		return;
117 
118 	/*
119 	 * We have already closed the LDI handle. Clean up the LDI event
120 	 * callbacks and free vd->vdev_tsd.
121 	 */
122 	while ((lcb = list_head(&dvd->vd_ldi_cbs)) != NULL) {
123 		list_remove(&dvd->vd_ldi_cbs, lcb);
124 		(void) ldi_ev_remove_callbacks(lcb->lcb_id);
125 		kmem_free(lcb, sizeof (vdev_disk_ldi_cb_t));
126 	}
127 	list_destroy(&dvd->vd_ldi_cbs);
128 	kmem_free(dvd, sizeof (vdev_disk_t));
129 	vd->vdev_tsd = NULL;
130 }
131 
132 static int
vdev_disk_off_notify(ldi_handle_t lh __unused,ldi_ev_cookie_t ecookie,void * arg,void * ev_data __unused)133 vdev_disk_off_notify(ldi_handle_t lh __unused, ldi_ev_cookie_t ecookie,
134     void *arg, void *ev_data __unused)
135 {
136 	vdev_t *vd = (vdev_t *)arg;
137 	vdev_disk_t *dvd = vd->vdev_tsd;
138 
139 	/*
140 	 * Ignore events other than offline.
141 	 */
142 	if (strcmp(ldi_ev_get_type(ecookie), LDI_EV_OFFLINE) != 0)
143 		return (LDI_EV_SUCCESS);
144 
145 	/*
146 	 * Tell any new threads that stumble upon this vdev that they should not
147 	 * try to do I/O.
148 	 */
149 	dvd->vd_ldi_offline = B_TRUE;
150 
151 	/*
152 	 * Request that the spa_async_thread mark the device as REMOVED and
153 	 * notify FMA of the removal.  This should also trigger a vdev_close()
154 	 * in the async thread.
155 	 */
156 	zfs_post_remove(vd->vdev_spa, vd);
157 	vd->vdev_remove_wanted = B_TRUE;
158 	spa_async_request(vd->vdev_spa, SPA_ASYNC_REMOVE);
159 
160 	return (LDI_EV_SUCCESS);
161 }
162 
163 static void
vdev_disk_off_finalize(ldi_handle_t lh __unused,ldi_ev_cookie_t ecookie,int ldi_result,void * arg,void * ev_data __unused)164 vdev_disk_off_finalize(ldi_handle_t lh __unused, ldi_ev_cookie_t ecookie,
165     int ldi_result, void *arg, void *ev_data __unused)
166 {
167 	vdev_t *vd = (vdev_t *)arg;
168 
169 	/*
170 	 * Ignore events other than offline.
171 	 */
172 	if (strcmp(ldi_ev_get_type(ecookie), LDI_EV_OFFLINE) != 0)
173 		return;
174 
175 	/*
176 	 * Request that the vdev be reopened if the offline state change was
177 	 * unsuccessful.
178 	 */
179 	if (ldi_result != LDI_EV_SUCCESS) {
180 		vd->vdev_probe_wanted = B_TRUE;
181 		spa_async_request(vd->vdev_spa, SPA_ASYNC_PROBE);
182 	}
183 }
184 
185 static ldi_ev_callback_t vdev_disk_off_callb = {
186 	.cb_vers = LDI_EV_CB_VERS,
187 	.cb_notify = vdev_disk_off_notify,
188 	.cb_finalize = vdev_disk_off_finalize
189 };
190 
191 static void
vdev_disk_dgrd_finalize(ldi_handle_t lh __unused,ldi_ev_cookie_t ecookie,int ldi_result,void * arg,void * ev_data __unused)192 vdev_disk_dgrd_finalize(ldi_handle_t lh __unused, ldi_ev_cookie_t ecookie,
193     int ldi_result, void *arg, void *ev_data __unused)
194 {
195 	vdev_t *vd = (vdev_t *)arg;
196 
197 	/*
198 	 * Ignore events other than degrade.
199 	 */
200 	if (strcmp(ldi_ev_get_type(ecookie), LDI_EV_DEGRADE) != 0)
201 		return;
202 
203 	/*
204 	 * Degrade events always succeed. Mark the vdev as degraded.
205 	 * This status is purely informative for the user.
206 	 */
207 	(void) vdev_degrade(vd->vdev_spa, vd->vdev_guid, 0);
208 }
209 
210 static ldi_ev_callback_t vdev_disk_dgrd_callb = {
211 	.cb_vers = LDI_EV_CB_VERS,
212 	.cb_notify = NULL,
213 	.cb_finalize = vdev_disk_dgrd_finalize
214 };
215 
216 static void
vdev_disk_hold(vdev_t * vd)217 vdev_disk_hold(vdev_t *vd)
218 {
219 	ddi_devid_t devid;
220 	char *minor;
221 
222 	ASSERT(spa_config_held(vd->vdev_spa, SCL_STATE, RW_WRITER));
223 
224 	/*
225 	 * We must have a pathname, and it must be absolute.
226 	 */
227 	if (vd->vdev_path == NULL || vd->vdev_path[0] != '/')
228 		return;
229 
230 	/*
231 	 * Only prefetch path and devid info if the device has
232 	 * never been opened.
233 	 */
234 	if (vd->vdev_tsd != NULL)
235 		return;
236 
237 	if (vd->vdev_wholedisk == -1ULL) {
238 		size_t len = strlen(vd->vdev_path) + 3;
239 		char *buf = kmem_alloc(len, KM_SLEEP);
240 
241 		(void) snprintf(buf, len, "%ss0", vd->vdev_path);
242 
243 		(void) ldi_vp_from_name(buf, &vd->vdev_name_vp);
244 		kmem_free(buf, len);
245 	}
246 
247 	if (vd->vdev_name_vp == NULL)
248 		(void) ldi_vp_from_name(vd->vdev_path, &vd->vdev_name_vp);
249 
250 	if (vd->vdev_devid != NULL &&
251 	    ddi_devid_str_decode(vd->vdev_devid, &devid, &minor) == 0) {
252 		(void) ldi_vp_from_devid(devid, minor, &vd->vdev_devid_vp);
253 		ddi_devid_str_free(minor);
254 		ddi_devid_free(devid);
255 	}
256 }
257 
258 static void
vdev_disk_rele(vdev_t * vd)259 vdev_disk_rele(vdev_t *vd)
260 {
261 	ASSERT(spa_config_held(vd->vdev_spa, SCL_STATE, RW_WRITER));
262 
263 	if (vd->vdev_name_vp) {
264 		VN_RELE_ASYNC(vd->vdev_name_vp,
265 		    dsl_pool_vnrele_taskq(vd->vdev_spa->spa_dsl_pool));
266 		vd->vdev_name_vp = NULL;
267 	}
268 	if (vd->vdev_devid_vp) {
269 		VN_RELE_ASYNC(vd->vdev_devid_vp,
270 		    dsl_pool_vnrele_taskq(vd->vdev_spa->spa_dsl_pool));
271 		vd->vdev_devid_vp = NULL;
272 	}
273 }
274 
275 /*
276  * We want to be loud in DEBUG kernels when DKIOCGMEDIAINFOEXT fails, or when
277  * even a fallback to DKIOCGMEDIAINFO fails.
278  */
279 #ifdef DEBUG
280 #define	VDEV_DEBUG(...)	cmn_err(CE_NOTE, __VA_ARGS__)
281 #else
282 #define	VDEV_DEBUG(...)	/* Nothing... */
283 #endif
284 
285 static int
vdev_disk_open(vdev_t * vd,uint64_t * psize,uint64_t * max_psize,uint64_t * ashift)286 vdev_disk_open(vdev_t *vd, uint64_t *psize, uint64_t *max_psize,
287     uint64_t *ashift)
288 {
289 	spa_t *spa = vd->vdev_spa;
290 	vdev_disk_t *dvd = vd->vdev_tsd;
291 	ldi_ev_cookie_t ecookie;
292 	vdev_disk_ldi_cb_t *lcb;
293 	union {
294 		struct dk_minfo_ext ude;
295 		struct dk_minfo ud;
296 	} dks;
297 	struct dk_minfo_ext *dkmext = &dks.ude;
298 	struct dk_minfo *dkm = &dks.ud;
299 	int error, can_free;
300 	dev_t dev;
301 	int otyp;
302 	boolean_t validate_devid = B_FALSE;
303 	uint64_t capacity = 0, blksz = 0, pbsize;
304 	const char *rdpath = vdev_disk_preroot_force_path();
305 
306 	/*
307 	 * We must have a pathname, and it must be absolute.
308 	 */
309 	if (vd->vdev_path == NULL || vd->vdev_path[0] != '/') {
310 		vd->vdev_stat.vs_aux = VDEV_AUX_BAD_LABEL;
311 		return (SET_ERROR(EINVAL));
312 	}
313 
314 	/*
315 	 * Reopen the device if it's not currently open. Otherwise,
316 	 * just update the physical size of the device.
317 	 */
318 	if (dvd != NULL) {
319 		ASSERT(vd->vdev_reopening);
320 		goto skip_open;
321 	}
322 
323 	/*
324 	 * Create vd->vdev_tsd.
325 	 */
326 	vdev_disk_alloc(vd);
327 	dvd = vd->vdev_tsd;
328 
329 	/*
330 	 * Allow bypassing the devid.
331 	 */
332 	if (vd->vdev_devid != NULL &&
333 	    (vdev_disk_bypass_devid || rdpath != NULL)) {
334 		vdev_dbgmsg(vd, "vdev_disk_open, devid %s bypassed",
335 		    vd->vdev_devid);
336 		spa_strfree(vd->vdev_devid);
337 		vd->vdev_devid = NULL;
338 	}
339 
340 	/*
341 	 * When opening a disk device, we want to preserve the user's original
342 	 * intent.  We always want to open the device by the path the user gave
343 	 * us, even if it is one of multiple paths to the same device.  But we
344 	 * also want to be able to survive disks being removed/recabled.
345 	 * Therefore the sequence of opening devices is:
346 	 *
347 	 * 1. Try opening the device by path.  For legacy pools without the
348 	 *    'whole_disk' property, attempt to fix the path by appending 's0'.
349 	 *
350 	 * 2. If the devid of the device matches the stored value, return
351 	 *    success.
352 	 *
353 	 * 3. Otherwise, the device may have moved.  Try opening the device
354 	 *    by the devid instead.
355 	 */
356 	if (vd->vdev_devid != NULL) {
357 		if (ddi_devid_str_decode(vd->vdev_devid, &dvd->vd_devid,
358 		    &dvd->vd_minor) != 0) {
359 			vdev_dbgmsg(vd,
360 			    "vdev_disk_open, invalid devid %s bypassed",
361 			    vd->vdev_devid);
362 			spa_strfree(vd->vdev_devid);
363 			vd->vdev_devid = NULL;
364 		}
365 	}
366 
367 	error = EINVAL;		/* presume failure */
368 
369 	if (rdpath != NULL) {
370 		/*
371 		 * We have been asked to open only a specific root device, and
372 		 * to fail otherwise.
373 		 */
374 		error = ldi_open_by_name((char *)rdpath, spa_mode(spa), kcred,
375 		    &dvd->vd_lh, zfs_li);
376 		validate_devid = B_TRUE;
377 		goto rootdisk_only;
378 	}
379 
380 	if (vd->vdev_path != NULL) {
381 		if (vd->vdev_wholedisk == -1ULL) {
382 			size_t len = strlen(vd->vdev_path) + 3;
383 			char *buf = kmem_alloc(len, KM_SLEEP);
384 
385 			(void) snprintf(buf, len, "%ss0", vd->vdev_path);
386 
387 			error = ldi_open_by_name(buf, spa_mode(spa), kcred,
388 			    &dvd->vd_lh, zfs_li);
389 			if (error == 0) {
390 				spa_strfree(vd->vdev_path);
391 				vd->vdev_path = buf;
392 				vd->vdev_wholedisk = 1ULL;
393 			} else {
394 				kmem_free(buf, len);
395 			}
396 		}
397 
398 		/*
399 		 * If we have not yet opened the device, try to open it by the
400 		 * specified path.
401 		 */
402 		if (error != 0) {
403 			error = ldi_open_by_name(vd->vdev_path, spa_mode(spa),
404 			    kcred, &dvd->vd_lh, zfs_li);
405 		}
406 
407 		/*
408 		 * Compare the devid to the stored value.
409 		 */
410 		if (error == 0 && vd->vdev_devid != NULL) {
411 			ddi_devid_t devid = NULL;
412 
413 			if (ldi_get_devid(dvd->vd_lh, &devid) != 0) {
414 				/*
415 				 * We expected a devid on this device but it no
416 				 * longer appears to have one.  The validation
417 				 * step may need to remove it from the
418 				 * configuration.
419 				 */
420 				validate_devid = B_TRUE;
421 
422 			} else if (ddi_devid_compare(devid, dvd->vd_devid) !=
423 			    0) {
424 				/*
425 				 * A mismatch here is unexpected, log it.
426 				 */
427 				char *devid_str = ddi_devid_str_encode(devid,
428 				    dvd->vd_minor);
429 				vdev_dbgmsg(vd, "vdev_disk_open: devid "
430 				    "mismatch: %s != %s", vd->vdev_devid,
431 				    devid_str);
432 				cmn_err(CE_NOTE, "vdev_disk_open %s: devid "
433 				    "mismatch: %s != %s", vd->vdev_path,
434 				    vd->vdev_devid, devid_str);
435 				ddi_devid_str_free(devid_str);
436 
437 				error = SET_ERROR(EINVAL);
438 				(void) ldi_close(dvd->vd_lh, spa_mode(spa),
439 				    kcred);
440 				dvd->vd_lh = NULL;
441 			}
442 
443 			if (devid != NULL) {
444 				ddi_devid_free(devid);
445 			}
446 		}
447 
448 		/*
449 		 * If we succeeded in opening the device, but 'vdev_wholedisk'
450 		 * is not yet set, then this must be a slice.
451 		 */
452 		if (error == 0 && vd->vdev_wholedisk == -1ULL)
453 			vd->vdev_wholedisk = 0;
454 	}
455 
456 	/*
457 	 * If we were unable to open by path, or the devid check fails, open by
458 	 * devid instead.
459 	 */
460 	if (error != 0 && vd->vdev_devid != NULL) {
461 		error = ldi_open_by_devid(dvd->vd_devid, dvd->vd_minor,
462 		    spa_mode(spa), kcred, &dvd->vd_lh, zfs_li);
463 		if (error != 0) {
464 			vdev_dbgmsg(vd, "Failed to open by devid (%s)",
465 			    vd->vdev_devid);
466 		}
467 	}
468 
469 	/*
470 	 * If all else fails, then try opening by physical path (if available)
471 	 * or the logical path (if we failed due to the devid check).  While not
472 	 * as reliable as the devid, this will give us something, and the higher
473 	 * level vdev validation will prevent us from opening the wrong device.
474 	 */
475 	if (error != 0) {
476 		validate_devid = B_TRUE;
477 
478 		if (vd->vdev_physpath != NULL &&
479 		    (dev = ddi_pathname_to_dev_t(vd->vdev_physpath)) != NODEV) {
480 			error = ldi_open_by_dev(&dev, OTYP_BLK, spa_mode(spa),
481 			    kcred, &dvd->vd_lh, zfs_li);
482 		}
483 
484 		/*
485 		 * Note that we don't support the legacy auto-wholedisk support
486 		 * as above.  This hasn't been used in a very long time and we
487 		 * don't need to propagate its oddities to this edge condition.
488 		 */
489 		if (error != 0 && vd->vdev_path != NULL) {
490 			error = ldi_open_by_name(vd->vdev_path, spa_mode(spa),
491 			    kcred, &dvd->vd_lh, zfs_li);
492 		}
493 	}
494 
495 	/*
496 	 * If this is early in boot, a sweep of available block devices may
497 	 * locate an alternative path that we can try.
498 	 */
499 	if (error != 0) {
500 		const char *altdevpath = vdev_disk_preroot_lookup(
501 		    spa_guid(spa), vd->vdev_guid);
502 
503 		if (altdevpath != NULL) {
504 			vdev_dbgmsg(vd, "Trying alternate preroot path (%s)",
505 			    altdevpath);
506 
507 			validate_devid = B_TRUE;
508 
509 			if ((error = ldi_open_by_name((char *)altdevpath,
510 			    spa_mode(spa), kcred, &dvd->vd_lh, zfs_li)) != 0) {
511 				vdev_dbgmsg(vd, "Failed to open by preroot "
512 				    "path (%s)", altdevpath);
513 			}
514 		}
515 	}
516 
517 rootdisk_only:
518 	if (error != 0) {
519 		vd->vdev_stat.vs_aux = VDEV_AUX_OPEN_FAILED;
520 		vdev_dbgmsg(vd, "vdev_disk_open: failed to open [error=%d]",
521 		    error);
522 		return (error);
523 	}
524 
525 	/*
526 	 * Now that the device has been successfully opened, update the devid
527 	 * if necessary.
528 	 */
529 	if (validate_devid) {
530 		ddi_devid_t devid = NULL;
531 		char *minorname = NULL;
532 		char *vd_devid = NULL;
533 		boolean_t remove = B_FALSE, update = B_FALSE;
534 
535 		/*
536 		 * Get the current devid and minor name for the device we
537 		 * opened.
538 		 */
539 		if (ldi_get_devid(dvd->vd_lh, &devid) != 0 ||
540 		    ldi_get_minor_name(dvd->vd_lh, &minorname) != 0) {
541 			/*
542 			 * If we are unable to get the devid or the minor name
543 			 * for the device, we need to remove them from the
544 			 * configuration to prevent potential inconsistencies.
545 			 */
546 			if (dvd->vd_minor != NULL || dvd->vd_devid != NULL ||
547 			    vd->vdev_devid != NULL) {
548 				/*
549 				 * We only need to remove the devid if one
550 				 * exists.
551 				 */
552 				remove = B_TRUE;
553 			}
554 
555 		} else if (dvd->vd_devid == NULL || dvd->vd_minor == NULL) {
556 			/*
557 			 * There was previously no devid at all so we need to
558 			 * add one.
559 			 */
560 			update = B_TRUE;
561 
562 		} else if (ddi_devid_compare(devid, dvd->vd_devid) != 0 ||
563 		    strcmp(minorname, dvd->vd_minor) != 0) {
564 			/*
565 			 * The devid or minor name on file does not match the
566 			 * one from the opened device.
567 			 */
568 			update = B_TRUE;
569 		}
570 
571 		if (update) {
572 			/*
573 			 * Render the new devid and minor name as a string for
574 			 * logging and to store in the vdev configuration.
575 			 */
576 			vd_devid = ddi_devid_str_encode(devid, minorname);
577 		}
578 
579 		if (update || remove) {
580 			vdev_dbgmsg(vd, "vdev_disk_open: update devid from "
581 			    "'%s' to '%s'",
582 			    vd->vdev_devid != NULL ? vd->vdev_devid : "<none>",
583 			    vd_devid != NULL ? vd_devid : "<none>");
584 			cmn_err(CE_NOTE, "vdev_disk_open %s: update devid "
585 			    "from '%s' to '%s'",
586 			    vd->vdev_path != NULL ? vd->vdev_path : "?",
587 			    vd->vdev_devid != NULL ? vd->vdev_devid : "<none>",
588 			    vd_devid != NULL ? vd_devid : "<none>");
589 
590 			/*
591 			 * Remove and free any existing values.
592 			 */
593 			if (dvd->vd_minor != NULL) {
594 				ddi_devid_str_free(dvd->vd_minor);
595 				dvd->vd_minor = NULL;
596 			}
597 			if (dvd->vd_devid != NULL) {
598 				ddi_devid_free(dvd->vd_devid);
599 				dvd->vd_devid = NULL;
600 			}
601 			if (vd->vdev_devid != NULL) {
602 				spa_strfree(vd->vdev_devid);
603 				vd->vdev_devid = NULL;
604 			}
605 		}
606 
607 		if (update) {
608 			/*
609 			 * Install the new values.
610 			 */
611 			vd->vdev_devid = vd_devid;
612 			dvd->vd_minor = minorname;
613 			dvd->vd_devid = devid;
614 
615 		} else {
616 			if (devid != NULL) {
617 				ddi_devid_free(devid);
618 			}
619 			if (minorname != NULL) {
620 				kmem_free(minorname, strlen(minorname) + 1);
621 			}
622 		}
623 	}
624 
625 	/*
626 	 * Once a device is opened, verify that the physical device path (if
627 	 * available) is up to date.
628 	 */
629 	if (ldi_get_dev(dvd->vd_lh, &dev) == 0 &&
630 	    ldi_get_otyp(dvd->vd_lh, &otyp) == 0) {
631 		char *physpath, *minorname;
632 
633 		physpath = kmem_alloc(MAXPATHLEN, KM_SLEEP);
634 		minorname = NULL;
635 		if (ddi_dev_pathname(dev, otyp, physpath) == 0 &&
636 		    ldi_get_minor_name(dvd->vd_lh, &minorname) == 0 &&
637 		    (vd->vdev_physpath == NULL ||
638 		    strcmp(vd->vdev_physpath, physpath) != 0)) {
639 			if (vd->vdev_physpath)
640 				spa_strfree(vd->vdev_physpath);
641 			(void) strlcat(physpath, ":", MAXPATHLEN);
642 			(void) strlcat(physpath, minorname, MAXPATHLEN);
643 			vd->vdev_physpath = spa_strdup(physpath);
644 		}
645 		if (minorname)
646 			kmem_free(minorname, strlen(minorname) + 1);
647 		kmem_free(physpath, MAXPATHLEN);
648 	}
649 
650 	/*
651 	 * Register callbacks for the LDI offline event.
652 	 */
653 	if (ldi_ev_get_cookie(dvd->vd_lh, LDI_EV_OFFLINE, &ecookie) ==
654 	    LDI_EV_SUCCESS) {
655 		lcb = kmem_zalloc(sizeof (vdev_disk_ldi_cb_t), KM_SLEEP);
656 		list_insert_tail(&dvd->vd_ldi_cbs, lcb);
657 		(void) ldi_ev_register_callbacks(dvd->vd_lh, ecookie,
658 		    &vdev_disk_off_callb, (void *) vd, &lcb->lcb_id);
659 	}
660 
661 	/*
662 	 * Register callbacks for the LDI degrade event.
663 	 */
664 	if (ldi_ev_get_cookie(dvd->vd_lh, LDI_EV_DEGRADE, &ecookie) ==
665 	    LDI_EV_SUCCESS) {
666 		lcb = kmem_zalloc(sizeof (vdev_disk_ldi_cb_t), KM_SLEEP);
667 		list_insert_tail(&dvd->vd_ldi_cbs, lcb);
668 		(void) ldi_ev_register_callbacks(dvd->vd_lh, ecookie,
669 		    &vdev_disk_dgrd_callb, (void *) vd, &lcb->lcb_id);
670 	}
671 
672 skip_open:
673 	/*
674 	 * Determine the actual size of the device.
675 	 */
676 	if (ldi_get_size(dvd->vd_lh, psize) != 0) {
677 		vd->vdev_stat.vs_aux = VDEV_AUX_OPEN_FAILED;
678 		vdev_dbgmsg(vd, "vdev_disk_open: failed to get size");
679 		return (SET_ERROR(EINVAL));
680 	}
681 
682 	*max_psize = *psize;
683 
684 	/*
685 	 * Determine the device's minimum transfer size.
686 	 * If the ioctl isn't supported, assume DEV_BSIZE.
687 	 */
688 	if ((error = ldi_ioctl(dvd->vd_lh, DKIOCGMEDIAINFOEXT,
689 	    (intptr_t)dkmext, FKIOCTL, kcred, NULL)) == 0) {
690 		capacity = dkmext->dki_capacity - 1;
691 		blksz = dkmext->dki_lbsize;
692 		pbsize = dkmext->dki_pbsize;
693 	} else if ((error = ldi_ioctl(dvd->vd_lh, DKIOCGMEDIAINFO,
694 	    (intptr_t)dkm, FKIOCTL, kcred, NULL)) == 0) {
695 		VDEV_DEBUG(
696 		    "vdev_disk_open(\"%s\"): fallback to DKIOCGMEDIAINFO\n",
697 		    vd->vdev_path);
698 		capacity = dkm->dki_capacity - 1;
699 		blksz = dkm->dki_lbsize;
700 		pbsize = blksz;
701 	} else {
702 		VDEV_DEBUG("vdev_disk_open(\"%s\"): "
703 		    "both DKIOCGMEDIAINFO{,EXT} calls failed, %d\n",
704 		    vd->vdev_path, error);
705 		pbsize = DEV_BSIZE;
706 	}
707 
708 	*ashift = highbit64(MAX(pbsize, SPA_MINBLOCKSIZE)) - 1;
709 
710 	if (vd->vdev_wholedisk == 1) {
711 		int wce = 1;
712 
713 		if (error == 0) {
714 			/*
715 			 * If we have the capability to expand, we'd have
716 			 * found out via success from DKIOCGMEDIAINFO{,EXT}.
717 			 * Adjust max_psize upward accordingly since we know
718 			 * we own the whole disk now.
719 			 */
720 			*max_psize = capacity * blksz;
721 		}
722 
723 		/*
724 		 * Since we own the whole disk, try to enable disk write
725 		 * caching.  We ignore errors because it's OK if we can't do it.
726 		 */
727 		(void) ldi_ioctl(dvd->vd_lh, DKIOCSETWCE, (intptr_t)&wce,
728 		    FKIOCTL, kcred, NULL);
729 	}
730 
731 	/*
732 	 * Clear the nowritecache bit, so that on a vdev_reopen() we will
733 	 * try again.
734 	 */
735 	vd->vdev_nowritecache = B_FALSE;
736 
737 	if (ldi_ioctl(dvd->vd_lh, DKIOC_CANFREE, (intptr_t)&can_free, FKIOCTL,
738 	    kcred, NULL) == 0 && can_free == 1) {
739 		vd->vdev_has_trim = B_TRUE;
740 	} else {
741 		vd->vdev_has_trim = B_FALSE;
742 	}
743 
744 	if (zfs_no_trim == 1)
745 		vd->vdev_has_trim = B_FALSE;
746 
747 	/* Currently only supported for ZoL. */
748 	vd->vdev_has_securetrim = B_FALSE;
749 
750 	/* Inform the ZIO pipeline that we are non-rotational */
751 	vd->vdev_nonrot = B_FALSE;
752 	if (ldi_prop_exists(dvd->vd_lh, DDI_PROP_DONTPASS | DDI_PROP_NOTPROM,
753 	    "device-solid-state")) {
754 		if (ldi_prop_get_int(dvd->vd_lh,
755 		    LDI_DEV_T_ANY | DDI_PROP_DONTPASS | DDI_PROP_NOTPROM,
756 		    "device-solid-state", B_FALSE) != 0)
757 			vd->vdev_nonrot = B_TRUE;
758 	}
759 
760 	return (0);
761 }
762 
763 static void
vdev_disk_close(vdev_t * vd)764 vdev_disk_close(vdev_t *vd)
765 {
766 	vdev_disk_t *dvd = vd->vdev_tsd;
767 
768 	if (vd->vdev_reopening || dvd == NULL)
769 		return;
770 
771 	if (dvd->vd_minor != NULL) {
772 		ddi_devid_str_free(dvd->vd_minor);
773 		dvd->vd_minor = NULL;
774 	}
775 
776 	if (dvd->vd_devid != NULL) {
777 		ddi_devid_free(dvd->vd_devid);
778 		dvd->vd_devid = NULL;
779 	}
780 
781 	if (dvd->vd_lh != NULL) {
782 		(void) ldi_close(dvd->vd_lh, spa_mode(vd->vdev_spa), kcred);
783 		dvd->vd_lh = NULL;
784 	}
785 
786 	vd->vdev_delayed_close = B_FALSE;
787 	vdev_disk_free(vd);
788 }
789 
790 static int
vdev_disk_ldi_physio(ldi_handle_t vd_lh,caddr_t data,size_t size,uint64_t offset,int flags)791 vdev_disk_ldi_physio(ldi_handle_t vd_lh, caddr_t data,
792     size_t size, uint64_t offset, int flags)
793 {
794 	buf_t *bp;
795 	int error = 0;
796 
797 	if (vd_lh == NULL)
798 		return (SET_ERROR(EINVAL));
799 
800 	ASSERT(flags & B_READ || flags & B_WRITE);
801 
802 	bp = getrbuf(KM_SLEEP);
803 	bp->b_flags = flags | B_BUSY | B_NOCACHE | B_FAILFAST;
804 	bp->b_bcount = size;
805 	bp->b_un.b_addr = (void *)data;
806 	bp->b_lblkno = lbtodb(offset);
807 	bp->b_bufsize = size;
808 
809 	error = ldi_strategy(vd_lh, bp);
810 	ASSERT(error == 0);
811 	if ((error = biowait(bp)) == 0 && bp->b_resid != 0)
812 		error = SET_ERROR(EIO);
813 	freerbuf(bp);
814 
815 	return (error);
816 }
817 
818 static int
vdev_disk_dumpio(vdev_t * vd,caddr_t data,size_t size,uint64_t offset,uint64_t origoffset __unused,boolean_t doread,boolean_t isdump)819 vdev_disk_dumpio(vdev_t *vd, caddr_t data, size_t size,
820     uint64_t offset, uint64_t origoffset __unused, boolean_t doread,
821     boolean_t isdump)
822 {
823 	vdev_disk_t *dvd = vd->vdev_tsd;
824 	int flags = doread ? B_READ : B_WRITE;
825 
826 	/*
827 	 * If the vdev is closed, it's likely in the REMOVED or FAULTED state.
828 	 * Nothing to be done here but return failure.
829 	 */
830 	if (dvd == NULL || dvd->vd_ldi_offline) {
831 		return (SET_ERROR(ENXIO));
832 	}
833 
834 	ASSERT(vd->vdev_ops == &vdev_disk_ops);
835 
836 	offset += VDEV_LABEL_START_SIZE;
837 
838 	/*
839 	 * If in the context of an active crash dump, use the ldi_dump(9F)
840 	 * call instead of ldi_strategy(9F) as usual.
841 	 */
842 	if (isdump) {
843 		ASSERT3P(dvd, !=, NULL);
844 		return (ldi_dump(dvd->vd_lh, data, lbtodb(offset),
845 		    lbtodb(size)));
846 	}
847 
848 	return (vdev_disk_ldi_physio(dvd->vd_lh, data, size, offset, flags));
849 }
850 
851 static int
vdev_disk_io_intr(buf_t * bp)852 vdev_disk_io_intr(buf_t *bp)
853 {
854 	vdev_buf_t *vb = (vdev_buf_t *)bp;
855 	zio_t *zio = vb->vb_io;
856 
857 	/*
858 	 * The rest of the zio stack only deals with EIO, ECKSUM, and ENXIO.
859 	 * Rather than teach the rest of the stack about other error
860 	 * possibilities (EFAULT, etc), we normalize the error value here.
861 	 */
862 	zio->io_error = (geterror(bp) != 0 ? EIO : 0);
863 
864 	if (zio->io_error == 0 && bp->b_resid != 0)
865 		zio->io_error = SET_ERROR(EIO);
866 
867 	if (zio->io_type == ZIO_TYPE_READ) {
868 		abd_return_buf_copy(zio->io_abd, bp->b_un.b_addr, zio->io_size);
869 	} else {
870 		abd_return_buf(zio->io_abd, bp->b_un.b_addr, zio->io_size);
871 	}
872 
873 	kmem_free(vb, sizeof (vdev_buf_t));
874 
875 	zio_delay_interrupt(zio);
876 	return (0);
877 }
878 
879 static void
vdev_disk_ioctl_free(zio_t * zio)880 vdev_disk_ioctl_free(zio_t *zio)
881 {
882 	kmem_free(zio->io_vsd, sizeof (struct dk_callback));
883 }
884 
885 static const zio_vsd_ops_t vdev_disk_vsd_ops = {
886 	vdev_disk_ioctl_free,
887 	zio_vsd_default_cksum_report
888 };
889 
890 static void
vdev_disk_ioctl_done(void * zio_arg,int error)891 vdev_disk_ioctl_done(void *zio_arg, int error)
892 {
893 	zio_t *zio = zio_arg;
894 
895 	zio->io_error = error;
896 
897 	zio_interrupt(zio);
898 }
899 
900 static void
vdev_disk_io_start(zio_t * zio)901 vdev_disk_io_start(zio_t *zio)
902 {
903 	vdev_t *vd = zio->io_vd;
904 	vdev_disk_t *dvd = vd->vdev_tsd;
905 	unsigned long trim_flags = 0;
906 	vdev_buf_t *vb;
907 	struct dk_callback *dkc;
908 	buf_t *bp;
909 	int error;
910 
911 	/*
912 	 * If the vdev is closed, it's likely in the REMOVED or FAULTED state.
913 	 * Nothing to be done here but return failure.
914 	 */
915 	if (dvd == NULL || dvd->vd_ldi_offline) {
916 		zio->io_error = ENXIO;
917 		zio_interrupt(zio);
918 		return;
919 	}
920 
921 	switch (zio->io_type) {
922 	case ZIO_TYPE_IOCTL:
923 		/* XXPOLICY */
924 		if (!vdev_readable(vd)) {
925 			zio->io_error = SET_ERROR(ENXIO);
926 			zio_interrupt(zio);
927 			return;
928 		}
929 
930 		switch (zio->io_cmd) {
931 
932 		case DKIOCFLUSHWRITECACHE:
933 
934 			if (zfs_nocacheflush)
935 				break;
936 
937 			if (vd->vdev_nowritecache) {
938 				zio->io_error = SET_ERROR(ENOTSUP);
939 				break;
940 			}
941 
942 			zio->io_vsd = dkc = kmem_alloc(sizeof (*dkc), KM_SLEEP);
943 			zio->io_vsd_ops = &vdev_disk_vsd_ops;
944 
945 			dkc->dkc_callback = vdev_disk_ioctl_done;
946 			dkc->dkc_flag = FLUSH_VOLATILE;
947 			dkc->dkc_cookie = zio;
948 
949 			error = ldi_ioctl(dvd->vd_lh, zio->io_cmd,
950 			    (uintptr_t)dkc, FKIOCTL, kcred, NULL);
951 
952 			if (error == 0) {
953 				/*
954 				 * The ioctl will be done asychronously,
955 				 * and will call vdev_disk_ioctl_done()
956 				 * upon completion.
957 				 */
958 				return;
959 			}
960 
961 			zio->io_error = error;
962 
963 			break;
964 
965 		default:
966 			zio->io_error = SET_ERROR(ENOTSUP);
967 		}
968 
969 		zio_execute(zio);
970 		return;
971 
972 	case ZIO_TYPE_TRIM:
973 		if (zfs_no_trim == 1 || !vd->vdev_has_trim) {
974 			zio->io_error = SET_ERROR(ENOTSUP);
975 			zio_execute(zio);
976 			return;
977 		}
978 		/* Currently only supported on ZoL. */
979 		ASSERT0(zio->io_trim_flags & ZIO_TRIM_SECURE);
980 
981 		/* dkioc_free_list_t is already declared to hold one entry */
982 		dkioc_free_list_t dfl;
983 		dfl.dfl_flags = 0;
984 		dfl.dfl_num_exts = 1;
985 		dfl.dfl_offset = 0;
986 		dfl.dfl_exts[0].dfle_start = zio->io_offset;
987 		dfl.dfl_exts[0].dfle_length = zio->io_size;
988 
989 		zio->io_error = ldi_ioctl(dvd->vd_lh, DKIOCFREE,
990 		    (uintptr_t)&dfl, FKIOCTL, kcred, NULL);
991 
992 		if (zio->io_error == ENOTSUP || zio->io_error == ENOTTY) {
993 			/*
994 			 * The device must have changed and now TRIM is
995 			 * no longer supported.
996 			 */
997 			vd->vdev_has_trim = B_FALSE;
998 		}
999 
1000 		zio_interrupt(zio);
1001 		return;
1002 	}
1003 
1004 	ASSERT(zio->io_type == ZIO_TYPE_READ || zio->io_type == ZIO_TYPE_WRITE);
1005 	zio->io_target_timestamp = zio_handle_io_delay(zio);
1006 
1007 	vb = kmem_alloc(sizeof (vdev_buf_t), KM_SLEEP);
1008 
1009 	vb->vb_io = zio;
1010 	bp = &vb->vb_buf;
1011 
1012 	bioinit(bp);
1013 	bp->b_flags = B_BUSY | B_NOCACHE |
1014 	    (zio->io_type == ZIO_TYPE_READ ? B_READ : B_WRITE);
1015 	if (!(zio->io_flags & (ZIO_FLAG_IO_RETRY | ZIO_FLAG_TRYHARD)))
1016 		bp->b_flags |= B_FAILFAST;
1017 	bp->b_bcount = zio->io_size;
1018 
1019 	if (zio->io_type == ZIO_TYPE_READ) {
1020 		bp->b_un.b_addr =
1021 		    abd_borrow_buf(zio->io_abd, zio->io_size);
1022 	} else {
1023 		bp->b_un.b_addr =
1024 		    abd_borrow_buf_copy(zio->io_abd, zio->io_size);
1025 	}
1026 
1027 	bp->b_lblkno = lbtodb(zio->io_offset);
1028 	bp->b_bufsize = zio->io_size;
1029 	bp->b_iodone = vdev_disk_io_intr;
1030 
1031 	/*
1032 	 * In general we would expect ldi_strategy() to return non-zero only
1033 	 * because of programming errors, but we've also seen this fail shortly
1034 	 * after a disk dies.
1035 	 */
1036 	if (ldi_strategy(dvd->vd_lh, bp) != 0) {
1037 		zio->io_error = ENXIO;
1038 		zio_interrupt(zio);
1039 	}
1040 }
1041 
1042 static void
vdev_disk_io_done(zio_t * zio)1043 vdev_disk_io_done(zio_t *zio)
1044 {
1045 	vdev_t *vd = zio->io_vd;
1046 
1047 	/*
1048 	 * If the device returned EIO, then attempt a DKIOCSTATE ioctl to see if
1049 	 * the device has been removed.  If this is the case, then we trigger an
1050 	 * asynchronous removal of the device. Otherwise, probe the device and
1051 	 * make sure it's still accessible.
1052 	 */
1053 	if (zio->io_error == EIO && !vd->vdev_remove_wanted) {
1054 		vdev_disk_t *dvd = vd->vdev_tsd;
1055 		int state = DKIO_NONE;
1056 
1057 		if (ldi_ioctl(dvd->vd_lh, DKIOCSTATE, (intptr_t)&state,
1058 		    FKIOCTL, kcred, NULL) == 0 && state != DKIO_INSERTED) {
1059 			/*
1060 			 * We post the resource as soon as possible, instead of
1061 			 * when the async removal actually happens, because the
1062 			 * DE is using this information to discard previous I/O
1063 			 * errors.
1064 			 */
1065 			zfs_post_remove(zio->io_spa, vd);
1066 			vd->vdev_remove_wanted = B_TRUE;
1067 			spa_async_request(zio->io_spa, SPA_ASYNC_REMOVE);
1068 		} else if (!vd->vdev_delayed_close) {
1069 			vd->vdev_delayed_close = B_TRUE;
1070 		}
1071 	}
1072 }
1073 
1074 vdev_ops_t vdev_disk_ops = {
1075 	.vdev_op_open = vdev_disk_open,
1076 	.vdev_op_close = vdev_disk_close,
1077 	.vdev_op_asize = vdev_default_asize,
1078 	.vdev_op_io_start = vdev_disk_io_start,
1079 	.vdev_op_io_done = vdev_disk_io_done,
1080 	.vdev_op_state_change = NULL,
1081 	.vdev_op_need_resilver = NULL,
1082 	.vdev_op_hold = vdev_disk_hold,
1083 	.vdev_op_rele = vdev_disk_rele,
1084 	.vdev_op_remap = NULL,
1085 	.vdev_op_xlate = vdev_default_xlate,
1086 	.vdev_op_dumpio = vdev_disk_dumpio,
1087 	.vdev_op_type = VDEV_TYPE_DISK,		/* name of this vdev type */
1088 	.vdev_op_leaf = B_TRUE			/* leaf vdev */
1089 };
1090 
1091 /*
1092  * Given the root disk device devid or pathname, read the label from
1093  * the device, and construct a configuration nvlist.
1094  */
1095 int
vdev_disk_read_rootlabel(const char * devpath,const char * devid,nvlist_t ** config)1096 vdev_disk_read_rootlabel(const char *devpath, const char *devid,
1097     nvlist_t **config)
1098 {
1099 	ldi_handle_t vd_lh;
1100 	vdev_label_t *label;
1101 	uint64_t s, size;
1102 	int l;
1103 	ddi_devid_t tmpdevid;
1104 	int error = -1;
1105 	char *minor_name;
1106 
1107 	/*
1108 	 * Read the device label and build the nvlist.
1109 	 */
1110 	if (devid != NULL && ddi_devid_str_decode((char *)devid, &tmpdevid,
1111 	    &minor_name) == 0) {
1112 		error = ldi_open_by_devid(tmpdevid, minor_name,
1113 		    FREAD, kcred, &vd_lh, zfs_li);
1114 		ddi_devid_free(tmpdevid);
1115 		ddi_devid_str_free(minor_name);
1116 	}
1117 
1118 	if (error != 0 && (error = ldi_open_by_name((char *)devpath, FREAD,
1119 	    kcred, &vd_lh, zfs_li)) != 0) {
1120 		return (error);
1121 	}
1122 
1123 	if (ldi_get_size(vd_lh, &s)) {
1124 		(void) ldi_close(vd_lh, FREAD, kcred);
1125 		return (SET_ERROR(EIO));
1126 	}
1127 
1128 	size = P2ALIGN_TYPED(s, sizeof (vdev_label_t), uint64_t);
1129 	label = kmem_alloc(sizeof (vdev_label_t), KM_SLEEP);
1130 
1131 	*config = NULL;
1132 	for (l = 0; l < VDEV_LABELS; l++) {
1133 		uint64_t offset, state, txg = 0;
1134 
1135 		/* read vdev label */
1136 		offset = vdev_label_offset(size, l, 0);
1137 		if (vdev_disk_ldi_physio(vd_lh, (caddr_t)label,
1138 		    VDEV_SKIP_SIZE + VDEV_PHYS_SIZE, offset, B_READ) != 0)
1139 			continue;
1140 
1141 		if (nvlist_unpack(label->vl_vdev_phys.vp_nvlist,
1142 		    sizeof (label->vl_vdev_phys.vp_nvlist), config, 0) != 0) {
1143 			*config = NULL;
1144 			continue;
1145 		}
1146 
1147 		if (nvlist_lookup_uint64(*config, ZPOOL_CONFIG_POOL_STATE,
1148 		    &state) != 0 || state >= POOL_STATE_DESTROYED) {
1149 			nvlist_free(*config);
1150 			*config = NULL;
1151 			continue;
1152 		}
1153 
1154 		if (nvlist_lookup_uint64(*config, ZPOOL_CONFIG_POOL_TXG,
1155 		    &txg) != 0 || txg == 0) {
1156 			nvlist_free(*config);
1157 			*config = NULL;
1158 			continue;
1159 		}
1160 
1161 		break;
1162 	}
1163 
1164 	kmem_free(label, sizeof (vdev_label_t));
1165 	(void) ldi_close(vd_lh, FREAD, kcred);
1166 	if (*config == NULL)
1167 		error = SET_ERROR(EIDRM);
1168 
1169 	return (error);
1170 }
1171 
1172 struct veb {
1173 	list_t veb_ents;
1174 	boolean_t veb_scanned;
1175 	char *veb_force_path;
1176 };
1177 
1178 struct veb_ent {
1179 	uint64_t vebe_pool_guid;
1180 	uint64_t vebe_vdev_guid;
1181 
1182 	char *vebe_devpath;
1183 
1184 	list_node_t vebe_link;
1185 };
1186 
1187 static kmutex_t veb_lock;
1188 static struct veb *veb;
1189 
1190 static int
vdev_disk_preroot_scan_walk(const char * devpath,void * arg)1191 vdev_disk_preroot_scan_walk(const char *devpath, void *arg)
1192 {
1193 	int r;
1194 	nvlist_t *cfg = NULL;
1195 	uint64_t pguid = 0, vguid = 0;
1196 
1197 	/*
1198 	 * Attempt to read the label from this block device.
1199 	 */
1200 	if ((r = vdev_disk_read_rootlabel(devpath, NULL, &cfg)) != 0) {
1201 		/*
1202 		 * Many of the available block devices will represent slices or
1203 		 * partitions of disks, or may represent disks that are not at
1204 		 * all initialised with ZFS.  As this is a best effort
1205 		 * mechanism to locate an alternate path to a particular vdev,
1206 		 * we will ignore any failures and keep scanning.
1207 		 */
1208 		return (PREROOT_WALK_BLOCK_DEVICES_NEXT);
1209 	}
1210 
1211 	/*
1212 	 * Determine the pool and vdev GUID read from the label for this
1213 	 * device.  Both values must be present and have a non-zero value.
1214 	 */
1215 	if (nvlist_lookup_uint64(cfg, ZPOOL_CONFIG_POOL_GUID, &pguid) != 0 ||
1216 	    nvlist_lookup_uint64(cfg, ZPOOL_CONFIG_GUID, &vguid) != 0 ||
1217 	    pguid == 0 || vguid == 0) {
1218 		/*
1219 		 * This label was not complete.
1220 		 */
1221 		goto out;
1222 	}
1223 
1224 	/*
1225 	 * Keep track of all of the GUID-to-devpath mappings we find so that
1226 	 * vdev_disk_preroot_lookup() can search them.
1227 	 */
1228 	struct veb_ent *vebe = kmem_zalloc(sizeof (*vebe), KM_SLEEP);
1229 	vebe->vebe_pool_guid = pguid;
1230 	vebe->vebe_vdev_guid = vguid;
1231 	vebe->vebe_devpath = spa_strdup(devpath);
1232 
1233 	list_insert_tail(&veb->veb_ents, vebe);
1234 
1235 out:
1236 	nvlist_free(cfg);
1237 	return (PREROOT_WALK_BLOCK_DEVICES_NEXT);
1238 }
1239 
1240 const char *
vdev_disk_preroot_lookup(uint64_t pool_guid,uint64_t vdev_guid)1241 vdev_disk_preroot_lookup(uint64_t pool_guid, uint64_t vdev_guid)
1242 {
1243 	if (pool_guid == 0 || vdev_guid == 0) {
1244 		/*
1245 		 * If we aren't provided both a pool and a vdev GUID, we cannot
1246 		 * perform a lookup.
1247 		 */
1248 		return (NULL);
1249 	}
1250 
1251 	mutex_enter(&veb_lock);
1252 	if (veb == NULL) {
1253 		/*
1254 		 * If vdev_disk_preroot_fini() has been called already, there
1255 		 * is nothing we can do.
1256 		 */
1257 		mutex_exit(&veb_lock);
1258 		return (NULL);
1259 	}
1260 
1261 	/*
1262 	 * We want to perform at most one scan of all block devices per boot.
1263 	 */
1264 	if (!veb->veb_scanned) {
1265 		cmn_err(CE_NOTE, "Performing full ZFS device scan!");
1266 
1267 		preroot_walk_block_devices(vdev_disk_preroot_scan_walk, NULL);
1268 
1269 		veb->veb_scanned = B_TRUE;
1270 	}
1271 
1272 	const char *path = NULL;
1273 	for (struct veb_ent *vebe = list_head(&veb->veb_ents); vebe != NULL;
1274 	    vebe = list_next(&veb->veb_ents, vebe)) {
1275 		if (vebe->vebe_pool_guid == pool_guid &&
1276 		    vebe->vebe_vdev_guid == vdev_guid) {
1277 			path = vebe->vebe_devpath;
1278 			break;
1279 		}
1280 	}
1281 
1282 	mutex_exit(&veb_lock);
1283 
1284 	return (path);
1285 }
1286 
1287 const char *
vdev_disk_preroot_force_path(void)1288 vdev_disk_preroot_force_path(void)
1289 {
1290 	const char *force_path = NULL;
1291 
1292 	mutex_enter(&veb_lock);
1293 	if (veb != NULL) {
1294 		force_path = veb->veb_force_path;
1295 	}
1296 	mutex_exit(&veb_lock);
1297 
1298 	return (force_path);
1299 }
1300 
1301 void
vdev_disk_preroot_init(const char * force_path)1302 vdev_disk_preroot_init(const char *force_path)
1303 {
1304 	mutex_init(&veb_lock, NULL, MUTEX_DEFAULT, NULL);
1305 
1306 	VERIFY3P(veb, ==, NULL);
1307 	veb = kmem_zalloc(sizeof (*veb), KM_SLEEP);
1308 	list_create(&veb->veb_ents, sizeof (struct veb_ent),
1309 	    offsetof(struct veb_ent, vebe_link));
1310 	veb->veb_scanned = B_FALSE;
1311 	if (force_path != NULL) {
1312 		veb->veb_force_path = spa_strdup(force_path);
1313 	}
1314 }
1315 
1316 void
vdev_disk_preroot_fini(void)1317 vdev_disk_preroot_fini(void)
1318 {
1319 	mutex_enter(&veb_lock);
1320 
1321 	if (veb != NULL) {
1322 		while (!list_is_empty(&veb->veb_ents)) {
1323 			struct veb_ent *vebe = list_remove_head(&veb->veb_ents);
1324 
1325 			spa_strfree(vebe->vebe_devpath);
1326 
1327 			kmem_free(vebe, sizeof (*vebe));
1328 		}
1329 
1330 		if (veb->veb_force_path != NULL) {
1331 			spa_strfree(veb->veb_force_path);
1332 		}
1333 
1334 		kmem_free(veb, sizeof (*veb));
1335 		veb = NULL;
1336 	}
1337 
1338 	mutex_exit(&veb_lock);
1339 }
1340