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