1/*-
2 * SPDX-License-Identifier: BSD-2-Clause
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/param.h>
30#include <sys/bio.h>
31#include <sys/endian.h>
32#include <sys/kernel.h>
33#include <sys/kobj.h>
34#include <sys/limits.h>
35#include <sys/lock.h>
36#include <sys/malloc.h>
37#include <sys/mutex.h>
38#include <sys/sysctl.h>
39#include <sys/systm.h>
40#include <geom/geom.h>
41#include <geom/geom_dbg.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
401static void
402g_raid_tr_raid1_maybe_rebuild(struct g_raid_tr_object *tr,
403    struct g_raid_subdisk *sd)
404{
405	struct g_raid_volume *vol;
406	struct g_raid_tr_raid1_object *trs;
407	int na, nr;
408
409	/*
410	 * If we're stopping, don't do anything.  If we don't have at least one
411	 * good disk and one bad disk, we don't do anything.  And if there's a
412	 * 'good disk' stored in the trs, then we're in progress and we punt.
413	 * If we make it past all these checks, we need to rebuild.
414	 */
415	vol = tr->tro_volume;
416	trs = (struct g_raid_tr_raid1_object *)tr;
417	if (trs->trso_stopping)
418		return;
419	na = g_raid_nsubdisks(vol, G_RAID_SUBDISK_S_ACTIVE);
420	nr = g_raid_nsubdisks(vol, G_RAID_SUBDISK_S_REBUILD) +
421	    g_raid_nsubdisks(vol, G_RAID_SUBDISK_S_RESYNC);
422	switch(trs->trso_type) {
423	case TR_RAID1_NONE:
424		if (na == 0)
425			return;
426		if (nr == 0) {
427			nr = g_raid_nsubdisks(vol, G_RAID_SUBDISK_S_NEW) +
428			    g_raid_nsubdisks(vol, G_RAID_SUBDISK_S_STALE) +
429			    g_raid_nsubdisks(vol, G_RAID_SUBDISK_S_UNINITIALIZED);
430			if (nr == 0)
431				return;
432		}
433		g_raid_tr_raid1_rebuild_start(tr);
434		break;
435	case TR_RAID1_REBUILD:
436		if (na == 0 || nr == 0 || trs->trso_failed_sd == sd)
437			g_raid_tr_raid1_rebuild_abort(tr);
438		break;
439	case TR_RAID1_RESYNC:
440		break;
441	}
442}
443
444static int
445g_raid_tr_event_raid1(struct g_raid_tr_object *tr,
446    struct g_raid_subdisk *sd, u_int event)
447{
448
449	g_raid_tr_update_state_raid1(tr->tro_volume, sd);
450	return (0);
451}
452
453static int
454g_raid_tr_start_raid1(struct g_raid_tr_object *tr)
455{
456	struct g_raid_tr_raid1_object *trs;
457	struct g_raid_volume *vol;
458
459	trs = (struct g_raid_tr_raid1_object *)tr;
460	vol = tr->tro_volume;
461	trs->trso_starting = 0;
462	g_raid_tr_update_state_raid1(vol, NULL);
463	return (0);
464}
465
466static int
467g_raid_tr_stop_raid1(struct g_raid_tr_object *tr)
468{
469	struct g_raid_tr_raid1_object *trs;
470	struct g_raid_volume *vol;
471
472	trs = (struct g_raid_tr_raid1_object *)tr;
473	vol = tr->tro_volume;
474	trs->trso_starting = 0;
475	trs->trso_stopping = 1;
476	g_raid_tr_update_state_raid1(vol, NULL);
477	return (0);
478}
479
480/*
481 * Select the disk to read from.  Take into account: subdisk state, running
482 * error recovery, average disk load, head position and possible cache hits.
483 */
484#define ABS(x)		(((x) >= 0) ? (x) : (-(x)))
485static struct g_raid_subdisk *
486g_raid_tr_raid1_select_read_disk(struct g_raid_volume *vol, struct bio *bp,
487    u_int mask)
488{
489	struct g_raid_subdisk *sd, *best;
490	int i, prio, bestprio;
491
492	best = NULL;
493	bestprio = INT_MAX;
494	for (i = 0; i < vol->v_disks_count; i++) {
495		sd = &vol->v_subdisks[i];
496		if (sd->sd_state != G_RAID_SUBDISK_S_ACTIVE &&
497		    ((sd->sd_state != G_RAID_SUBDISK_S_REBUILD &&
498		      sd->sd_state != G_RAID_SUBDISK_S_RESYNC) ||
499		     bp->bio_offset + bp->bio_length > sd->sd_rebuild_pos))
500			continue;
501		if ((mask & (1 << i)) != 0)
502			continue;
503		prio = G_RAID_SUBDISK_LOAD(sd);
504		prio += min(sd->sd_recovery, 255) << 22;
505		prio += (G_RAID_SUBDISK_S_ACTIVE - sd->sd_state) << 16;
506		/* If disk head is precisely in position - highly prefer it. */
507		if (G_RAID_SUBDISK_POS(sd) == bp->bio_offset)
508			prio -= 2 * G_RAID_SUBDISK_LOAD_SCALE;
509		else
510		/* If disk head is close to position - prefer it. */
511		if (ABS(G_RAID_SUBDISK_POS(sd) - bp->bio_offset) <
512		    G_RAID_SUBDISK_TRACK_SIZE)
513			prio -= 1 * G_RAID_SUBDISK_LOAD_SCALE;
514		if (prio < bestprio) {
515			best = sd;
516			bestprio = prio;
517		}
518	}
519	return (best);
520}
521
522static void
523g_raid_tr_iostart_raid1_read(struct g_raid_tr_object *tr, struct bio *bp)
524{
525	struct g_raid_subdisk *sd;
526	struct bio *cbp;
527
528	sd = g_raid_tr_raid1_select_read_disk(tr->tro_volume, bp, 0);
529	KASSERT(sd != NULL, ("No active disks in volume %s.",
530		tr->tro_volume->v_name));
531
532	cbp = g_clone_bio(bp);
533	if (cbp == NULL) {
534		g_raid_iodone(bp, ENOMEM);
535		return;
536	}
537
538	g_raid_subdisk_iostart(sd, cbp);
539}
540
541static void
542g_raid_tr_iostart_raid1_write(struct g_raid_tr_object *tr, struct bio *bp)
543{
544	struct g_raid_volume *vol;
545	struct g_raid_subdisk *sd;
546	struct bio_queue_head queue;
547	struct bio *cbp;
548	int i;
549
550	vol = tr->tro_volume;
551
552	/*
553	 * Allocate all bios before sending any request, so we can return
554	 * ENOMEM in nice and clean way.
555	 */
556	bioq_init(&queue);
557	for (i = 0; i < vol->v_disks_count; i++) {
558		sd = &vol->v_subdisks[i];
559		switch (sd->sd_state) {
560		case G_RAID_SUBDISK_S_ACTIVE:
561			break;
562		case G_RAID_SUBDISK_S_REBUILD:
563			/*
564			 * When rebuilding, only part of this subdisk is
565			 * writable, the rest will be written as part of the
566			 * that process.
567			 */
568			if (bp->bio_offset >= sd->sd_rebuild_pos)
569				continue;
570			break;
571		case G_RAID_SUBDISK_S_STALE:
572		case G_RAID_SUBDISK_S_RESYNC:
573			/*
574			 * Resyncing still writes on the theory that the
575			 * resync'd disk is very close and writing it will
576			 * keep it that way better if we keep up while
577			 * resyncing.
578			 */
579			break;
580		default:
581			continue;
582		}
583		cbp = g_clone_bio(bp);
584		if (cbp == NULL)
585			goto failure;
586		cbp->bio_caller1 = sd;
587		bioq_insert_tail(&queue, cbp);
588	}
589	while ((cbp = bioq_takefirst(&queue)) != NULL) {
590		sd = cbp->bio_caller1;
591		cbp->bio_caller1 = NULL;
592		g_raid_subdisk_iostart(sd, cbp);
593	}
594	return;
595failure:
596	while ((cbp = bioq_takefirst(&queue)) != NULL)
597		g_destroy_bio(cbp);
598	if (bp->bio_error == 0)
599		bp->bio_error = ENOMEM;
600	g_raid_iodone(bp, bp->bio_error);
601}
602
603static void
604g_raid_tr_iostart_raid1(struct g_raid_tr_object *tr, struct bio *bp)
605{
606	struct g_raid_volume *vol;
607	struct g_raid_tr_raid1_object *trs;
608
609	vol = tr->tro_volume;
610	trs = (struct g_raid_tr_raid1_object *)tr;
611	if (vol->v_state != G_RAID_VOLUME_S_OPTIMAL &&
612	    vol->v_state != G_RAID_VOLUME_S_SUBOPTIMAL &&
613	    vol->v_state != G_RAID_VOLUME_S_DEGRADED) {
614		g_raid_iodone(bp, EIO);
615		return;
616	}
617	/*
618	 * If we're rebuilding, squeeze in rebuild activity every so often,
619	 * even when the disk is busy.  Be sure to only count real I/O
620	 * to the disk.  All 'SPECIAL' I/O is traffic generated to the disk
621	 * by this module.
622	 */
623	if (trs->trso_failed_sd != NULL &&
624	    !(bp->bio_cflags & G_RAID_BIO_FLAG_SPECIAL)) {
625		/* Make this new or running now round short. */
626		trs->trso_recover_slabs = 0;
627		if (--trs->trso_fair_io <= 0) {
628			trs->trso_fair_io = g_raid1_rebuild_fair_io;
629			g_raid_tr_raid1_rebuild_some(tr);
630		}
631	}
632	switch (bp->bio_cmd) {
633	case BIO_READ:
634		g_raid_tr_iostart_raid1_read(tr, bp);
635		break;
636	case BIO_WRITE:
637	case BIO_DELETE:
638		g_raid_tr_iostart_raid1_write(tr, bp);
639		break;
640	case BIO_SPEEDUP:
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				/* Immediately abort rebuild, if requested. */
683				if (trs->trso_flags & TR_RAID1_F_ABORT) {
684					trs->trso_flags &= ~TR_RAID1_F_DOING_SOME;
685					g_raid_tr_raid1_rebuild_abort(tr);
686					return;
687				}
688
689				/* On read error, skip and cross fingers. */
690				if (bp->bio_error != 0) {
691					G_RAID_LOGREQ(0, bp,
692					    "Read error during rebuild (%d), "
693					    "possible data loss!",
694					    bp->bio_error);
695					goto rebuild_round_done;
696				}
697
698				/*
699				 * The read operation finished, queue the
700				 * write and get out.
701				 */
702				G_RAID_LOGREQ(4, bp, "rebuild read done. %d",
703				    bp->bio_error);
704				bp->bio_cmd = BIO_WRITE;
705				bp->bio_cflags = G_RAID_BIO_FLAG_SYNC;
706				G_RAID_LOGREQ(4, bp, "Queueing rebuild write.");
707				g_raid_subdisk_iostart(trs->trso_failed_sd, bp);
708			} else {
709				/*
710				 * The write operation just finished.  Do
711				 * another.  We keep cloning the master bio
712				 * since it has the right buffers allocated to
713				 * it.
714				 */
715				G_RAID_LOGREQ(4, bp,
716				    "rebuild write done. Error %d",
717				    bp->bio_error);
718				nsd = trs->trso_failed_sd;
719				if (bp->bio_error != 0 ||
720				    trs->trso_flags & TR_RAID1_F_ABORT) {
721					if ((trs->trso_flags &
722					    TR_RAID1_F_ABORT) == 0) {
723						g_raid_tr_raid1_fail_disk(sd->sd_softc,
724						    nsd, nsd->sd_disk);
725					}
726					trs->trso_flags &= ~TR_RAID1_F_DOING_SOME;
727					g_raid_tr_raid1_rebuild_abort(tr);
728					return;
729				}
730rebuild_round_done:
731				nsd = trs->trso_failed_sd;
732				trs->trso_flags &= ~TR_RAID1_F_LOCKED;
733				g_raid_unlock_range(sd->sd_volume,
734				    bp->bio_offset, bp->bio_length);
735				nsd->sd_rebuild_pos += bp->bio_length;
736				if (nsd->sd_rebuild_pos >= nsd->sd_size) {
737					g_raid_tr_raid1_rebuild_finish(tr);
738					return;
739				}
740
741				/* Abort rebuild if we are stopping */
742				if (trs->trso_stopping) {
743					trs->trso_flags &= ~TR_RAID1_F_DOING_SOME;
744					g_raid_tr_raid1_rebuild_abort(tr);
745					return;
746				}
747
748				if (--trs->trso_meta_update <= 0) {
749					g_raid_write_metadata(vol->v_softc,
750					    vol, nsd, nsd->sd_disk);
751					trs->trso_meta_update =
752					    g_raid1_rebuild_meta_update;
753				}
754				trs->trso_flags &= ~TR_RAID1_F_DOING_SOME;
755				if (--trs->trso_recover_slabs <= 0)
756					return;
757				g_raid_tr_raid1_rebuild_some(tr);
758			}
759		} else if (trs->trso_type == TR_RAID1_RESYNC) {
760			/*
761			 * read good sd, read bad sd in parallel.  when both
762			 * done, compare the buffers.  write good to the bad
763			 * if different.  do the next bit of work.
764			 */
765			panic("Somehow, we think we're doing a resync");
766		}
767		return;
768	}
769	pbp = bp->bio_parent;
770	pbp->bio_inbed++;
771	if (bp->bio_cmd == BIO_READ && bp->bio_error != 0) {
772		/*
773		 * Read failed on first drive.  Retry the read error on
774		 * another disk drive, if available, before erroring out the
775		 * read.
776		 */
777		sd->sd_disk->d_read_errs++;
778		G_RAID_LOGREQ(0, bp,
779		    "Read error (%d), %d read errors total",
780		    bp->bio_error, sd->sd_disk->d_read_errs);
781
782		/*
783		 * If there are too many read errors, we move to degraded.
784		 * XXX Do we want to FAIL the drive (eg, make the user redo
785		 * everything to get it back in sync), or just degrade the
786		 * drive, which kicks off a resync?
787		 */
788		do_write = 1;
789		if (sd->sd_disk->d_read_errs > g_raid_read_err_thresh) {
790			g_raid_tr_raid1_fail_disk(sd->sd_softc, sd, sd->sd_disk);
791			if (pbp->bio_children == 1)
792				do_write = 0;
793		}
794
795		/*
796		 * Find the other disk, and try to do the I/O to it.
797		 */
798		mask = (uintptr_t *)(&pbp->bio_driver2);
799		if (pbp->bio_children == 1) {
800			/* Save original subdisk. */
801			pbp->bio_driver1 = do_write ? sd : NULL;
802			*mask = 0;
803		}
804		*mask |= 1 << sd->sd_pos;
805		nsd = g_raid_tr_raid1_select_read_disk(vol, pbp, *mask);
806		if (nsd != NULL && (cbp = g_clone_bio(pbp)) != NULL) {
807			g_destroy_bio(bp);
808			G_RAID_LOGREQ(2, cbp, "Retrying read from %d",
809			    nsd->sd_pos);
810			if (pbp->bio_children == 2 && do_write) {
811				sd->sd_recovery++;
812				cbp->bio_caller1 = nsd;
813				pbp->bio_pflags = G_RAID_BIO_FLAG_LOCKED;
814				/* Lock callback starts I/O */
815				g_raid_lock_range(sd->sd_volume,
816				    cbp->bio_offset, cbp->bio_length, pbp, cbp);
817			} else {
818				g_raid_subdisk_iostart(nsd, cbp);
819			}
820			return;
821		}
822		/*
823		 * We can't retry.  Return the original error by falling
824		 * through.  This will happen when there's only one good disk.
825		 * We don't need to fail the raid, since its actual state is
826		 * based on the state of the subdisks.
827		 */
828		G_RAID_LOGREQ(2, bp, "Couldn't retry read, failing it");
829	}
830	if (bp->bio_cmd == BIO_READ &&
831	    bp->bio_error == 0 &&
832	    pbp->bio_children > 1 &&
833	    pbp->bio_driver1 != NULL) {
834		/*
835		 * If it was a read, and bio_children is >1, then we just
836		 * recovered the data from the second drive.  We should try to
837		 * write that data to the first drive if sector remapping is
838		 * enabled.  A write should put the data in a new place on the
839		 * disk, remapping the bad sector.  Do we need to do that by
840		 * queueing a request to the main worker thread?  It doesn't
841		 * affect the return code of this current read, and can be
842		 * done at our leisure.  However, to make the code simpler, it
843		 * is done synchronously.
844		 */
845		G_RAID_LOGREQ(3, bp, "Recovered data from other drive");
846		cbp = g_clone_bio(pbp);
847		if (cbp != NULL) {
848			g_destroy_bio(bp);
849			cbp->bio_cmd = BIO_WRITE;
850			cbp->bio_cflags = G_RAID_BIO_FLAG_REMAP;
851			G_RAID_LOGREQ(2, cbp,
852			    "Attempting bad sector remap on failing drive.");
853			g_raid_subdisk_iostart(pbp->bio_driver1, cbp);
854			return;
855		}
856	}
857	if (pbp->bio_pflags & G_RAID_BIO_FLAG_LOCKED) {
858		/*
859		 * We're done with a recovery, mark the range as unlocked.
860		 * For any write errors, we aggressively fail the disk since
861		 * there was both a READ and a WRITE error at this location.
862		 * Both types of errors generally indicates the drive is on
863		 * the verge of total failure anyway.  Better to stop trusting
864		 * it now.  However, we need to reset error to 0 in that case
865		 * because we're not failing the original I/O which succeeded.
866		 */
867		if (bp->bio_cmd == BIO_WRITE && bp->bio_error) {
868			G_RAID_LOGREQ(0, bp, "Remap write failed: "
869			    "failing subdisk.");
870			g_raid_tr_raid1_fail_disk(sd->sd_softc, sd, sd->sd_disk);
871			bp->bio_error = 0;
872		}
873		if (pbp->bio_driver1 != NULL) {
874			((struct g_raid_subdisk *)pbp->bio_driver1)
875			    ->sd_recovery--;
876		}
877		G_RAID_LOGREQ(2, bp, "REMAP done %d.", bp->bio_error);
878		g_raid_unlock_range(sd->sd_volume, bp->bio_offset,
879		    bp->bio_length);
880	}
881	if (pbp->bio_cmd != BIO_READ) {
882		if (pbp->bio_inbed == 1 || pbp->bio_error != 0)
883			pbp->bio_error = bp->bio_error;
884		if (pbp->bio_cmd == BIO_WRITE && bp->bio_error != 0) {
885			G_RAID_LOGREQ(0, bp, "Write failed: failing subdisk.");
886			g_raid_tr_raid1_fail_disk(sd->sd_softc, sd, sd->sd_disk);
887		}
888		error = pbp->bio_error;
889	} else
890		error = bp->bio_error;
891	g_destroy_bio(bp);
892	if (pbp->bio_children == pbp->bio_inbed) {
893		pbp->bio_completed = pbp->bio_length;
894		g_raid_iodone(pbp, error);
895	}
896}
897
898static int
899g_raid_tr_kerneldump_raid1(struct g_raid_tr_object *tr, void *virtual,
900    off_t offset, size_t length)
901{
902	struct g_raid_volume *vol;
903	struct g_raid_subdisk *sd;
904	int error, i, ok;
905
906	vol = tr->tro_volume;
907	error = 0;
908	ok = 0;
909	for (i = 0; i < vol->v_disks_count; i++) {
910		sd = &vol->v_subdisks[i];
911		switch (sd->sd_state) {
912		case G_RAID_SUBDISK_S_ACTIVE:
913			break;
914		case G_RAID_SUBDISK_S_REBUILD:
915			/*
916			 * When rebuilding, only part of this subdisk is
917			 * writable, the rest will be written as part of the
918			 * that process.
919			 */
920			if (offset >= sd->sd_rebuild_pos)
921				continue;
922			break;
923		case G_RAID_SUBDISK_S_STALE:
924		case G_RAID_SUBDISK_S_RESYNC:
925			/*
926			 * Resyncing still writes on the theory that the
927			 * resync'd disk is very close and writing it will
928			 * keep it that way better if we keep up while
929			 * resyncing.
930			 */
931			break;
932		default:
933			continue;
934		}
935		error = g_raid_subdisk_kerneldump(sd, virtual, offset, length);
936		if (error == 0)
937			ok++;
938	}
939	return (ok > 0 ? 0 : error);
940}
941
942static int
943g_raid_tr_locked_raid1(struct g_raid_tr_object *tr, void *argp)
944{
945	struct bio *bp;
946	struct g_raid_subdisk *sd;
947
948	bp = (struct bio *)argp;
949	sd = (struct g_raid_subdisk *)bp->bio_caller1;
950	g_raid_subdisk_iostart(sd, bp);
951
952	return (0);
953}
954
955static int
956g_raid_tr_idle_raid1(struct g_raid_tr_object *tr)
957{
958	struct g_raid_tr_raid1_object *trs;
959
960	trs = (struct g_raid_tr_raid1_object *)tr;
961	trs->trso_fair_io = g_raid1_rebuild_fair_io;
962	trs->trso_recover_slabs = g_raid1_rebuild_cluster_idle;
963	if (trs->trso_type == TR_RAID1_REBUILD)
964		g_raid_tr_raid1_rebuild_some(tr);
965	return (0);
966}
967
968static int
969g_raid_tr_free_raid1(struct g_raid_tr_object *tr)
970{
971	struct g_raid_tr_raid1_object *trs;
972
973	trs = (struct g_raid_tr_raid1_object *)tr;
974
975	if (trs->trso_buffer != NULL) {
976		free(trs->trso_buffer, M_TR_RAID1);
977		trs->trso_buffer = NULL;
978	}
979	return (0);
980}
981
982G_RAID_TR_DECLARE(raid1, "RAID1");
983