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: releng/11.0/sys/geom/raid/tr_raid1.c 298808 2016-04-29 20:56:58Z pfg $");
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
45SYSCTL_DECL(_kern_geom_raid_raid1);
46
47#define RAID1_REBUILD_SLAB	(1 << 20) /* One transation in a rebuild */
48static int g_raid1_rebuild_slab = RAID1_REBUILD_SLAB;
49SYSCTL_UINT(_kern_geom_raid_raid1, OID_AUTO, rebuild_slab_size, CTLFLAG_RWTUN,
50    &g_raid1_rebuild_slab, 0,
51    "Amount of the disk to rebuild each read/write cycle of the rebuild.");
52
53#define RAID1_REBUILD_FAIR_IO 20 /* use 1/x of the available I/O */
54static int g_raid1_rebuild_fair_io = RAID1_REBUILD_FAIR_IO;
55SYSCTL_UINT(_kern_geom_raid_raid1, OID_AUTO, rebuild_fair_io, CTLFLAG_RWTUN,
56    &g_raid1_rebuild_fair_io, 0,
57    "Fraction of the I/O bandwidth to use when disk busy for rebuild.");
58
59#define RAID1_REBUILD_CLUSTER_IDLE 100
60static int g_raid1_rebuild_cluster_idle = RAID1_REBUILD_CLUSTER_IDLE;
61SYSCTL_UINT(_kern_geom_raid_raid1, OID_AUTO, rebuild_cluster_idle, CTLFLAG_RWTUN,
62    &g_raid1_rebuild_cluster_idle, 0,
63    "Number of slabs to do each time we trigger a rebuild cycle");
64
65#define RAID1_REBUILD_META_UPDATE 1024 /* update meta data every 1GB or so */
66static int g_raid1_rebuild_meta_update = RAID1_REBUILD_META_UPDATE;
67SYSCTL_UINT(_kern_geom_raid_raid1, OID_AUTO, rebuild_meta_update, CTLFLAG_RWTUN,
68    &g_raid1_rebuild_meta_update, 0,
69    "When to update the meta data.");
70
71static MALLOC_DEFINE(M_TR_RAID1, "tr_raid1_data", "GEOM_RAID RAID1 data");
72
73#define TR_RAID1_NONE 0
74#define TR_RAID1_REBUILD 1
75#define TR_RAID1_RESYNC 2
76
77#define TR_RAID1_F_DOING_SOME	0x1
78#define TR_RAID1_F_LOCKED	0x2
79#define TR_RAID1_F_ABORT	0x4
80
81struct g_raid_tr_raid1_object {
82	struct g_raid_tr_object	 trso_base;
83	int			 trso_starting;
84	int			 trso_stopping;
85	int			 trso_type;
86	int			 trso_recover_slabs; /* slabs before rest */
87	int			 trso_fair_io;
88	int			 trso_meta_update;
89	int			 trso_flags;
90	struct g_raid_subdisk	*trso_failed_sd; /* like per volume */
91	void			*trso_buffer;	 /* Buffer space */
92	struct bio		 trso_bio;
93};
94
95static g_raid_tr_taste_t g_raid_tr_taste_raid1;
96static g_raid_tr_event_t g_raid_tr_event_raid1;
97static g_raid_tr_start_t g_raid_tr_start_raid1;
98static g_raid_tr_stop_t g_raid_tr_stop_raid1;
99static g_raid_tr_iostart_t g_raid_tr_iostart_raid1;
100static g_raid_tr_iodone_t g_raid_tr_iodone_raid1;
101static g_raid_tr_kerneldump_t g_raid_tr_kerneldump_raid1;
102static g_raid_tr_locked_t g_raid_tr_locked_raid1;
103static g_raid_tr_idle_t g_raid_tr_idle_raid1;
104static g_raid_tr_free_t g_raid_tr_free_raid1;
105
106static kobj_method_t g_raid_tr_raid1_methods[] = {
107	KOBJMETHOD(g_raid_tr_taste,	g_raid_tr_taste_raid1),
108	KOBJMETHOD(g_raid_tr_event,	g_raid_tr_event_raid1),
109	KOBJMETHOD(g_raid_tr_start,	g_raid_tr_start_raid1),
110	KOBJMETHOD(g_raid_tr_stop,	g_raid_tr_stop_raid1),
111	KOBJMETHOD(g_raid_tr_iostart,	g_raid_tr_iostart_raid1),
112	KOBJMETHOD(g_raid_tr_iodone,	g_raid_tr_iodone_raid1),
113	KOBJMETHOD(g_raid_tr_kerneldump, g_raid_tr_kerneldump_raid1),
114	KOBJMETHOD(g_raid_tr_locked,	g_raid_tr_locked_raid1),
115	KOBJMETHOD(g_raid_tr_idle,	g_raid_tr_idle_raid1),
116	KOBJMETHOD(g_raid_tr_free,	g_raid_tr_free_raid1),
117	{ 0, 0 }
118};
119
120static struct g_raid_tr_class g_raid_tr_raid1_class = {
121	"RAID1",
122	g_raid_tr_raid1_methods,
123	sizeof(struct g_raid_tr_raid1_object),
124	.trc_enable = 1,
125	.trc_priority = 100,
126	.trc_accept_unmapped = 1
127};
128
129static void g_raid_tr_raid1_rebuild_abort(struct g_raid_tr_object *tr);
130static void g_raid_tr_raid1_maybe_rebuild(struct g_raid_tr_object *tr,
131    struct g_raid_subdisk *sd);
132
133static int
134g_raid_tr_taste_raid1(struct g_raid_tr_object *tr, struct g_raid_volume *vol)
135{
136	struct g_raid_tr_raid1_object *trs;
137
138	trs = (struct g_raid_tr_raid1_object *)tr;
139	if (tr->tro_volume->v_raid_level != G_RAID_VOLUME_RL_RAID1 ||
140	    (tr->tro_volume->v_raid_level_qualifier != G_RAID_VOLUME_RLQ_R1SM &&
141	     tr->tro_volume->v_raid_level_qualifier != G_RAID_VOLUME_RLQ_R1MM))
142		return (G_RAID_TR_TASTE_FAIL);
143	trs->trso_starting = 1;
144	return (G_RAID_TR_TASTE_SUCCEED);
145}
146
147static int
148g_raid_tr_update_state_raid1(struct g_raid_volume *vol,
149    struct g_raid_subdisk *sd)
150{
151	struct g_raid_tr_raid1_object *trs;
152	struct g_raid_softc *sc;
153	struct g_raid_subdisk *tsd, *bestsd;
154	u_int s;
155	int i, na, ns;
156
157	sc = vol->v_softc;
158	trs = (struct g_raid_tr_raid1_object *)vol->v_tr;
159	if (trs->trso_stopping &&
160	    (trs->trso_flags & TR_RAID1_F_DOING_SOME) == 0)
161		s = G_RAID_VOLUME_S_STOPPED;
162	else if (trs->trso_starting)
163		s = G_RAID_VOLUME_S_STARTING;
164	else {
165		/* Make sure we have at least one ACTIVE disk. */
166		na = g_raid_nsubdisks(vol, G_RAID_SUBDISK_S_ACTIVE);
167		if (na == 0) {
168			/*
169			 * Critical situation! We have no any active disk!
170			 * Choose the best disk we have to make it active.
171			 */
172			bestsd = &vol->v_subdisks[0];
173			for (i = 1; i < vol->v_disks_count; i++) {
174				tsd = &vol->v_subdisks[i];
175				if (tsd->sd_state > bestsd->sd_state)
176					bestsd = tsd;
177				else if (tsd->sd_state == bestsd->sd_state &&
178				    (tsd->sd_state == G_RAID_SUBDISK_S_REBUILD ||
179				     tsd->sd_state == G_RAID_SUBDISK_S_RESYNC) &&
180				    tsd->sd_rebuild_pos > bestsd->sd_rebuild_pos)
181					bestsd = tsd;
182			}
183			if (bestsd->sd_state >= G_RAID_SUBDISK_S_UNINITIALIZED) {
184				/* We found reasonable candidate. */
185				G_RAID_DEBUG1(1, sc,
186				    "Promote subdisk %s:%d from %s to ACTIVE.",
187				    vol->v_name, bestsd->sd_pos,
188				    g_raid_subdisk_state2str(bestsd->sd_state));
189				g_raid_change_subdisk_state(bestsd,
190				    G_RAID_SUBDISK_S_ACTIVE);
191				g_raid_write_metadata(sc,
192				    vol, bestsd, bestsd->sd_disk);
193			}
194		}
195		na = g_raid_nsubdisks(vol, G_RAID_SUBDISK_S_ACTIVE);
196		ns = g_raid_nsubdisks(vol, G_RAID_SUBDISK_S_STALE) +
197		     g_raid_nsubdisks(vol, G_RAID_SUBDISK_S_RESYNC);
198		if (na == vol->v_disks_count)
199			s = G_RAID_VOLUME_S_OPTIMAL;
200		else if (na + ns == vol->v_disks_count)
201			s = G_RAID_VOLUME_S_SUBOPTIMAL;
202		else if (na > 0)
203			s = G_RAID_VOLUME_S_DEGRADED;
204		else
205			s = G_RAID_VOLUME_S_BROKEN;
206		g_raid_tr_raid1_maybe_rebuild(vol->v_tr, sd);
207	}
208	if (s != vol->v_state) {
209		g_raid_event_send(vol, G_RAID_VOLUME_S_ALIVE(s) ?
210		    G_RAID_VOLUME_E_UP : G_RAID_VOLUME_E_DOWN,
211		    G_RAID_EVENT_VOLUME);
212		g_raid_change_volume_state(vol, s);
213		if (!trs->trso_starting && !trs->trso_stopping)
214			g_raid_write_metadata(sc, vol, NULL, NULL);
215	}
216	return (0);
217}
218
219static void
220g_raid_tr_raid1_fail_disk(struct g_raid_softc *sc, struct g_raid_subdisk *sd,
221    struct g_raid_disk *disk)
222{
223	/*
224	 * We don't fail the last disk in the pack, since it still has decent
225	 * data on it and that's better than failing the disk if it is the root
226	 * file system.
227	 *
228	 * XXX should this be controlled via a tunable?  It makes sense for
229	 * the volume that has / on it.  I can't think of a case where we'd
230	 * want the volume to go away on this kind of event.
231	 */
232	if (g_raid_nsubdisks(sd->sd_volume, G_RAID_SUBDISK_S_ACTIVE) == 1 &&
233	    g_raid_get_subdisk(sd->sd_volume, G_RAID_SUBDISK_S_ACTIVE) == sd)
234		return;
235	g_raid_fail_disk(sc, sd, disk);
236}
237
238static void
239g_raid_tr_raid1_rebuild_some(struct g_raid_tr_object *tr)
240{
241	struct g_raid_tr_raid1_object *trs;
242	struct g_raid_subdisk *sd, *good_sd;
243	struct bio *bp;
244
245	trs = (struct g_raid_tr_raid1_object *)tr;
246	if (trs->trso_flags & TR_RAID1_F_DOING_SOME)
247		return;
248	sd = trs->trso_failed_sd;
249	good_sd = g_raid_get_subdisk(sd->sd_volume, G_RAID_SUBDISK_S_ACTIVE);
250	if (good_sd == NULL) {
251		g_raid_tr_raid1_rebuild_abort(tr);
252		return;
253	}
254	bp = &trs->trso_bio;
255	memset(bp, 0, sizeof(*bp));
256	bp->bio_offset = sd->sd_rebuild_pos;
257	bp->bio_length = MIN(g_raid1_rebuild_slab,
258	    sd->sd_size - sd->sd_rebuild_pos);
259	bp->bio_data = trs->trso_buffer;
260	bp->bio_cmd = BIO_READ;
261	bp->bio_cflags = G_RAID_BIO_FLAG_SYNC;
262	bp->bio_caller1 = good_sd;
263	trs->trso_flags |= TR_RAID1_F_DOING_SOME;
264	trs->trso_flags |= TR_RAID1_F_LOCKED;
265	g_raid_lock_range(sd->sd_volume,	/* Lock callback starts I/O */
266	   bp->bio_offset, bp->bio_length, NULL, bp);
267}
268
269static void
270g_raid_tr_raid1_rebuild_done(struct g_raid_tr_raid1_object *trs)
271{
272	struct g_raid_volume *vol;
273	struct g_raid_subdisk *sd;
274
275	vol = trs->trso_base.tro_volume;
276	sd = trs->trso_failed_sd;
277	g_raid_write_metadata(vol->v_softc, vol, sd, sd->sd_disk);
278	free(trs->trso_buffer, M_TR_RAID1);
279	trs->trso_buffer = NULL;
280	trs->trso_flags &= ~TR_RAID1_F_DOING_SOME;
281	trs->trso_type = TR_RAID1_NONE;
282	trs->trso_recover_slabs = 0;
283	trs->trso_failed_sd = NULL;
284	g_raid_tr_update_state_raid1(vol, NULL);
285}
286
287static void
288g_raid_tr_raid1_rebuild_finish(struct g_raid_tr_object *tr)
289{
290	struct g_raid_tr_raid1_object *trs;
291	struct g_raid_subdisk *sd;
292
293	trs = (struct g_raid_tr_raid1_object *)tr;
294	sd = trs->trso_failed_sd;
295	G_RAID_DEBUG1(0, tr->tro_volume->v_softc,
296	    "Subdisk %s:%d-%s rebuild completed.",
297	    sd->sd_volume->v_name, sd->sd_pos,
298	    sd->sd_disk ? g_raid_get_diskname(sd->sd_disk) : "[none]");
299	g_raid_change_subdisk_state(sd, G_RAID_SUBDISK_S_ACTIVE);
300	sd->sd_rebuild_pos = 0;
301	g_raid_tr_raid1_rebuild_done(trs);
302}
303
304static void
305g_raid_tr_raid1_rebuild_abort(struct g_raid_tr_object *tr)
306{
307	struct g_raid_tr_raid1_object *trs;
308	struct g_raid_subdisk *sd;
309	struct g_raid_volume *vol;
310	off_t len;
311
312	vol = tr->tro_volume;
313	trs = (struct g_raid_tr_raid1_object *)tr;
314	sd = trs->trso_failed_sd;
315	if (trs->trso_flags & TR_RAID1_F_DOING_SOME) {
316		G_RAID_DEBUG1(1, vol->v_softc,
317		    "Subdisk %s:%d-%s rebuild is aborting.",
318		    sd->sd_volume->v_name, sd->sd_pos,
319		    sd->sd_disk ? g_raid_get_diskname(sd->sd_disk) : "[none]");
320		trs->trso_flags |= TR_RAID1_F_ABORT;
321	} else {
322		G_RAID_DEBUG1(0, vol->v_softc,
323		    "Subdisk %s:%d-%s rebuild aborted.",
324		    sd->sd_volume->v_name, sd->sd_pos,
325		    sd->sd_disk ? g_raid_get_diskname(sd->sd_disk) : "[none]");
326		trs->trso_flags &= ~TR_RAID1_F_ABORT;
327		if (trs->trso_flags & TR_RAID1_F_LOCKED) {
328			trs->trso_flags &= ~TR_RAID1_F_LOCKED;
329			len = MIN(g_raid1_rebuild_slab,
330			    sd->sd_size - sd->sd_rebuild_pos);
331			g_raid_unlock_range(tr->tro_volume,
332			    sd->sd_rebuild_pos, len);
333		}
334		g_raid_tr_raid1_rebuild_done(trs);
335	}
336}
337
338static void
339g_raid_tr_raid1_rebuild_start(struct g_raid_tr_object *tr)
340{
341	struct g_raid_volume *vol;
342	struct g_raid_tr_raid1_object *trs;
343	struct g_raid_subdisk *sd, *fsd;
344
345	vol = tr->tro_volume;
346	trs = (struct g_raid_tr_raid1_object *)tr;
347	if (trs->trso_failed_sd) {
348		G_RAID_DEBUG1(1, vol->v_softc,
349		    "Already rebuild in start rebuild. pos %jd\n",
350		    (intmax_t)trs->trso_failed_sd->sd_rebuild_pos);
351		return;
352	}
353	sd = g_raid_get_subdisk(vol, G_RAID_SUBDISK_S_ACTIVE);
354	if (sd == NULL) {
355		G_RAID_DEBUG1(1, vol->v_softc,
356		    "No active disk to rebuild.  night night.");
357		return;
358	}
359	fsd = g_raid_get_subdisk(vol, G_RAID_SUBDISK_S_RESYNC);
360	if (fsd == NULL)
361		fsd = g_raid_get_subdisk(vol, G_RAID_SUBDISK_S_REBUILD);
362	if (fsd == NULL) {
363		fsd = g_raid_get_subdisk(vol, G_RAID_SUBDISK_S_STALE);
364		if (fsd != NULL) {
365			fsd->sd_rebuild_pos = 0;
366			g_raid_change_subdisk_state(fsd,
367			    G_RAID_SUBDISK_S_RESYNC);
368			g_raid_write_metadata(vol->v_softc, vol, fsd, NULL);
369		} else {
370			fsd = g_raid_get_subdisk(vol,
371			    G_RAID_SUBDISK_S_UNINITIALIZED);
372			if (fsd == NULL)
373				fsd = g_raid_get_subdisk(vol,
374				    G_RAID_SUBDISK_S_NEW);
375			if (fsd != NULL) {
376				fsd->sd_rebuild_pos = 0;
377				g_raid_change_subdisk_state(fsd,
378				    G_RAID_SUBDISK_S_REBUILD);
379				g_raid_write_metadata(vol->v_softc,
380				    vol, fsd, NULL);
381			}
382		}
383	}
384	if (fsd == NULL) {
385		G_RAID_DEBUG1(1, vol->v_softc,
386		    "No failed disk to rebuild.  night night.");
387		return;
388	}
389	trs->trso_failed_sd = fsd;
390	G_RAID_DEBUG1(0, vol->v_softc,
391	    "Subdisk %s:%d-%s rebuild start at %jd.",
392	    fsd->sd_volume->v_name, fsd->sd_pos,
393	    fsd->sd_disk ? g_raid_get_diskname(fsd->sd_disk) : "[none]",
394	    trs->trso_failed_sd->sd_rebuild_pos);
395	trs->trso_type = TR_RAID1_REBUILD;
396	trs->trso_buffer = malloc(g_raid1_rebuild_slab, M_TR_RAID1, M_WAITOK);
397	trs->trso_meta_update = g_raid1_rebuild_meta_update;
398	g_raid_tr_raid1_rebuild_some(tr);
399}
400
401
402static void
403g_raid_tr_raid1_maybe_rebuild(struct g_raid_tr_object *tr,
404    struct g_raid_subdisk *sd)
405{
406	struct g_raid_volume *vol;
407	struct g_raid_tr_raid1_object *trs;
408	int na, nr;
409
410	/*
411	 * If we're stopping, don't do anything.  If we don't have at least one
412	 * good disk and one bad disk, we don't do anything.  And if there's a
413	 * 'good disk' stored in the trs, then we're in progress and we punt.
414	 * If we make it past all these checks, we need to rebuild.
415	 */
416	vol = tr->tro_volume;
417	trs = (struct g_raid_tr_raid1_object *)tr;
418	if (trs->trso_stopping)
419		return;
420	na = g_raid_nsubdisks(vol, G_RAID_SUBDISK_S_ACTIVE);
421	nr = g_raid_nsubdisks(vol, G_RAID_SUBDISK_S_REBUILD) +
422	    g_raid_nsubdisks(vol, G_RAID_SUBDISK_S_RESYNC);
423	switch(trs->trso_type) {
424	case TR_RAID1_NONE:
425		if (na == 0)
426			return;
427		if (nr == 0) {
428			nr = g_raid_nsubdisks(vol, G_RAID_SUBDISK_S_NEW) +
429			    g_raid_nsubdisks(vol, G_RAID_SUBDISK_S_STALE) +
430			    g_raid_nsubdisks(vol, G_RAID_SUBDISK_S_UNINITIALIZED);
431			if (nr == 0)
432				return;
433		}
434		g_raid_tr_raid1_rebuild_start(tr);
435		break;
436	case TR_RAID1_REBUILD:
437		if (na == 0 || nr == 0 || trs->trso_failed_sd == sd)
438			g_raid_tr_raid1_rebuild_abort(tr);
439		break;
440	case TR_RAID1_RESYNC:
441		break;
442	}
443}
444
445static int
446g_raid_tr_event_raid1(struct g_raid_tr_object *tr,
447    struct g_raid_subdisk *sd, u_int event)
448{
449
450	g_raid_tr_update_state_raid1(tr->tro_volume, sd);
451	return (0);
452}
453
454static int
455g_raid_tr_start_raid1(struct g_raid_tr_object *tr)
456{
457	struct g_raid_tr_raid1_object *trs;
458	struct g_raid_volume *vol;
459
460	trs = (struct g_raid_tr_raid1_object *)tr;
461	vol = tr->tro_volume;
462	trs->trso_starting = 0;
463	g_raid_tr_update_state_raid1(vol, NULL);
464	return (0);
465}
466
467static int
468g_raid_tr_stop_raid1(struct g_raid_tr_object *tr)
469{
470	struct g_raid_tr_raid1_object *trs;
471	struct g_raid_volume *vol;
472
473	trs = (struct g_raid_tr_raid1_object *)tr;
474	vol = tr->tro_volume;
475	trs->trso_starting = 0;
476	trs->trso_stopping = 1;
477	g_raid_tr_update_state_raid1(vol, NULL);
478	return (0);
479}
480
481/*
482 * Select the disk to read from.  Take into account: subdisk state, running
483 * error recovery, average disk load, head position and possible cache hits.
484 */
485#define ABS(x)		(((x) >= 0) ? (x) : (-(x)))
486static struct g_raid_subdisk *
487g_raid_tr_raid1_select_read_disk(struct g_raid_volume *vol, struct bio *bp,
488    u_int mask)
489{
490	struct g_raid_subdisk *sd, *best;
491	int i, prio, bestprio;
492
493	best = NULL;
494	bestprio = INT_MAX;
495	for (i = 0; i < vol->v_disks_count; i++) {
496		sd = &vol->v_subdisks[i];
497		if (sd->sd_state != G_RAID_SUBDISK_S_ACTIVE &&
498		    ((sd->sd_state != G_RAID_SUBDISK_S_REBUILD &&
499		      sd->sd_state != G_RAID_SUBDISK_S_RESYNC) ||
500		     bp->bio_offset + bp->bio_length > sd->sd_rebuild_pos))
501			continue;
502		if ((mask & (1 << i)) != 0)
503			continue;
504		prio = G_RAID_SUBDISK_LOAD(sd);
505		prio += min(sd->sd_recovery, 255) << 22;
506		prio += (G_RAID_SUBDISK_S_ACTIVE - sd->sd_state) << 16;
507		/* If disk head is precisely in position - highly prefer it. */
508		if (G_RAID_SUBDISK_POS(sd) == bp->bio_offset)
509			prio -= 2 * G_RAID_SUBDISK_LOAD_SCALE;
510		else
511		/* If disk head is close to position - prefer it. */
512		if (ABS(G_RAID_SUBDISK_POS(sd) - bp->bio_offset) <
513		    G_RAID_SUBDISK_TRACK_SIZE)
514			prio -= 1 * G_RAID_SUBDISK_LOAD_SCALE;
515		if (prio < bestprio) {
516			best = sd;
517			bestprio = prio;
518		}
519	}
520	return (best);
521}
522
523static void
524g_raid_tr_iostart_raid1_read(struct g_raid_tr_object *tr, struct bio *bp)
525{
526	struct g_raid_subdisk *sd;
527	struct bio *cbp;
528
529	sd = g_raid_tr_raid1_select_read_disk(tr->tro_volume, bp, 0);
530	KASSERT(sd != NULL, ("No active disks in volume %s.",
531		tr->tro_volume->v_name));
532
533	cbp = g_clone_bio(bp);
534	if (cbp == NULL) {
535		g_raid_iodone(bp, ENOMEM);
536		return;
537	}
538
539	g_raid_subdisk_iostart(sd, cbp);
540}
541
542static void
543g_raid_tr_iostart_raid1_write(struct g_raid_tr_object *tr, struct bio *bp)
544{
545	struct g_raid_volume *vol;
546	struct g_raid_subdisk *sd;
547	struct bio_queue_head queue;
548	struct bio *cbp;
549	int i;
550
551	vol = tr->tro_volume;
552
553	/*
554	 * Allocate all bios before sending any request, so we can return
555	 * ENOMEM in nice and clean way.
556	 */
557	bioq_init(&queue);
558	for (i = 0; i < vol->v_disks_count; i++) {
559		sd = &vol->v_subdisks[i];
560		switch (sd->sd_state) {
561		case G_RAID_SUBDISK_S_ACTIVE:
562			break;
563		case G_RAID_SUBDISK_S_REBUILD:
564			/*
565			 * When rebuilding, only part of this subdisk is
566			 * writable, the rest will be written as part of the
567			 * that process.
568			 */
569			if (bp->bio_offset >= sd->sd_rebuild_pos)
570				continue;
571			break;
572		case G_RAID_SUBDISK_S_STALE:
573		case G_RAID_SUBDISK_S_RESYNC:
574			/*
575			 * Resyncing still writes on the theory that the
576			 * resync'd disk is very close and writing it will
577			 * keep it that way better if we keep up while
578			 * resyncing.
579			 */
580			break;
581		default:
582			continue;
583		}
584		cbp = g_clone_bio(bp);
585		if (cbp == NULL)
586			goto failure;
587		cbp->bio_caller1 = sd;
588		bioq_insert_tail(&queue, cbp);
589	}
590	while ((cbp = bioq_takefirst(&queue)) != NULL) {
591		sd = cbp->bio_caller1;
592		cbp->bio_caller1 = NULL;
593		g_raid_subdisk_iostart(sd, cbp);
594	}
595	return;
596failure:
597	while ((cbp = bioq_takefirst(&queue)) != NULL)
598		g_destroy_bio(cbp);
599	if (bp->bio_error == 0)
600		bp->bio_error = ENOMEM;
601	g_raid_iodone(bp, bp->bio_error);
602}
603
604static void
605g_raid_tr_iostart_raid1(struct g_raid_tr_object *tr, struct bio *bp)
606{
607	struct g_raid_volume *vol;
608	struct g_raid_tr_raid1_object *trs;
609
610	vol = tr->tro_volume;
611	trs = (struct g_raid_tr_raid1_object *)tr;
612	if (vol->v_state != G_RAID_VOLUME_S_OPTIMAL &&
613	    vol->v_state != G_RAID_VOLUME_S_SUBOPTIMAL &&
614	    vol->v_state != G_RAID_VOLUME_S_DEGRADED) {
615		g_raid_iodone(bp, EIO);
616		return;
617	}
618	/*
619	 * If we're rebuilding, squeeze in rebuild activity every so often,
620	 * even when the disk is busy.  Be sure to only count real I/O
621	 * to the disk.  All 'SPECIAL' I/O is traffic generated to the disk
622	 * by this module.
623	 */
624	if (trs->trso_failed_sd != NULL &&
625	    !(bp->bio_cflags & G_RAID_BIO_FLAG_SPECIAL)) {
626		/* Make this new or running now round short. */
627		trs->trso_recover_slabs = 0;
628		if (--trs->trso_fair_io <= 0) {
629			trs->trso_fair_io = g_raid1_rebuild_fair_io;
630			g_raid_tr_raid1_rebuild_some(tr);
631		}
632	}
633	switch (bp->bio_cmd) {
634	case BIO_READ:
635		g_raid_tr_iostart_raid1_read(tr, bp);
636		break;
637	case BIO_WRITE:
638	case BIO_DELETE:
639		g_raid_tr_iostart_raid1_write(tr, bp);
640		break;
641	case BIO_FLUSH:
642		g_raid_tr_flush_common(tr, bp);
643		break;
644	default:
645		KASSERT(1 == 0, ("Invalid command here: %u (volume=%s)",
646		    bp->bio_cmd, vol->v_name));
647		break;
648	}
649}
650
651static void
652g_raid_tr_iodone_raid1(struct g_raid_tr_object *tr,
653    struct g_raid_subdisk *sd, struct bio *bp)
654{
655	struct bio *cbp;
656	struct g_raid_subdisk *nsd;
657	struct g_raid_volume *vol;
658	struct bio *pbp;
659	struct g_raid_tr_raid1_object *trs;
660	uintptr_t *mask;
661	int error, do_write;
662
663	trs = (struct g_raid_tr_raid1_object *)tr;
664	vol = tr->tro_volume;
665	if (bp->bio_cflags & G_RAID_BIO_FLAG_SYNC) {
666		/*
667		 * This operation is part of a rebuild or resync operation.
668		 * See what work just got done, then schedule the next bit of
669		 * work, if any.  Rebuild/resync is done a little bit at a
670		 * time.  Either when a timeout happens, or after we get a
671		 * bunch of I/Os to the disk (to make sure an active system
672		 * will complete in a sane amount of time).
673		 *
674		 * We are setup to do differing amounts of work for each of
675		 * these cases.  so long as the slabs is smallish (less than
676		 * 50 or so, I'd guess, but that's just a WAG), we shouldn't
677		 * have any bio starvation issues.  For active disks, we do
678		 * 5MB of data, for inactive ones, we do 50MB.
679		 */
680		if (trs->trso_type == TR_RAID1_REBUILD) {
681			if (bp->bio_cmd == BIO_READ) {
682
683				/* Immediately abort rebuild, if requested. */
684				if (trs->trso_flags & TR_RAID1_F_ABORT) {
685					trs->trso_flags &= ~TR_RAID1_F_DOING_SOME;
686					g_raid_tr_raid1_rebuild_abort(tr);
687					return;
688				}
689
690				/* On read error, skip and cross fingers. */
691				if (bp->bio_error != 0) {
692					G_RAID_LOGREQ(0, bp,
693					    "Read error during rebuild (%d), "
694					    "possible data loss!",
695					    bp->bio_error);
696					goto rebuild_round_done;
697				}
698
699				/*
700				 * The read operation finished, queue the
701				 * write and get out.
702				 */
703				G_RAID_LOGREQ(4, bp, "rebuild read done. %d",
704				    bp->bio_error);
705				bp->bio_cmd = BIO_WRITE;
706				bp->bio_cflags = G_RAID_BIO_FLAG_SYNC;
707				G_RAID_LOGREQ(4, bp, "Queueing rebuild write.");
708				g_raid_subdisk_iostart(trs->trso_failed_sd, bp);
709			} else {
710				/*
711				 * The write operation just finished.  Do
712				 * another.  We keep cloning the master bio
713				 * since it has the right buffers allocated to
714				 * it.
715				 */
716				G_RAID_LOGREQ(4, bp,
717				    "rebuild write done. Error %d",
718				    bp->bio_error);
719				nsd = trs->trso_failed_sd;
720				if (bp->bio_error != 0 ||
721				    trs->trso_flags & TR_RAID1_F_ABORT) {
722					if ((trs->trso_flags &
723					    TR_RAID1_F_ABORT) == 0) {
724						g_raid_tr_raid1_fail_disk(sd->sd_softc,
725						    nsd, nsd->sd_disk);
726					}
727					trs->trso_flags &= ~TR_RAID1_F_DOING_SOME;
728					g_raid_tr_raid1_rebuild_abort(tr);
729					return;
730				}
731rebuild_round_done:
732				nsd = trs->trso_failed_sd;
733				trs->trso_flags &= ~TR_RAID1_F_LOCKED;
734				g_raid_unlock_range(sd->sd_volume,
735				    bp->bio_offset, bp->bio_length);
736				nsd->sd_rebuild_pos += bp->bio_length;
737				if (nsd->sd_rebuild_pos >= nsd->sd_size) {
738					g_raid_tr_raid1_rebuild_finish(tr);
739					return;
740				}
741
742				/* Abort rebuild if we are stopping */
743				if (trs->trso_stopping) {
744					trs->trso_flags &= ~TR_RAID1_F_DOING_SOME;
745					g_raid_tr_raid1_rebuild_abort(tr);
746					return;
747				}
748
749				if (--trs->trso_meta_update <= 0) {
750					g_raid_write_metadata(vol->v_softc,
751					    vol, nsd, nsd->sd_disk);
752					trs->trso_meta_update =
753					    g_raid1_rebuild_meta_update;
754				}
755				trs->trso_flags &= ~TR_RAID1_F_DOING_SOME;
756				if (--trs->trso_recover_slabs <= 0)
757					return;
758				g_raid_tr_raid1_rebuild_some(tr);
759			}
760		} else if (trs->trso_type == TR_RAID1_RESYNC) {
761			/*
762			 * read good sd, read bad sd in parallel.  when both
763			 * done, compare the buffers.  write good to the bad
764			 * if different.  do the next bit of work.
765			 */
766			panic("Somehow, we think we're doing a resync");
767		}
768		return;
769	}
770	pbp = bp->bio_parent;
771	pbp->bio_inbed++;
772	if (bp->bio_cmd == BIO_READ && bp->bio_error != 0) {
773		/*
774		 * Read failed on first drive.  Retry the read error on
775		 * another disk drive, if available, before erroring out the
776		 * read.
777		 */
778		sd->sd_disk->d_read_errs++;
779		G_RAID_LOGREQ(0, bp,
780		    "Read error (%d), %d read errors total",
781		    bp->bio_error, sd->sd_disk->d_read_errs);
782
783		/*
784		 * If there are too many read errors, we move to degraded.
785		 * XXX Do we want to FAIL the drive (eg, make the user redo
786		 * everything to get it back in sync), or just degrade the
787		 * drive, which kicks off a resync?
788		 */
789		do_write = 1;
790		if (sd->sd_disk->d_read_errs > g_raid_read_err_thresh) {
791			g_raid_tr_raid1_fail_disk(sd->sd_softc, sd, sd->sd_disk);
792			if (pbp->bio_children == 1)
793				do_write = 0;
794		}
795
796		/*
797		 * Find the other disk, and try to do the I/O to it.
798		 */
799		mask = (uintptr_t *)(&pbp->bio_driver2);
800		if (pbp->bio_children == 1) {
801			/* Save original subdisk. */
802			pbp->bio_driver1 = do_write ? sd : NULL;
803			*mask = 0;
804		}
805		*mask |= 1 << sd->sd_pos;
806		nsd = g_raid_tr_raid1_select_read_disk(vol, pbp, *mask);
807		if (nsd != NULL && (cbp = g_clone_bio(pbp)) != NULL) {
808			g_destroy_bio(bp);
809			G_RAID_LOGREQ(2, cbp, "Retrying read from %d",
810			    nsd->sd_pos);
811			if (pbp->bio_children == 2 && do_write) {
812				sd->sd_recovery++;
813				cbp->bio_caller1 = nsd;
814				pbp->bio_pflags = G_RAID_BIO_FLAG_LOCKED;
815				/* Lock callback starts I/O */
816				g_raid_lock_range(sd->sd_volume,
817				    cbp->bio_offset, cbp->bio_length, pbp, cbp);
818			} else {
819				g_raid_subdisk_iostart(nsd, cbp);
820			}
821			return;
822		}
823		/*
824		 * We can't retry.  Return the original error by falling
825		 * through.  This will happen when there's only one good disk.
826		 * We don't need to fail the raid, since its actual state is
827		 * based on the state of the subdisks.
828		 */
829		G_RAID_LOGREQ(2, bp, "Couldn't retry read, failing it");
830	}
831	if (bp->bio_cmd == BIO_READ &&
832	    bp->bio_error == 0 &&
833	    pbp->bio_children > 1 &&
834	    pbp->bio_driver1 != NULL) {
835		/*
836		 * If it was a read, and bio_children is >1, then we just
837		 * recovered the data from the second drive.  We should try to
838		 * write that data to the first drive if sector remapping is
839		 * enabled.  A write should put the data in a new place on the
840		 * disk, remapping the bad sector.  Do we need to do that by
841		 * queueing a request to the main worker thread?  It doesn't
842		 * affect the return code of this current read, and can be
843		 * done at our leisure.  However, to make the code simpler, it
844		 * is done synchronously.
845		 */
846		G_RAID_LOGREQ(3, bp, "Recovered data from other drive");
847		cbp = g_clone_bio(pbp);
848		if (cbp != NULL) {
849			g_destroy_bio(bp);
850			cbp->bio_cmd = BIO_WRITE;
851			cbp->bio_cflags = G_RAID_BIO_FLAG_REMAP;
852			G_RAID_LOGREQ(2, cbp,
853			    "Attempting bad sector remap on failing drive.");
854			g_raid_subdisk_iostart(pbp->bio_driver1, cbp);
855			return;
856		}
857	}
858	if (pbp->bio_pflags & G_RAID_BIO_FLAG_LOCKED) {
859		/*
860		 * We're done with a recovery, mark the range as unlocked.
861		 * For any write errors, we aggressively fail the disk since
862		 * there was both a READ and a WRITE error at this location.
863		 * Both types of errors generally indicates the drive is on
864		 * the verge of total failure anyway.  Better to stop trusting
865		 * it now.  However, we need to reset error to 0 in that case
866		 * because we're not failing the original I/O which succeeded.
867		 */
868		if (bp->bio_cmd == BIO_WRITE && bp->bio_error) {
869			G_RAID_LOGREQ(0, bp, "Remap write failed: "
870			    "failing subdisk.");
871			g_raid_tr_raid1_fail_disk(sd->sd_softc, sd, sd->sd_disk);
872			bp->bio_error = 0;
873		}
874		if (pbp->bio_driver1 != NULL) {
875			((struct g_raid_subdisk *)pbp->bio_driver1)
876			    ->sd_recovery--;
877		}
878		G_RAID_LOGREQ(2, bp, "REMAP done %d.", bp->bio_error);
879		g_raid_unlock_range(sd->sd_volume, bp->bio_offset,
880		    bp->bio_length);
881	}
882	if (pbp->bio_cmd != BIO_READ) {
883		if (pbp->bio_inbed == 1 || pbp->bio_error != 0)
884			pbp->bio_error = bp->bio_error;
885		if (pbp->bio_cmd == BIO_WRITE && bp->bio_error != 0) {
886			G_RAID_LOGREQ(0, bp, "Write failed: failing subdisk.");
887			g_raid_tr_raid1_fail_disk(sd->sd_softc, sd, sd->sd_disk);
888		}
889		error = pbp->bio_error;
890	} else
891		error = bp->bio_error;
892	g_destroy_bio(bp);
893	if (pbp->bio_children == pbp->bio_inbed) {
894		pbp->bio_completed = pbp->bio_length;
895		g_raid_iodone(pbp, error);
896	}
897}
898
899static int
900g_raid_tr_kerneldump_raid1(struct g_raid_tr_object *tr,
901    void *virtual, vm_offset_t physical, off_t offset, size_t length)
902{
903	struct g_raid_volume *vol;
904	struct g_raid_subdisk *sd;
905	int error, i, ok;
906
907	vol = tr->tro_volume;
908	error = 0;
909	ok = 0;
910	for (i = 0; i < vol->v_disks_count; i++) {
911		sd = &vol->v_subdisks[i];
912		switch (sd->sd_state) {
913		case G_RAID_SUBDISK_S_ACTIVE:
914			break;
915		case G_RAID_SUBDISK_S_REBUILD:
916			/*
917			 * When rebuilding, only part of this subdisk is
918			 * writable, the rest will be written as part of the
919			 * that process.
920			 */
921			if (offset >= sd->sd_rebuild_pos)
922				continue;
923			break;
924		case G_RAID_SUBDISK_S_STALE:
925		case G_RAID_SUBDISK_S_RESYNC:
926			/*
927			 * Resyncing still writes on the theory that the
928			 * resync'd disk is very close and writing it will
929			 * keep it that way better if we keep up while
930			 * resyncing.
931			 */
932			break;
933		default:
934			continue;
935		}
936		error = g_raid_subdisk_kerneldump(sd,
937		    virtual, physical, offset, length);
938		if (error == 0)
939			ok++;
940	}
941	return (ok > 0 ? 0 : error);
942}
943
944static int
945g_raid_tr_locked_raid1(struct g_raid_tr_object *tr, void *argp)
946{
947	struct bio *bp;
948	struct g_raid_subdisk *sd;
949
950	bp = (struct bio *)argp;
951	sd = (struct g_raid_subdisk *)bp->bio_caller1;
952	g_raid_subdisk_iostart(sd, bp);
953
954	return (0);
955}
956
957static int
958g_raid_tr_idle_raid1(struct g_raid_tr_object *tr)
959{
960	struct g_raid_tr_raid1_object *trs;
961
962	trs = (struct g_raid_tr_raid1_object *)tr;
963	trs->trso_fair_io = g_raid1_rebuild_fair_io;
964	trs->trso_recover_slabs = g_raid1_rebuild_cluster_idle;
965	if (trs->trso_type == TR_RAID1_REBUILD)
966		g_raid_tr_raid1_rebuild_some(tr);
967	return (0);
968}
969
970static int
971g_raid_tr_free_raid1(struct g_raid_tr_object *tr)
972{
973	struct g_raid_tr_raid1_object *trs;
974
975	trs = (struct g_raid_tr_raid1_object *)tr;
976
977	if (trs->trso_buffer != NULL) {
978		free(trs->trso_buffer, M_TR_RAID1);
979		trs->trso_buffer = NULL;
980	}
981	return (0);
982}
983
984G_RAID_TR_DECLARE(raid1, "RAID1");
985