xref: /linux/drivers/md/raid1.c (revision 8a61cb6e150ea907b580a1b5e705decb0a3ffc86)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * raid1.c : Multiple Devices driver for Linux
4  *
5  * Copyright (C) 1999, 2000, 2001 Ingo Molnar, Red Hat
6  *
7  * Copyright (C) 1996, 1997, 1998 Ingo Molnar, Miguel de Icaza, Gadi Oxman
8  *
9  * RAID-1 management functions.
10  *
11  * Better read-balancing code written by Mika Kuoppala <miku@iki.fi>, 2000
12  *
13  * Fixes to reconstruction by Jakob Østergaard" <jakob@ostenfeld.dk>
14  * Various fixes by Neil Brown <neilb@cse.unsw.edu.au>
15  *
16  * Changes by Peter T. Breuer <ptb@it.uc3m.es> 31/1/2003 to support
17  * bitmapped intelligence in resync:
18  *
19  *      - bitmap marked during normal i/o
20  *      - bitmap used to skip nondirty blocks during sync
21  *
22  * Additions to bitmap code, (C) 2003-2004 Paul Clements, SteelEye Technology:
23  * - persistent bitmap code
24  */
25 
26 #include <linux/slab.h>
27 #include <linux/delay.h>
28 #include <linux/blkdev.h>
29 #include <linux/module.h>
30 #include <linux/seq_file.h>
31 #include <linux/ratelimit.h>
32 #include <linux/interval_tree_generic.h>
33 
34 #include <trace/events/block.h>
35 
36 #include "md.h"
37 #include "raid1.h"
38 #include "md-bitmap.h"
39 
40 #define UNSUPPORTED_MDDEV_FLAGS		\
41 	((1L << MD_HAS_JOURNAL) |	\
42 	 (1L << MD_JOURNAL_CLEAN) |	\
43 	 (1L << MD_HAS_PPL) |		\
44 	 (1L << MD_HAS_MULTIPLE_PPLS))
45 
46 static void allow_barrier(struct r1conf *conf, sector_t sector_nr);
47 static void lower_barrier(struct r1conf *conf, sector_t sector_nr);
48 
49 #define RAID_1_10_NAME "raid1"
50 #include "raid1-10.c"
51 
52 #define START(node) ((node)->start)
53 #define LAST(node) ((node)->last)
54 INTERVAL_TREE_DEFINE(struct serial_info, node, sector_t, _subtree_last,
55 		     START, LAST, static inline, raid1_rb);
56 
check_and_add_serial(struct md_rdev * rdev,struct r1bio * r1_bio,struct serial_info * si,int idx)57 static int check_and_add_serial(struct md_rdev *rdev, struct r1bio *r1_bio,
58 				struct serial_info *si, int idx)
59 {
60 	unsigned long flags;
61 	int ret = 0;
62 	sector_t lo = r1_bio->sector;
63 	sector_t hi = lo + r1_bio->sectors;
64 	struct serial_in_rdev *serial = &rdev->serial[idx];
65 
66 	spin_lock_irqsave(&serial->serial_lock, flags);
67 	/* collision happened */
68 	if (raid1_rb_iter_first(&serial->serial_rb, lo, hi))
69 		ret = -EBUSY;
70 	else {
71 		si->start = lo;
72 		si->last = hi;
73 		raid1_rb_insert(si, &serial->serial_rb);
74 	}
75 	spin_unlock_irqrestore(&serial->serial_lock, flags);
76 
77 	return ret;
78 }
79 
wait_for_serialization(struct md_rdev * rdev,struct r1bio * r1_bio)80 static void wait_for_serialization(struct md_rdev *rdev, struct r1bio *r1_bio)
81 {
82 	struct mddev *mddev = rdev->mddev;
83 	struct serial_info *si;
84 	int idx = sector_to_idx(r1_bio->sector);
85 	struct serial_in_rdev *serial = &rdev->serial[idx];
86 
87 	if (WARN_ON(!mddev->serial_info_pool))
88 		return;
89 	si = mempool_alloc(mddev->serial_info_pool, GFP_NOIO);
90 	wait_event(serial->serial_io_wait,
91 		   check_and_add_serial(rdev, r1_bio, si, idx) == 0);
92 }
93 
remove_serial(struct md_rdev * rdev,sector_t lo,sector_t hi)94 static void remove_serial(struct md_rdev *rdev, sector_t lo, sector_t hi)
95 {
96 	struct serial_info *si;
97 	unsigned long flags;
98 	int found = 0;
99 	struct mddev *mddev = rdev->mddev;
100 	int idx = sector_to_idx(lo);
101 	struct serial_in_rdev *serial = &rdev->serial[idx];
102 
103 	spin_lock_irqsave(&serial->serial_lock, flags);
104 	for (si = raid1_rb_iter_first(&serial->serial_rb, lo, hi);
105 	     si; si = raid1_rb_iter_next(si, lo, hi)) {
106 		if (si->start == lo && si->last == hi) {
107 			raid1_rb_remove(si, &serial->serial_rb);
108 			mempool_free(si, mddev->serial_info_pool);
109 			found = 1;
110 			break;
111 		}
112 	}
113 	if (!found)
114 		WARN(1, "The write IO is not recorded for serialization\n");
115 	spin_unlock_irqrestore(&serial->serial_lock, flags);
116 	wake_up(&serial->serial_io_wait);
117 }
118 
119 /*
120  * for resync bio, r1bio pointer can be retrieved from the per-bio
121  * 'struct resync_pages'.
122  */
get_resync_r1bio(struct bio * bio)123 static inline struct r1bio *get_resync_r1bio(struct bio *bio)
124 {
125 	return get_resync_pages(bio)->raid_bio;
126 }
127 
r1bio_pool_alloc(gfp_t gfp_flags,void * data)128 static void * r1bio_pool_alloc(gfp_t gfp_flags, void *data)
129 {
130 	struct pool_info *pi = data;
131 	int size = offsetof(struct r1bio, bios[pi->raid_disks]);
132 
133 	/* allocate a r1bio with room for raid_disks entries in the bios array */
134 	return kzalloc(size, gfp_flags);
135 }
136 
137 #define RESYNC_DEPTH 32
138 #define RESYNC_SECTORS (RESYNC_BLOCK_SIZE >> 9)
139 #define RESYNC_WINDOW (RESYNC_BLOCK_SIZE * RESYNC_DEPTH)
140 #define RESYNC_WINDOW_SECTORS (RESYNC_WINDOW >> 9)
141 #define CLUSTER_RESYNC_WINDOW (16 * RESYNC_WINDOW)
142 #define CLUSTER_RESYNC_WINDOW_SECTORS (CLUSTER_RESYNC_WINDOW >> 9)
143 
r1buf_pool_alloc(gfp_t gfp_flags,void * data)144 static void * r1buf_pool_alloc(gfp_t gfp_flags, void *data)
145 {
146 	struct pool_info *pi = data;
147 	struct r1bio *r1_bio;
148 	struct bio *bio;
149 	int need_pages;
150 	int j;
151 	struct resync_pages *rps;
152 
153 	r1_bio = r1bio_pool_alloc(gfp_flags, pi);
154 	if (!r1_bio)
155 		return NULL;
156 
157 	rps = kmalloc_array(pi->raid_disks, sizeof(struct resync_pages),
158 			    gfp_flags);
159 	if (!rps)
160 		goto out_free_r1bio;
161 
162 	/*
163 	 * Allocate bios : 1 for reading, n-1 for writing
164 	 */
165 	for (j = pi->raid_disks ; j-- ; ) {
166 		bio = bio_kmalloc(RESYNC_PAGES, gfp_flags);
167 		if (!bio)
168 			goto out_free_bio;
169 		bio_init(bio, NULL, bio->bi_inline_vecs, RESYNC_PAGES, 0);
170 		r1_bio->bios[j] = bio;
171 	}
172 	/*
173 	 * Allocate RESYNC_PAGES data pages and attach them to
174 	 * the first bio.
175 	 * If this is a user-requested check/repair, allocate
176 	 * RESYNC_PAGES for each bio.
177 	 */
178 	if (test_bit(MD_RECOVERY_REQUESTED, &pi->mddev->recovery))
179 		need_pages = pi->raid_disks;
180 	else
181 		need_pages = 1;
182 	for (j = 0; j < pi->raid_disks; j++) {
183 		struct resync_pages *rp = &rps[j];
184 
185 		bio = r1_bio->bios[j];
186 
187 		if (j < need_pages) {
188 			if (resync_alloc_pages(rp, gfp_flags))
189 				goto out_free_pages;
190 		} else {
191 			memcpy(rp, &rps[0], sizeof(*rp));
192 			resync_get_all_pages(rp);
193 		}
194 
195 		rp->raid_bio = r1_bio;
196 		bio->bi_private = rp;
197 	}
198 
199 	r1_bio->master_bio = NULL;
200 
201 	return r1_bio;
202 
203 out_free_pages:
204 	while (--j >= 0)
205 		resync_free_pages(&rps[j]);
206 
207 out_free_bio:
208 	while (++j < pi->raid_disks) {
209 		bio_uninit(r1_bio->bios[j]);
210 		kfree(r1_bio->bios[j]);
211 	}
212 	kfree(rps);
213 
214 out_free_r1bio:
215 	rbio_pool_free(r1_bio, data);
216 	return NULL;
217 }
218 
r1buf_pool_free(void * __r1_bio,void * data)219 static void r1buf_pool_free(void *__r1_bio, void *data)
220 {
221 	struct pool_info *pi = data;
222 	int i;
223 	struct r1bio *r1bio = __r1_bio;
224 	struct resync_pages *rp = NULL;
225 
226 	for (i = pi->raid_disks; i--; ) {
227 		rp = get_resync_pages(r1bio->bios[i]);
228 		resync_free_pages(rp);
229 		bio_uninit(r1bio->bios[i]);
230 		kfree(r1bio->bios[i]);
231 	}
232 
233 	/* resync pages array stored in the 1st bio's .bi_private */
234 	kfree(rp);
235 
236 	rbio_pool_free(r1bio, data);
237 }
238 
put_all_bios(struct r1conf * conf,struct r1bio * r1_bio)239 static void put_all_bios(struct r1conf *conf, struct r1bio *r1_bio)
240 {
241 	int i;
242 
243 	for (i = 0; i < conf->raid_disks * 2; i++) {
244 		struct bio **bio = r1_bio->bios + i;
245 		if (!BIO_SPECIAL(*bio))
246 			bio_put(*bio);
247 		*bio = NULL;
248 	}
249 }
250 
free_r1bio(struct r1bio * r1_bio)251 static void free_r1bio(struct r1bio *r1_bio)
252 {
253 	struct r1conf *conf = r1_bio->mddev->private;
254 
255 	put_all_bios(conf, r1_bio);
256 	mempool_free(r1_bio, &conf->r1bio_pool);
257 }
258 
put_buf(struct r1bio * r1_bio)259 static void put_buf(struct r1bio *r1_bio)
260 {
261 	struct r1conf *conf = r1_bio->mddev->private;
262 	sector_t sect = r1_bio->sector;
263 	int i;
264 
265 	for (i = 0; i < conf->raid_disks * 2; i++) {
266 		struct bio *bio = r1_bio->bios[i];
267 		if (bio->bi_end_io)
268 			rdev_dec_pending(conf->mirrors[i].rdev, r1_bio->mddev);
269 	}
270 
271 	mempool_free(r1_bio, &conf->r1buf_pool);
272 
273 	lower_barrier(conf, sect);
274 }
275 
reschedule_retry(struct r1bio * r1_bio)276 static void reschedule_retry(struct r1bio *r1_bio)
277 {
278 	unsigned long flags;
279 	struct mddev *mddev = r1_bio->mddev;
280 	struct r1conf *conf = mddev->private;
281 	int idx;
282 
283 	idx = sector_to_idx(r1_bio->sector);
284 	spin_lock_irqsave(&conf->device_lock, flags);
285 	list_add(&r1_bio->retry_list, &conf->retry_list);
286 	atomic_inc(&conf->nr_queued[idx]);
287 	spin_unlock_irqrestore(&conf->device_lock, flags);
288 
289 	wake_up(&conf->wait_barrier);
290 	md_wakeup_thread(mddev->thread);
291 }
292 
293 /*
294  * raid_end_bio_io() is called when we have finished servicing a mirrored
295  * operation and are ready to return a success/failure code to the buffer
296  * cache layer.
297  */
call_bio_endio(struct r1bio * r1_bio)298 static void call_bio_endio(struct r1bio *r1_bio)
299 {
300 	struct bio *bio = r1_bio->master_bio;
301 
302 	if (!test_bit(R1BIO_Uptodate, &r1_bio->state))
303 		bio->bi_status = BLK_STS_IOERR;
304 
305 	bio_endio(bio);
306 }
307 
raid_end_bio_io(struct r1bio * r1_bio)308 static void raid_end_bio_io(struct r1bio *r1_bio)
309 {
310 	struct bio *bio = r1_bio->master_bio;
311 	struct r1conf *conf = r1_bio->mddev->private;
312 	sector_t sector = r1_bio->sector;
313 
314 	/* if nobody has done the final endio yet, do it now */
315 	if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
316 		pr_debug("raid1: sync end %s on sectors %llu-%llu\n",
317 			 (bio_data_dir(bio) == WRITE) ? "write" : "read",
318 			 (unsigned long long) bio->bi_iter.bi_sector,
319 			 (unsigned long long) bio_end_sector(bio) - 1);
320 
321 		call_bio_endio(r1_bio);
322 	}
323 
324 	free_r1bio(r1_bio);
325 	/*
326 	 * Wake up any possible resync thread that waits for the device
327 	 * to go idle.  All I/Os, even write-behind writes, are done.
328 	 */
329 	allow_barrier(conf, sector);
330 }
331 
332 /*
333  * Update disk head position estimator based on IRQ completion info.
334  */
update_head_pos(int disk,struct r1bio * r1_bio)335 static inline void update_head_pos(int disk, struct r1bio *r1_bio)
336 {
337 	struct r1conf *conf = r1_bio->mddev->private;
338 
339 	conf->mirrors[disk].head_position =
340 		r1_bio->sector + (r1_bio->sectors);
341 }
342 
343 /*
344  * Find the disk number which triggered given bio
345  */
find_bio_disk(struct r1bio * r1_bio,struct bio * bio)346 static int find_bio_disk(struct r1bio *r1_bio, struct bio *bio)
347 {
348 	int mirror;
349 	struct r1conf *conf = r1_bio->mddev->private;
350 	int raid_disks = conf->raid_disks;
351 
352 	for (mirror = 0; mirror < raid_disks * 2; mirror++)
353 		if (r1_bio->bios[mirror] == bio)
354 			break;
355 
356 	BUG_ON(mirror == raid_disks * 2);
357 	update_head_pos(mirror, r1_bio);
358 
359 	return mirror;
360 }
361 
raid1_end_read_request(struct bio * bio)362 static void raid1_end_read_request(struct bio *bio)
363 {
364 	int uptodate = !bio->bi_status;
365 	struct r1bio *r1_bio = bio->bi_private;
366 	struct r1conf *conf = r1_bio->mddev->private;
367 	struct md_rdev *rdev = conf->mirrors[r1_bio->read_disk].rdev;
368 
369 	/*
370 	 * this branch is our 'one mirror IO has finished' event handler:
371 	 */
372 	update_head_pos(r1_bio->read_disk, r1_bio);
373 
374 	if (uptodate)
375 		set_bit(R1BIO_Uptodate, &r1_bio->state);
376 	else if (test_bit(FailFast, &rdev->flags) &&
377 		 test_bit(R1BIO_FailFast, &r1_bio->state))
378 		/* This was a fail-fast read so we definitely
379 		 * want to retry */
380 		;
381 	else {
382 		/* If all other devices have failed, we want to return
383 		 * the error upwards rather than fail the last device.
384 		 * Here we redefine "uptodate" to mean "Don't want to retry"
385 		 */
386 		unsigned long flags;
387 		spin_lock_irqsave(&conf->device_lock, flags);
388 		if (r1_bio->mddev->degraded == conf->raid_disks ||
389 		    (r1_bio->mddev->degraded == conf->raid_disks-1 &&
390 		     test_bit(In_sync, &rdev->flags)))
391 			uptodate = 1;
392 		spin_unlock_irqrestore(&conf->device_lock, flags);
393 	}
394 
395 	if (uptodate) {
396 		raid_end_bio_io(r1_bio);
397 		rdev_dec_pending(rdev, conf->mddev);
398 	} else {
399 		/*
400 		 * oops, read error:
401 		 */
402 		pr_err_ratelimited("md/raid1:%s: %pg: rescheduling sector %llu\n",
403 				   mdname(conf->mddev),
404 				   rdev->bdev,
405 				   (unsigned long long)r1_bio->sector);
406 		set_bit(R1BIO_ReadError, &r1_bio->state);
407 		reschedule_retry(r1_bio);
408 		/* don't drop the reference on read_disk yet */
409 	}
410 }
411 
close_write(struct r1bio * r1_bio)412 static void close_write(struct r1bio *r1_bio)
413 {
414 	struct mddev *mddev = r1_bio->mddev;
415 
416 	/* it really is the end of this request */
417 	if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
418 		bio_free_pages(r1_bio->behind_master_bio);
419 		bio_put(r1_bio->behind_master_bio);
420 		r1_bio->behind_master_bio = NULL;
421 	}
422 
423 	if (test_bit(R1BIO_BehindIO, &r1_bio->state))
424 		mddev->bitmap_ops->end_behind_write(mddev);
425 	md_write_end(mddev);
426 }
427 
r1_bio_write_done(struct r1bio * r1_bio)428 static void r1_bio_write_done(struct r1bio *r1_bio)
429 {
430 	if (!atomic_dec_and_test(&r1_bio->remaining))
431 		return;
432 
433 	if (test_bit(R1BIO_WriteError, &r1_bio->state))
434 		reschedule_retry(r1_bio);
435 	else {
436 		close_write(r1_bio);
437 		if (test_bit(R1BIO_MadeGood, &r1_bio->state))
438 			reschedule_retry(r1_bio);
439 		else
440 			raid_end_bio_io(r1_bio);
441 	}
442 }
443 
raid1_end_write_request(struct bio * bio)444 static void raid1_end_write_request(struct bio *bio)
445 {
446 	struct r1bio *r1_bio = bio->bi_private;
447 	int behind = test_bit(R1BIO_BehindIO, &r1_bio->state);
448 	struct r1conf *conf = r1_bio->mddev->private;
449 	struct bio *to_put = NULL;
450 	int mirror = find_bio_disk(r1_bio, bio);
451 	struct md_rdev *rdev = conf->mirrors[mirror].rdev;
452 	bool discard_error;
453 	sector_t lo = r1_bio->sector;
454 	sector_t hi = r1_bio->sector + r1_bio->sectors;
455 
456 	discard_error = bio->bi_status && bio_op(bio) == REQ_OP_DISCARD;
457 
458 	/*
459 	 * 'one mirror IO has finished' event handler:
460 	 */
461 	if (bio->bi_status && !discard_error) {
462 		set_bit(WriteErrorSeen,	&rdev->flags);
463 		if (!test_and_set_bit(WantReplacement, &rdev->flags))
464 			set_bit(MD_RECOVERY_NEEDED, &
465 				conf->mddev->recovery);
466 
467 		if (test_bit(FailFast, &rdev->flags) &&
468 		    (bio->bi_opf & MD_FAILFAST) &&
469 		    /* We never try FailFast to WriteMostly devices */
470 		    !test_bit(WriteMostly, &rdev->flags)) {
471 			md_error(r1_bio->mddev, rdev);
472 		}
473 
474 		/*
475 		 * When the device is faulty, it is not necessary to
476 		 * handle write error.
477 		 */
478 		if (!test_bit(Faulty, &rdev->flags))
479 			set_bit(R1BIO_WriteError, &r1_bio->state);
480 		else {
481 			/* Finished with this branch */
482 			r1_bio->bios[mirror] = NULL;
483 			to_put = bio;
484 		}
485 	} else {
486 		/*
487 		 * Set R1BIO_Uptodate in our master bio, so that we
488 		 * will return a good error code for to the higher
489 		 * levels even if IO on some other mirrored buffer
490 		 * fails.
491 		 *
492 		 * The 'master' represents the composite IO operation
493 		 * to user-side. So if something waits for IO, then it
494 		 * will wait for the 'master' bio.
495 		 */
496 		r1_bio->bios[mirror] = NULL;
497 		to_put = bio;
498 		/*
499 		 * Do not set R1BIO_Uptodate if the current device is
500 		 * rebuilding or Faulty. This is because we cannot use
501 		 * such device for properly reading the data back (we could
502 		 * potentially use it, if the current write would have felt
503 		 * before rdev->recovery_offset, but for simplicity we don't
504 		 * check this here.
505 		 */
506 		if (test_bit(In_sync, &rdev->flags) &&
507 		    !test_bit(Faulty, &rdev->flags))
508 			set_bit(R1BIO_Uptodate, &r1_bio->state);
509 
510 		/* Maybe we can clear some bad blocks. */
511 		if (rdev_has_badblock(rdev, r1_bio->sector, r1_bio->sectors) &&
512 		    !discard_error) {
513 			r1_bio->bios[mirror] = IO_MADE_GOOD;
514 			set_bit(R1BIO_MadeGood, &r1_bio->state);
515 		}
516 	}
517 
518 	if (behind) {
519 		if (test_bit(CollisionCheck, &rdev->flags))
520 			remove_serial(rdev, lo, hi);
521 		if (test_bit(WriteMostly, &rdev->flags))
522 			atomic_dec(&r1_bio->behind_remaining);
523 
524 		/*
525 		 * In behind mode, we ACK the master bio once the I/O
526 		 * has safely reached all non-writemostly
527 		 * disks. Setting the Returned bit ensures that this
528 		 * gets done only once -- we don't ever want to return
529 		 * -EIO here, instead we'll wait
530 		 */
531 		if (atomic_read(&r1_bio->behind_remaining) >= (atomic_read(&r1_bio->remaining)-1) &&
532 		    test_bit(R1BIO_Uptodate, &r1_bio->state)) {
533 			/* Maybe we can return now */
534 			if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
535 				struct bio *mbio = r1_bio->master_bio;
536 				pr_debug("raid1: behind end write sectors"
537 					 " %llu-%llu\n",
538 					 (unsigned long long) mbio->bi_iter.bi_sector,
539 					 (unsigned long long) bio_end_sector(mbio) - 1);
540 				call_bio_endio(r1_bio);
541 			}
542 		}
543 	} else if (rdev->mddev->serialize_policy)
544 		remove_serial(rdev, lo, hi);
545 	if (r1_bio->bios[mirror] == NULL)
546 		rdev_dec_pending(rdev, conf->mddev);
547 
548 	/*
549 	 * Let's see if all mirrored write operations have finished
550 	 * already.
551 	 */
552 	r1_bio_write_done(r1_bio);
553 
554 	if (to_put)
555 		bio_put(to_put);
556 }
557 
align_to_barrier_unit_end(sector_t start_sector,sector_t sectors)558 static sector_t align_to_barrier_unit_end(sector_t start_sector,
559 					  sector_t sectors)
560 {
561 	sector_t len;
562 
563 	WARN_ON(sectors == 0);
564 	/*
565 	 * len is the number of sectors from start_sector to end of the
566 	 * barrier unit which start_sector belongs to.
567 	 */
568 	len = round_up(start_sector + 1, BARRIER_UNIT_SECTOR_SIZE) -
569 	      start_sector;
570 
571 	if (len > sectors)
572 		len = sectors;
573 
574 	return len;
575 }
576 
update_read_sectors(struct r1conf * conf,int disk,sector_t this_sector,int len)577 static void update_read_sectors(struct r1conf *conf, int disk,
578 				sector_t this_sector, int len)
579 {
580 	struct raid1_info *info = &conf->mirrors[disk];
581 
582 	atomic_inc(&info->rdev->nr_pending);
583 	if (info->next_seq_sect != this_sector)
584 		info->seq_start = this_sector;
585 	info->next_seq_sect = this_sector + len;
586 }
587 
choose_first_rdev(struct r1conf * conf,struct r1bio * r1_bio,int * max_sectors)588 static int choose_first_rdev(struct r1conf *conf, struct r1bio *r1_bio,
589 			     int *max_sectors)
590 {
591 	sector_t this_sector = r1_bio->sector;
592 	int len = r1_bio->sectors;
593 	int disk;
594 
595 	for (disk = 0 ; disk < conf->raid_disks * 2 ; disk++) {
596 		struct md_rdev *rdev;
597 		int read_len;
598 
599 		if (r1_bio->bios[disk] == IO_BLOCKED)
600 			continue;
601 
602 		rdev = conf->mirrors[disk].rdev;
603 		if (!rdev || test_bit(Faulty, &rdev->flags))
604 			continue;
605 
606 		/* choose the first disk even if it has some bad blocks. */
607 		read_len = raid1_check_read_range(rdev, this_sector, &len);
608 		if (read_len > 0) {
609 			update_read_sectors(conf, disk, this_sector, read_len);
610 			*max_sectors = read_len;
611 			return disk;
612 		}
613 	}
614 
615 	return -1;
616 }
617 
rdev_in_recovery(struct md_rdev * rdev,struct r1bio * r1_bio)618 static bool rdev_in_recovery(struct md_rdev *rdev, struct r1bio *r1_bio)
619 {
620 	return !test_bit(In_sync, &rdev->flags) &&
621 	       rdev->recovery_offset < r1_bio->sector + r1_bio->sectors;
622 }
623 
choose_bb_rdev(struct r1conf * conf,struct r1bio * r1_bio,int * max_sectors)624 static int choose_bb_rdev(struct r1conf *conf, struct r1bio *r1_bio,
625 			  int *max_sectors)
626 {
627 	sector_t this_sector = r1_bio->sector;
628 	int best_disk = -1;
629 	int best_len = 0;
630 	int disk;
631 
632 	for (disk = 0 ; disk < conf->raid_disks * 2 ; disk++) {
633 		struct md_rdev *rdev;
634 		int len;
635 		int read_len;
636 
637 		if (r1_bio->bios[disk] == IO_BLOCKED)
638 			continue;
639 
640 		rdev = conf->mirrors[disk].rdev;
641 		if (!rdev || test_bit(Faulty, &rdev->flags) ||
642 		    rdev_in_recovery(rdev, r1_bio) ||
643 		    test_bit(WriteMostly, &rdev->flags))
644 			continue;
645 
646 		/* keep track of the disk with the most readable sectors. */
647 		len = r1_bio->sectors;
648 		read_len = raid1_check_read_range(rdev, this_sector, &len);
649 		if (read_len > best_len) {
650 			best_disk = disk;
651 			best_len = read_len;
652 		}
653 	}
654 
655 	if (best_disk != -1) {
656 		*max_sectors = best_len;
657 		update_read_sectors(conf, best_disk, this_sector, best_len);
658 	}
659 
660 	return best_disk;
661 }
662 
choose_slow_rdev(struct r1conf * conf,struct r1bio * r1_bio,int * max_sectors)663 static int choose_slow_rdev(struct r1conf *conf, struct r1bio *r1_bio,
664 			    int *max_sectors)
665 {
666 	sector_t this_sector = r1_bio->sector;
667 	int bb_disk = -1;
668 	int bb_read_len = 0;
669 	int disk;
670 
671 	for (disk = 0 ; disk < conf->raid_disks * 2 ; disk++) {
672 		struct md_rdev *rdev;
673 		int len;
674 		int read_len;
675 
676 		if (r1_bio->bios[disk] == IO_BLOCKED)
677 			continue;
678 
679 		rdev = conf->mirrors[disk].rdev;
680 		if (!rdev || test_bit(Faulty, &rdev->flags) ||
681 		    !test_bit(WriteMostly, &rdev->flags) ||
682 		    rdev_in_recovery(rdev, r1_bio))
683 			continue;
684 
685 		/* there are no bad blocks, we can use this disk */
686 		len = r1_bio->sectors;
687 		read_len = raid1_check_read_range(rdev, this_sector, &len);
688 		if (read_len == r1_bio->sectors) {
689 			*max_sectors = read_len;
690 			update_read_sectors(conf, disk, this_sector, read_len);
691 			return disk;
692 		}
693 
694 		/*
695 		 * there are partial bad blocks, choose the rdev with largest
696 		 * read length.
697 		 */
698 		if (read_len > bb_read_len) {
699 			bb_disk = disk;
700 			bb_read_len = read_len;
701 		}
702 	}
703 
704 	if (bb_disk != -1) {
705 		*max_sectors = bb_read_len;
706 		update_read_sectors(conf, bb_disk, this_sector, bb_read_len);
707 	}
708 
709 	return bb_disk;
710 }
711 
is_sequential(struct r1conf * conf,int disk,struct r1bio * r1_bio)712 static bool is_sequential(struct r1conf *conf, int disk, struct r1bio *r1_bio)
713 {
714 	/* TODO: address issues with this check and concurrency. */
715 	return conf->mirrors[disk].next_seq_sect == r1_bio->sector ||
716 	       conf->mirrors[disk].head_position == r1_bio->sector;
717 }
718 
719 /*
720  * If buffered sequential IO size exceeds optimal iosize, check if there is idle
721  * disk. If yes, choose the idle disk.
722  */
should_choose_next(struct r1conf * conf,int disk)723 static bool should_choose_next(struct r1conf *conf, int disk)
724 {
725 	struct raid1_info *mirror = &conf->mirrors[disk];
726 	int opt_iosize;
727 
728 	if (!test_bit(Nonrot, &mirror->rdev->flags))
729 		return false;
730 
731 	opt_iosize = bdev_io_opt(mirror->rdev->bdev) >> 9;
732 	return opt_iosize > 0 && mirror->seq_start != MaxSector &&
733 	       mirror->next_seq_sect > opt_iosize &&
734 	       mirror->next_seq_sect - opt_iosize >= mirror->seq_start;
735 }
736 
rdev_readable(struct md_rdev * rdev,struct r1bio * r1_bio)737 static bool rdev_readable(struct md_rdev *rdev, struct r1bio *r1_bio)
738 {
739 	if (!rdev || test_bit(Faulty, &rdev->flags))
740 		return false;
741 
742 	if (rdev_in_recovery(rdev, r1_bio))
743 		return false;
744 
745 	/* don't read from slow disk unless have to */
746 	if (test_bit(WriteMostly, &rdev->flags))
747 		return false;
748 
749 	/* don't split IO for bad blocks unless have to */
750 	if (rdev_has_badblock(rdev, r1_bio->sector, r1_bio->sectors))
751 		return false;
752 
753 	return true;
754 }
755 
756 struct read_balance_ctl {
757 	sector_t closest_dist;
758 	int closest_dist_disk;
759 	int min_pending;
760 	int min_pending_disk;
761 	int sequential_disk;
762 	int readable_disks;
763 };
764 
choose_best_rdev(struct r1conf * conf,struct r1bio * r1_bio)765 static int choose_best_rdev(struct r1conf *conf, struct r1bio *r1_bio)
766 {
767 	int disk;
768 	struct read_balance_ctl ctl = {
769 		.closest_dist_disk      = -1,
770 		.closest_dist           = MaxSector,
771 		.min_pending_disk       = -1,
772 		.min_pending            = UINT_MAX,
773 		.sequential_disk	= -1,
774 	};
775 
776 	for (disk = 0 ; disk < conf->raid_disks * 2 ; disk++) {
777 		struct md_rdev *rdev;
778 		sector_t dist;
779 		unsigned int pending;
780 
781 		if (r1_bio->bios[disk] == IO_BLOCKED)
782 			continue;
783 
784 		rdev = conf->mirrors[disk].rdev;
785 		if (!rdev_readable(rdev, r1_bio))
786 			continue;
787 
788 		/* At least two disks to choose from so failfast is OK */
789 		if (ctl.readable_disks++ == 1)
790 			set_bit(R1BIO_FailFast, &r1_bio->state);
791 
792 		pending = atomic_read(&rdev->nr_pending);
793 		dist = abs(r1_bio->sector - conf->mirrors[disk].head_position);
794 
795 		/* Don't change to another disk for sequential reads */
796 		if (is_sequential(conf, disk, r1_bio)) {
797 			if (!should_choose_next(conf, disk))
798 				return disk;
799 
800 			/*
801 			 * Add 'pending' to avoid choosing this disk if
802 			 * there is other idle disk.
803 			 */
804 			pending++;
805 			/*
806 			 * If there is no other idle disk, this disk
807 			 * will be chosen.
808 			 */
809 			ctl.sequential_disk = disk;
810 		}
811 
812 		if (ctl.min_pending > pending) {
813 			ctl.min_pending = pending;
814 			ctl.min_pending_disk = disk;
815 		}
816 
817 		if (ctl.closest_dist > dist) {
818 			ctl.closest_dist = dist;
819 			ctl.closest_dist_disk = disk;
820 		}
821 	}
822 
823 	/*
824 	 * sequential IO size exceeds optimal iosize, however, there is no other
825 	 * idle disk, so choose the sequential disk.
826 	 */
827 	if (ctl.sequential_disk != -1 && ctl.min_pending != 0)
828 		return ctl.sequential_disk;
829 
830 	/*
831 	 * If all disks are rotational, choose the closest disk. If any disk is
832 	 * non-rotational, choose the disk with less pending request even the
833 	 * disk is rotational, which might/might not be optimal for raids with
834 	 * mixed ratation/non-rotational disks depending on workload.
835 	 */
836 	if (ctl.min_pending_disk != -1 &&
837 	    (READ_ONCE(conf->nonrot_disks) || ctl.min_pending == 0))
838 		return ctl.min_pending_disk;
839 	else
840 		return ctl.closest_dist_disk;
841 }
842 
843 /*
844  * This routine returns the disk from which the requested read should be done.
845  *
846  * 1) If resync is in progress, find the first usable disk and use it even if it
847  * has some bad blocks.
848  *
849  * 2) Now that there is no resync, loop through all disks and skipping slow
850  * disks and disks with bad blocks for now. Only pay attention to key disk
851  * choice.
852  *
853  * 3) If we've made it this far, now look for disks with bad blocks and choose
854  * the one with most number of sectors.
855  *
856  * 4) If we are all the way at the end, we have no choice but to use a disk even
857  * if it is write mostly.
858  *
859  * The rdev for the device selected will have nr_pending incremented.
860  */
read_balance(struct r1conf * conf,struct r1bio * r1_bio,int * max_sectors)861 static int read_balance(struct r1conf *conf, struct r1bio *r1_bio,
862 			int *max_sectors)
863 {
864 	int disk;
865 
866 	clear_bit(R1BIO_FailFast, &r1_bio->state);
867 
868 	if (raid1_should_read_first(conf->mddev, r1_bio->sector,
869 				    r1_bio->sectors))
870 		return choose_first_rdev(conf, r1_bio, max_sectors);
871 
872 	disk = choose_best_rdev(conf, r1_bio);
873 	if (disk >= 0) {
874 		*max_sectors = r1_bio->sectors;
875 		update_read_sectors(conf, disk, r1_bio->sector,
876 				    r1_bio->sectors);
877 		return disk;
878 	}
879 
880 	/*
881 	 * If we are here it means we didn't find a perfectly good disk so
882 	 * now spend a bit more time trying to find one with the most good
883 	 * sectors.
884 	 */
885 	disk = choose_bb_rdev(conf, r1_bio, max_sectors);
886 	if (disk >= 0)
887 		return disk;
888 
889 	return choose_slow_rdev(conf, r1_bio, max_sectors);
890 }
891 
wake_up_barrier(struct r1conf * conf)892 static void wake_up_barrier(struct r1conf *conf)
893 {
894 	if (wq_has_sleeper(&conf->wait_barrier))
895 		wake_up(&conf->wait_barrier);
896 }
897 
flush_bio_list(struct r1conf * conf,struct bio * bio)898 static void flush_bio_list(struct r1conf *conf, struct bio *bio)
899 {
900 	/* flush any pending bitmap writes to disk before proceeding w/ I/O */
901 	raid1_prepare_flush_writes(conf->mddev);
902 	wake_up_barrier(conf);
903 
904 	while (bio) { /* submit pending writes */
905 		struct bio *next = bio->bi_next;
906 
907 		raid1_submit_write(bio);
908 		bio = next;
909 		cond_resched();
910 	}
911 }
912 
flush_pending_writes(struct r1conf * conf)913 static void flush_pending_writes(struct r1conf *conf)
914 {
915 	/* Any writes that have been queued but are awaiting
916 	 * bitmap updates get flushed here.
917 	 */
918 	spin_lock_irq(&conf->device_lock);
919 
920 	if (conf->pending_bio_list.head) {
921 		struct blk_plug plug;
922 		struct bio *bio;
923 
924 		bio = bio_list_get(&conf->pending_bio_list);
925 		spin_unlock_irq(&conf->device_lock);
926 
927 		/*
928 		 * As this is called in a wait_event() loop (see freeze_array),
929 		 * current->state might be TASK_UNINTERRUPTIBLE which will
930 		 * cause a warning when we prepare to wait again.  As it is
931 		 * rare that this path is taken, it is perfectly safe to force
932 		 * us to go around the wait_event() loop again, so the warning
933 		 * is a false-positive.  Silence the warning by resetting
934 		 * thread state
935 		 */
936 		__set_current_state(TASK_RUNNING);
937 		blk_start_plug(&plug);
938 		flush_bio_list(conf, bio);
939 		blk_finish_plug(&plug);
940 	} else
941 		spin_unlock_irq(&conf->device_lock);
942 }
943 
944 /* Barriers....
945  * Sometimes we need to suspend IO while we do something else,
946  * either some resync/recovery, or reconfigure the array.
947  * To do this we raise a 'barrier'.
948  * The 'barrier' is a counter that can be raised multiple times
949  * to count how many activities are happening which preclude
950  * normal IO.
951  * We can only raise the barrier if there is no pending IO.
952  * i.e. if nr_pending == 0.
953  * We choose only to raise the barrier if no-one is waiting for the
954  * barrier to go down.  This means that as soon as an IO request
955  * is ready, no other operations which require a barrier will start
956  * until the IO request has had a chance.
957  *
958  * So: regular IO calls 'wait_barrier'.  When that returns there
959  *    is no backgroup IO happening,  It must arrange to call
960  *    allow_barrier when it has finished its IO.
961  * backgroup IO calls must call raise_barrier.  Once that returns
962  *    there is no normal IO happeing.  It must arrange to call
963  *    lower_barrier when the particular background IO completes.
964  *
965  * If resync/recovery is interrupted, returns -EINTR;
966  * Otherwise, returns 0.
967  */
raise_barrier(struct r1conf * conf,sector_t sector_nr)968 static int raise_barrier(struct r1conf *conf, sector_t sector_nr)
969 {
970 	int idx = sector_to_idx(sector_nr);
971 
972 	spin_lock_irq(&conf->resync_lock);
973 
974 	/* Wait until no block IO is waiting */
975 	wait_event_lock_irq(conf->wait_barrier,
976 			    !atomic_read(&conf->nr_waiting[idx]),
977 			    conf->resync_lock);
978 
979 	/* block any new IO from starting */
980 	atomic_inc(&conf->barrier[idx]);
981 	/*
982 	 * In raise_barrier() we firstly increase conf->barrier[idx] then
983 	 * check conf->nr_pending[idx]. In _wait_barrier() we firstly
984 	 * increase conf->nr_pending[idx] then check conf->barrier[idx].
985 	 * A memory barrier here to make sure conf->nr_pending[idx] won't
986 	 * be fetched before conf->barrier[idx] is increased. Otherwise
987 	 * there will be a race between raise_barrier() and _wait_barrier().
988 	 */
989 	smp_mb__after_atomic();
990 
991 	/* For these conditions we must wait:
992 	 * A: while the array is in frozen state
993 	 * B: while conf->nr_pending[idx] is not 0, meaning regular I/O
994 	 *    existing in corresponding I/O barrier bucket.
995 	 * C: while conf->barrier[idx] >= RESYNC_DEPTH, meaning reaches
996 	 *    max resync count which allowed on current I/O barrier bucket.
997 	 */
998 	wait_event_lock_irq(conf->wait_barrier,
999 			    (!conf->array_frozen &&
1000 			     !atomic_read(&conf->nr_pending[idx]) &&
1001 			     atomic_read(&conf->barrier[idx]) < RESYNC_DEPTH) ||
1002 				test_bit(MD_RECOVERY_INTR, &conf->mddev->recovery),
1003 			    conf->resync_lock);
1004 
1005 	if (test_bit(MD_RECOVERY_INTR, &conf->mddev->recovery)) {
1006 		atomic_dec(&conf->barrier[idx]);
1007 		spin_unlock_irq(&conf->resync_lock);
1008 		wake_up(&conf->wait_barrier);
1009 		return -EINTR;
1010 	}
1011 
1012 	atomic_inc(&conf->nr_sync_pending);
1013 	spin_unlock_irq(&conf->resync_lock);
1014 
1015 	return 0;
1016 }
1017 
lower_barrier(struct r1conf * conf,sector_t sector_nr)1018 static void lower_barrier(struct r1conf *conf, sector_t sector_nr)
1019 {
1020 	int idx = sector_to_idx(sector_nr);
1021 
1022 	BUG_ON(atomic_read(&conf->barrier[idx]) <= 0);
1023 
1024 	atomic_dec(&conf->barrier[idx]);
1025 	atomic_dec(&conf->nr_sync_pending);
1026 	wake_up(&conf->wait_barrier);
1027 }
1028 
_wait_barrier(struct r1conf * conf,int idx,bool nowait)1029 static bool _wait_barrier(struct r1conf *conf, int idx, bool nowait)
1030 {
1031 	bool ret = true;
1032 
1033 	/*
1034 	 * We need to increase conf->nr_pending[idx] very early here,
1035 	 * then raise_barrier() can be blocked when it waits for
1036 	 * conf->nr_pending[idx] to be 0. Then we can avoid holding
1037 	 * conf->resync_lock when there is no barrier raised in same
1038 	 * barrier unit bucket. Also if the array is frozen, I/O
1039 	 * should be blocked until array is unfrozen.
1040 	 */
1041 	atomic_inc(&conf->nr_pending[idx]);
1042 	/*
1043 	 * In _wait_barrier() we firstly increase conf->nr_pending[idx], then
1044 	 * check conf->barrier[idx]. In raise_barrier() we firstly increase
1045 	 * conf->barrier[idx], then check conf->nr_pending[idx]. A memory
1046 	 * barrier is necessary here to make sure conf->barrier[idx] won't be
1047 	 * fetched before conf->nr_pending[idx] is increased. Otherwise there
1048 	 * will be a race between _wait_barrier() and raise_barrier().
1049 	 */
1050 	smp_mb__after_atomic();
1051 
1052 	/*
1053 	 * Don't worry about checking two atomic_t variables at same time
1054 	 * here. If during we check conf->barrier[idx], the array is
1055 	 * frozen (conf->array_frozen is 1), and chonf->barrier[idx] is
1056 	 * 0, it is safe to return and make the I/O continue. Because the
1057 	 * array is frozen, all I/O returned here will eventually complete
1058 	 * or be queued, no race will happen. See code comment in
1059 	 * frozen_array().
1060 	 */
1061 	if (!READ_ONCE(conf->array_frozen) &&
1062 	    !atomic_read(&conf->barrier[idx]))
1063 		return ret;
1064 
1065 	/*
1066 	 * After holding conf->resync_lock, conf->nr_pending[idx]
1067 	 * should be decreased before waiting for barrier to drop.
1068 	 * Otherwise, we may encounter a race condition because
1069 	 * raise_barrer() might be waiting for conf->nr_pending[idx]
1070 	 * to be 0 at same time.
1071 	 */
1072 	spin_lock_irq(&conf->resync_lock);
1073 	atomic_inc(&conf->nr_waiting[idx]);
1074 	atomic_dec(&conf->nr_pending[idx]);
1075 	/*
1076 	 * In case freeze_array() is waiting for
1077 	 * get_unqueued_pending() == extra
1078 	 */
1079 	wake_up_barrier(conf);
1080 	/* Wait for the barrier in same barrier unit bucket to drop. */
1081 
1082 	/* Return false when nowait flag is set */
1083 	if (nowait) {
1084 		ret = false;
1085 	} else {
1086 		wait_event_lock_irq(conf->wait_barrier,
1087 				!conf->array_frozen &&
1088 				!atomic_read(&conf->barrier[idx]),
1089 				conf->resync_lock);
1090 		atomic_inc(&conf->nr_pending[idx]);
1091 	}
1092 
1093 	atomic_dec(&conf->nr_waiting[idx]);
1094 	spin_unlock_irq(&conf->resync_lock);
1095 	return ret;
1096 }
1097 
wait_read_barrier(struct r1conf * conf,sector_t sector_nr,bool nowait)1098 static bool wait_read_barrier(struct r1conf *conf, sector_t sector_nr, bool nowait)
1099 {
1100 	int idx = sector_to_idx(sector_nr);
1101 	bool ret = true;
1102 
1103 	/*
1104 	 * Very similar to _wait_barrier(). The difference is, for read
1105 	 * I/O we don't need wait for sync I/O, but if the whole array
1106 	 * is frozen, the read I/O still has to wait until the array is
1107 	 * unfrozen. Since there is no ordering requirement with
1108 	 * conf->barrier[idx] here, memory barrier is unnecessary as well.
1109 	 */
1110 	atomic_inc(&conf->nr_pending[idx]);
1111 
1112 	if (!READ_ONCE(conf->array_frozen))
1113 		return ret;
1114 
1115 	spin_lock_irq(&conf->resync_lock);
1116 	atomic_inc(&conf->nr_waiting[idx]);
1117 	atomic_dec(&conf->nr_pending[idx]);
1118 	/*
1119 	 * In case freeze_array() is waiting for
1120 	 * get_unqueued_pending() == extra
1121 	 */
1122 	wake_up_barrier(conf);
1123 	/* Wait for array to be unfrozen */
1124 
1125 	/* Return false when nowait flag is set */
1126 	if (nowait) {
1127 		/* Return false when nowait flag is set */
1128 		ret = false;
1129 	} else {
1130 		wait_event_lock_irq(conf->wait_barrier,
1131 				!conf->array_frozen,
1132 				conf->resync_lock);
1133 		atomic_inc(&conf->nr_pending[idx]);
1134 	}
1135 
1136 	atomic_dec(&conf->nr_waiting[idx]);
1137 	spin_unlock_irq(&conf->resync_lock);
1138 	return ret;
1139 }
1140 
wait_barrier(struct r1conf * conf,sector_t sector_nr,bool nowait)1141 static bool wait_barrier(struct r1conf *conf, sector_t sector_nr, bool nowait)
1142 {
1143 	int idx = sector_to_idx(sector_nr);
1144 
1145 	return _wait_barrier(conf, idx, nowait);
1146 }
1147 
_allow_barrier(struct r1conf * conf,int idx)1148 static void _allow_barrier(struct r1conf *conf, int idx)
1149 {
1150 	atomic_dec(&conf->nr_pending[idx]);
1151 	wake_up_barrier(conf);
1152 }
1153 
allow_barrier(struct r1conf * conf,sector_t sector_nr)1154 static void allow_barrier(struct r1conf *conf, sector_t sector_nr)
1155 {
1156 	int idx = sector_to_idx(sector_nr);
1157 
1158 	_allow_barrier(conf, idx);
1159 }
1160 
1161 /* conf->resync_lock should be held */
get_unqueued_pending(struct r1conf * conf)1162 static int get_unqueued_pending(struct r1conf *conf)
1163 {
1164 	int idx, ret;
1165 
1166 	ret = atomic_read(&conf->nr_sync_pending);
1167 	for (idx = 0; idx < BARRIER_BUCKETS_NR; idx++)
1168 		ret += atomic_read(&conf->nr_pending[idx]) -
1169 			atomic_read(&conf->nr_queued[idx]);
1170 
1171 	return ret;
1172 }
1173 
freeze_array(struct r1conf * conf,int extra)1174 static void freeze_array(struct r1conf *conf, int extra)
1175 {
1176 	/* Stop sync I/O and normal I/O and wait for everything to
1177 	 * go quiet.
1178 	 * This is called in two situations:
1179 	 * 1) management command handlers (reshape, remove disk, quiesce).
1180 	 * 2) one normal I/O request failed.
1181 
1182 	 * After array_frozen is set to 1, new sync IO will be blocked at
1183 	 * raise_barrier(), and new normal I/O will blocked at _wait_barrier()
1184 	 * or wait_read_barrier(). The flying I/Os will either complete or be
1185 	 * queued. When everything goes quite, there are only queued I/Os left.
1186 
1187 	 * Every flying I/O contributes to a conf->nr_pending[idx], idx is the
1188 	 * barrier bucket index which this I/O request hits. When all sync and
1189 	 * normal I/O are queued, sum of all conf->nr_pending[] will match sum
1190 	 * of all conf->nr_queued[]. But normal I/O failure is an exception,
1191 	 * in handle_read_error(), we may call freeze_array() before trying to
1192 	 * fix the read error. In this case, the error read I/O is not queued,
1193 	 * so get_unqueued_pending() == 1.
1194 	 *
1195 	 * Therefore before this function returns, we need to wait until
1196 	 * get_unqueued_pendings(conf) gets equal to extra. For
1197 	 * normal I/O context, extra is 1, in rested situations extra is 0.
1198 	 */
1199 	spin_lock_irq(&conf->resync_lock);
1200 	conf->array_frozen = 1;
1201 	mddev_add_trace_msg(conf->mddev, "raid1 wait freeze");
1202 	wait_event_lock_irq_cmd(
1203 		conf->wait_barrier,
1204 		get_unqueued_pending(conf) == extra,
1205 		conf->resync_lock,
1206 		flush_pending_writes(conf));
1207 	spin_unlock_irq(&conf->resync_lock);
1208 }
unfreeze_array(struct r1conf * conf)1209 static void unfreeze_array(struct r1conf *conf)
1210 {
1211 	/* reverse the effect of the freeze */
1212 	spin_lock_irq(&conf->resync_lock);
1213 	conf->array_frozen = 0;
1214 	spin_unlock_irq(&conf->resync_lock);
1215 	wake_up(&conf->wait_barrier);
1216 }
1217 
alloc_behind_master_bio(struct r1bio * r1_bio,struct bio * bio)1218 static void alloc_behind_master_bio(struct r1bio *r1_bio,
1219 					   struct bio *bio)
1220 {
1221 	int size = bio->bi_iter.bi_size;
1222 	unsigned vcnt = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
1223 	int i = 0;
1224 	struct bio *behind_bio = NULL;
1225 
1226 	behind_bio = bio_alloc_bioset(NULL, vcnt, 0, GFP_NOIO,
1227 				      &r1_bio->mddev->bio_set);
1228 
1229 	/* discard op, we don't support writezero/writesame yet */
1230 	if (!bio_has_data(bio)) {
1231 		behind_bio->bi_iter.bi_size = size;
1232 		goto skip_copy;
1233 	}
1234 
1235 	while (i < vcnt && size) {
1236 		struct page *page;
1237 		int len = min_t(int, PAGE_SIZE, size);
1238 
1239 		page = alloc_page(GFP_NOIO);
1240 		if (unlikely(!page))
1241 			goto free_pages;
1242 
1243 		if (!bio_add_page(behind_bio, page, len, 0)) {
1244 			put_page(page);
1245 			goto free_pages;
1246 		}
1247 
1248 		size -= len;
1249 		i++;
1250 	}
1251 
1252 	bio_copy_data(behind_bio, bio);
1253 skip_copy:
1254 	r1_bio->behind_master_bio = behind_bio;
1255 	set_bit(R1BIO_BehindIO, &r1_bio->state);
1256 
1257 	return;
1258 
1259 free_pages:
1260 	pr_debug("%dB behind alloc failed, doing sync I/O\n",
1261 		 bio->bi_iter.bi_size);
1262 	bio_free_pages(behind_bio);
1263 	bio_put(behind_bio);
1264 }
1265 
raid1_unplug(struct blk_plug_cb * cb,bool from_schedule)1266 static void raid1_unplug(struct blk_plug_cb *cb, bool from_schedule)
1267 {
1268 	struct raid1_plug_cb *plug = container_of(cb, struct raid1_plug_cb,
1269 						  cb);
1270 	struct mddev *mddev = plug->cb.data;
1271 	struct r1conf *conf = mddev->private;
1272 	struct bio *bio;
1273 
1274 	if (from_schedule) {
1275 		spin_lock_irq(&conf->device_lock);
1276 		bio_list_merge(&conf->pending_bio_list, &plug->pending);
1277 		spin_unlock_irq(&conf->device_lock);
1278 		wake_up_barrier(conf);
1279 		md_wakeup_thread(mddev->thread);
1280 		kfree(plug);
1281 		return;
1282 	}
1283 
1284 	/* we aren't scheduling, so we can do the write-out directly. */
1285 	bio = bio_list_get(&plug->pending);
1286 	flush_bio_list(conf, bio);
1287 	kfree(plug);
1288 }
1289 
init_r1bio(struct r1bio * r1_bio,struct mddev * mddev,struct bio * bio)1290 static void init_r1bio(struct r1bio *r1_bio, struct mddev *mddev, struct bio *bio)
1291 {
1292 	r1_bio->master_bio = bio;
1293 	r1_bio->sectors = bio_sectors(bio);
1294 	r1_bio->state = 0;
1295 	r1_bio->mddev = mddev;
1296 	r1_bio->sector = bio->bi_iter.bi_sector;
1297 }
1298 
1299 static inline struct r1bio *
alloc_r1bio(struct mddev * mddev,struct bio * bio)1300 alloc_r1bio(struct mddev *mddev, struct bio *bio)
1301 {
1302 	struct r1conf *conf = mddev->private;
1303 	struct r1bio *r1_bio;
1304 
1305 	r1_bio = mempool_alloc(&conf->r1bio_pool, GFP_NOIO);
1306 	/* Ensure no bio records IO_BLOCKED */
1307 	memset(r1_bio->bios, 0, conf->raid_disks * sizeof(r1_bio->bios[0]));
1308 	init_r1bio(r1_bio, mddev, bio);
1309 	return r1_bio;
1310 }
1311 
raid1_read_request(struct mddev * mddev,struct bio * bio,int max_read_sectors,struct r1bio * r1_bio)1312 static void raid1_read_request(struct mddev *mddev, struct bio *bio,
1313 			       int max_read_sectors, struct r1bio *r1_bio)
1314 {
1315 	struct r1conf *conf = mddev->private;
1316 	struct raid1_info *mirror;
1317 	struct bio *read_bio;
1318 	const enum req_op op = bio_op(bio);
1319 	const blk_opf_t do_sync = bio->bi_opf & REQ_SYNC;
1320 	int max_sectors;
1321 	int rdisk, error;
1322 	bool r1bio_existed = !!r1_bio;
1323 
1324 	/*
1325 	 * If r1_bio is set, we are blocking the raid1d thread
1326 	 * so there is a tiny risk of deadlock.  So ask for
1327 	 * emergency memory if needed.
1328 	 */
1329 	gfp_t gfp = r1_bio ? (GFP_NOIO | __GFP_HIGH) : GFP_NOIO;
1330 
1331 	/*
1332 	 * Still need barrier for READ in case that whole
1333 	 * array is frozen.
1334 	 */
1335 	if (!wait_read_barrier(conf, bio->bi_iter.bi_sector,
1336 				bio->bi_opf & REQ_NOWAIT)) {
1337 		bio_wouldblock_error(bio);
1338 		return;
1339 	}
1340 
1341 	if (!r1_bio)
1342 		r1_bio = alloc_r1bio(mddev, bio);
1343 	else
1344 		init_r1bio(r1_bio, mddev, bio);
1345 	r1_bio->sectors = max_read_sectors;
1346 
1347 	/*
1348 	 * make_request() can abort the operation when read-ahead is being
1349 	 * used and no empty request is available.
1350 	 */
1351 	rdisk = read_balance(conf, r1_bio, &max_sectors);
1352 	if (rdisk < 0) {
1353 		/* couldn't find anywhere to read from */
1354 		if (r1bio_existed)
1355 			pr_crit_ratelimited("md/raid1:%s: %pg: unrecoverable I/O read error for block %llu\n",
1356 					    mdname(mddev),
1357 					    conf->mirrors[r1_bio->read_disk].rdev->bdev,
1358 					    r1_bio->sector);
1359 		raid_end_bio_io(r1_bio);
1360 		return;
1361 	}
1362 	mirror = conf->mirrors + rdisk;
1363 
1364 	if (r1bio_existed)
1365 		pr_info_ratelimited("md/raid1:%s: redirecting sector %llu to other mirror: %pg\n",
1366 				    mdname(mddev),
1367 				    (unsigned long long)r1_bio->sector,
1368 				    mirror->rdev->bdev);
1369 
1370 	if (test_bit(WriteMostly, &mirror->rdev->flags)) {
1371 		/*
1372 		 * Reading from a write-mostly device must take care not to
1373 		 * over-take any writes that are 'behind'
1374 		 */
1375 		mddev_add_trace_msg(mddev, "raid1 wait behind writes");
1376 		mddev->bitmap_ops->wait_behind_writes(mddev);
1377 	}
1378 
1379 	if (max_sectors < bio_sectors(bio)) {
1380 		struct bio *split = bio_split(bio, max_sectors,
1381 					      gfp, &conf->bio_split);
1382 
1383 		if (IS_ERR(split)) {
1384 			error = PTR_ERR(split);
1385 			goto err_handle;
1386 		}
1387 		bio_chain(split, bio);
1388 		submit_bio_noacct(bio);
1389 		bio = split;
1390 		r1_bio->master_bio = bio;
1391 		r1_bio->sectors = max_sectors;
1392 	}
1393 
1394 	r1_bio->read_disk = rdisk;
1395 	if (!r1bio_existed) {
1396 		md_account_bio(mddev, &bio);
1397 		r1_bio->master_bio = bio;
1398 	}
1399 	read_bio = bio_alloc_clone(mirror->rdev->bdev, bio, gfp,
1400 				   &mddev->bio_set);
1401 
1402 	r1_bio->bios[rdisk] = read_bio;
1403 
1404 	read_bio->bi_iter.bi_sector = r1_bio->sector +
1405 		mirror->rdev->data_offset;
1406 	read_bio->bi_end_io = raid1_end_read_request;
1407 	read_bio->bi_opf = op | do_sync;
1408 	if (test_bit(FailFast, &mirror->rdev->flags) &&
1409 	    test_bit(R1BIO_FailFast, &r1_bio->state))
1410 	        read_bio->bi_opf |= MD_FAILFAST;
1411 	read_bio->bi_private = r1_bio;
1412 	mddev_trace_remap(mddev, read_bio, r1_bio->sector);
1413 	submit_bio_noacct(read_bio);
1414 	return;
1415 
1416 err_handle:
1417 	atomic_dec(&mirror->rdev->nr_pending);
1418 	bio->bi_status = errno_to_blk_status(error);
1419 	set_bit(R1BIO_Uptodate, &r1_bio->state);
1420 	raid_end_bio_io(r1_bio);
1421 }
1422 
wait_blocked_rdev(struct mddev * mddev,struct bio * bio)1423 static bool wait_blocked_rdev(struct mddev *mddev, struct bio *bio)
1424 {
1425 	struct r1conf *conf = mddev->private;
1426 	int disks = conf->raid_disks * 2;
1427 	int i;
1428 
1429 retry:
1430 	for (i = 0; i < disks; i++) {
1431 		struct md_rdev *rdev = conf->mirrors[i].rdev;
1432 
1433 		if (!rdev)
1434 			continue;
1435 
1436 		/* don't write here until the bad block is acknowledged */
1437 		if (test_bit(WriteErrorSeen, &rdev->flags) &&
1438 		    rdev_has_badblock(rdev, bio->bi_iter.bi_sector,
1439 				      bio_sectors(bio)) < 0)
1440 			set_bit(BlockedBadBlocks, &rdev->flags);
1441 
1442 		if (rdev_blocked(rdev)) {
1443 			if (bio->bi_opf & REQ_NOWAIT)
1444 				return false;
1445 
1446 			mddev_add_trace_msg(rdev->mddev, "raid1 wait rdev %d blocked",
1447 					    rdev->raid_disk);
1448 			atomic_inc(&rdev->nr_pending);
1449 			md_wait_for_blocked_rdev(rdev, rdev->mddev);
1450 			goto retry;
1451 		}
1452 	}
1453 
1454 	return true;
1455 }
1456 
raid1_write_request(struct mddev * mddev,struct bio * bio,int max_write_sectors)1457 static void raid1_write_request(struct mddev *mddev, struct bio *bio,
1458 				int max_write_sectors)
1459 {
1460 	struct r1conf *conf = mddev->private;
1461 	struct r1bio *r1_bio;
1462 	int i, disks, k, error;
1463 	unsigned long flags;
1464 	int first_clone;
1465 	int max_sectors;
1466 	bool write_behind = false;
1467 	bool is_discard = (bio_op(bio) == REQ_OP_DISCARD);
1468 
1469 	if (mddev_is_clustered(mddev) &&
1470 	     md_cluster_ops->area_resyncing(mddev, WRITE,
1471 		     bio->bi_iter.bi_sector, bio_end_sector(bio))) {
1472 
1473 		DEFINE_WAIT(w);
1474 		if (bio->bi_opf & REQ_NOWAIT) {
1475 			bio_wouldblock_error(bio);
1476 			return;
1477 		}
1478 		for (;;) {
1479 			prepare_to_wait(&conf->wait_barrier,
1480 					&w, TASK_IDLE);
1481 			if (!md_cluster_ops->area_resyncing(mddev, WRITE,
1482 							bio->bi_iter.bi_sector,
1483 							bio_end_sector(bio)))
1484 				break;
1485 			schedule();
1486 		}
1487 		finish_wait(&conf->wait_barrier, &w);
1488 	}
1489 
1490 	/*
1491 	 * Register the new request and wait if the reconstruction
1492 	 * thread has put up a bar for new requests.
1493 	 * Continue immediately if no resync is active currently.
1494 	 */
1495 	if (!wait_barrier(conf, bio->bi_iter.bi_sector,
1496 				bio->bi_opf & REQ_NOWAIT)) {
1497 		bio_wouldblock_error(bio);
1498 		return;
1499 	}
1500 
1501 	if (!wait_blocked_rdev(mddev, bio)) {
1502 		bio_wouldblock_error(bio);
1503 		return;
1504 	}
1505 
1506 	r1_bio = alloc_r1bio(mddev, bio);
1507 	r1_bio->sectors = max_write_sectors;
1508 
1509 	/* first select target devices under rcu_lock and
1510 	 * inc refcount on their rdev.  Record them by setting
1511 	 * bios[x] to bio
1512 	 * If there are known/acknowledged bad blocks on any device on
1513 	 * which we have seen a write error, we want to avoid writing those
1514 	 * blocks.
1515 	 * This potentially requires several writes to write around
1516 	 * the bad blocks.  Each set of writes gets it's own r1bio
1517 	 * with a set of bios attached.
1518 	 */
1519 
1520 	disks = conf->raid_disks * 2;
1521 	max_sectors = r1_bio->sectors;
1522 	for (i = 0;  i < disks; i++) {
1523 		struct md_rdev *rdev = conf->mirrors[i].rdev;
1524 
1525 		/*
1526 		 * The write-behind io is only attempted on drives marked as
1527 		 * write-mostly, which means we could allocate write behind
1528 		 * bio later.
1529 		 */
1530 		if (!is_discard && rdev && test_bit(WriteMostly, &rdev->flags))
1531 			write_behind = true;
1532 
1533 		r1_bio->bios[i] = NULL;
1534 		if (!rdev || test_bit(Faulty, &rdev->flags))
1535 			continue;
1536 
1537 		atomic_inc(&rdev->nr_pending);
1538 		if (test_bit(WriteErrorSeen, &rdev->flags)) {
1539 			sector_t first_bad;
1540 			int bad_sectors;
1541 			int is_bad;
1542 
1543 			is_bad = is_badblock(rdev, r1_bio->sector, max_sectors,
1544 					     &first_bad, &bad_sectors);
1545 			if (is_bad && first_bad <= r1_bio->sector) {
1546 				/* Cannot write here at all */
1547 				bad_sectors -= (r1_bio->sector - first_bad);
1548 				if (bad_sectors < max_sectors)
1549 					/* mustn't write more than bad_sectors
1550 					 * to other devices yet
1551 					 */
1552 					max_sectors = bad_sectors;
1553 				rdev_dec_pending(rdev, mddev);
1554 				continue;
1555 			}
1556 			if (is_bad) {
1557 				int good_sectors;
1558 
1559 				/*
1560 				 * We cannot atomically write this, so just
1561 				 * error in that case. It could be possible to
1562 				 * atomically write other mirrors, but the
1563 				 * complexity of supporting that is not worth
1564 				 * the benefit.
1565 				 */
1566 				if (bio->bi_opf & REQ_ATOMIC) {
1567 					error = -EIO;
1568 					goto err_handle;
1569 				}
1570 
1571 				good_sectors = first_bad - r1_bio->sector;
1572 				if (good_sectors < max_sectors)
1573 					max_sectors = good_sectors;
1574 			}
1575 		}
1576 		r1_bio->bios[i] = bio;
1577 	}
1578 
1579 	/*
1580 	 * When using a bitmap, we may call alloc_behind_master_bio below.
1581 	 * alloc_behind_master_bio allocates a copy of the data payload a page
1582 	 * at a time and thus needs a new bio that can fit the whole payload
1583 	 * this bio in page sized chunks.
1584 	 */
1585 	if (write_behind && mddev->bitmap)
1586 		max_sectors = min_t(int, max_sectors,
1587 				    BIO_MAX_VECS * (PAGE_SIZE >> 9));
1588 	if (max_sectors < bio_sectors(bio)) {
1589 		struct bio *split = bio_split(bio, max_sectors,
1590 					      GFP_NOIO, &conf->bio_split);
1591 
1592 		if (IS_ERR(split)) {
1593 			error = PTR_ERR(split);
1594 			goto err_handle;
1595 		}
1596 		bio_chain(split, bio);
1597 		submit_bio_noacct(bio);
1598 		bio = split;
1599 		r1_bio->master_bio = bio;
1600 		r1_bio->sectors = max_sectors;
1601 	}
1602 
1603 	md_account_bio(mddev, &bio);
1604 	r1_bio->master_bio = bio;
1605 	atomic_set(&r1_bio->remaining, 1);
1606 	atomic_set(&r1_bio->behind_remaining, 0);
1607 
1608 	first_clone = 1;
1609 
1610 	for (i = 0; i < disks; i++) {
1611 		struct bio *mbio = NULL;
1612 		struct md_rdev *rdev = conf->mirrors[i].rdev;
1613 		if (!r1_bio->bios[i])
1614 			continue;
1615 
1616 		if (first_clone) {
1617 			unsigned long max_write_behind =
1618 				mddev->bitmap_info.max_write_behind;
1619 			struct md_bitmap_stats stats;
1620 			int err;
1621 
1622 			/* do behind I/O ?
1623 			 * Not if there are too many, or cannot
1624 			 * allocate memory, or a reader on WriteMostly
1625 			 * is waiting for behind writes to flush */
1626 			err = mddev->bitmap_ops->get_stats(mddev->bitmap, &stats);
1627 			if (!err && write_behind && !stats.behind_wait &&
1628 			    stats.behind_writes < max_write_behind)
1629 				alloc_behind_master_bio(r1_bio, bio);
1630 
1631 			if (test_bit(R1BIO_BehindIO, &r1_bio->state))
1632 				mddev->bitmap_ops->start_behind_write(mddev);
1633 			first_clone = 0;
1634 		}
1635 
1636 		if (r1_bio->behind_master_bio) {
1637 			mbio = bio_alloc_clone(rdev->bdev,
1638 					       r1_bio->behind_master_bio,
1639 					       GFP_NOIO, &mddev->bio_set);
1640 			if (test_bit(CollisionCheck, &rdev->flags))
1641 				wait_for_serialization(rdev, r1_bio);
1642 			if (test_bit(WriteMostly, &rdev->flags))
1643 				atomic_inc(&r1_bio->behind_remaining);
1644 		} else {
1645 			mbio = bio_alloc_clone(rdev->bdev, bio, GFP_NOIO,
1646 					       &mddev->bio_set);
1647 
1648 			if (mddev->serialize_policy)
1649 				wait_for_serialization(rdev, r1_bio);
1650 		}
1651 
1652 		r1_bio->bios[i] = mbio;
1653 
1654 		mbio->bi_iter.bi_sector	= (r1_bio->sector + rdev->data_offset);
1655 		mbio->bi_end_io	= raid1_end_write_request;
1656 		mbio->bi_opf = bio_op(bio) |
1657 			(bio->bi_opf & (REQ_SYNC | REQ_FUA | REQ_ATOMIC));
1658 		if (test_bit(FailFast, &rdev->flags) &&
1659 		    !test_bit(WriteMostly, &rdev->flags) &&
1660 		    conf->raid_disks - mddev->degraded > 1)
1661 			mbio->bi_opf |= MD_FAILFAST;
1662 		mbio->bi_private = r1_bio;
1663 
1664 		atomic_inc(&r1_bio->remaining);
1665 		mddev_trace_remap(mddev, mbio, r1_bio->sector);
1666 		/* flush_pending_writes() needs access to the rdev so...*/
1667 		mbio->bi_bdev = (void *)rdev;
1668 		if (!raid1_add_bio_to_plug(mddev, mbio, raid1_unplug, disks)) {
1669 			spin_lock_irqsave(&conf->device_lock, flags);
1670 			bio_list_add(&conf->pending_bio_list, mbio);
1671 			spin_unlock_irqrestore(&conf->device_lock, flags);
1672 			md_wakeup_thread(mddev->thread);
1673 		}
1674 	}
1675 
1676 	r1_bio_write_done(r1_bio);
1677 
1678 	/* In case raid1d snuck in to freeze_array */
1679 	wake_up_barrier(conf);
1680 	return;
1681 err_handle:
1682 	for (k = 0; k < i; k++) {
1683 		if (r1_bio->bios[k]) {
1684 			rdev_dec_pending(conf->mirrors[k].rdev, mddev);
1685 			r1_bio->bios[k] = NULL;
1686 		}
1687 	}
1688 
1689 	bio->bi_status = errno_to_blk_status(error);
1690 	set_bit(R1BIO_Uptodate, &r1_bio->state);
1691 	raid_end_bio_io(r1_bio);
1692 }
1693 
raid1_make_request(struct mddev * mddev,struct bio * bio)1694 static bool raid1_make_request(struct mddev *mddev, struct bio *bio)
1695 {
1696 	sector_t sectors;
1697 
1698 	if (unlikely(bio->bi_opf & REQ_PREFLUSH)
1699 	    && md_flush_request(mddev, bio))
1700 		return true;
1701 
1702 	/*
1703 	 * There is a limit to the maximum size, but
1704 	 * the read/write handler might find a lower limit
1705 	 * due to bad blocks.  To avoid multiple splits,
1706 	 * we pass the maximum number of sectors down
1707 	 * and let the lower level perform the split.
1708 	 */
1709 	sectors = align_to_barrier_unit_end(
1710 		bio->bi_iter.bi_sector, bio_sectors(bio));
1711 
1712 	if (bio_data_dir(bio) == READ)
1713 		raid1_read_request(mddev, bio, sectors, NULL);
1714 	else {
1715 		md_write_start(mddev,bio);
1716 		raid1_write_request(mddev, bio, sectors);
1717 	}
1718 	return true;
1719 }
1720 
raid1_status(struct seq_file * seq,struct mddev * mddev)1721 static void raid1_status(struct seq_file *seq, struct mddev *mddev)
1722 {
1723 	struct r1conf *conf = mddev->private;
1724 	int i;
1725 
1726 	lockdep_assert_held(&mddev->lock);
1727 
1728 	seq_printf(seq, " [%d/%d] [", conf->raid_disks,
1729 		   conf->raid_disks - mddev->degraded);
1730 	for (i = 0; i < conf->raid_disks; i++) {
1731 		struct md_rdev *rdev = READ_ONCE(conf->mirrors[i].rdev);
1732 
1733 		seq_printf(seq, "%s",
1734 			   rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_");
1735 	}
1736 	seq_printf(seq, "]");
1737 }
1738 
1739 /**
1740  * raid1_error() - RAID1 error handler.
1741  * @mddev: affected md device.
1742  * @rdev: member device to fail.
1743  *
1744  * The routine acknowledges &rdev failure and determines new @mddev state.
1745  * If it failed, then:
1746  *	- &MD_BROKEN flag is set in &mddev->flags.
1747  *	- recovery is disabled.
1748  * Otherwise, it must be degraded:
1749  *	- recovery is interrupted.
1750  *	- &mddev->degraded is bumped.
1751  *
1752  * @rdev is marked as &Faulty excluding case when array is failed and
1753  * &mddev->fail_last_dev is off.
1754  */
raid1_error(struct mddev * mddev,struct md_rdev * rdev)1755 static void raid1_error(struct mddev *mddev, struct md_rdev *rdev)
1756 {
1757 	struct r1conf *conf = mddev->private;
1758 	unsigned long flags;
1759 
1760 	spin_lock_irqsave(&conf->device_lock, flags);
1761 
1762 	if (test_bit(In_sync, &rdev->flags) &&
1763 	    (conf->raid_disks - mddev->degraded) == 1) {
1764 		set_bit(MD_BROKEN, &mddev->flags);
1765 
1766 		if (!mddev->fail_last_dev) {
1767 			conf->recovery_disabled = mddev->recovery_disabled;
1768 			spin_unlock_irqrestore(&conf->device_lock, flags);
1769 			return;
1770 		}
1771 	}
1772 	set_bit(Blocked, &rdev->flags);
1773 	if (test_and_clear_bit(In_sync, &rdev->flags))
1774 		mddev->degraded++;
1775 	set_bit(Faulty, &rdev->flags);
1776 	spin_unlock_irqrestore(&conf->device_lock, flags);
1777 	/*
1778 	 * if recovery is running, make sure it aborts.
1779 	 */
1780 	set_bit(MD_RECOVERY_INTR, &mddev->recovery);
1781 	set_mask_bits(&mddev->sb_flags, 0,
1782 		      BIT(MD_SB_CHANGE_DEVS) | BIT(MD_SB_CHANGE_PENDING));
1783 	pr_crit("md/raid1:%s: Disk failure on %pg, disabling device.\n"
1784 		"md/raid1:%s: Operation continuing on %d devices.\n",
1785 		mdname(mddev), rdev->bdev,
1786 		mdname(mddev), conf->raid_disks - mddev->degraded);
1787 }
1788 
print_conf(struct r1conf * conf)1789 static void print_conf(struct r1conf *conf)
1790 {
1791 	int i;
1792 
1793 	pr_debug("RAID1 conf printout:\n");
1794 	if (!conf) {
1795 		pr_debug("(!conf)\n");
1796 		return;
1797 	}
1798 	pr_debug(" --- wd:%d rd:%d\n", conf->raid_disks - conf->mddev->degraded,
1799 		 conf->raid_disks);
1800 
1801 	lockdep_assert_held(&conf->mddev->reconfig_mutex);
1802 	for (i = 0; i < conf->raid_disks; i++) {
1803 		struct md_rdev *rdev = conf->mirrors[i].rdev;
1804 		if (rdev)
1805 			pr_debug(" disk %d, wo:%d, o:%d, dev:%pg\n",
1806 				 i, !test_bit(In_sync, &rdev->flags),
1807 				 !test_bit(Faulty, &rdev->flags),
1808 				 rdev->bdev);
1809 	}
1810 }
1811 
close_sync(struct r1conf * conf)1812 static void close_sync(struct r1conf *conf)
1813 {
1814 	int idx;
1815 
1816 	for (idx = 0; idx < BARRIER_BUCKETS_NR; idx++) {
1817 		_wait_barrier(conf, idx, false);
1818 		_allow_barrier(conf, idx);
1819 	}
1820 
1821 	mempool_exit(&conf->r1buf_pool);
1822 }
1823 
raid1_spare_active(struct mddev * mddev)1824 static int raid1_spare_active(struct mddev *mddev)
1825 {
1826 	int i;
1827 	struct r1conf *conf = mddev->private;
1828 	int count = 0;
1829 	unsigned long flags;
1830 
1831 	/*
1832 	 * Find all failed disks within the RAID1 configuration
1833 	 * and mark them readable.
1834 	 * Called under mddev lock, so rcu protection not needed.
1835 	 * device_lock used to avoid races with raid1_end_read_request
1836 	 * which expects 'In_sync' flags and ->degraded to be consistent.
1837 	 */
1838 	spin_lock_irqsave(&conf->device_lock, flags);
1839 	for (i = 0; i < conf->raid_disks; i++) {
1840 		struct md_rdev *rdev = conf->mirrors[i].rdev;
1841 		struct md_rdev *repl = conf->mirrors[conf->raid_disks + i].rdev;
1842 		if (repl
1843 		    && !test_bit(Candidate, &repl->flags)
1844 		    && repl->recovery_offset == MaxSector
1845 		    && !test_bit(Faulty, &repl->flags)
1846 		    && !test_and_set_bit(In_sync, &repl->flags)) {
1847 			/* replacement has just become active */
1848 			if (!rdev ||
1849 			    !test_and_clear_bit(In_sync, &rdev->flags))
1850 				count++;
1851 			if (rdev) {
1852 				/* Replaced device not technically
1853 				 * faulty, but we need to be sure
1854 				 * it gets removed and never re-added
1855 				 */
1856 				set_bit(Faulty, &rdev->flags);
1857 				sysfs_notify_dirent_safe(
1858 					rdev->sysfs_state);
1859 			}
1860 		}
1861 		if (rdev
1862 		    && rdev->recovery_offset == MaxSector
1863 		    && !test_bit(Faulty, &rdev->flags)
1864 		    && !test_and_set_bit(In_sync, &rdev->flags)) {
1865 			count++;
1866 			sysfs_notify_dirent_safe(rdev->sysfs_state);
1867 		}
1868 	}
1869 	mddev->degraded -= count;
1870 	spin_unlock_irqrestore(&conf->device_lock, flags);
1871 
1872 	print_conf(conf);
1873 	return count;
1874 }
1875 
raid1_add_conf(struct r1conf * conf,struct md_rdev * rdev,int disk,bool replacement)1876 static bool raid1_add_conf(struct r1conf *conf, struct md_rdev *rdev, int disk,
1877 			   bool replacement)
1878 {
1879 	struct raid1_info *info = conf->mirrors + disk;
1880 
1881 	if (replacement)
1882 		info += conf->raid_disks;
1883 
1884 	if (info->rdev)
1885 		return false;
1886 
1887 	if (bdev_nonrot(rdev->bdev)) {
1888 		set_bit(Nonrot, &rdev->flags);
1889 		WRITE_ONCE(conf->nonrot_disks, conf->nonrot_disks + 1);
1890 	}
1891 
1892 	rdev->raid_disk = disk;
1893 	info->head_position = 0;
1894 	info->seq_start = MaxSector;
1895 	WRITE_ONCE(info->rdev, rdev);
1896 
1897 	return true;
1898 }
1899 
raid1_remove_conf(struct r1conf * conf,int disk)1900 static bool raid1_remove_conf(struct r1conf *conf, int disk)
1901 {
1902 	struct raid1_info *info = conf->mirrors + disk;
1903 	struct md_rdev *rdev = info->rdev;
1904 
1905 	if (!rdev || test_bit(In_sync, &rdev->flags) ||
1906 	    atomic_read(&rdev->nr_pending))
1907 		return false;
1908 
1909 	/* Only remove non-faulty devices if recovery is not possible. */
1910 	if (!test_bit(Faulty, &rdev->flags) &&
1911 	    rdev->mddev->recovery_disabled != conf->recovery_disabled &&
1912 	    rdev->mddev->degraded < conf->raid_disks)
1913 		return false;
1914 
1915 	if (test_and_clear_bit(Nonrot, &rdev->flags))
1916 		WRITE_ONCE(conf->nonrot_disks, conf->nonrot_disks - 1);
1917 
1918 	WRITE_ONCE(info->rdev, NULL);
1919 	return true;
1920 }
1921 
raid1_add_disk(struct mddev * mddev,struct md_rdev * rdev)1922 static int raid1_add_disk(struct mddev *mddev, struct md_rdev *rdev)
1923 {
1924 	struct r1conf *conf = mddev->private;
1925 	int err = -EEXIST;
1926 	int mirror = 0, repl_slot = -1;
1927 	struct raid1_info *p;
1928 	int first = 0;
1929 	int last = conf->raid_disks - 1;
1930 
1931 	if (mddev->recovery_disabled == conf->recovery_disabled)
1932 		return -EBUSY;
1933 
1934 	if (rdev->raid_disk >= 0)
1935 		first = last = rdev->raid_disk;
1936 
1937 	/*
1938 	 * find the disk ... but prefer rdev->saved_raid_disk
1939 	 * if possible.
1940 	 */
1941 	if (rdev->saved_raid_disk >= 0 &&
1942 	    rdev->saved_raid_disk >= first &&
1943 	    rdev->saved_raid_disk < conf->raid_disks &&
1944 	    conf->mirrors[rdev->saved_raid_disk].rdev == NULL)
1945 		first = last = rdev->saved_raid_disk;
1946 
1947 	for (mirror = first; mirror <= last; mirror++) {
1948 		p = conf->mirrors + mirror;
1949 		if (!p->rdev) {
1950 			err = mddev_stack_new_rdev(mddev, rdev);
1951 			if (err)
1952 				return err;
1953 
1954 			raid1_add_conf(conf, rdev, mirror, false);
1955 			/* As all devices are equivalent, we don't need a full recovery
1956 			 * if this was recently any drive of the array
1957 			 */
1958 			if (rdev->saved_raid_disk < 0)
1959 				conf->fullsync = 1;
1960 			break;
1961 		}
1962 		if (test_bit(WantReplacement, &p->rdev->flags) &&
1963 		    p[conf->raid_disks].rdev == NULL && repl_slot < 0)
1964 			repl_slot = mirror;
1965 	}
1966 
1967 	if (err && repl_slot >= 0) {
1968 		/* Add this device as a replacement */
1969 		clear_bit(In_sync, &rdev->flags);
1970 		set_bit(Replacement, &rdev->flags);
1971 		raid1_add_conf(conf, rdev, repl_slot, true);
1972 		err = 0;
1973 		conf->fullsync = 1;
1974 	}
1975 
1976 	print_conf(conf);
1977 	return err;
1978 }
1979 
raid1_remove_disk(struct mddev * mddev,struct md_rdev * rdev)1980 static int raid1_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
1981 {
1982 	struct r1conf *conf = mddev->private;
1983 	int err = 0;
1984 	int number = rdev->raid_disk;
1985 	struct raid1_info *p = conf->mirrors + number;
1986 
1987 	if (unlikely(number >= conf->raid_disks))
1988 		goto abort;
1989 
1990 	if (rdev != p->rdev) {
1991 		number += conf->raid_disks;
1992 		p = conf->mirrors + number;
1993 	}
1994 
1995 	print_conf(conf);
1996 	if (rdev == p->rdev) {
1997 		if (!raid1_remove_conf(conf, number)) {
1998 			err = -EBUSY;
1999 			goto abort;
2000 		}
2001 
2002 		if (number < conf->raid_disks &&
2003 		    conf->mirrors[conf->raid_disks + number].rdev) {
2004 			/* We just removed a device that is being replaced.
2005 			 * Move down the replacement.  We drain all IO before
2006 			 * doing this to avoid confusion.
2007 			 */
2008 			struct md_rdev *repl =
2009 				conf->mirrors[conf->raid_disks + number].rdev;
2010 			freeze_array(conf, 0);
2011 			if (atomic_read(&repl->nr_pending)) {
2012 				/* It means that some queued IO of retry_list
2013 				 * hold repl. Thus, we cannot set replacement
2014 				 * as NULL, avoiding rdev NULL pointer
2015 				 * dereference in sync_request_write and
2016 				 * handle_write_finished.
2017 				 */
2018 				err = -EBUSY;
2019 				unfreeze_array(conf);
2020 				goto abort;
2021 			}
2022 			clear_bit(Replacement, &repl->flags);
2023 			WRITE_ONCE(p->rdev, repl);
2024 			conf->mirrors[conf->raid_disks + number].rdev = NULL;
2025 			unfreeze_array(conf);
2026 		}
2027 
2028 		clear_bit(WantReplacement, &rdev->flags);
2029 		err = md_integrity_register(mddev);
2030 	}
2031 abort:
2032 
2033 	print_conf(conf);
2034 	return err;
2035 }
2036 
end_sync_read(struct bio * bio)2037 static void end_sync_read(struct bio *bio)
2038 {
2039 	struct r1bio *r1_bio = get_resync_r1bio(bio);
2040 
2041 	update_head_pos(r1_bio->read_disk, r1_bio);
2042 
2043 	/*
2044 	 * we have read a block, now it needs to be re-written,
2045 	 * or re-read if the read failed.
2046 	 * We don't do much here, just schedule handling by raid1d
2047 	 */
2048 	if (!bio->bi_status)
2049 		set_bit(R1BIO_Uptodate, &r1_bio->state);
2050 
2051 	if (atomic_dec_and_test(&r1_bio->remaining))
2052 		reschedule_retry(r1_bio);
2053 }
2054 
abort_sync_write(struct mddev * mddev,struct r1bio * r1_bio)2055 static void abort_sync_write(struct mddev *mddev, struct r1bio *r1_bio)
2056 {
2057 	sector_t sync_blocks = 0;
2058 	sector_t s = r1_bio->sector;
2059 	long sectors_to_go = r1_bio->sectors;
2060 
2061 	/* make sure these bits don't get cleared. */
2062 	do {
2063 		mddev->bitmap_ops->end_sync(mddev, s, &sync_blocks);
2064 		s += sync_blocks;
2065 		sectors_to_go -= sync_blocks;
2066 	} while (sectors_to_go > 0);
2067 }
2068 
put_sync_write_buf(struct r1bio * r1_bio,int uptodate)2069 static void put_sync_write_buf(struct r1bio *r1_bio, int uptodate)
2070 {
2071 	if (atomic_dec_and_test(&r1_bio->remaining)) {
2072 		struct mddev *mddev = r1_bio->mddev;
2073 		int s = r1_bio->sectors;
2074 
2075 		if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
2076 		    test_bit(R1BIO_WriteError, &r1_bio->state))
2077 			reschedule_retry(r1_bio);
2078 		else {
2079 			put_buf(r1_bio);
2080 			md_done_sync(mddev, s, uptodate);
2081 		}
2082 	}
2083 }
2084 
end_sync_write(struct bio * bio)2085 static void end_sync_write(struct bio *bio)
2086 {
2087 	int uptodate = !bio->bi_status;
2088 	struct r1bio *r1_bio = get_resync_r1bio(bio);
2089 	struct mddev *mddev = r1_bio->mddev;
2090 	struct r1conf *conf = mddev->private;
2091 	struct md_rdev *rdev = conf->mirrors[find_bio_disk(r1_bio, bio)].rdev;
2092 
2093 	if (!uptodate) {
2094 		abort_sync_write(mddev, r1_bio);
2095 		set_bit(WriteErrorSeen, &rdev->flags);
2096 		if (!test_and_set_bit(WantReplacement, &rdev->flags))
2097 			set_bit(MD_RECOVERY_NEEDED, &
2098 				mddev->recovery);
2099 		set_bit(R1BIO_WriteError, &r1_bio->state);
2100 	} else if (rdev_has_badblock(rdev, r1_bio->sector, r1_bio->sectors) &&
2101 		   !rdev_has_badblock(conf->mirrors[r1_bio->read_disk].rdev,
2102 				      r1_bio->sector, r1_bio->sectors)) {
2103 		set_bit(R1BIO_MadeGood, &r1_bio->state);
2104 	}
2105 
2106 	put_sync_write_buf(r1_bio, uptodate);
2107 }
2108 
r1_sync_page_io(struct md_rdev * rdev,sector_t sector,int sectors,struct page * page,blk_opf_t rw)2109 static int r1_sync_page_io(struct md_rdev *rdev, sector_t sector,
2110 			   int sectors, struct page *page, blk_opf_t rw)
2111 {
2112 	if (sync_page_io(rdev, sector, sectors << 9, page, rw, false))
2113 		/* success */
2114 		return 1;
2115 	if (rw == REQ_OP_WRITE) {
2116 		set_bit(WriteErrorSeen, &rdev->flags);
2117 		if (!test_and_set_bit(WantReplacement,
2118 				      &rdev->flags))
2119 			set_bit(MD_RECOVERY_NEEDED, &
2120 				rdev->mddev->recovery);
2121 	}
2122 	/* need to record an error - either for the block or the device */
2123 	if (!rdev_set_badblocks(rdev, sector, sectors, 0))
2124 		md_error(rdev->mddev, rdev);
2125 	return 0;
2126 }
2127 
fix_sync_read_error(struct r1bio * r1_bio)2128 static int fix_sync_read_error(struct r1bio *r1_bio)
2129 {
2130 	/* Try some synchronous reads of other devices to get
2131 	 * good data, much like with normal read errors.  Only
2132 	 * read into the pages we already have so we don't
2133 	 * need to re-issue the read request.
2134 	 * We don't need to freeze the array, because being in an
2135 	 * active sync request, there is no normal IO, and
2136 	 * no overlapping syncs.
2137 	 * We don't need to check is_badblock() again as we
2138 	 * made sure that anything with a bad block in range
2139 	 * will have bi_end_io clear.
2140 	 */
2141 	struct mddev *mddev = r1_bio->mddev;
2142 	struct r1conf *conf = mddev->private;
2143 	struct bio *bio = r1_bio->bios[r1_bio->read_disk];
2144 	struct page **pages = get_resync_pages(bio)->pages;
2145 	sector_t sect = r1_bio->sector;
2146 	int sectors = r1_bio->sectors;
2147 	int idx = 0;
2148 	struct md_rdev *rdev;
2149 
2150 	rdev = conf->mirrors[r1_bio->read_disk].rdev;
2151 	if (test_bit(FailFast, &rdev->flags)) {
2152 		/* Don't try recovering from here - just fail it
2153 		 * ... unless it is the last working device of course */
2154 		md_error(mddev, rdev);
2155 		if (test_bit(Faulty, &rdev->flags))
2156 			/* Don't try to read from here, but make sure
2157 			 * put_buf does it's thing
2158 			 */
2159 			bio->bi_end_io = end_sync_write;
2160 	}
2161 
2162 	while(sectors) {
2163 		int s = sectors;
2164 		int d = r1_bio->read_disk;
2165 		int success = 0;
2166 		int start;
2167 
2168 		if (s > (PAGE_SIZE>>9))
2169 			s = PAGE_SIZE >> 9;
2170 		do {
2171 			if (r1_bio->bios[d]->bi_end_io == end_sync_read) {
2172 				/* No rcu protection needed here devices
2173 				 * can only be removed when no resync is
2174 				 * active, and resync is currently active
2175 				 */
2176 				rdev = conf->mirrors[d].rdev;
2177 				if (sync_page_io(rdev, sect, s<<9,
2178 						 pages[idx],
2179 						 REQ_OP_READ, false)) {
2180 					success = 1;
2181 					break;
2182 				}
2183 			}
2184 			d++;
2185 			if (d == conf->raid_disks * 2)
2186 				d = 0;
2187 		} while (!success && d != r1_bio->read_disk);
2188 
2189 		if (!success) {
2190 			int abort = 0;
2191 			/* Cannot read from anywhere, this block is lost.
2192 			 * Record a bad block on each device.  If that doesn't
2193 			 * work just disable and interrupt the recovery.
2194 			 * Don't fail devices as that won't really help.
2195 			 */
2196 			pr_crit_ratelimited("md/raid1:%s: %pg: unrecoverable I/O read error for block %llu\n",
2197 					    mdname(mddev), bio->bi_bdev,
2198 					    (unsigned long long)r1_bio->sector);
2199 			for (d = 0; d < conf->raid_disks * 2; d++) {
2200 				rdev = conf->mirrors[d].rdev;
2201 				if (!rdev || test_bit(Faulty, &rdev->flags))
2202 					continue;
2203 				if (!rdev_set_badblocks(rdev, sect, s, 0))
2204 					abort = 1;
2205 			}
2206 			if (abort) {
2207 				conf->recovery_disabled =
2208 					mddev->recovery_disabled;
2209 				set_bit(MD_RECOVERY_INTR, &mddev->recovery);
2210 				md_done_sync(mddev, r1_bio->sectors, 0);
2211 				put_buf(r1_bio);
2212 				return 0;
2213 			}
2214 			/* Try next page */
2215 			sectors -= s;
2216 			sect += s;
2217 			idx++;
2218 			continue;
2219 		}
2220 
2221 		start = d;
2222 		/* write it back and re-read */
2223 		while (d != r1_bio->read_disk) {
2224 			if (d == 0)
2225 				d = conf->raid_disks * 2;
2226 			d--;
2227 			if (r1_bio->bios[d]->bi_end_io != end_sync_read)
2228 				continue;
2229 			rdev = conf->mirrors[d].rdev;
2230 			if (r1_sync_page_io(rdev, sect, s,
2231 					    pages[idx],
2232 					    REQ_OP_WRITE) == 0) {
2233 				r1_bio->bios[d]->bi_end_io = NULL;
2234 				rdev_dec_pending(rdev, mddev);
2235 			}
2236 		}
2237 		d = start;
2238 		while (d != r1_bio->read_disk) {
2239 			if (d == 0)
2240 				d = conf->raid_disks * 2;
2241 			d--;
2242 			if (r1_bio->bios[d]->bi_end_io != end_sync_read)
2243 				continue;
2244 			rdev = conf->mirrors[d].rdev;
2245 			if (r1_sync_page_io(rdev, sect, s,
2246 					    pages[idx],
2247 					    REQ_OP_READ) != 0)
2248 				atomic_add(s, &rdev->corrected_errors);
2249 		}
2250 		sectors -= s;
2251 		sect += s;
2252 		idx ++;
2253 	}
2254 	set_bit(R1BIO_Uptodate, &r1_bio->state);
2255 	bio->bi_status = 0;
2256 	return 1;
2257 }
2258 
process_checks(struct r1bio * r1_bio)2259 static void process_checks(struct r1bio *r1_bio)
2260 {
2261 	/* We have read all readable devices.  If we haven't
2262 	 * got the block, then there is no hope left.
2263 	 * If we have, then we want to do a comparison
2264 	 * and skip the write if everything is the same.
2265 	 * If any blocks failed to read, then we need to
2266 	 * attempt an over-write
2267 	 */
2268 	struct mddev *mddev = r1_bio->mddev;
2269 	struct r1conf *conf = mddev->private;
2270 	int primary;
2271 	int i;
2272 	int vcnt;
2273 
2274 	/* Fix variable parts of all bios */
2275 	vcnt = (r1_bio->sectors + PAGE_SIZE / 512 - 1) >> (PAGE_SHIFT - 9);
2276 	for (i = 0; i < conf->raid_disks * 2; i++) {
2277 		blk_status_t status;
2278 		struct bio *b = r1_bio->bios[i];
2279 		struct resync_pages *rp = get_resync_pages(b);
2280 		if (b->bi_end_io != end_sync_read)
2281 			continue;
2282 		/* fixup the bio for reuse, but preserve errno */
2283 		status = b->bi_status;
2284 		bio_reset(b, conf->mirrors[i].rdev->bdev, REQ_OP_READ);
2285 		b->bi_status = status;
2286 		b->bi_iter.bi_sector = r1_bio->sector +
2287 			conf->mirrors[i].rdev->data_offset;
2288 		b->bi_end_io = end_sync_read;
2289 		rp->raid_bio = r1_bio;
2290 		b->bi_private = rp;
2291 
2292 		/* initialize bvec table again */
2293 		md_bio_reset_resync_pages(b, rp, r1_bio->sectors << 9);
2294 	}
2295 	for (primary = 0; primary < conf->raid_disks * 2; primary++)
2296 		if (r1_bio->bios[primary]->bi_end_io == end_sync_read &&
2297 		    !r1_bio->bios[primary]->bi_status) {
2298 			r1_bio->bios[primary]->bi_end_io = NULL;
2299 			rdev_dec_pending(conf->mirrors[primary].rdev, mddev);
2300 			break;
2301 		}
2302 	r1_bio->read_disk = primary;
2303 	for (i = 0; i < conf->raid_disks * 2; i++) {
2304 		int j = 0;
2305 		struct bio *pbio = r1_bio->bios[primary];
2306 		struct bio *sbio = r1_bio->bios[i];
2307 		blk_status_t status = sbio->bi_status;
2308 		struct page **ppages = get_resync_pages(pbio)->pages;
2309 		struct page **spages = get_resync_pages(sbio)->pages;
2310 		struct bio_vec *bi;
2311 		int page_len[RESYNC_PAGES] = { 0 };
2312 		struct bvec_iter_all iter_all;
2313 
2314 		if (sbio->bi_end_io != end_sync_read)
2315 			continue;
2316 		/* Now we can 'fixup' the error value */
2317 		sbio->bi_status = 0;
2318 
2319 		bio_for_each_segment_all(bi, sbio, iter_all)
2320 			page_len[j++] = bi->bv_len;
2321 
2322 		if (!status) {
2323 			for (j = vcnt; j-- ; ) {
2324 				if (memcmp(page_address(ppages[j]),
2325 					   page_address(spages[j]),
2326 					   page_len[j]))
2327 					break;
2328 			}
2329 		} else
2330 			j = 0;
2331 		if (j >= 0)
2332 			atomic64_add(r1_bio->sectors, &mddev->resync_mismatches);
2333 		if (j < 0 || (test_bit(MD_RECOVERY_CHECK, &mddev->recovery)
2334 			      && !status)) {
2335 			/* No need to write to this device. */
2336 			sbio->bi_end_io = NULL;
2337 			rdev_dec_pending(conf->mirrors[i].rdev, mddev);
2338 			continue;
2339 		}
2340 
2341 		bio_copy_data(sbio, pbio);
2342 	}
2343 }
2344 
sync_request_write(struct mddev * mddev,struct r1bio * r1_bio)2345 static void sync_request_write(struct mddev *mddev, struct r1bio *r1_bio)
2346 {
2347 	struct r1conf *conf = mddev->private;
2348 	int i;
2349 	int disks = conf->raid_disks * 2;
2350 	struct bio *wbio;
2351 
2352 	if (!test_bit(R1BIO_Uptodate, &r1_bio->state))
2353 		/* ouch - failed to read all of that. */
2354 		if (!fix_sync_read_error(r1_bio))
2355 			return;
2356 
2357 	if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
2358 		process_checks(r1_bio);
2359 
2360 	/*
2361 	 * schedule writes
2362 	 */
2363 	atomic_set(&r1_bio->remaining, 1);
2364 	for (i = 0; i < disks ; i++) {
2365 		wbio = r1_bio->bios[i];
2366 		if (wbio->bi_end_io == NULL ||
2367 		    (wbio->bi_end_io == end_sync_read &&
2368 		     (i == r1_bio->read_disk ||
2369 		      !test_bit(MD_RECOVERY_SYNC, &mddev->recovery))))
2370 			continue;
2371 		if (test_bit(Faulty, &conf->mirrors[i].rdev->flags)) {
2372 			abort_sync_write(mddev, r1_bio);
2373 			continue;
2374 		}
2375 
2376 		wbio->bi_opf = REQ_OP_WRITE;
2377 		if (test_bit(FailFast, &conf->mirrors[i].rdev->flags))
2378 			wbio->bi_opf |= MD_FAILFAST;
2379 
2380 		wbio->bi_end_io = end_sync_write;
2381 		atomic_inc(&r1_bio->remaining);
2382 		md_sync_acct(conf->mirrors[i].rdev->bdev, bio_sectors(wbio));
2383 
2384 		submit_bio_noacct(wbio);
2385 	}
2386 
2387 	put_sync_write_buf(r1_bio, 1);
2388 }
2389 
2390 /*
2391  * This is a kernel thread which:
2392  *
2393  *	1.	Retries failed read operations on working mirrors.
2394  *	2.	Updates the raid superblock when problems encounter.
2395  *	3.	Performs writes following reads for array synchronising.
2396  */
2397 
fix_read_error(struct r1conf * conf,struct r1bio * r1_bio)2398 static void fix_read_error(struct r1conf *conf, struct r1bio *r1_bio)
2399 {
2400 	sector_t sect = r1_bio->sector;
2401 	int sectors = r1_bio->sectors;
2402 	int read_disk = r1_bio->read_disk;
2403 	struct mddev *mddev = conf->mddev;
2404 	struct md_rdev *rdev = conf->mirrors[read_disk].rdev;
2405 
2406 	if (exceed_read_errors(mddev, rdev)) {
2407 		r1_bio->bios[r1_bio->read_disk] = IO_BLOCKED;
2408 		return;
2409 	}
2410 
2411 	while(sectors) {
2412 		int s = sectors;
2413 		int d = read_disk;
2414 		int success = 0;
2415 		int start;
2416 
2417 		if (s > (PAGE_SIZE>>9))
2418 			s = PAGE_SIZE >> 9;
2419 
2420 		do {
2421 			rdev = conf->mirrors[d].rdev;
2422 			if (rdev &&
2423 			    (test_bit(In_sync, &rdev->flags) ||
2424 			     (!test_bit(Faulty, &rdev->flags) &&
2425 			      rdev->recovery_offset >= sect + s)) &&
2426 			    rdev_has_badblock(rdev, sect, s) == 0) {
2427 				atomic_inc(&rdev->nr_pending);
2428 				if (sync_page_io(rdev, sect, s<<9,
2429 					 conf->tmppage, REQ_OP_READ, false))
2430 					success = 1;
2431 				rdev_dec_pending(rdev, mddev);
2432 				if (success)
2433 					break;
2434 			}
2435 
2436 			d++;
2437 			if (d == conf->raid_disks * 2)
2438 				d = 0;
2439 		} while (d != read_disk);
2440 
2441 		if (!success) {
2442 			/* Cannot read from anywhere - mark it bad */
2443 			struct md_rdev *rdev = conf->mirrors[read_disk].rdev;
2444 			if (!rdev_set_badblocks(rdev, sect, s, 0))
2445 				md_error(mddev, rdev);
2446 			break;
2447 		}
2448 		/* write it back and re-read */
2449 		start = d;
2450 		while (d != read_disk) {
2451 			if (d==0)
2452 				d = conf->raid_disks * 2;
2453 			d--;
2454 			rdev = conf->mirrors[d].rdev;
2455 			if (rdev &&
2456 			    !test_bit(Faulty, &rdev->flags)) {
2457 				atomic_inc(&rdev->nr_pending);
2458 				r1_sync_page_io(rdev, sect, s,
2459 						conf->tmppage, REQ_OP_WRITE);
2460 				rdev_dec_pending(rdev, mddev);
2461 			}
2462 		}
2463 		d = start;
2464 		while (d != read_disk) {
2465 			if (d==0)
2466 				d = conf->raid_disks * 2;
2467 			d--;
2468 			rdev = conf->mirrors[d].rdev;
2469 			if (rdev &&
2470 			    !test_bit(Faulty, &rdev->flags)) {
2471 				atomic_inc(&rdev->nr_pending);
2472 				if (r1_sync_page_io(rdev, sect, s,
2473 						conf->tmppage, REQ_OP_READ)) {
2474 					atomic_add(s, &rdev->corrected_errors);
2475 					pr_info("md/raid1:%s: read error corrected (%d sectors at %llu on %pg)\n",
2476 						mdname(mddev), s,
2477 						(unsigned long long)(sect +
2478 								     rdev->data_offset),
2479 						rdev->bdev);
2480 				}
2481 				rdev_dec_pending(rdev, mddev);
2482 			}
2483 		}
2484 		sectors -= s;
2485 		sect += s;
2486 	}
2487 }
2488 
narrow_write_error(struct r1bio * r1_bio,int i)2489 static int narrow_write_error(struct r1bio *r1_bio, int i)
2490 {
2491 	struct mddev *mddev = r1_bio->mddev;
2492 	struct r1conf *conf = mddev->private;
2493 	struct md_rdev *rdev = conf->mirrors[i].rdev;
2494 
2495 	/* bio has the data to be written to device 'i' where
2496 	 * we just recently had a write error.
2497 	 * We repeatedly clone the bio and trim down to one block,
2498 	 * then try the write.  Where the write fails we record
2499 	 * a bad block.
2500 	 * It is conceivable that the bio doesn't exactly align with
2501 	 * blocks.  We must handle this somehow.
2502 	 *
2503 	 * We currently own a reference on the rdev.
2504 	 */
2505 
2506 	int block_sectors;
2507 	sector_t sector;
2508 	int sectors;
2509 	int sect_to_write = r1_bio->sectors;
2510 	int ok = 1;
2511 
2512 	if (rdev->badblocks.shift < 0)
2513 		return 0;
2514 
2515 	block_sectors = roundup(1 << rdev->badblocks.shift,
2516 				bdev_logical_block_size(rdev->bdev) >> 9);
2517 	sector = r1_bio->sector;
2518 	sectors = ((sector + block_sectors)
2519 		   & ~(sector_t)(block_sectors - 1))
2520 		- sector;
2521 
2522 	while (sect_to_write) {
2523 		struct bio *wbio;
2524 		if (sectors > sect_to_write)
2525 			sectors = sect_to_write;
2526 		/* Write at 'sector' for 'sectors'*/
2527 
2528 		if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
2529 			wbio = bio_alloc_clone(rdev->bdev,
2530 					       r1_bio->behind_master_bio,
2531 					       GFP_NOIO, &mddev->bio_set);
2532 		} else {
2533 			wbio = bio_alloc_clone(rdev->bdev, r1_bio->master_bio,
2534 					       GFP_NOIO, &mddev->bio_set);
2535 		}
2536 
2537 		wbio->bi_opf = REQ_OP_WRITE;
2538 		wbio->bi_iter.bi_sector = r1_bio->sector;
2539 		wbio->bi_iter.bi_size = r1_bio->sectors << 9;
2540 
2541 		bio_trim(wbio, sector - r1_bio->sector, sectors);
2542 		wbio->bi_iter.bi_sector += rdev->data_offset;
2543 
2544 		if (submit_bio_wait(wbio) < 0)
2545 			/* failure! */
2546 			ok = rdev_set_badblocks(rdev, sector,
2547 						sectors, 0)
2548 				&& ok;
2549 
2550 		bio_put(wbio);
2551 		sect_to_write -= sectors;
2552 		sector += sectors;
2553 		sectors = block_sectors;
2554 	}
2555 	return ok;
2556 }
2557 
handle_sync_write_finished(struct r1conf * conf,struct r1bio * r1_bio)2558 static void handle_sync_write_finished(struct r1conf *conf, struct r1bio *r1_bio)
2559 {
2560 	int m;
2561 	int s = r1_bio->sectors;
2562 	for (m = 0; m < conf->raid_disks * 2 ; m++) {
2563 		struct md_rdev *rdev = conf->mirrors[m].rdev;
2564 		struct bio *bio = r1_bio->bios[m];
2565 		if (bio->bi_end_io == NULL)
2566 			continue;
2567 		if (!bio->bi_status &&
2568 		    test_bit(R1BIO_MadeGood, &r1_bio->state)) {
2569 			rdev_clear_badblocks(rdev, r1_bio->sector, s, 0);
2570 		}
2571 		if (bio->bi_status &&
2572 		    test_bit(R1BIO_WriteError, &r1_bio->state)) {
2573 			if (!rdev_set_badblocks(rdev, r1_bio->sector, s, 0))
2574 				md_error(conf->mddev, rdev);
2575 		}
2576 	}
2577 	put_buf(r1_bio);
2578 	md_done_sync(conf->mddev, s, 1);
2579 }
2580 
handle_write_finished(struct r1conf * conf,struct r1bio * r1_bio)2581 static void handle_write_finished(struct r1conf *conf, struct r1bio *r1_bio)
2582 {
2583 	int m, idx;
2584 	bool fail = false;
2585 
2586 	for (m = 0; m < conf->raid_disks * 2 ; m++)
2587 		if (r1_bio->bios[m] == IO_MADE_GOOD) {
2588 			struct md_rdev *rdev = conf->mirrors[m].rdev;
2589 			rdev_clear_badblocks(rdev,
2590 					     r1_bio->sector,
2591 					     r1_bio->sectors, 0);
2592 			rdev_dec_pending(rdev, conf->mddev);
2593 		} else if (r1_bio->bios[m] != NULL) {
2594 			/* This drive got a write error.  We need to
2595 			 * narrow down and record precise write
2596 			 * errors.
2597 			 */
2598 			fail = true;
2599 			if (!narrow_write_error(r1_bio, m))
2600 				md_error(conf->mddev,
2601 					 conf->mirrors[m].rdev);
2602 				/* an I/O failed, we can't clear the bitmap */
2603 			rdev_dec_pending(conf->mirrors[m].rdev,
2604 					 conf->mddev);
2605 		}
2606 	if (fail) {
2607 		spin_lock_irq(&conf->device_lock);
2608 		list_add(&r1_bio->retry_list, &conf->bio_end_io_list);
2609 		idx = sector_to_idx(r1_bio->sector);
2610 		atomic_inc(&conf->nr_queued[idx]);
2611 		spin_unlock_irq(&conf->device_lock);
2612 		/*
2613 		 * In case freeze_array() is waiting for condition
2614 		 * get_unqueued_pending() == extra to be true.
2615 		 */
2616 		wake_up(&conf->wait_barrier);
2617 		md_wakeup_thread(conf->mddev->thread);
2618 	} else {
2619 		if (test_bit(R1BIO_WriteError, &r1_bio->state))
2620 			close_write(r1_bio);
2621 		raid_end_bio_io(r1_bio);
2622 	}
2623 }
2624 
handle_read_error(struct r1conf * conf,struct r1bio * r1_bio)2625 static void handle_read_error(struct r1conf *conf, struct r1bio *r1_bio)
2626 {
2627 	struct mddev *mddev = conf->mddev;
2628 	struct bio *bio;
2629 	struct md_rdev *rdev;
2630 	sector_t sector;
2631 
2632 	clear_bit(R1BIO_ReadError, &r1_bio->state);
2633 	/* we got a read error. Maybe the drive is bad.  Maybe just
2634 	 * the block and we can fix it.
2635 	 * We freeze all other IO, and try reading the block from
2636 	 * other devices.  When we find one, we re-write
2637 	 * and check it that fixes the read error.
2638 	 * This is all done synchronously while the array is
2639 	 * frozen
2640 	 */
2641 
2642 	bio = r1_bio->bios[r1_bio->read_disk];
2643 	bio_put(bio);
2644 	r1_bio->bios[r1_bio->read_disk] = NULL;
2645 
2646 	rdev = conf->mirrors[r1_bio->read_disk].rdev;
2647 	if (mddev->ro == 0
2648 	    && !test_bit(FailFast, &rdev->flags)) {
2649 		freeze_array(conf, 1);
2650 		fix_read_error(conf, r1_bio);
2651 		unfreeze_array(conf);
2652 	} else if (mddev->ro == 0 && test_bit(FailFast, &rdev->flags)) {
2653 		md_error(mddev, rdev);
2654 	} else {
2655 		r1_bio->bios[r1_bio->read_disk] = IO_BLOCKED;
2656 	}
2657 
2658 	rdev_dec_pending(rdev, conf->mddev);
2659 	sector = r1_bio->sector;
2660 	bio = r1_bio->master_bio;
2661 
2662 	/* Reuse the old r1_bio so that the IO_BLOCKED settings are preserved */
2663 	r1_bio->state = 0;
2664 	raid1_read_request(mddev, bio, r1_bio->sectors, r1_bio);
2665 	allow_barrier(conf, sector);
2666 }
2667 
raid1d(struct md_thread * thread)2668 static void raid1d(struct md_thread *thread)
2669 {
2670 	struct mddev *mddev = thread->mddev;
2671 	struct r1bio *r1_bio;
2672 	unsigned long flags;
2673 	struct r1conf *conf = mddev->private;
2674 	struct list_head *head = &conf->retry_list;
2675 	struct blk_plug plug;
2676 	int idx;
2677 
2678 	md_check_recovery(mddev);
2679 
2680 	if (!list_empty_careful(&conf->bio_end_io_list) &&
2681 	    !test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags)) {
2682 		LIST_HEAD(tmp);
2683 		spin_lock_irqsave(&conf->device_lock, flags);
2684 		if (!test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags))
2685 			list_splice_init(&conf->bio_end_io_list, &tmp);
2686 		spin_unlock_irqrestore(&conf->device_lock, flags);
2687 		while (!list_empty(&tmp)) {
2688 			r1_bio = list_first_entry(&tmp, struct r1bio,
2689 						  retry_list);
2690 			list_del(&r1_bio->retry_list);
2691 			idx = sector_to_idx(r1_bio->sector);
2692 			atomic_dec(&conf->nr_queued[idx]);
2693 			if (test_bit(R1BIO_WriteError, &r1_bio->state))
2694 				close_write(r1_bio);
2695 			raid_end_bio_io(r1_bio);
2696 		}
2697 	}
2698 
2699 	blk_start_plug(&plug);
2700 	for (;;) {
2701 
2702 		flush_pending_writes(conf);
2703 
2704 		spin_lock_irqsave(&conf->device_lock, flags);
2705 		if (list_empty(head)) {
2706 			spin_unlock_irqrestore(&conf->device_lock, flags);
2707 			break;
2708 		}
2709 		r1_bio = list_entry(head->prev, struct r1bio, retry_list);
2710 		list_del(head->prev);
2711 		idx = sector_to_idx(r1_bio->sector);
2712 		atomic_dec(&conf->nr_queued[idx]);
2713 		spin_unlock_irqrestore(&conf->device_lock, flags);
2714 
2715 		mddev = r1_bio->mddev;
2716 		conf = mddev->private;
2717 		if (test_bit(R1BIO_IsSync, &r1_bio->state)) {
2718 			if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
2719 			    test_bit(R1BIO_WriteError, &r1_bio->state))
2720 				handle_sync_write_finished(conf, r1_bio);
2721 			else
2722 				sync_request_write(mddev, r1_bio);
2723 		} else if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
2724 			   test_bit(R1BIO_WriteError, &r1_bio->state))
2725 			handle_write_finished(conf, r1_bio);
2726 		else if (test_bit(R1BIO_ReadError, &r1_bio->state))
2727 			handle_read_error(conf, r1_bio);
2728 		else
2729 			WARN_ON_ONCE(1);
2730 
2731 		cond_resched();
2732 		if (mddev->sb_flags & ~(1<<MD_SB_CHANGE_PENDING))
2733 			md_check_recovery(mddev);
2734 	}
2735 	blk_finish_plug(&plug);
2736 }
2737 
init_resync(struct r1conf * conf)2738 static int init_resync(struct r1conf *conf)
2739 {
2740 	int buffs;
2741 
2742 	buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE;
2743 	BUG_ON(mempool_initialized(&conf->r1buf_pool));
2744 
2745 	return mempool_init(&conf->r1buf_pool, buffs, r1buf_pool_alloc,
2746 			    r1buf_pool_free, conf->poolinfo);
2747 }
2748 
raid1_alloc_init_r1buf(struct r1conf * conf)2749 static struct r1bio *raid1_alloc_init_r1buf(struct r1conf *conf)
2750 {
2751 	struct r1bio *r1bio = mempool_alloc(&conf->r1buf_pool, GFP_NOIO);
2752 	struct resync_pages *rps;
2753 	struct bio *bio;
2754 	int i;
2755 
2756 	for (i = conf->poolinfo->raid_disks; i--; ) {
2757 		bio = r1bio->bios[i];
2758 		rps = bio->bi_private;
2759 		bio_reset(bio, NULL, 0);
2760 		bio->bi_private = rps;
2761 	}
2762 	r1bio->master_bio = NULL;
2763 	return r1bio;
2764 }
2765 
2766 /*
2767  * perform a "sync" on one "block"
2768  *
2769  * We need to make sure that no normal I/O request - particularly write
2770  * requests - conflict with active sync requests.
2771  *
2772  * This is achieved by tracking pending requests and a 'barrier' concept
2773  * that can be installed to exclude normal IO requests.
2774  */
2775 
raid1_sync_request(struct mddev * mddev,sector_t sector_nr,sector_t max_sector,int * skipped)2776 static sector_t raid1_sync_request(struct mddev *mddev, sector_t sector_nr,
2777 				   sector_t max_sector, int *skipped)
2778 {
2779 	struct r1conf *conf = mddev->private;
2780 	struct r1bio *r1_bio;
2781 	struct bio *bio;
2782 	sector_t nr_sectors;
2783 	int disk = -1;
2784 	int i;
2785 	int wonly = -1;
2786 	int write_targets = 0, read_targets = 0;
2787 	sector_t sync_blocks;
2788 	bool still_degraded = false;
2789 	int good_sectors = RESYNC_SECTORS;
2790 	int min_bad = 0; /* number of sectors that are bad in all devices */
2791 	int idx = sector_to_idx(sector_nr);
2792 	int page_idx = 0;
2793 
2794 	if (!mempool_initialized(&conf->r1buf_pool))
2795 		if (init_resync(conf))
2796 			return 0;
2797 
2798 	if (sector_nr >= max_sector) {
2799 		/* If we aborted, we need to abort the
2800 		 * sync on the 'current' bitmap chunk (there will
2801 		 * only be one in raid1 resync.
2802 		 * We can find the current addess in mddev->curr_resync
2803 		 */
2804 		if (mddev->curr_resync < max_sector) /* aborted */
2805 			mddev->bitmap_ops->end_sync(mddev, mddev->curr_resync,
2806 						    &sync_blocks);
2807 		else /* completed sync */
2808 			conf->fullsync = 0;
2809 
2810 		mddev->bitmap_ops->close_sync(mddev);
2811 		close_sync(conf);
2812 
2813 		if (mddev_is_clustered(mddev)) {
2814 			conf->cluster_sync_low = 0;
2815 			conf->cluster_sync_high = 0;
2816 		}
2817 		return 0;
2818 	}
2819 
2820 	if (mddev->bitmap == NULL &&
2821 	    mddev->recovery_cp == MaxSector &&
2822 	    !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
2823 	    conf->fullsync == 0) {
2824 		*skipped = 1;
2825 		return max_sector - sector_nr;
2826 	}
2827 	/* before building a request, check if we can skip these blocks..
2828 	 * This call the bitmap_start_sync doesn't actually record anything
2829 	 */
2830 	if (!mddev->bitmap_ops->start_sync(mddev, sector_nr, &sync_blocks, true) &&
2831 	    !conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
2832 		/* We can skip this block, and probably several more */
2833 		*skipped = 1;
2834 		return sync_blocks;
2835 	}
2836 
2837 	/*
2838 	 * If there is non-resync activity waiting for a turn, then let it
2839 	 * though before starting on this new sync request.
2840 	 */
2841 	if (atomic_read(&conf->nr_waiting[idx]))
2842 		schedule_timeout_uninterruptible(1);
2843 
2844 	/* we are incrementing sector_nr below. To be safe, we check against
2845 	 * sector_nr + two times RESYNC_SECTORS
2846 	 */
2847 
2848 	mddev->bitmap_ops->cond_end_sync(mddev, sector_nr,
2849 		mddev_is_clustered(mddev) &&
2850 		(sector_nr + 2 * RESYNC_SECTORS > conf->cluster_sync_high));
2851 
2852 	if (raise_barrier(conf, sector_nr))
2853 		return 0;
2854 
2855 	r1_bio = raid1_alloc_init_r1buf(conf);
2856 
2857 	/*
2858 	 * If we get a correctably read error during resync or recovery,
2859 	 * we might want to read from a different device.  So we
2860 	 * flag all drives that could conceivably be read from for READ,
2861 	 * and any others (which will be non-In_sync devices) for WRITE.
2862 	 * If a read fails, we try reading from something else for which READ
2863 	 * is OK.
2864 	 */
2865 
2866 	r1_bio->mddev = mddev;
2867 	r1_bio->sector = sector_nr;
2868 	r1_bio->state = 0;
2869 	set_bit(R1BIO_IsSync, &r1_bio->state);
2870 	/* make sure good_sectors won't go across barrier unit boundary */
2871 	good_sectors = align_to_barrier_unit_end(sector_nr, good_sectors);
2872 
2873 	for (i = 0; i < conf->raid_disks * 2; i++) {
2874 		struct md_rdev *rdev;
2875 		bio = r1_bio->bios[i];
2876 
2877 		rdev = conf->mirrors[i].rdev;
2878 		if (rdev == NULL ||
2879 		    test_bit(Faulty, &rdev->flags)) {
2880 			if (i < conf->raid_disks)
2881 				still_degraded = true;
2882 		} else if (!test_bit(In_sync, &rdev->flags)) {
2883 			bio->bi_opf = REQ_OP_WRITE;
2884 			bio->bi_end_io = end_sync_write;
2885 			write_targets ++;
2886 		} else {
2887 			/* may need to read from here */
2888 			sector_t first_bad = MaxSector;
2889 			int bad_sectors;
2890 
2891 			if (is_badblock(rdev, sector_nr, good_sectors,
2892 					&first_bad, &bad_sectors)) {
2893 				if (first_bad > sector_nr)
2894 					good_sectors = first_bad - sector_nr;
2895 				else {
2896 					bad_sectors -= (sector_nr - first_bad);
2897 					if (min_bad == 0 ||
2898 					    min_bad > bad_sectors)
2899 						min_bad = bad_sectors;
2900 				}
2901 			}
2902 			if (sector_nr < first_bad) {
2903 				if (test_bit(WriteMostly, &rdev->flags)) {
2904 					if (wonly < 0)
2905 						wonly = i;
2906 				} else {
2907 					if (disk < 0)
2908 						disk = i;
2909 				}
2910 				bio->bi_opf = REQ_OP_READ;
2911 				bio->bi_end_io = end_sync_read;
2912 				read_targets++;
2913 			} else if (!test_bit(WriteErrorSeen, &rdev->flags) &&
2914 				test_bit(MD_RECOVERY_SYNC, &mddev->recovery) &&
2915 				!test_bit(MD_RECOVERY_CHECK, &mddev->recovery)) {
2916 				/*
2917 				 * The device is suitable for reading (InSync),
2918 				 * but has bad block(s) here. Let's try to correct them,
2919 				 * if we are doing resync or repair. Otherwise, leave
2920 				 * this device alone for this sync request.
2921 				 */
2922 				bio->bi_opf = REQ_OP_WRITE;
2923 				bio->bi_end_io = end_sync_write;
2924 				write_targets++;
2925 			}
2926 		}
2927 		if (rdev && bio->bi_end_io) {
2928 			atomic_inc(&rdev->nr_pending);
2929 			bio->bi_iter.bi_sector = sector_nr + rdev->data_offset;
2930 			bio_set_dev(bio, rdev->bdev);
2931 			if (test_bit(FailFast, &rdev->flags))
2932 				bio->bi_opf |= MD_FAILFAST;
2933 		}
2934 	}
2935 	if (disk < 0)
2936 		disk = wonly;
2937 	r1_bio->read_disk = disk;
2938 
2939 	if (read_targets == 0 && min_bad > 0) {
2940 		/* These sectors are bad on all InSync devices, so we
2941 		 * need to mark them bad on all write targets
2942 		 */
2943 		int ok = 1;
2944 		for (i = 0 ; i < conf->raid_disks * 2 ; i++)
2945 			if (r1_bio->bios[i]->bi_end_io == end_sync_write) {
2946 				struct md_rdev *rdev = conf->mirrors[i].rdev;
2947 				ok = rdev_set_badblocks(rdev, sector_nr,
2948 							min_bad, 0
2949 					) && ok;
2950 			}
2951 		set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
2952 		*skipped = 1;
2953 		put_buf(r1_bio);
2954 
2955 		if (!ok) {
2956 			/* Cannot record the badblocks, so need to
2957 			 * abort the resync.
2958 			 * If there are multiple read targets, could just
2959 			 * fail the really bad ones ???
2960 			 */
2961 			conf->recovery_disabled = mddev->recovery_disabled;
2962 			set_bit(MD_RECOVERY_INTR, &mddev->recovery);
2963 			return 0;
2964 		} else
2965 			return min_bad;
2966 
2967 	}
2968 	if (min_bad > 0 && min_bad < good_sectors) {
2969 		/* only resync enough to reach the next bad->good
2970 		 * transition */
2971 		good_sectors = min_bad;
2972 	}
2973 
2974 	if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) && read_targets > 0)
2975 		/* extra read targets are also write targets */
2976 		write_targets += read_targets-1;
2977 
2978 	if (write_targets == 0 || read_targets == 0) {
2979 		/* There is nowhere to write, so all non-sync
2980 		 * drives must be failed - so we are finished
2981 		 */
2982 		sector_t rv;
2983 		if (min_bad > 0)
2984 			max_sector = sector_nr + min_bad;
2985 		rv = max_sector - sector_nr;
2986 		*skipped = 1;
2987 		put_buf(r1_bio);
2988 		return rv;
2989 	}
2990 
2991 	if (max_sector > mddev->resync_max)
2992 		max_sector = mddev->resync_max; /* Don't do IO beyond here */
2993 	if (max_sector > sector_nr + good_sectors)
2994 		max_sector = sector_nr + good_sectors;
2995 	nr_sectors = 0;
2996 	sync_blocks = 0;
2997 	do {
2998 		struct page *page;
2999 		int len = PAGE_SIZE;
3000 		if (sector_nr + (len>>9) > max_sector)
3001 			len = (max_sector - sector_nr) << 9;
3002 		if (len == 0)
3003 			break;
3004 		if (sync_blocks == 0) {
3005 			if (!mddev->bitmap_ops->start_sync(mddev, sector_nr,
3006 						&sync_blocks, still_degraded) &&
3007 			    !conf->fullsync &&
3008 			    !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
3009 				break;
3010 			if ((len >> 9) > sync_blocks)
3011 				len = sync_blocks<<9;
3012 		}
3013 
3014 		for (i = 0 ; i < conf->raid_disks * 2; i++) {
3015 			struct resync_pages *rp;
3016 
3017 			bio = r1_bio->bios[i];
3018 			rp = get_resync_pages(bio);
3019 			if (bio->bi_end_io) {
3020 				page = resync_fetch_page(rp, page_idx);
3021 
3022 				/*
3023 				 * won't fail because the vec table is big
3024 				 * enough to hold all these pages
3025 				 */
3026 				__bio_add_page(bio, page, len, 0);
3027 			}
3028 		}
3029 		nr_sectors += len>>9;
3030 		sector_nr += len>>9;
3031 		sync_blocks -= (len>>9);
3032 	} while (++page_idx < RESYNC_PAGES);
3033 
3034 	r1_bio->sectors = nr_sectors;
3035 
3036 	if (mddev_is_clustered(mddev) &&
3037 			conf->cluster_sync_high < sector_nr + nr_sectors) {
3038 		conf->cluster_sync_low = mddev->curr_resync_completed;
3039 		conf->cluster_sync_high = conf->cluster_sync_low + CLUSTER_RESYNC_WINDOW_SECTORS;
3040 		/* Send resync message */
3041 		md_cluster_ops->resync_info_update(mddev,
3042 				conf->cluster_sync_low,
3043 				conf->cluster_sync_high);
3044 	}
3045 
3046 	/* For a user-requested sync, we read all readable devices and do a
3047 	 * compare
3048 	 */
3049 	if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
3050 		atomic_set(&r1_bio->remaining, read_targets);
3051 		for (i = 0; i < conf->raid_disks * 2 && read_targets; i++) {
3052 			bio = r1_bio->bios[i];
3053 			if (bio->bi_end_io == end_sync_read) {
3054 				read_targets--;
3055 				md_sync_acct_bio(bio, nr_sectors);
3056 				if (read_targets == 1)
3057 					bio->bi_opf &= ~MD_FAILFAST;
3058 				submit_bio_noacct(bio);
3059 			}
3060 		}
3061 	} else {
3062 		atomic_set(&r1_bio->remaining, 1);
3063 		bio = r1_bio->bios[r1_bio->read_disk];
3064 		md_sync_acct_bio(bio, nr_sectors);
3065 		if (read_targets == 1)
3066 			bio->bi_opf &= ~MD_FAILFAST;
3067 		submit_bio_noacct(bio);
3068 	}
3069 	return nr_sectors;
3070 }
3071 
raid1_size(struct mddev * mddev,sector_t sectors,int raid_disks)3072 static sector_t raid1_size(struct mddev *mddev, sector_t sectors, int raid_disks)
3073 {
3074 	if (sectors)
3075 		return sectors;
3076 
3077 	return mddev->dev_sectors;
3078 }
3079 
setup_conf(struct mddev * mddev)3080 static struct r1conf *setup_conf(struct mddev *mddev)
3081 {
3082 	struct r1conf *conf;
3083 	int i;
3084 	struct raid1_info *disk;
3085 	struct md_rdev *rdev;
3086 	int err = -ENOMEM;
3087 
3088 	conf = kzalloc(sizeof(struct r1conf), GFP_KERNEL);
3089 	if (!conf)
3090 		goto abort;
3091 
3092 	conf->nr_pending = kcalloc(BARRIER_BUCKETS_NR,
3093 				   sizeof(atomic_t), GFP_KERNEL);
3094 	if (!conf->nr_pending)
3095 		goto abort;
3096 
3097 	conf->nr_waiting = kcalloc(BARRIER_BUCKETS_NR,
3098 				   sizeof(atomic_t), GFP_KERNEL);
3099 	if (!conf->nr_waiting)
3100 		goto abort;
3101 
3102 	conf->nr_queued = kcalloc(BARRIER_BUCKETS_NR,
3103 				  sizeof(atomic_t), GFP_KERNEL);
3104 	if (!conf->nr_queued)
3105 		goto abort;
3106 
3107 	conf->barrier = kcalloc(BARRIER_BUCKETS_NR,
3108 				sizeof(atomic_t), GFP_KERNEL);
3109 	if (!conf->barrier)
3110 		goto abort;
3111 
3112 	conf->mirrors = kzalloc(array3_size(sizeof(struct raid1_info),
3113 					    mddev->raid_disks, 2),
3114 				GFP_KERNEL);
3115 	if (!conf->mirrors)
3116 		goto abort;
3117 
3118 	conf->tmppage = alloc_page(GFP_KERNEL);
3119 	if (!conf->tmppage)
3120 		goto abort;
3121 
3122 	conf->poolinfo = kzalloc(sizeof(*conf->poolinfo), GFP_KERNEL);
3123 	if (!conf->poolinfo)
3124 		goto abort;
3125 	conf->poolinfo->raid_disks = mddev->raid_disks * 2;
3126 	err = mempool_init(&conf->r1bio_pool, NR_RAID_BIOS, r1bio_pool_alloc,
3127 			   rbio_pool_free, conf->poolinfo);
3128 	if (err)
3129 		goto abort;
3130 
3131 	err = bioset_init(&conf->bio_split, BIO_POOL_SIZE, 0, 0);
3132 	if (err)
3133 		goto abort;
3134 
3135 	conf->poolinfo->mddev = mddev;
3136 
3137 	err = -EINVAL;
3138 	spin_lock_init(&conf->device_lock);
3139 	conf->raid_disks = mddev->raid_disks;
3140 	rdev_for_each(rdev, mddev) {
3141 		int disk_idx = rdev->raid_disk;
3142 
3143 		if (disk_idx >= conf->raid_disks || disk_idx < 0)
3144 			continue;
3145 
3146 		if (!raid1_add_conf(conf, rdev, disk_idx,
3147 				    test_bit(Replacement, &rdev->flags)))
3148 			goto abort;
3149 	}
3150 	conf->mddev = mddev;
3151 	INIT_LIST_HEAD(&conf->retry_list);
3152 	INIT_LIST_HEAD(&conf->bio_end_io_list);
3153 
3154 	spin_lock_init(&conf->resync_lock);
3155 	init_waitqueue_head(&conf->wait_barrier);
3156 
3157 	bio_list_init(&conf->pending_bio_list);
3158 	conf->recovery_disabled = mddev->recovery_disabled - 1;
3159 
3160 	err = -EIO;
3161 	for (i = 0; i < conf->raid_disks * 2; i++) {
3162 
3163 		disk = conf->mirrors + i;
3164 
3165 		if (i < conf->raid_disks &&
3166 		    disk[conf->raid_disks].rdev) {
3167 			/* This slot has a replacement. */
3168 			if (!disk->rdev) {
3169 				/* No original, just make the replacement
3170 				 * a recovering spare
3171 				 */
3172 				disk->rdev =
3173 					disk[conf->raid_disks].rdev;
3174 				disk[conf->raid_disks].rdev = NULL;
3175 			} else if (!test_bit(In_sync, &disk->rdev->flags))
3176 				/* Original is not in_sync - bad */
3177 				goto abort;
3178 		}
3179 
3180 		if (!disk->rdev ||
3181 		    !test_bit(In_sync, &disk->rdev->flags)) {
3182 			disk->head_position = 0;
3183 			if (disk->rdev &&
3184 			    (disk->rdev->saved_raid_disk < 0))
3185 				conf->fullsync = 1;
3186 		}
3187 	}
3188 
3189 	err = -ENOMEM;
3190 	rcu_assign_pointer(conf->thread,
3191 			   md_register_thread(raid1d, mddev, "raid1"));
3192 	if (!conf->thread)
3193 		goto abort;
3194 
3195 	return conf;
3196 
3197  abort:
3198 	if (conf) {
3199 		mempool_exit(&conf->r1bio_pool);
3200 		kfree(conf->mirrors);
3201 		safe_put_page(conf->tmppage);
3202 		kfree(conf->poolinfo);
3203 		kfree(conf->nr_pending);
3204 		kfree(conf->nr_waiting);
3205 		kfree(conf->nr_queued);
3206 		kfree(conf->barrier);
3207 		bioset_exit(&conf->bio_split);
3208 		kfree(conf);
3209 	}
3210 	return ERR_PTR(err);
3211 }
3212 
raid1_set_limits(struct mddev * mddev)3213 static int raid1_set_limits(struct mddev *mddev)
3214 {
3215 	struct queue_limits lim;
3216 	int err;
3217 
3218 	md_init_stacking_limits(&lim);
3219 	lim.max_write_zeroes_sectors = 0;
3220 	lim.features |= BLK_FEAT_ATOMIC_WRITES;
3221 	err = mddev_stack_rdev_limits(mddev, &lim, MDDEV_STACK_INTEGRITY);
3222 	if (err)
3223 		return err;
3224 	return queue_limits_set(mddev->gendisk->queue, &lim);
3225 }
3226 
raid1_run(struct mddev * mddev)3227 static int raid1_run(struct mddev *mddev)
3228 {
3229 	struct r1conf *conf;
3230 	int i;
3231 	int ret;
3232 
3233 	if (mddev->level != 1) {
3234 		pr_warn("md/raid1:%s: raid level not set to mirroring (%d)\n",
3235 			mdname(mddev), mddev->level);
3236 		return -EIO;
3237 	}
3238 	if (mddev->reshape_position != MaxSector) {
3239 		pr_warn("md/raid1:%s: reshape_position set but not supported\n",
3240 			mdname(mddev));
3241 		return -EIO;
3242 	}
3243 
3244 	/*
3245 	 * copy the already verified devices into our private RAID1
3246 	 * bookkeeping area. [whatever we allocate in run(),
3247 	 * should be freed in raid1_free()]
3248 	 */
3249 	if (mddev->private == NULL)
3250 		conf = setup_conf(mddev);
3251 	else
3252 		conf = mddev->private;
3253 
3254 	if (IS_ERR(conf))
3255 		return PTR_ERR(conf);
3256 
3257 	if (!mddev_is_dm(mddev)) {
3258 		ret = raid1_set_limits(mddev);
3259 		if (ret)
3260 			return ret;
3261 	}
3262 
3263 	mddev->degraded = 0;
3264 	for (i = 0; i < conf->raid_disks; i++)
3265 		if (conf->mirrors[i].rdev == NULL ||
3266 		    !test_bit(In_sync, &conf->mirrors[i].rdev->flags) ||
3267 		    test_bit(Faulty, &conf->mirrors[i].rdev->flags))
3268 			mddev->degraded++;
3269 	/*
3270 	 * RAID1 needs at least one disk in active
3271 	 */
3272 	if (conf->raid_disks - mddev->degraded < 1) {
3273 		md_unregister_thread(mddev, &conf->thread);
3274 		return -EINVAL;
3275 	}
3276 
3277 	if (conf->raid_disks - mddev->degraded == 1)
3278 		mddev->recovery_cp = MaxSector;
3279 
3280 	if (mddev->recovery_cp != MaxSector)
3281 		pr_info("md/raid1:%s: not clean -- starting background reconstruction\n",
3282 			mdname(mddev));
3283 	pr_info("md/raid1:%s: active with %d out of %d mirrors\n",
3284 		mdname(mddev), mddev->raid_disks - mddev->degraded,
3285 		mddev->raid_disks);
3286 
3287 	/*
3288 	 * Ok, everything is just fine now
3289 	 */
3290 	rcu_assign_pointer(mddev->thread, conf->thread);
3291 	rcu_assign_pointer(conf->thread, NULL);
3292 	mddev->private = conf;
3293 	set_bit(MD_FAILFAST_SUPPORTED, &mddev->flags);
3294 
3295 	md_set_array_sectors(mddev, raid1_size(mddev, 0, 0));
3296 
3297 	ret = md_integrity_register(mddev);
3298 	if (ret)
3299 		md_unregister_thread(mddev, &mddev->thread);
3300 	return ret;
3301 }
3302 
raid1_free(struct mddev * mddev,void * priv)3303 static void raid1_free(struct mddev *mddev, void *priv)
3304 {
3305 	struct r1conf *conf = priv;
3306 
3307 	mempool_exit(&conf->r1bio_pool);
3308 	kfree(conf->mirrors);
3309 	safe_put_page(conf->tmppage);
3310 	kfree(conf->poolinfo);
3311 	kfree(conf->nr_pending);
3312 	kfree(conf->nr_waiting);
3313 	kfree(conf->nr_queued);
3314 	kfree(conf->barrier);
3315 	bioset_exit(&conf->bio_split);
3316 	kfree(conf);
3317 }
3318 
raid1_resize(struct mddev * mddev,sector_t sectors)3319 static int raid1_resize(struct mddev *mddev, sector_t sectors)
3320 {
3321 	/* no resync is happening, and there is enough space
3322 	 * on all devices, so we can resize.
3323 	 * We need to make sure resync covers any new space.
3324 	 * If the array is shrinking we should possibly wait until
3325 	 * any io in the removed space completes, but it hardly seems
3326 	 * worth it.
3327 	 */
3328 	sector_t newsize = raid1_size(mddev, sectors, 0);
3329 	int ret;
3330 
3331 	if (mddev->external_size &&
3332 	    mddev->array_sectors > newsize)
3333 		return -EINVAL;
3334 
3335 	ret = mddev->bitmap_ops->resize(mddev, newsize, 0, false);
3336 	if (ret)
3337 		return ret;
3338 
3339 	md_set_array_sectors(mddev, newsize);
3340 	if (sectors > mddev->dev_sectors &&
3341 	    mddev->recovery_cp > mddev->dev_sectors) {
3342 		mddev->recovery_cp = mddev->dev_sectors;
3343 		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3344 	}
3345 	mddev->dev_sectors = sectors;
3346 	mddev->resync_max_sectors = sectors;
3347 	return 0;
3348 }
3349 
raid1_reshape(struct mddev * mddev)3350 static int raid1_reshape(struct mddev *mddev)
3351 {
3352 	/* We need to:
3353 	 * 1/ resize the r1bio_pool
3354 	 * 2/ resize conf->mirrors
3355 	 *
3356 	 * We allocate a new r1bio_pool if we can.
3357 	 * Then raise a device barrier and wait until all IO stops.
3358 	 * Then resize conf->mirrors and swap in the new r1bio pool.
3359 	 *
3360 	 * At the same time, we "pack" the devices so that all the missing
3361 	 * devices have the higher raid_disk numbers.
3362 	 */
3363 	mempool_t newpool, oldpool;
3364 	struct pool_info *newpoolinfo;
3365 	struct raid1_info *newmirrors;
3366 	struct r1conf *conf = mddev->private;
3367 	int cnt, raid_disks;
3368 	unsigned long flags;
3369 	int d, d2;
3370 	int ret;
3371 
3372 	memset(&newpool, 0, sizeof(newpool));
3373 	memset(&oldpool, 0, sizeof(oldpool));
3374 
3375 	/* Cannot change chunk_size, layout, or level */
3376 	if (mddev->chunk_sectors != mddev->new_chunk_sectors ||
3377 	    mddev->layout != mddev->new_layout ||
3378 	    mddev->level != mddev->new_level) {
3379 		mddev->new_chunk_sectors = mddev->chunk_sectors;
3380 		mddev->new_layout = mddev->layout;
3381 		mddev->new_level = mddev->level;
3382 		return -EINVAL;
3383 	}
3384 
3385 	if (!mddev_is_clustered(mddev))
3386 		md_allow_write(mddev);
3387 
3388 	raid_disks = mddev->raid_disks + mddev->delta_disks;
3389 
3390 	if (raid_disks < conf->raid_disks) {
3391 		cnt=0;
3392 		for (d= 0; d < conf->raid_disks; d++)
3393 			if (conf->mirrors[d].rdev)
3394 				cnt++;
3395 		if (cnt > raid_disks)
3396 			return -EBUSY;
3397 	}
3398 
3399 	newpoolinfo = kmalloc(sizeof(*newpoolinfo), GFP_KERNEL);
3400 	if (!newpoolinfo)
3401 		return -ENOMEM;
3402 	newpoolinfo->mddev = mddev;
3403 	newpoolinfo->raid_disks = raid_disks * 2;
3404 
3405 	ret = mempool_init(&newpool, NR_RAID_BIOS, r1bio_pool_alloc,
3406 			   rbio_pool_free, newpoolinfo);
3407 	if (ret) {
3408 		kfree(newpoolinfo);
3409 		return ret;
3410 	}
3411 	newmirrors = kzalloc(array3_size(sizeof(struct raid1_info),
3412 					 raid_disks, 2),
3413 			     GFP_KERNEL);
3414 	if (!newmirrors) {
3415 		kfree(newpoolinfo);
3416 		mempool_exit(&newpool);
3417 		return -ENOMEM;
3418 	}
3419 
3420 	freeze_array(conf, 0);
3421 
3422 	/* ok, everything is stopped */
3423 	oldpool = conf->r1bio_pool;
3424 	conf->r1bio_pool = newpool;
3425 
3426 	for (d = d2 = 0; d < conf->raid_disks; d++) {
3427 		struct md_rdev *rdev = conf->mirrors[d].rdev;
3428 		if (rdev && rdev->raid_disk != d2) {
3429 			sysfs_unlink_rdev(mddev, rdev);
3430 			rdev->raid_disk = d2;
3431 			sysfs_unlink_rdev(mddev, rdev);
3432 			if (sysfs_link_rdev(mddev, rdev))
3433 				pr_warn("md/raid1:%s: cannot register rd%d\n",
3434 					mdname(mddev), rdev->raid_disk);
3435 		}
3436 		if (rdev)
3437 			newmirrors[d2++].rdev = rdev;
3438 	}
3439 	kfree(conf->mirrors);
3440 	conf->mirrors = newmirrors;
3441 	kfree(conf->poolinfo);
3442 	conf->poolinfo = newpoolinfo;
3443 
3444 	spin_lock_irqsave(&conf->device_lock, flags);
3445 	mddev->degraded += (raid_disks - conf->raid_disks);
3446 	spin_unlock_irqrestore(&conf->device_lock, flags);
3447 	conf->raid_disks = mddev->raid_disks = raid_disks;
3448 	mddev->delta_disks = 0;
3449 
3450 	unfreeze_array(conf);
3451 
3452 	set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
3453 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3454 	md_wakeup_thread(mddev->thread);
3455 
3456 	mempool_exit(&oldpool);
3457 	return 0;
3458 }
3459 
raid1_quiesce(struct mddev * mddev,int quiesce)3460 static void raid1_quiesce(struct mddev *mddev, int quiesce)
3461 {
3462 	struct r1conf *conf = mddev->private;
3463 
3464 	if (quiesce)
3465 		freeze_array(conf, 0);
3466 	else
3467 		unfreeze_array(conf);
3468 }
3469 
raid1_takeover(struct mddev * mddev)3470 static void *raid1_takeover(struct mddev *mddev)
3471 {
3472 	/* raid1 can take over:
3473 	 *  raid5 with 2 devices, any layout or chunk size
3474 	 */
3475 	if (mddev->level == 5 && mddev->raid_disks == 2) {
3476 		struct r1conf *conf;
3477 		mddev->new_level = 1;
3478 		mddev->new_layout = 0;
3479 		mddev->new_chunk_sectors = 0;
3480 		conf = setup_conf(mddev);
3481 		if (!IS_ERR(conf)) {
3482 			/* Array must appear to be quiesced */
3483 			conf->array_frozen = 1;
3484 			mddev_clear_unsupported_flags(mddev,
3485 				UNSUPPORTED_MDDEV_FLAGS);
3486 		}
3487 		return conf;
3488 	}
3489 	return ERR_PTR(-EINVAL);
3490 }
3491 
3492 static struct md_personality raid1_personality =
3493 {
3494 	.name		= "raid1",
3495 	.level		= 1,
3496 	.owner		= THIS_MODULE,
3497 	.make_request	= raid1_make_request,
3498 	.run		= raid1_run,
3499 	.free		= raid1_free,
3500 	.status		= raid1_status,
3501 	.error_handler	= raid1_error,
3502 	.hot_add_disk	= raid1_add_disk,
3503 	.hot_remove_disk= raid1_remove_disk,
3504 	.spare_active	= raid1_spare_active,
3505 	.sync_request	= raid1_sync_request,
3506 	.resize		= raid1_resize,
3507 	.size		= raid1_size,
3508 	.check_reshape	= raid1_reshape,
3509 	.quiesce	= raid1_quiesce,
3510 	.takeover	= raid1_takeover,
3511 };
3512 
raid_init(void)3513 static int __init raid_init(void)
3514 {
3515 	return register_md_personality(&raid1_personality);
3516 }
3517 
raid_exit(void)3518 static void raid_exit(void)
3519 {
3520 	unregister_md_personality(&raid1_personality);
3521 }
3522 
3523 module_init(raid_init);
3524 module_exit(raid_exit);
3525 MODULE_LICENSE("GPL");
3526 MODULE_DESCRIPTION("RAID1 (mirroring) personality for MD");
3527 MODULE_ALIAS("md-personality-3"); /* RAID1 */
3528 MODULE_ALIAS("md-raid1");
3529 MODULE_ALIAS("md-level-1");
3530