xref: /freebsd/sys/geom/raid/tr_raid1.c (revision 1c6d60de932c8553af44629218cb9697bc0f2ef1)
1 /*-
2  * Copyright (c) 2010 Alexander Motin <mav@FreeBSD.org>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include <sys/param.h>
31 #include <sys/bio.h>
32 #include <sys/endian.h>
33 #include <sys/kernel.h>
34 #include <sys/kobj.h>
35 #include <sys/limits.h>
36 #include <sys/lock.h>
37 #include <sys/malloc.h>
38 #include <sys/mutex.h>
39 #include <sys/sysctl.h>
40 #include <sys/systm.h>
41 #include <geom/geom.h>
42 #include "geom/raid/g_raid.h"
43 #include "g_raid_tr_if.h"
44 
45 SYSCTL_DECL(_kern_geom_raid_raid1);
46 
47 #define RAID1_REBUILD_SLAB	(1 << 20) /* One transation in a rebuild */
48 static int g_raid1_rebuild_slab = RAID1_REBUILD_SLAB;
49 TUNABLE_INT("kern.geom.raid.raid1.rebuild_slab_size",
50     &g_raid1_rebuild_slab);
51 SYSCTL_UINT(_kern_geom_raid_raid1, OID_AUTO, rebuild_slab_size, CTLFLAG_RW,
52     &g_raid1_rebuild_slab, 0,
53     "Amount of the disk to rebuild each read/write cycle of the rebuild.");
54 
55 #define RAID1_REBUILD_FAIR_IO 20 /* use 1/x of the available I/O */
56 static int g_raid1_rebuild_fair_io = RAID1_REBUILD_FAIR_IO;
57 TUNABLE_INT("kern.geom.raid.raid1.rebuild_fair_io",
58     &g_raid1_rebuild_fair_io);
59 SYSCTL_UINT(_kern_geom_raid_raid1, OID_AUTO, rebuild_fair_io, CTLFLAG_RW,
60     &g_raid1_rebuild_fair_io, 0,
61     "Fraction of the I/O bandwidth to use when disk busy for rebuild.");
62 
63 #define RAID1_REBUILD_CLUSTER_IDLE 100
64 static int g_raid1_rebuild_cluster_idle = RAID1_REBUILD_CLUSTER_IDLE;
65 TUNABLE_INT("kern.geom.raid.raid1.rebuild_cluster_idle",
66     &g_raid1_rebuild_cluster_idle);
67 SYSCTL_UINT(_kern_geom_raid_raid1, OID_AUTO, rebuild_cluster_idle, CTLFLAG_RW,
68     &g_raid1_rebuild_cluster_idle, 0,
69     "Number of slabs to do each time we trigger a rebuild cycle");
70 
71 #define RAID1_REBUILD_META_UPDATE 1024 /* update meta data every 1GB or so */
72 static int g_raid1_rebuild_meta_update = RAID1_REBUILD_META_UPDATE;
73 TUNABLE_INT("kern.geom.raid.raid1.rebuild_meta_update",
74     &g_raid1_rebuild_meta_update);
75 SYSCTL_UINT(_kern_geom_raid_raid1, OID_AUTO, rebuild_meta_update, CTLFLAG_RW,
76     &g_raid1_rebuild_meta_update, 0,
77     "When to update the meta data.");
78 
79 static MALLOC_DEFINE(M_TR_RAID1, "tr_raid1_data", "GEOM_RAID RAID1 data");
80 
81 #define TR_RAID1_NONE 0
82 #define TR_RAID1_REBUILD 1
83 #define TR_RAID1_RESYNC 2
84 
85 #define TR_RAID1_F_DOING_SOME	0x1
86 #define TR_RAID1_F_LOCKED	0x2
87 #define TR_RAID1_F_ABORT	0x4
88 
89 struct g_raid_tr_raid1_object {
90 	struct g_raid_tr_object	 trso_base;
91 	int			 trso_starting;
92 	int			 trso_stopping;
93 	int			 trso_type;
94 	int			 trso_recover_slabs; /* slabs before rest */
95 	int			 trso_fair_io;
96 	int			 trso_meta_update;
97 	int			 trso_flags;
98 	struct g_raid_subdisk	*trso_failed_sd; /* like per volume */
99 	void			*trso_buffer;	 /* Buffer space */
100 	struct bio		 trso_bio;
101 };
102 
103 static g_raid_tr_taste_t g_raid_tr_taste_raid1;
104 static g_raid_tr_event_t g_raid_tr_event_raid1;
105 static g_raid_tr_start_t g_raid_tr_start_raid1;
106 static g_raid_tr_stop_t g_raid_tr_stop_raid1;
107 static g_raid_tr_iostart_t g_raid_tr_iostart_raid1;
108 static g_raid_tr_iodone_t g_raid_tr_iodone_raid1;
109 static g_raid_tr_kerneldump_t g_raid_tr_kerneldump_raid1;
110 static g_raid_tr_locked_t g_raid_tr_locked_raid1;
111 static g_raid_tr_idle_t g_raid_tr_idle_raid1;
112 static g_raid_tr_free_t g_raid_tr_free_raid1;
113 
114 static kobj_method_t g_raid_tr_raid1_methods[] = {
115 	KOBJMETHOD(g_raid_tr_taste,	g_raid_tr_taste_raid1),
116 	KOBJMETHOD(g_raid_tr_event,	g_raid_tr_event_raid1),
117 	KOBJMETHOD(g_raid_tr_start,	g_raid_tr_start_raid1),
118 	KOBJMETHOD(g_raid_tr_stop,	g_raid_tr_stop_raid1),
119 	KOBJMETHOD(g_raid_tr_iostart,	g_raid_tr_iostart_raid1),
120 	KOBJMETHOD(g_raid_tr_iodone,	g_raid_tr_iodone_raid1),
121 	KOBJMETHOD(g_raid_tr_kerneldump, g_raid_tr_kerneldump_raid1),
122 	KOBJMETHOD(g_raid_tr_locked,	g_raid_tr_locked_raid1),
123 	KOBJMETHOD(g_raid_tr_idle,	g_raid_tr_idle_raid1),
124 	KOBJMETHOD(g_raid_tr_free,	g_raid_tr_free_raid1),
125 	{ 0, 0 }
126 };
127 
128 static struct g_raid_tr_class g_raid_tr_raid1_class = {
129 	"RAID1",
130 	g_raid_tr_raid1_methods,
131 	sizeof(struct g_raid_tr_raid1_object),
132 	.trc_enable = 1,
133 	.trc_priority = 100,
134 	.trc_accept_unmapped = 1
135 };
136 
137 static void g_raid_tr_raid1_rebuild_abort(struct g_raid_tr_object *tr);
138 static void g_raid_tr_raid1_maybe_rebuild(struct g_raid_tr_object *tr,
139     struct g_raid_subdisk *sd);
140 
141 static int
142 g_raid_tr_taste_raid1(struct g_raid_tr_object *tr, struct g_raid_volume *vol)
143 {
144 	struct g_raid_tr_raid1_object *trs;
145 
146 	trs = (struct g_raid_tr_raid1_object *)tr;
147 	if (tr->tro_volume->v_raid_level != G_RAID_VOLUME_RL_RAID1 ||
148 	    (tr->tro_volume->v_raid_level_qualifier != G_RAID_VOLUME_RLQ_R1SM &&
149 	     tr->tro_volume->v_raid_level_qualifier != G_RAID_VOLUME_RLQ_R1MM))
150 		return (G_RAID_TR_TASTE_FAIL);
151 	trs->trso_starting = 1;
152 	return (G_RAID_TR_TASTE_SUCCEED);
153 }
154 
155 static int
156 g_raid_tr_update_state_raid1(struct g_raid_volume *vol,
157     struct g_raid_subdisk *sd)
158 {
159 	struct g_raid_tr_raid1_object *trs;
160 	struct g_raid_softc *sc;
161 	struct g_raid_subdisk *tsd, *bestsd;
162 	u_int s;
163 	int i, na, ns;
164 
165 	sc = vol->v_softc;
166 	trs = (struct g_raid_tr_raid1_object *)vol->v_tr;
167 	if (trs->trso_stopping &&
168 	    (trs->trso_flags & TR_RAID1_F_DOING_SOME) == 0)
169 		s = G_RAID_VOLUME_S_STOPPED;
170 	else if (trs->trso_starting)
171 		s = G_RAID_VOLUME_S_STARTING;
172 	else {
173 		/* Make sure we have at least one ACTIVE disk. */
174 		na = g_raid_nsubdisks(vol, G_RAID_SUBDISK_S_ACTIVE);
175 		if (na == 0) {
176 			/*
177 			 * Critical situation! We have no any active disk!
178 			 * Choose the best disk we have to make it active.
179 			 */
180 			bestsd = &vol->v_subdisks[0];
181 			for (i = 1; i < vol->v_disks_count; i++) {
182 				tsd = &vol->v_subdisks[i];
183 				if (tsd->sd_state > bestsd->sd_state)
184 					bestsd = tsd;
185 				else if (tsd->sd_state == bestsd->sd_state &&
186 				    (tsd->sd_state == G_RAID_SUBDISK_S_REBUILD ||
187 				     tsd->sd_state == G_RAID_SUBDISK_S_RESYNC) &&
188 				    tsd->sd_rebuild_pos > bestsd->sd_rebuild_pos)
189 					bestsd = tsd;
190 			}
191 			if (bestsd->sd_state >= G_RAID_SUBDISK_S_UNINITIALIZED) {
192 				/* We found reasonable candidate. */
193 				G_RAID_DEBUG1(1, sc,
194 				    "Promote subdisk %s:%d from %s to ACTIVE.",
195 				    vol->v_name, bestsd->sd_pos,
196 				    g_raid_subdisk_state2str(bestsd->sd_state));
197 				g_raid_change_subdisk_state(bestsd,
198 				    G_RAID_SUBDISK_S_ACTIVE);
199 				g_raid_write_metadata(sc,
200 				    vol, bestsd, bestsd->sd_disk);
201 			}
202 		}
203 		na = g_raid_nsubdisks(vol, G_RAID_SUBDISK_S_ACTIVE);
204 		ns = g_raid_nsubdisks(vol, G_RAID_SUBDISK_S_STALE) +
205 		     g_raid_nsubdisks(vol, G_RAID_SUBDISK_S_RESYNC);
206 		if (na == vol->v_disks_count)
207 			s = G_RAID_VOLUME_S_OPTIMAL;
208 		else if (na + ns == vol->v_disks_count)
209 			s = G_RAID_VOLUME_S_SUBOPTIMAL;
210 		else if (na > 0)
211 			s = G_RAID_VOLUME_S_DEGRADED;
212 		else
213 			s = G_RAID_VOLUME_S_BROKEN;
214 		g_raid_tr_raid1_maybe_rebuild(vol->v_tr, sd);
215 	}
216 	if (s != vol->v_state) {
217 		g_raid_event_send(vol, G_RAID_VOLUME_S_ALIVE(s) ?
218 		    G_RAID_VOLUME_E_UP : G_RAID_VOLUME_E_DOWN,
219 		    G_RAID_EVENT_VOLUME);
220 		g_raid_change_volume_state(vol, s);
221 		if (!trs->trso_starting && !trs->trso_stopping)
222 			g_raid_write_metadata(sc, vol, NULL, NULL);
223 	}
224 	return (0);
225 }
226 
227 static void
228 g_raid_tr_raid1_fail_disk(struct g_raid_softc *sc, struct g_raid_subdisk *sd,
229     struct g_raid_disk *disk)
230 {
231 	/*
232 	 * We don't fail the last disk in the pack, since it still has decent
233 	 * data on it and that's better than failing the disk if it is the root
234 	 * file system.
235 	 *
236 	 * XXX should this be controlled via a tunable?  It makes sense for
237 	 * the volume that has / on it.  I can't think of a case where we'd
238 	 * want the volume to go away on this kind of event.
239 	 */
240 	if (g_raid_nsubdisks(sd->sd_volume, G_RAID_SUBDISK_S_ACTIVE) == 1 &&
241 	    g_raid_get_subdisk(sd->sd_volume, G_RAID_SUBDISK_S_ACTIVE) == sd)
242 		return;
243 	g_raid_fail_disk(sc, sd, disk);
244 }
245 
246 static void
247 g_raid_tr_raid1_rebuild_some(struct g_raid_tr_object *tr)
248 {
249 	struct g_raid_tr_raid1_object *trs;
250 	struct g_raid_subdisk *sd, *good_sd;
251 	struct bio *bp;
252 
253 	trs = (struct g_raid_tr_raid1_object *)tr;
254 	if (trs->trso_flags & TR_RAID1_F_DOING_SOME)
255 		return;
256 	sd = trs->trso_failed_sd;
257 	good_sd = g_raid_get_subdisk(sd->sd_volume, G_RAID_SUBDISK_S_ACTIVE);
258 	if (good_sd == NULL) {
259 		g_raid_tr_raid1_rebuild_abort(tr);
260 		return;
261 	}
262 	bp = &trs->trso_bio;
263 	memset(bp, 0, sizeof(*bp));
264 	bp->bio_offset = sd->sd_rebuild_pos;
265 	bp->bio_length = MIN(g_raid1_rebuild_slab,
266 	    sd->sd_size - sd->sd_rebuild_pos);
267 	bp->bio_data = trs->trso_buffer;
268 	bp->bio_cmd = BIO_READ;
269 	bp->bio_cflags = G_RAID_BIO_FLAG_SYNC;
270 	bp->bio_caller1 = good_sd;
271 	trs->trso_flags |= TR_RAID1_F_DOING_SOME;
272 	trs->trso_flags |= TR_RAID1_F_LOCKED;
273 	g_raid_lock_range(sd->sd_volume,	/* Lock callback starts I/O */
274 	   bp->bio_offset, bp->bio_length, NULL, bp);
275 }
276 
277 static void
278 g_raid_tr_raid1_rebuild_done(struct g_raid_tr_raid1_object *trs)
279 {
280 	struct g_raid_volume *vol;
281 	struct g_raid_subdisk *sd;
282 
283 	vol = trs->trso_base.tro_volume;
284 	sd = trs->trso_failed_sd;
285 	g_raid_write_metadata(vol->v_softc, vol, sd, sd->sd_disk);
286 	free(trs->trso_buffer, M_TR_RAID1);
287 	trs->trso_buffer = NULL;
288 	trs->trso_flags &= ~TR_RAID1_F_DOING_SOME;
289 	trs->trso_type = TR_RAID1_NONE;
290 	trs->trso_recover_slabs = 0;
291 	trs->trso_failed_sd = NULL;
292 	g_raid_tr_update_state_raid1(vol, NULL);
293 }
294 
295 static void
296 g_raid_tr_raid1_rebuild_finish(struct g_raid_tr_object *tr)
297 {
298 	struct g_raid_tr_raid1_object *trs;
299 	struct g_raid_subdisk *sd;
300 
301 	trs = (struct g_raid_tr_raid1_object *)tr;
302 	sd = trs->trso_failed_sd;
303 	G_RAID_DEBUG1(0, tr->tro_volume->v_softc,
304 	    "Subdisk %s:%d-%s rebuild completed.",
305 	    sd->sd_volume->v_name, sd->sd_pos,
306 	    sd->sd_disk ? g_raid_get_diskname(sd->sd_disk) : "[none]");
307 	g_raid_change_subdisk_state(sd, G_RAID_SUBDISK_S_ACTIVE);
308 	sd->sd_rebuild_pos = 0;
309 	g_raid_tr_raid1_rebuild_done(trs);
310 }
311 
312 static void
313 g_raid_tr_raid1_rebuild_abort(struct g_raid_tr_object *tr)
314 {
315 	struct g_raid_tr_raid1_object *trs;
316 	struct g_raid_subdisk *sd;
317 	struct g_raid_volume *vol;
318 	off_t len;
319 
320 	vol = tr->tro_volume;
321 	trs = (struct g_raid_tr_raid1_object *)tr;
322 	sd = trs->trso_failed_sd;
323 	if (trs->trso_flags & TR_RAID1_F_DOING_SOME) {
324 		G_RAID_DEBUG1(1, vol->v_softc,
325 		    "Subdisk %s:%d-%s rebuild is aborting.",
326 		    sd->sd_volume->v_name, sd->sd_pos,
327 		    sd->sd_disk ? g_raid_get_diskname(sd->sd_disk) : "[none]");
328 		trs->trso_flags |= TR_RAID1_F_ABORT;
329 	} else {
330 		G_RAID_DEBUG1(0, vol->v_softc,
331 		    "Subdisk %s:%d-%s rebuild aborted.",
332 		    sd->sd_volume->v_name, sd->sd_pos,
333 		    sd->sd_disk ? g_raid_get_diskname(sd->sd_disk) : "[none]");
334 		trs->trso_flags &= ~TR_RAID1_F_ABORT;
335 		if (trs->trso_flags & TR_RAID1_F_LOCKED) {
336 			trs->trso_flags &= ~TR_RAID1_F_LOCKED;
337 			len = MIN(g_raid1_rebuild_slab,
338 			    sd->sd_size - sd->sd_rebuild_pos);
339 			g_raid_unlock_range(tr->tro_volume,
340 			    sd->sd_rebuild_pos, len);
341 		}
342 		g_raid_tr_raid1_rebuild_done(trs);
343 	}
344 }
345 
346 static void
347 g_raid_tr_raid1_rebuild_start(struct g_raid_tr_object *tr)
348 {
349 	struct g_raid_volume *vol;
350 	struct g_raid_tr_raid1_object *trs;
351 	struct g_raid_subdisk *sd, *fsd;
352 
353 	vol = tr->tro_volume;
354 	trs = (struct g_raid_tr_raid1_object *)tr;
355 	if (trs->trso_failed_sd) {
356 		G_RAID_DEBUG1(1, vol->v_softc,
357 		    "Already rebuild in start rebuild. pos %jd\n",
358 		    (intmax_t)trs->trso_failed_sd->sd_rebuild_pos);
359 		return;
360 	}
361 	sd = g_raid_get_subdisk(vol, G_RAID_SUBDISK_S_ACTIVE);
362 	if (sd == NULL) {
363 		G_RAID_DEBUG1(1, vol->v_softc,
364 		    "No active disk to rebuild.  night night.");
365 		return;
366 	}
367 	fsd = g_raid_get_subdisk(vol, G_RAID_SUBDISK_S_RESYNC);
368 	if (fsd == NULL)
369 		fsd = g_raid_get_subdisk(vol, G_RAID_SUBDISK_S_REBUILD);
370 	if (fsd == NULL) {
371 		fsd = g_raid_get_subdisk(vol, G_RAID_SUBDISK_S_STALE);
372 		if (fsd != NULL) {
373 			fsd->sd_rebuild_pos = 0;
374 			g_raid_change_subdisk_state(fsd,
375 			    G_RAID_SUBDISK_S_RESYNC);
376 			g_raid_write_metadata(vol->v_softc, vol, fsd, NULL);
377 		} else {
378 			fsd = g_raid_get_subdisk(vol,
379 			    G_RAID_SUBDISK_S_UNINITIALIZED);
380 			if (fsd == NULL)
381 				fsd = g_raid_get_subdisk(vol,
382 				    G_RAID_SUBDISK_S_NEW);
383 			if (fsd != NULL) {
384 				fsd->sd_rebuild_pos = 0;
385 				g_raid_change_subdisk_state(fsd,
386 				    G_RAID_SUBDISK_S_REBUILD);
387 				g_raid_write_metadata(vol->v_softc,
388 				    vol, fsd, NULL);
389 			}
390 		}
391 	}
392 	if (fsd == NULL) {
393 		G_RAID_DEBUG1(1, vol->v_softc,
394 		    "No failed disk to rebuild.  night night.");
395 		return;
396 	}
397 	trs->trso_failed_sd = fsd;
398 	G_RAID_DEBUG1(0, vol->v_softc,
399 	    "Subdisk %s:%d-%s rebuild start at %jd.",
400 	    fsd->sd_volume->v_name, fsd->sd_pos,
401 	    fsd->sd_disk ? g_raid_get_diskname(fsd->sd_disk) : "[none]",
402 	    trs->trso_failed_sd->sd_rebuild_pos);
403 	trs->trso_type = TR_RAID1_REBUILD;
404 	trs->trso_buffer = malloc(g_raid1_rebuild_slab, M_TR_RAID1, M_WAITOK);
405 	trs->trso_meta_update = g_raid1_rebuild_meta_update;
406 	g_raid_tr_raid1_rebuild_some(tr);
407 }
408 
409 
410 static void
411 g_raid_tr_raid1_maybe_rebuild(struct g_raid_tr_object *tr,
412     struct g_raid_subdisk *sd)
413 {
414 	struct g_raid_volume *vol;
415 	struct g_raid_tr_raid1_object *trs;
416 	int na, nr;
417 
418 	/*
419 	 * If we're stopping, don't do anything.  If we don't have at least one
420 	 * good disk and one bad disk, we don't do anything.  And if there's a
421 	 * 'good disk' stored in the trs, then we're in progress and we punt.
422 	 * If we make it past all these checks, we need to rebuild.
423 	 */
424 	vol = tr->tro_volume;
425 	trs = (struct g_raid_tr_raid1_object *)tr;
426 	if (trs->trso_stopping)
427 		return;
428 	na = g_raid_nsubdisks(vol, G_RAID_SUBDISK_S_ACTIVE);
429 	nr = g_raid_nsubdisks(vol, G_RAID_SUBDISK_S_REBUILD) +
430 	    g_raid_nsubdisks(vol, G_RAID_SUBDISK_S_RESYNC);
431 	switch(trs->trso_type) {
432 	case TR_RAID1_NONE:
433 		if (na == 0)
434 			return;
435 		if (nr == 0) {
436 			nr = g_raid_nsubdisks(vol, G_RAID_SUBDISK_S_NEW) +
437 			    g_raid_nsubdisks(vol, G_RAID_SUBDISK_S_STALE) +
438 			    g_raid_nsubdisks(vol, G_RAID_SUBDISK_S_UNINITIALIZED);
439 			if (nr == 0)
440 				return;
441 		}
442 		g_raid_tr_raid1_rebuild_start(tr);
443 		break;
444 	case TR_RAID1_REBUILD:
445 		if (na == 0 || nr == 0 || trs->trso_failed_sd == sd)
446 			g_raid_tr_raid1_rebuild_abort(tr);
447 		break;
448 	case TR_RAID1_RESYNC:
449 		break;
450 	}
451 }
452 
453 static int
454 g_raid_tr_event_raid1(struct g_raid_tr_object *tr,
455     struct g_raid_subdisk *sd, u_int event)
456 {
457 
458 	g_raid_tr_update_state_raid1(tr->tro_volume, sd);
459 	return (0);
460 }
461 
462 static int
463 g_raid_tr_start_raid1(struct g_raid_tr_object *tr)
464 {
465 	struct g_raid_tr_raid1_object *trs;
466 	struct g_raid_volume *vol;
467 
468 	trs = (struct g_raid_tr_raid1_object *)tr;
469 	vol = tr->tro_volume;
470 	trs->trso_starting = 0;
471 	g_raid_tr_update_state_raid1(vol, NULL);
472 	return (0);
473 }
474 
475 static int
476 g_raid_tr_stop_raid1(struct g_raid_tr_object *tr)
477 {
478 	struct g_raid_tr_raid1_object *trs;
479 	struct g_raid_volume *vol;
480 
481 	trs = (struct g_raid_tr_raid1_object *)tr;
482 	vol = tr->tro_volume;
483 	trs->trso_starting = 0;
484 	trs->trso_stopping = 1;
485 	g_raid_tr_update_state_raid1(vol, NULL);
486 	return (0);
487 }
488 
489 /*
490  * Select the disk to read from.  Take into account: subdisk state, running
491  * error recovery, average disk load, head position and possible cache hits.
492  */
493 #define ABS(x)		(((x) >= 0) ? (x) : (-(x)))
494 static struct g_raid_subdisk *
495 g_raid_tr_raid1_select_read_disk(struct g_raid_volume *vol, struct bio *bp,
496     u_int mask)
497 {
498 	struct g_raid_subdisk *sd, *best;
499 	int i, prio, bestprio;
500 
501 	best = NULL;
502 	bestprio = INT_MAX;
503 	for (i = 0; i < vol->v_disks_count; i++) {
504 		sd = &vol->v_subdisks[i];
505 		if (sd->sd_state != G_RAID_SUBDISK_S_ACTIVE &&
506 		    ((sd->sd_state != G_RAID_SUBDISK_S_REBUILD &&
507 		      sd->sd_state != G_RAID_SUBDISK_S_RESYNC) ||
508 		     bp->bio_offset + bp->bio_length > sd->sd_rebuild_pos))
509 			continue;
510 		if ((mask & (1 << i)) != 0)
511 			continue;
512 		prio = G_RAID_SUBDISK_LOAD(sd);
513 		prio += min(sd->sd_recovery, 255) << 22;
514 		prio += (G_RAID_SUBDISK_S_ACTIVE - sd->sd_state) << 16;
515 		/* If disk head is precisely in position - highly prefer it. */
516 		if (G_RAID_SUBDISK_POS(sd) == bp->bio_offset)
517 			prio -= 2 * G_RAID_SUBDISK_LOAD_SCALE;
518 		else
519 		/* If disk head is close to position - prefer it. */
520 		if (ABS(G_RAID_SUBDISK_POS(sd) - bp->bio_offset) <
521 		    G_RAID_SUBDISK_TRACK_SIZE)
522 			prio -= 1 * G_RAID_SUBDISK_LOAD_SCALE;
523 		if (prio < bestprio) {
524 			best = sd;
525 			bestprio = prio;
526 		}
527 	}
528 	return (best);
529 }
530 
531 static void
532 g_raid_tr_iostart_raid1_read(struct g_raid_tr_object *tr, struct bio *bp)
533 {
534 	struct g_raid_subdisk *sd;
535 	struct bio *cbp;
536 
537 	sd = g_raid_tr_raid1_select_read_disk(tr->tro_volume, bp, 0);
538 	KASSERT(sd != NULL, ("No active disks in volume %s.",
539 		tr->tro_volume->v_name));
540 
541 	cbp = g_clone_bio(bp);
542 	if (cbp == NULL) {
543 		g_raid_iodone(bp, ENOMEM);
544 		return;
545 	}
546 
547 	g_raid_subdisk_iostart(sd, cbp);
548 }
549 
550 static void
551 g_raid_tr_iostart_raid1_write(struct g_raid_tr_object *tr, struct bio *bp)
552 {
553 	struct g_raid_volume *vol;
554 	struct g_raid_subdisk *sd;
555 	struct bio_queue_head queue;
556 	struct bio *cbp;
557 	int i;
558 
559 	vol = tr->tro_volume;
560 
561 	/*
562 	 * Allocate all bios before sending any request, so we can return
563 	 * ENOMEM in nice and clean way.
564 	 */
565 	bioq_init(&queue);
566 	for (i = 0; i < vol->v_disks_count; i++) {
567 		sd = &vol->v_subdisks[i];
568 		switch (sd->sd_state) {
569 		case G_RAID_SUBDISK_S_ACTIVE:
570 			break;
571 		case G_RAID_SUBDISK_S_REBUILD:
572 			/*
573 			 * When rebuilding, only part of this subdisk is
574 			 * writable, the rest will be written as part of the
575 			 * that process.
576 			 */
577 			if (bp->bio_offset >= sd->sd_rebuild_pos)
578 				continue;
579 			break;
580 		case G_RAID_SUBDISK_S_STALE:
581 		case G_RAID_SUBDISK_S_RESYNC:
582 			/*
583 			 * Resyncing still writes on the theory that the
584 			 * resync'd disk is very close and writing it will
585 			 * keep it that way better if we keep up while
586 			 * resyncing.
587 			 */
588 			break;
589 		default:
590 			continue;
591 		}
592 		cbp = g_clone_bio(bp);
593 		if (cbp == NULL)
594 			goto failure;
595 		cbp->bio_caller1 = sd;
596 		bioq_insert_tail(&queue, cbp);
597 	}
598 	while ((cbp = bioq_takefirst(&queue)) != NULL) {
599 		sd = cbp->bio_caller1;
600 		cbp->bio_caller1 = NULL;
601 		g_raid_subdisk_iostart(sd, cbp);
602 	}
603 	return;
604 failure:
605 	while ((cbp = bioq_takefirst(&queue)) != NULL)
606 		g_destroy_bio(cbp);
607 	if (bp->bio_error == 0)
608 		bp->bio_error = ENOMEM;
609 	g_raid_iodone(bp, bp->bio_error);
610 }
611 
612 static void
613 g_raid_tr_iostart_raid1(struct g_raid_tr_object *tr, struct bio *bp)
614 {
615 	struct g_raid_volume *vol;
616 	struct g_raid_tr_raid1_object *trs;
617 
618 	vol = tr->tro_volume;
619 	trs = (struct g_raid_tr_raid1_object *)tr;
620 	if (vol->v_state != G_RAID_VOLUME_S_OPTIMAL &&
621 	    vol->v_state != G_RAID_VOLUME_S_SUBOPTIMAL &&
622 	    vol->v_state != G_RAID_VOLUME_S_DEGRADED) {
623 		g_raid_iodone(bp, EIO);
624 		return;
625 	}
626 	/*
627 	 * If we're rebuilding, squeeze in rebuild activity every so often,
628 	 * even when the disk is busy.  Be sure to only count real I/O
629 	 * to the disk.  All 'SPECIAL' I/O is traffic generated to the disk
630 	 * by this module.
631 	 */
632 	if (trs->trso_failed_sd != NULL &&
633 	    !(bp->bio_cflags & G_RAID_BIO_FLAG_SPECIAL)) {
634 		/* Make this new or running now round short. */
635 		trs->trso_recover_slabs = 0;
636 		if (--trs->trso_fair_io <= 0) {
637 			trs->trso_fair_io = g_raid1_rebuild_fair_io;
638 			g_raid_tr_raid1_rebuild_some(tr);
639 		}
640 	}
641 	switch (bp->bio_cmd) {
642 	case BIO_READ:
643 		g_raid_tr_iostart_raid1_read(tr, bp);
644 		break;
645 	case BIO_WRITE:
646 	case BIO_DELETE:
647 		g_raid_tr_iostart_raid1_write(tr, bp);
648 		break;
649 	case BIO_FLUSH:
650 		g_raid_tr_flush_common(tr, bp);
651 		break;
652 	default:
653 		KASSERT(1 == 0, ("Invalid command here: %u (volume=%s)",
654 		    bp->bio_cmd, vol->v_name));
655 		break;
656 	}
657 }
658 
659 static void
660 g_raid_tr_iodone_raid1(struct g_raid_tr_object *tr,
661     struct g_raid_subdisk *sd, struct bio *bp)
662 {
663 	struct bio *cbp;
664 	struct g_raid_subdisk *nsd;
665 	struct g_raid_volume *vol;
666 	struct bio *pbp;
667 	struct g_raid_tr_raid1_object *trs;
668 	uintptr_t *mask;
669 	int error, do_write;
670 
671 	trs = (struct g_raid_tr_raid1_object *)tr;
672 	vol = tr->tro_volume;
673 	if (bp->bio_cflags & G_RAID_BIO_FLAG_SYNC) {
674 		/*
675 		 * This operation is part of a rebuild or resync operation.
676 		 * See what work just got done, then schedule the next bit of
677 		 * work, if any.  Rebuild/resync is done a little bit at a
678 		 * time.  Either when a timeout happens, or after we get a
679 		 * bunch of I/Os to the disk (to make sure an active system
680 		 * will complete in a sane amount of time).
681 		 *
682 		 * We are setup to do differing amounts of work for each of
683 		 * these cases.  so long as the slabs is smallish (less than
684 		 * 50 or so, I'd guess, but that's just a WAG), we shouldn't
685 		 * have any bio starvation issues.  For active disks, we do
686 		 * 5MB of data, for inactive ones, we do 50MB.
687 		 */
688 		if (trs->trso_type == TR_RAID1_REBUILD) {
689 			if (bp->bio_cmd == BIO_READ) {
690 
691 				/* Immediately abort rebuild, if requested. */
692 				if (trs->trso_flags & TR_RAID1_F_ABORT) {
693 					trs->trso_flags &= ~TR_RAID1_F_DOING_SOME;
694 					g_raid_tr_raid1_rebuild_abort(tr);
695 					return;
696 				}
697 
698 				/* On read error, skip and cross fingers. */
699 				if (bp->bio_error != 0) {
700 					G_RAID_LOGREQ(0, bp,
701 					    "Read error during rebuild (%d), "
702 					    "possible data loss!",
703 					    bp->bio_error);
704 					goto rebuild_round_done;
705 				}
706 
707 				/*
708 				 * The read operation finished, queue the
709 				 * write and get out.
710 				 */
711 				G_RAID_LOGREQ(4, bp, "rebuild read done. %d",
712 				    bp->bio_error);
713 				bp->bio_cmd = BIO_WRITE;
714 				bp->bio_cflags = G_RAID_BIO_FLAG_SYNC;
715 				G_RAID_LOGREQ(4, bp, "Queueing rebuild write.");
716 				g_raid_subdisk_iostart(trs->trso_failed_sd, bp);
717 			} else {
718 				/*
719 				 * The write operation just finished.  Do
720 				 * another.  We keep cloning the master bio
721 				 * since it has the right buffers allocated to
722 				 * it.
723 				 */
724 				G_RAID_LOGREQ(4, bp,
725 				    "rebuild write done. Error %d",
726 				    bp->bio_error);
727 				nsd = trs->trso_failed_sd;
728 				if (bp->bio_error != 0 ||
729 				    trs->trso_flags & TR_RAID1_F_ABORT) {
730 					if ((trs->trso_flags &
731 					    TR_RAID1_F_ABORT) == 0) {
732 						g_raid_tr_raid1_fail_disk(sd->sd_softc,
733 						    nsd, nsd->sd_disk);
734 					}
735 					trs->trso_flags &= ~TR_RAID1_F_DOING_SOME;
736 					g_raid_tr_raid1_rebuild_abort(tr);
737 					return;
738 				}
739 rebuild_round_done:
740 				nsd = trs->trso_failed_sd;
741 				trs->trso_flags &= ~TR_RAID1_F_LOCKED;
742 				g_raid_unlock_range(sd->sd_volume,
743 				    bp->bio_offset, bp->bio_length);
744 				nsd->sd_rebuild_pos += bp->bio_length;
745 				if (nsd->sd_rebuild_pos >= nsd->sd_size) {
746 					g_raid_tr_raid1_rebuild_finish(tr);
747 					return;
748 				}
749 
750 				/* Abort rebuild if we are stopping */
751 				if (trs->trso_stopping) {
752 					trs->trso_flags &= ~TR_RAID1_F_DOING_SOME;
753 					g_raid_tr_raid1_rebuild_abort(tr);
754 					return;
755 				}
756 
757 				if (--trs->trso_meta_update <= 0) {
758 					g_raid_write_metadata(vol->v_softc,
759 					    vol, nsd, nsd->sd_disk);
760 					trs->trso_meta_update =
761 					    g_raid1_rebuild_meta_update;
762 				}
763 				trs->trso_flags &= ~TR_RAID1_F_DOING_SOME;
764 				if (--trs->trso_recover_slabs <= 0)
765 					return;
766 				g_raid_tr_raid1_rebuild_some(tr);
767 			}
768 		} else if (trs->trso_type == TR_RAID1_RESYNC) {
769 			/*
770 			 * read good sd, read bad sd in parallel.  when both
771 			 * done, compare the buffers.  write good to the bad
772 			 * if different.  do the next bit of work.
773 			 */
774 			panic("Somehow, we think we're doing a resync");
775 		}
776 		return;
777 	}
778 	pbp = bp->bio_parent;
779 	pbp->bio_inbed++;
780 	if (bp->bio_cmd == BIO_READ && bp->bio_error != 0) {
781 		/*
782 		 * Read failed on first drive.  Retry the read error on
783 		 * another disk drive, if available, before erroring out the
784 		 * read.
785 		 */
786 		sd->sd_disk->d_read_errs++;
787 		G_RAID_LOGREQ(0, bp,
788 		    "Read error (%d), %d read errors total",
789 		    bp->bio_error, sd->sd_disk->d_read_errs);
790 
791 		/*
792 		 * If there are too many read errors, we move to degraded.
793 		 * XXX Do we want to FAIL the drive (eg, make the user redo
794 		 * everything to get it back in sync), or just degrade the
795 		 * drive, which kicks off a resync?
796 		 */
797 		do_write = 1;
798 		if (sd->sd_disk->d_read_errs > g_raid_read_err_thresh) {
799 			g_raid_tr_raid1_fail_disk(sd->sd_softc, sd, sd->sd_disk);
800 			if (pbp->bio_children == 1)
801 				do_write = 0;
802 		}
803 
804 		/*
805 		 * Find the other disk, and try to do the I/O to it.
806 		 */
807 		mask = (uintptr_t *)(&pbp->bio_driver2);
808 		if (pbp->bio_children == 1) {
809 			/* Save original subdisk. */
810 			pbp->bio_driver1 = do_write ? sd : NULL;
811 			*mask = 0;
812 		}
813 		*mask |= 1 << sd->sd_pos;
814 		nsd = g_raid_tr_raid1_select_read_disk(vol, pbp, *mask);
815 		if (nsd != NULL && (cbp = g_clone_bio(pbp)) != NULL) {
816 			g_destroy_bio(bp);
817 			G_RAID_LOGREQ(2, cbp, "Retrying read from %d",
818 			    nsd->sd_pos);
819 			if (pbp->bio_children == 2 && do_write) {
820 				sd->sd_recovery++;
821 				cbp->bio_caller1 = nsd;
822 				pbp->bio_pflags = G_RAID_BIO_FLAG_LOCKED;
823 				/* Lock callback starts I/O */
824 				g_raid_lock_range(sd->sd_volume,
825 				    cbp->bio_offset, cbp->bio_length, pbp, cbp);
826 			} else {
827 				g_raid_subdisk_iostart(nsd, cbp);
828 			}
829 			return;
830 		}
831 		/*
832 		 * We can't retry.  Return the original error by falling
833 		 * through.  This will happen when there's only one good disk.
834 		 * We don't need to fail the raid, since its actual state is
835 		 * based on the state of the subdisks.
836 		 */
837 		G_RAID_LOGREQ(2, bp, "Couldn't retry read, failing it");
838 	}
839 	if (bp->bio_cmd == BIO_READ &&
840 	    bp->bio_error == 0 &&
841 	    pbp->bio_children > 1 &&
842 	    pbp->bio_driver1 != NULL) {
843 		/*
844 		 * If it was a read, and bio_children is >1, then we just
845 		 * recovered the data from the second drive.  We should try to
846 		 * write that data to the first drive if sector remapping is
847 		 * enabled.  A write should put the data in a new place on the
848 		 * disk, remapping the bad sector.  Do we need to do that by
849 		 * queueing a request to the main worker thread?  It doesn't
850 		 * affect the return code of this current read, and can be
851 		 * done at our liesure.  However, to make the code simpler, it
852 		 * is done syncrhonously.
853 		 */
854 		G_RAID_LOGREQ(3, bp, "Recovered data from other drive");
855 		cbp = g_clone_bio(pbp);
856 		if (cbp != NULL) {
857 			g_destroy_bio(bp);
858 			cbp->bio_cmd = BIO_WRITE;
859 			cbp->bio_cflags = G_RAID_BIO_FLAG_REMAP;
860 			G_RAID_LOGREQ(2, cbp,
861 			    "Attempting bad sector remap on failing drive.");
862 			g_raid_subdisk_iostart(pbp->bio_driver1, cbp);
863 			return;
864 		}
865 	}
866 	if (pbp->bio_pflags & G_RAID_BIO_FLAG_LOCKED) {
867 		/*
868 		 * We're done with a recovery, mark the range as unlocked.
869 		 * For any write errors, we agressively fail the disk since
870 		 * there was both a READ and a WRITE error at this location.
871 		 * Both types of errors generally indicates the drive is on
872 		 * the verge of total failure anyway.  Better to stop trusting
873 		 * it now.  However, we need to reset error to 0 in that case
874 		 * because we're not failing the original I/O which succeeded.
875 		 */
876 		if (bp->bio_cmd == BIO_WRITE && bp->bio_error) {
877 			G_RAID_LOGREQ(0, bp, "Remap write failed: "
878 			    "failing subdisk.");
879 			g_raid_tr_raid1_fail_disk(sd->sd_softc, sd, sd->sd_disk);
880 			bp->bio_error = 0;
881 		}
882 		if (pbp->bio_driver1 != NULL) {
883 			((struct g_raid_subdisk *)pbp->bio_driver1)
884 			    ->sd_recovery--;
885 		}
886 		G_RAID_LOGREQ(2, bp, "REMAP done %d.", bp->bio_error);
887 		g_raid_unlock_range(sd->sd_volume, bp->bio_offset,
888 		    bp->bio_length);
889 	}
890 	if (pbp->bio_cmd != BIO_READ) {
891 		if (pbp->bio_inbed == 1 || pbp->bio_error != 0)
892 			pbp->bio_error = bp->bio_error;
893 		if (pbp->bio_cmd == BIO_WRITE && bp->bio_error != 0) {
894 			G_RAID_LOGREQ(0, bp, "Write failed: failing subdisk.");
895 			g_raid_tr_raid1_fail_disk(sd->sd_softc, sd, sd->sd_disk);
896 		}
897 		error = pbp->bio_error;
898 	} else
899 		error = bp->bio_error;
900 	g_destroy_bio(bp);
901 	if (pbp->bio_children == pbp->bio_inbed) {
902 		pbp->bio_completed = pbp->bio_length;
903 		g_raid_iodone(pbp, error);
904 	}
905 }
906 
907 static int
908 g_raid_tr_kerneldump_raid1(struct g_raid_tr_object *tr,
909     void *virtual, vm_offset_t physical, off_t offset, size_t length)
910 {
911 	struct g_raid_volume *vol;
912 	struct g_raid_subdisk *sd;
913 	int error, i, ok;
914 
915 	vol = tr->tro_volume;
916 	error = 0;
917 	ok = 0;
918 	for (i = 0; i < vol->v_disks_count; i++) {
919 		sd = &vol->v_subdisks[i];
920 		switch (sd->sd_state) {
921 		case G_RAID_SUBDISK_S_ACTIVE:
922 			break;
923 		case G_RAID_SUBDISK_S_REBUILD:
924 			/*
925 			 * When rebuilding, only part of this subdisk is
926 			 * writable, the rest will be written as part of the
927 			 * that process.
928 			 */
929 			if (offset >= sd->sd_rebuild_pos)
930 				continue;
931 			break;
932 		case G_RAID_SUBDISK_S_STALE:
933 		case G_RAID_SUBDISK_S_RESYNC:
934 			/*
935 			 * Resyncing still writes on the theory that the
936 			 * resync'd disk is very close and writing it will
937 			 * keep it that way better if we keep up while
938 			 * resyncing.
939 			 */
940 			break;
941 		default:
942 			continue;
943 		}
944 		error = g_raid_subdisk_kerneldump(sd,
945 		    virtual, physical, offset, length);
946 		if (error == 0)
947 			ok++;
948 	}
949 	return (ok > 0 ? 0 : error);
950 }
951 
952 static int
953 g_raid_tr_locked_raid1(struct g_raid_tr_object *tr, void *argp)
954 {
955 	struct bio *bp;
956 	struct g_raid_subdisk *sd;
957 
958 	bp = (struct bio *)argp;
959 	sd = (struct g_raid_subdisk *)bp->bio_caller1;
960 	g_raid_subdisk_iostart(sd, bp);
961 
962 	return (0);
963 }
964 
965 static int
966 g_raid_tr_idle_raid1(struct g_raid_tr_object *tr)
967 {
968 	struct g_raid_tr_raid1_object *trs;
969 
970 	trs = (struct g_raid_tr_raid1_object *)tr;
971 	trs->trso_fair_io = g_raid1_rebuild_fair_io;
972 	trs->trso_recover_slabs = g_raid1_rebuild_cluster_idle;
973 	if (trs->trso_type == TR_RAID1_REBUILD)
974 		g_raid_tr_raid1_rebuild_some(tr);
975 	return (0);
976 }
977 
978 static int
979 g_raid_tr_free_raid1(struct g_raid_tr_object *tr)
980 {
981 	struct g_raid_tr_raid1_object *trs;
982 
983 	trs = (struct g_raid_tr_raid1_object *)tr;
984 
985 	if (trs->trso_buffer != NULL) {
986 		free(trs->trso_buffer, M_TR_RAID1);
987 		trs->trso_buffer = NULL;
988 	}
989 	return (0);
990 }
991 
992 G_RAID_TR_DECLARE(raid1, "RAID1");
993