xref: /freebsd/sys/geom/raid/tr_raid1.c (revision fdafd315ad0d0f28a11b9fb4476a9ab059c62b92)
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  
45  SYSCTL_DECL(_kern_geom_raid_raid1);
46  
47  #define RAID1_REBUILD_SLAB	(1 << 20) /* One transation in a rebuild */
48  static int g_raid1_rebuild_slab = RAID1_REBUILD_SLAB;
49  SYSCTL_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 */
54  static int g_raid1_rebuild_fair_io = RAID1_REBUILD_FAIR_IO;
55  SYSCTL_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
60  static int g_raid1_rebuild_cluster_idle = RAID1_REBUILD_CLUSTER_IDLE;
61  SYSCTL_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 */
66  static int g_raid1_rebuild_meta_update = RAID1_REBUILD_META_UPDATE;
67  SYSCTL_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  
71  static 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  
81  struct 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  
95  static g_raid_tr_taste_t g_raid_tr_taste_raid1;
96  static g_raid_tr_event_t g_raid_tr_event_raid1;
97  static g_raid_tr_start_t g_raid_tr_start_raid1;
98  static g_raid_tr_stop_t g_raid_tr_stop_raid1;
99  static g_raid_tr_iostart_t g_raid_tr_iostart_raid1;
100  static g_raid_tr_iodone_t g_raid_tr_iodone_raid1;
101  static g_raid_tr_kerneldump_t g_raid_tr_kerneldump_raid1;
102  static g_raid_tr_locked_t g_raid_tr_locked_raid1;
103  static g_raid_tr_idle_t g_raid_tr_idle_raid1;
104  static g_raid_tr_free_t g_raid_tr_free_raid1;
105  
106  static 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  
120  static 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  
129  static void g_raid_tr_raid1_rebuild_abort(struct g_raid_tr_object *tr);
130  static void g_raid_tr_raid1_maybe_rebuild(struct g_raid_tr_object *tr,
131      struct g_raid_subdisk *sd);
132  
133  static int
g_raid_tr_taste_raid1(struct g_raid_tr_object * tr,struct g_raid_volume * vol)134  g_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  
147  static int
g_raid_tr_update_state_raid1(struct g_raid_volume * vol,struct g_raid_subdisk * sd)148  g_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  
219  static void
g_raid_tr_raid1_fail_disk(struct g_raid_softc * sc,struct g_raid_subdisk * sd,struct g_raid_disk * disk)220  g_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  
238  static void
g_raid_tr_raid1_rebuild_some(struct g_raid_tr_object * tr)239  g_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  
269  static void
g_raid_tr_raid1_rebuild_done(struct g_raid_tr_raid1_object * trs)270  g_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  
287  static void
g_raid_tr_raid1_rebuild_finish(struct g_raid_tr_object * tr)288  g_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  
304  static void
g_raid_tr_raid1_rebuild_abort(struct g_raid_tr_object * tr)305  g_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  
338  static void
g_raid_tr_raid1_rebuild_start(struct g_raid_tr_object * tr)339  g_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  static void
g_raid_tr_raid1_maybe_rebuild(struct g_raid_tr_object * tr,struct g_raid_subdisk * sd)402  g_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  
444  static int
g_raid_tr_event_raid1(struct g_raid_tr_object * tr,struct g_raid_subdisk * sd,u_int event)445  g_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  
453  static int
g_raid_tr_start_raid1(struct g_raid_tr_object * tr)454  g_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  
466  static int
g_raid_tr_stop_raid1(struct g_raid_tr_object * tr)467  g_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)))
485  static struct g_raid_subdisk *
g_raid_tr_raid1_select_read_disk(struct g_raid_volume * vol,struct bio * bp,u_int mask)486  g_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  
522  static void
g_raid_tr_iostart_raid1_read(struct g_raid_tr_object * tr,struct bio * bp)523  g_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  
541  static void
g_raid_tr_iostart_raid1_write(struct g_raid_tr_object * tr,struct bio * bp)542  g_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;
595  failure:
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  
603  static void
g_raid_tr_iostart_raid1(struct g_raid_tr_object * tr,struct bio * bp)604  g_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  
651  static void
g_raid_tr_iodone_raid1(struct g_raid_tr_object * tr,struct g_raid_subdisk * sd,struct bio * bp)652  g_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  				}
730  rebuild_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  
898  static int
g_raid_tr_kerneldump_raid1(struct g_raid_tr_object * tr,void * virtual,off_t offset,size_t length)899  g_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  
942  static int
g_raid_tr_locked_raid1(struct g_raid_tr_object * tr,void * argp)943  g_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  
955  static int
g_raid_tr_idle_raid1(struct g_raid_tr_object * tr)956  g_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  
968  static int
g_raid_tr_free_raid1(struct g_raid_tr_object * tr)969  g_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  
982  G_RAID_TR_DECLARE(raid1, "RAID1");
983