1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Partial Parity Log for closing the RAID5 write hole
4 * Copyright (c) 2017, Intel Corporation.
5 */
6
7 #include <linux/kernel.h>
8 #include <linux/blkdev.h>
9 #include <linux/slab.h>
10 #include <linux/crc32c.h>
11 #include <linux/async_tx.h>
12 #include <linux/raid/md_p.h>
13 #include "md.h"
14 #include "raid5.h"
15 #include "raid5-log.h"
16
17 /*
18 * PPL consists of a 4KB header (struct ppl_header) and at least 128KB for
19 * partial parity data. The header contains an array of entries
20 * (struct ppl_header_entry) which describe the logged write requests.
21 * Partial parity for the entries comes after the header, written in the same
22 * sequence as the entries:
23 *
24 * Header
25 * entry0
26 * ...
27 * entryN
28 * PP data
29 * PP for entry0
30 * ...
31 * PP for entryN
32 *
33 * An entry describes one or more consecutive stripe_heads, up to a full
34 * stripe. The modifed raid data chunks form an m-by-n matrix, where m is the
35 * number of stripe_heads in the entry and n is the number of modified data
36 * disks. Every stripe_head in the entry must write to the same data disks.
37 * An example of a valid case described by a single entry (writes to the first
38 * stripe of a 4 disk array, 16k chunk size):
39 *
40 * sh->sector dd0 dd1 dd2 ppl
41 * +-----+-----+-----+
42 * 0 | --- | --- | --- | +----+
43 * 8 | -W- | -W- | --- | | pp | data_sector = 8
44 * 16 | -W- | -W- | --- | | pp | data_size = 3 * 2 * 4k
45 * 24 | -W- | -W- | --- | | pp | pp_size = 3 * 4k
46 * +-----+-----+-----+ +----+
47 *
48 * data_sector is the first raid sector of the modified data, data_size is the
49 * total size of modified data and pp_size is the size of partial parity for
50 * this entry. Entries for full stripe writes contain no partial parity
51 * (pp_size = 0), they only mark the stripes for which parity should be
52 * recalculated after an unclean shutdown. Every entry holds a checksum of its
53 * partial parity, the header also has a checksum of the header itself.
54 *
55 * A write request is always logged to the PPL instance stored on the parity
56 * disk of the corresponding stripe. For each member disk there is one ppl_log
57 * used to handle logging for this disk, independently from others. They are
58 * grouped in child_logs array in struct ppl_conf, which is assigned to
59 * r5conf->log_private.
60 *
61 * ppl_io_unit represents a full PPL write, header_page contains the ppl_header.
62 * PPL entries for logged stripes are added in ppl_log_stripe(). A stripe_head
63 * can be appended to the last entry if it meets the conditions for a valid
64 * entry described above, otherwise a new entry is added. Checksums of entries
65 * are calculated incrementally as stripes containing partial parity are being
66 * added. ppl_submit_iounit() calculates the checksum of the header and submits
67 * a bio containing the header page and partial parity pages (sh->ppl_page) for
68 * all stripes of the io_unit. When the PPL write completes, the stripes
69 * associated with the io_unit are released and raid5d starts writing their data
70 * and parity. When all stripes are written, the io_unit is freed and the next
71 * can be submitted.
72 *
73 * An io_unit is used to gather stripes until it is submitted or becomes full
74 * (if the maximum number of entries or size of PPL is reached). Another io_unit
75 * can't be submitted until the previous has completed (PPL and stripe
76 * data+parity is written). The log->io_list tracks all io_units of a log
77 * (for a single member disk). New io_units are added to the end of the list
78 * and the first io_unit is submitted, if it is not submitted already.
79 * The current io_unit accepting new stripes is always at the end of the list.
80 *
81 * If write-back cache is enabled for any of the disks in the array, its data
82 * must be flushed before next io_unit is submitted.
83 */
84
85 #define PPL_SPACE_SIZE (128 * 1024)
86
87 struct ppl_conf {
88 struct mddev *mddev;
89
90 /* array of child logs, one for each raid disk */
91 struct ppl_log *child_logs;
92 int count;
93
94 int block_size; /* the logical block size used for data_sector
95 * in ppl_header_entry */
96 u32 signature; /* raid array identifier */
97 atomic64_t seq; /* current log write sequence number */
98
99 struct kmem_cache *io_kc;
100 mempool_t io_pool;
101 struct bio_set bs;
102 struct bio_set flush_bs;
103
104 /* used only for recovery */
105 int recovered_entries;
106 int mismatch_count;
107
108 /* stripes to retry if failed to allocate io_unit */
109 struct list_head no_mem_stripes;
110 spinlock_t no_mem_stripes_lock;
111
112 unsigned short write_hint;
113 };
114
115 struct ppl_log {
116 struct ppl_conf *ppl_conf; /* shared between all log instances */
117
118 struct md_rdev *rdev; /* array member disk associated with
119 * this log instance */
120 struct mutex io_mutex;
121 struct ppl_io_unit *current_io; /* current io_unit accepting new data
122 * always at the end of io_list */
123 spinlock_t io_list_lock;
124 struct list_head io_list; /* all io_units of this log */
125
126 sector_t next_io_sector;
127 unsigned int entry_space;
128 bool use_multippl;
129 bool wb_cache_on;
130 unsigned long disk_flush_bitmap;
131 };
132
133 #define PPL_IO_INLINE_BVECS 32
134
135 struct ppl_io_unit {
136 struct ppl_log *log;
137
138 struct page *header_page; /* for ppl_header */
139
140 unsigned int entries_count; /* number of entries in ppl_header */
141 unsigned int pp_size; /* total size current of partial parity */
142
143 u64 seq; /* sequence number of this log write */
144 struct list_head log_sibling; /* log->io_list */
145
146 struct list_head stripe_list; /* stripes added to the io_unit */
147 atomic_t pending_stripes; /* how many stripes not written to raid */
148 atomic_t pending_flushes; /* how many disk flushes are in progress */
149
150 bool submitted; /* true if write to log started */
151
152 /* inline bio and its biovec for submitting the iounit */
153 struct bio bio;
154 struct bio_vec biovec[PPL_IO_INLINE_BVECS];
155 };
156
157 struct dma_async_tx_descriptor *
ops_run_partial_parity(struct stripe_head * sh,struct raid5_percpu * percpu,struct dma_async_tx_descriptor * tx)158 ops_run_partial_parity(struct stripe_head *sh, struct raid5_percpu *percpu,
159 struct dma_async_tx_descriptor *tx)
160 {
161 int disks = sh->disks;
162 struct page **srcs = percpu->scribble;
163 int count = 0, pd_idx = sh->pd_idx, i;
164 struct async_submit_ctl submit;
165
166 pr_debug("%s: stripe %llu\n", __func__, (unsigned long long)sh->sector);
167
168 /*
169 * Partial parity is the XOR of stripe data chunks that are not changed
170 * during the write request. Depending on available data
171 * (read-modify-write vs. reconstruct-write case) we calculate it
172 * differently.
173 */
174 if (sh->reconstruct_state == reconstruct_state_prexor_drain_run) {
175 /*
176 * rmw: xor old data and parity from updated disks
177 * This is calculated earlier by ops_run_prexor5() so just copy
178 * the parity dev page.
179 */
180 srcs[count++] = sh->dev[pd_idx].page;
181 } else if (sh->reconstruct_state == reconstruct_state_drain_run) {
182 /* rcw: xor data from all not updated disks */
183 for (i = disks; i--;) {
184 struct r5dev *dev = &sh->dev[i];
185 if (test_bit(R5_UPTODATE, &dev->flags))
186 srcs[count++] = dev->page;
187 }
188 } else {
189 return tx;
190 }
191
192 init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST, tx,
193 NULL, sh, (void *) (srcs + sh->disks + 2));
194
195 if (count == 1)
196 tx = async_memcpy(sh->ppl_page, srcs[0], 0, 0, PAGE_SIZE,
197 &submit);
198 else
199 tx = async_xor(sh->ppl_page, srcs, 0, count, PAGE_SIZE,
200 &submit);
201
202 return tx;
203 }
204
ppl_io_pool_alloc(gfp_t gfp_mask,void * pool_data)205 static void *ppl_io_pool_alloc(gfp_t gfp_mask, void *pool_data)
206 {
207 struct kmem_cache *kc = pool_data;
208 struct ppl_io_unit *io;
209
210 io = kmem_cache_alloc(kc, gfp_mask);
211 if (!io)
212 return NULL;
213
214 io->header_page = alloc_page(gfp_mask);
215 if (!io->header_page) {
216 kmem_cache_free(kc, io);
217 return NULL;
218 }
219
220 return io;
221 }
222
ppl_io_pool_free(void * element,void * pool_data)223 static void ppl_io_pool_free(void *element, void *pool_data)
224 {
225 struct kmem_cache *kc = pool_data;
226 struct ppl_io_unit *io = element;
227
228 __free_page(io->header_page);
229 kmem_cache_free(kc, io);
230 }
231
ppl_new_iounit(struct ppl_log * log,struct stripe_head * sh)232 static struct ppl_io_unit *ppl_new_iounit(struct ppl_log *log,
233 struct stripe_head *sh)
234 {
235 struct ppl_conf *ppl_conf = log->ppl_conf;
236 struct ppl_io_unit *io;
237 struct ppl_header *pplhdr;
238 struct page *header_page;
239
240 io = mempool_alloc(&ppl_conf->io_pool, GFP_NOWAIT);
241 if (!io)
242 return NULL;
243
244 header_page = io->header_page;
245 memset(io, 0, sizeof(*io));
246 io->header_page = header_page;
247
248 io->log = log;
249 INIT_LIST_HEAD(&io->log_sibling);
250 INIT_LIST_HEAD(&io->stripe_list);
251 atomic_set(&io->pending_stripes, 0);
252 atomic_set(&io->pending_flushes, 0);
253 bio_init(&io->bio, io->biovec, PPL_IO_INLINE_BVECS);
254
255 pplhdr = page_address(io->header_page);
256 clear_page(pplhdr);
257 memset(pplhdr->reserved, 0xff, PPL_HDR_RESERVED);
258 pplhdr->signature = cpu_to_le32(ppl_conf->signature);
259
260 io->seq = atomic64_add_return(1, &ppl_conf->seq);
261 pplhdr->generation = cpu_to_le64(io->seq);
262
263 return io;
264 }
265
ppl_log_stripe(struct ppl_log * log,struct stripe_head * sh)266 static int ppl_log_stripe(struct ppl_log *log, struct stripe_head *sh)
267 {
268 struct ppl_io_unit *io = log->current_io;
269 struct ppl_header_entry *e = NULL;
270 struct ppl_header *pplhdr;
271 int i;
272 sector_t data_sector = 0;
273 int data_disks = 0;
274 struct r5conf *conf = sh->raid_conf;
275
276 pr_debug("%s: stripe: %llu\n", __func__, (unsigned long long)sh->sector);
277
278 /* check if current io_unit is full */
279 if (io && (io->pp_size == log->entry_space ||
280 io->entries_count == PPL_HDR_MAX_ENTRIES)) {
281 pr_debug("%s: add io_unit blocked by seq: %llu\n",
282 __func__, io->seq);
283 io = NULL;
284 }
285
286 /* add a new unit if there is none or the current is full */
287 if (!io) {
288 io = ppl_new_iounit(log, sh);
289 if (!io)
290 return -ENOMEM;
291 spin_lock_irq(&log->io_list_lock);
292 list_add_tail(&io->log_sibling, &log->io_list);
293 spin_unlock_irq(&log->io_list_lock);
294
295 log->current_io = io;
296 }
297
298 for (i = 0; i < sh->disks; i++) {
299 struct r5dev *dev = &sh->dev[i];
300
301 if (i != sh->pd_idx && test_bit(R5_Wantwrite, &dev->flags)) {
302 if (!data_disks || dev->sector < data_sector)
303 data_sector = dev->sector;
304 data_disks++;
305 }
306 }
307 BUG_ON(!data_disks);
308
309 pr_debug("%s: seq: %llu data_sector: %llu data_disks: %d\n", __func__,
310 io->seq, (unsigned long long)data_sector, data_disks);
311
312 pplhdr = page_address(io->header_page);
313
314 if (io->entries_count > 0) {
315 struct ppl_header_entry *last =
316 &pplhdr->entries[io->entries_count - 1];
317 struct stripe_head *sh_last = list_last_entry(
318 &io->stripe_list, struct stripe_head, log_list);
319 u64 data_sector_last = le64_to_cpu(last->data_sector);
320 u32 data_size_last = le32_to_cpu(last->data_size);
321
322 /*
323 * Check if we can append the stripe to the last entry. It must
324 * be just after the last logged stripe and write to the same
325 * disks. Use bit shift and logarithm to avoid 64-bit division.
326 */
327 if ((sh->sector == sh_last->sector + RAID5_STRIPE_SECTORS(conf)) &&
328 (data_sector >> ilog2(conf->chunk_sectors) ==
329 data_sector_last >> ilog2(conf->chunk_sectors)) &&
330 ((data_sector - data_sector_last) * data_disks ==
331 data_size_last >> 9))
332 e = last;
333 }
334
335 if (!e) {
336 e = &pplhdr->entries[io->entries_count++];
337 e->data_sector = cpu_to_le64(data_sector);
338 e->parity_disk = cpu_to_le32(sh->pd_idx);
339 e->checksum = cpu_to_le32(~0);
340 }
341
342 le32_add_cpu(&e->data_size, data_disks << PAGE_SHIFT);
343
344 /* don't write any PP if full stripe write */
345 if (!test_bit(STRIPE_FULL_WRITE, &sh->state)) {
346 le32_add_cpu(&e->pp_size, PAGE_SIZE);
347 io->pp_size += PAGE_SIZE;
348 e->checksum = cpu_to_le32(crc32c_le(le32_to_cpu(e->checksum),
349 page_address(sh->ppl_page),
350 PAGE_SIZE));
351 }
352
353 list_add_tail(&sh->log_list, &io->stripe_list);
354 atomic_inc(&io->pending_stripes);
355 sh->ppl_io = io;
356
357 return 0;
358 }
359
ppl_write_stripe(struct r5conf * conf,struct stripe_head * sh)360 int ppl_write_stripe(struct r5conf *conf, struct stripe_head *sh)
361 {
362 struct ppl_conf *ppl_conf = conf->log_private;
363 struct ppl_io_unit *io = sh->ppl_io;
364 struct ppl_log *log;
365
366 if (io || test_bit(STRIPE_SYNCING, &sh->state) || !sh->ppl_page ||
367 !test_bit(R5_Wantwrite, &sh->dev[sh->pd_idx].flags) ||
368 !test_bit(R5_Insync, &sh->dev[sh->pd_idx].flags)) {
369 clear_bit(STRIPE_LOG_TRAPPED, &sh->state);
370 return -EAGAIN;
371 }
372
373 log = &ppl_conf->child_logs[sh->pd_idx];
374
375 mutex_lock(&log->io_mutex);
376
377 if (!log->rdev || test_bit(Faulty, &log->rdev->flags)) {
378 mutex_unlock(&log->io_mutex);
379 return -EAGAIN;
380 }
381
382 set_bit(STRIPE_LOG_TRAPPED, &sh->state);
383 clear_bit(STRIPE_DELAYED, &sh->state);
384 atomic_inc(&sh->count);
385
386 if (ppl_log_stripe(log, sh)) {
387 spin_lock_irq(&ppl_conf->no_mem_stripes_lock);
388 list_add_tail(&sh->log_list, &ppl_conf->no_mem_stripes);
389 spin_unlock_irq(&ppl_conf->no_mem_stripes_lock);
390 }
391
392 mutex_unlock(&log->io_mutex);
393
394 return 0;
395 }
396
ppl_log_endio(struct bio * bio)397 static void ppl_log_endio(struct bio *bio)
398 {
399 struct ppl_io_unit *io = bio->bi_private;
400 struct ppl_log *log = io->log;
401 struct ppl_conf *ppl_conf = log->ppl_conf;
402 struct stripe_head *sh, *next;
403
404 pr_debug("%s: seq: %llu\n", __func__, io->seq);
405
406 if (bio->bi_status)
407 md_error(ppl_conf->mddev, log->rdev);
408
409 list_for_each_entry_safe(sh, next, &io->stripe_list, log_list) {
410 list_del_init(&sh->log_list);
411
412 set_bit(STRIPE_HANDLE, &sh->state);
413 raid5_release_stripe(sh);
414 }
415 }
416
ppl_submit_iounit_bio(struct ppl_io_unit * io,struct bio * bio)417 static void ppl_submit_iounit_bio(struct ppl_io_unit *io, struct bio *bio)
418 {
419 char b[BDEVNAME_SIZE];
420
421 pr_debug("%s: seq: %llu size: %u sector: %llu dev: %s\n",
422 __func__, io->seq, bio->bi_iter.bi_size,
423 (unsigned long long)bio->bi_iter.bi_sector,
424 bio_devname(bio, b));
425
426 submit_bio(bio);
427 }
428
ppl_submit_iounit(struct ppl_io_unit * io)429 static void ppl_submit_iounit(struct ppl_io_unit *io)
430 {
431 struct ppl_log *log = io->log;
432 struct ppl_conf *ppl_conf = log->ppl_conf;
433 struct ppl_header *pplhdr = page_address(io->header_page);
434 struct bio *bio = &io->bio;
435 struct stripe_head *sh;
436 int i;
437
438 bio->bi_private = io;
439
440 if (!log->rdev || test_bit(Faulty, &log->rdev->flags)) {
441 ppl_log_endio(bio);
442 return;
443 }
444
445 for (i = 0; i < io->entries_count; i++) {
446 struct ppl_header_entry *e = &pplhdr->entries[i];
447
448 pr_debug("%s: seq: %llu entry: %d data_sector: %llu pp_size: %u data_size: %u\n",
449 __func__, io->seq, i, le64_to_cpu(e->data_sector),
450 le32_to_cpu(e->pp_size), le32_to_cpu(e->data_size));
451
452 e->data_sector = cpu_to_le64(le64_to_cpu(e->data_sector) >>
453 ilog2(ppl_conf->block_size >> 9));
454 e->checksum = cpu_to_le32(~le32_to_cpu(e->checksum));
455 }
456
457 pplhdr->entries_count = cpu_to_le32(io->entries_count);
458 pplhdr->checksum = cpu_to_le32(~crc32c_le(~0, pplhdr, PPL_HEADER_SIZE));
459
460 /* Rewind the buffer if current PPL is larger then remaining space */
461 if (log->use_multippl &&
462 log->rdev->ppl.sector + log->rdev->ppl.size - log->next_io_sector <
463 (PPL_HEADER_SIZE + io->pp_size) >> 9)
464 log->next_io_sector = log->rdev->ppl.sector;
465
466
467 bio->bi_end_io = ppl_log_endio;
468 bio->bi_opf = REQ_OP_WRITE | REQ_FUA;
469 bio_set_dev(bio, log->rdev->bdev);
470 bio->bi_iter.bi_sector = log->next_io_sector;
471 bio_add_page(bio, io->header_page, PAGE_SIZE, 0);
472 bio->bi_write_hint = ppl_conf->write_hint;
473
474 pr_debug("%s: log->current_io_sector: %llu\n", __func__,
475 (unsigned long long)log->next_io_sector);
476
477 if (log->use_multippl)
478 log->next_io_sector += (PPL_HEADER_SIZE + io->pp_size) >> 9;
479
480 WARN_ON(log->disk_flush_bitmap != 0);
481
482 list_for_each_entry(sh, &io->stripe_list, log_list) {
483 for (i = 0; i < sh->disks; i++) {
484 struct r5dev *dev = &sh->dev[i];
485
486 if ((ppl_conf->child_logs[i].wb_cache_on) &&
487 (test_bit(R5_Wantwrite, &dev->flags))) {
488 set_bit(i, &log->disk_flush_bitmap);
489 }
490 }
491
492 /* entries for full stripe writes have no partial parity */
493 if (test_bit(STRIPE_FULL_WRITE, &sh->state))
494 continue;
495
496 if (!bio_add_page(bio, sh->ppl_page, PAGE_SIZE, 0)) {
497 struct bio *prev = bio;
498
499 bio = bio_alloc_bioset(GFP_NOIO, BIO_MAX_VECS,
500 &ppl_conf->bs);
501 bio->bi_opf = prev->bi_opf;
502 bio->bi_write_hint = prev->bi_write_hint;
503 bio_copy_dev(bio, prev);
504 bio->bi_iter.bi_sector = bio_end_sector(prev);
505 bio_add_page(bio, sh->ppl_page, PAGE_SIZE, 0);
506
507 bio_chain(bio, prev);
508 ppl_submit_iounit_bio(io, prev);
509 }
510 }
511
512 ppl_submit_iounit_bio(io, bio);
513 }
514
ppl_submit_current_io(struct ppl_log * log)515 static void ppl_submit_current_io(struct ppl_log *log)
516 {
517 struct ppl_io_unit *io;
518
519 spin_lock_irq(&log->io_list_lock);
520
521 io = list_first_entry_or_null(&log->io_list, struct ppl_io_unit,
522 log_sibling);
523 if (io && io->submitted)
524 io = NULL;
525
526 spin_unlock_irq(&log->io_list_lock);
527
528 if (io) {
529 io->submitted = true;
530
531 if (io == log->current_io)
532 log->current_io = NULL;
533
534 ppl_submit_iounit(io);
535 }
536 }
537
ppl_write_stripe_run(struct r5conf * conf)538 void ppl_write_stripe_run(struct r5conf *conf)
539 {
540 struct ppl_conf *ppl_conf = conf->log_private;
541 struct ppl_log *log;
542 int i;
543
544 for (i = 0; i < ppl_conf->count; i++) {
545 log = &ppl_conf->child_logs[i];
546
547 mutex_lock(&log->io_mutex);
548 ppl_submit_current_io(log);
549 mutex_unlock(&log->io_mutex);
550 }
551 }
552
ppl_io_unit_finished(struct ppl_io_unit * io)553 static void ppl_io_unit_finished(struct ppl_io_unit *io)
554 {
555 struct ppl_log *log = io->log;
556 struct ppl_conf *ppl_conf = log->ppl_conf;
557 struct r5conf *conf = ppl_conf->mddev->private;
558 unsigned long flags;
559
560 pr_debug("%s: seq: %llu\n", __func__, io->seq);
561
562 local_irq_save(flags);
563
564 spin_lock(&log->io_list_lock);
565 list_del(&io->log_sibling);
566 spin_unlock(&log->io_list_lock);
567
568 mempool_free(io, &ppl_conf->io_pool);
569
570 spin_lock(&ppl_conf->no_mem_stripes_lock);
571 if (!list_empty(&ppl_conf->no_mem_stripes)) {
572 struct stripe_head *sh;
573
574 sh = list_first_entry(&ppl_conf->no_mem_stripes,
575 struct stripe_head, log_list);
576 list_del_init(&sh->log_list);
577 set_bit(STRIPE_HANDLE, &sh->state);
578 raid5_release_stripe(sh);
579 }
580 spin_unlock(&ppl_conf->no_mem_stripes_lock);
581
582 local_irq_restore(flags);
583
584 wake_up(&conf->wait_for_quiescent);
585 }
586
ppl_flush_endio(struct bio * bio)587 static void ppl_flush_endio(struct bio *bio)
588 {
589 struct ppl_io_unit *io = bio->bi_private;
590 struct ppl_log *log = io->log;
591 struct ppl_conf *ppl_conf = log->ppl_conf;
592 struct r5conf *conf = ppl_conf->mddev->private;
593 char b[BDEVNAME_SIZE];
594
595 pr_debug("%s: dev: %s\n", __func__, bio_devname(bio, b));
596
597 if (bio->bi_status) {
598 struct md_rdev *rdev;
599
600 rcu_read_lock();
601 rdev = md_find_rdev_rcu(conf->mddev, bio_dev(bio));
602 if (rdev)
603 md_error(rdev->mddev, rdev);
604 rcu_read_unlock();
605 }
606
607 bio_put(bio);
608
609 if (atomic_dec_and_test(&io->pending_flushes)) {
610 ppl_io_unit_finished(io);
611 md_wakeup_thread(conf->mddev->thread);
612 }
613 }
614
ppl_do_flush(struct ppl_io_unit * io)615 static void ppl_do_flush(struct ppl_io_unit *io)
616 {
617 struct ppl_log *log = io->log;
618 struct ppl_conf *ppl_conf = log->ppl_conf;
619 struct r5conf *conf = ppl_conf->mddev->private;
620 int raid_disks = conf->raid_disks;
621 int flushed_disks = 0;
622 int i;
623
624 atomic_set(&io->pending_flushes, raid_disks);
625
626 for_each_set_bit(i, &log->disk_flush_bitmap, raid_disks) {
627 struct md_rdev *rdev;
628 struct block_device *bdev = NULL;
629
630 rcu_read_lock();
631 rdev = rcu_dereference(conf->disks[i].rdev);
632 if (rdev && !test_bit(Faulty, &rdev->flags))
633 bdev = rdev->bdev;
634 rcu_read_unlock();
635
636 if (bdev) {
637 struct bio *bio;
638 char b[BDEVNAME_SIZE];
639
640 bio = bio_alloc_bioset(GFP_NOIO, 0, &ppl_conf->flush_bs);
641 bio_set_dev(bio, bdev);
642 bio->bi_private = io;
643 bio->bi_opf = REQ_OP_WRITE | REQ_PREFLUSH;
644 bio->bi_end_io = ppl_flush_endio;
645
646 pr_debug("%s: dev: %s\n", __func__,
647 bio_devname(bio, b));
648
649 submit_bio(bio);
650 flushed_disks++;
651 }
652 }
653
654 log->disk_flush_bitmap = 0;
655
656 for (i = flushed_disks ; i < raid_disks; i++) {
657 if (atomic_dec_and_test(&io->pending_flushes))
658 ppl_io_unit_finished(io);
659 }
660 }
661
ppl_no_io_unit_submitted(struct r5conf * conf,struct ppl_log * log)662 static inline bool ppl_no_io_unit_submitted(struct r5conf *conf,
663 struct ppl_log *log)
664 {
665 struct ppl_io_unit *io;
666
667 io = list_first_entry_or_null(&log->io_list, struct ppl_io_unit,
668 log_sibling);
669
670 return !io || !io->submitted;
671 }
672
ppl_quiesce(struct r5conf * conf,int quiesce)673 void ppl_quiesce(struct r5conf *conf, int quiesce)
674 {
675 struct ppl_conf *ppl_conf = conf->log_private;
676 int i;
677
678 if (quiesce) {
679 for (i = 0; i < ppl_conf->count; i++) {
680 struct ppl_log *log = &ppl_conf->child_logs[i];
681
682 spin_lock_irq(&log->io_list_lock);
683 wait_event_lock_irq(conf->wait_for_quiescent,
684 ppl_no_io_unit_submitted(conf, log),
685 log->io_list_lock);
686 spin_unlock_irq(&log->io_list_lock);
687 }
688 }
689 }
690
ppl_handle_flush_request(struct r5l_log * log,struct bio * bio)691 int ppl_handle_flush_request(struct r5l_log *log, struct bio *bio)
692 {
693 if (bio->bi_iter.bi_size == 0) {
694 bio_endio(bio);
695 return 0;
696 }
697 bio->bi_opf &= ~REQ_PREFLUSH;
698 return -EAGAIN;
699 }
700
ppl_stripe_write_finished(struct stripe_head * sh)701 void ppl_stripe_write_finished(struct stripe_head *sh)
702 {
703 struct ppl_io_unit *io;
704
705 io = sh->ppl_io;
706 sh->ppl_io = NULL;
707
708 if (io && atomic_dec_and_test(&io->pending_stripes)) {
709 if (io->log->disk_flush_bitmap)
710 ppl_do_flush(io);
711 else
712 ppl_io_unit_finished(io);
713 }
714 }
715
ppl_xor(int size,struct page * page1,struct page * page2)716 static void ppl_xor(int size, struct page *page1, struct page *page2)
717 {
718 struct async_submit_ctl submit;
719 struct dma_async_tx_descriptor *tx;
720 struct page *xor_srcs[] = { page1, page2 };
721
722 init_async_submit(&submit, ASYNC_TX_ACK|ASYNC_TX_XOR_DROP_DST,
723 NULL, NULL, NULL, NULL);
724 tx = async_xor(page1, xor_srcs, 0, 2, size, &submit);
725
726 async_tx_quiesce(&tx);
727 }
728
729 /*
730 * PPL recovery strategy: xor partial parity and data from all modified data
731 * disks within a stripe and write the result as the new stripe parity. If all
732 * stripe data disks are modified (full stripe write), no partial parity is
733 * available, so just xor the data disks.
734 *
735 * Recovery of a PPL entry shall occur only if all modified data disks are
736 * available and read from all of them succeeds.
737 *
738 * A PPL entry applies to a stripe, partial parity size for an entry is at most
739 * the size of the chunk. Examples of possible cases for a single entry:
740 *
741 * case 0: single data disk write:
742 * data0 data1 data2 ppl parity
743 * +--------+--------+--------+ +--------------------+
744 * | ------ | ------ | ------ | +----+ | (no change) |
745 * | ------ | -data- | ------ | | pp | -> | data1 ^ pp |
746 * | ------ | -data- | ------ | | pp | -> | data1 ^ pp |
747 * | ------ | ------ | ------ | +----+ | (no change) |
748 * +--------+--------+--------+ +--------------------+
749 * pp_size = data_size
750 *
751 * case 1: more than one data disk write:
752 * data0 data1 data2 ppl parity
753 * +--------+--------+--------+ +--------------------+
754 * | ------ | ------ | ------ | +----+ | (no change) |
755 * | -data- | -data- | ------ | | pp | -> | data0 ^ data1 ^ pp |
756 * | -data- | -data- | ------ | | pp | -> | data0 ^ data1 ^ pp |
757 * | ------ | ------ | ------ | +----+ | (no change) |
758 * +--------+--------+--------+ +--------------------+
759 * pp_size = data_size / modified_data_disks
760 *
761 * case 2: write to all data disks (also full stripe write):
762 * data0 data1 data2 parity
763 * +--------+--------+--------+ +--------------------+
764 * | ------ | ------ | ------ | | (no change) |
765 * | -data- | -data- | -data- | --------> | xor all data |
766 * | ------ | ------ | ------ | --------> | (no change) |
767 * | ------ | ------ | ------ | | (no change) |
768 * +--------+--------+--------+ +--------------------+
769 * pp_size = 0
770 *
771 * The following cases are possible only in other implementations. The recovery
772 * code can handle them, but they are not generated at runtime because they can
773 * be reduced to cases 0, 1 and 2:
774 *
775 * case 3:
776 * data0 data1 data2 ppl parity
777 * +--------+--------+--------+ +----+ +--------------------+
778 * | ------ | -data- | -data- | | pp | | data1 ^ data2 ^ pp |
779 * | ------ | -data- | -data- | | pp | -> | data1 ^ data2 ^ pp |
780 * | -data- | -data- | -data- | | -- | -> | xor all data |
781 * | -data- | -data- | ------ | | pp | | data0 ^ data1 ^ pp |
782 * +--------+--------+--------+ +----+ +--------------------+
783 * pp_size = chunk_size
784 *
785 * case 4:
786 * data0 data1 data2 ppl parity
787 * +--------+--------+--------+ +----+ +--------------------+
788 * | ------ | -data- | ------ | | pp | | data1 ^ pp |
789 * | ------ | ------ | ------ | | -- | -> | (no change) |
790 * | ------ | ------ | ------ | | -- | -> | (no change) |
791 * | -data- | ------ | ------ | | pp | | data0 ^ pp |
792 * +--------+--------+--------+ +----+ +--------------------+
793 * pp_size = chunk_size
794 */
ppl_recover_entry(struct ppl_log * log,struct ppl_header_entry * e,sector_t ppl_sector)795 static int ppl_recover_entry(struct ppl_log *log, struct ppl_header_entry *e,
796 sector_t ppl_sector)
797 {
798 struct ppl_conf *ppl_conf = log->ppl_conf;
799 struct mddev *mddev = ppl_conf->mddev;
800 struct r5conf *conf = mddev->private;
801 int block_size = ppl_conf->block_size;
802 struct page *page1;
803 struct page *page2;
804 sector_t r_sector_first;
805 sector_t r_sector_last;
806 int strip_sectors;
807 int data_disks;
808 int i;
809 int ret = 0;
810 char b[BDEVNAME_SIZE];
811 unsigned int pp_size = le32_to_cpu(e->pp_size);
812 unsigned int data_size = le32_to_cpu(e->data_size);
813
814 page1 = alloc_page(GFP_KERNEL);
815 page2 = alloc_page(GFP_KERNEL);
816
817 if (!page1 || !page2) {
818 ret = -ENOMEM;
819 goto out;
820 }
821
822 r_sector_first = le64_to_cpu(e->data_sector) * (block_size >> 9);
823
824 if ((pp_size >> 9) < conf->chunk_sectors) {
825 if (pp_size > 0) {
826 data_disks = data_size / pp_size;
827 strip_sectors = pp_size >> 9;
828 } else {
829 data_disks = conf->raid_disks - conf->max_degraded;
830 strip_sectors = (data_size >> 9) / data_disks;
831 }
832 r_sector_last = r_sector_first +
833 (data_disks - 1) * conf->chunk_sectors +
834 strip_sectors;
835 } else {
836 data_disks = conf->raid_disks - conf->max_degraded;
837 strip_sectors = conf->chunk_sectors;
838 r_sector_last = r_sector_first + (data_size >> 9);
839 }
840
841 pr_debug("%s: array sector first: %llu last: %llu\n", __func__,
842 (unsigned long long)r_sector_first,
843 (unsigned long long)r_sector_last);
844
845 /* if start and end is 4k aligned, use a 4k block */
846 if (block_size == 512 &&
847 (r_sector_first & (RAID5_STRIPE_SECTORS(conf) - 1)) == 0 &&
848 (r_sector_last & (RAID5_STRIPE_SECTORS(conf) - 1)) == 0)
849 block_size = RAID5_STRIPE_SIZE(conf);
850
851 /* iterate through blocks in strip */
852 for (i = 0; i < strip_sectors; i += (block_size >> 9)) {
853 bool update_parity = false;
854 sector_t parity_sector;
855 struct md_rdev *parity_rdev;
856 struct stripe_head sh;
857 int disk;
858 int indent = 0;
859
860 pr_debug("%s:%*s iter %d start\n", __func__, indent, "", i);
861 indent += 2;
862
863 memset(page_address(page1), 0, PAGE_SIZE);
864
865 /* iterate through data member disks */
866 for (disk = 0; disk < data_disks; disk++) {
867 int dd_idx;
868 struct md_rdev *rdev;
869 sector_t sector;
870 sector_t r_sector = r_sector_first + i +
871 (disk * conf->chunk_sectors);
872
873 pr_debug("%s:%*s data member disk %d start\n",
874 __func__, indent, "", disk);
875 indent += 2;
876
877 if (r_sector >= r_sector_last) {
878 pr_debug("%s:%*s array sector %llu doesn't need parity update\n",
879 __func__, indent, "",
880 (unsigned long long)r_sector);
881 indent -= 2;
882 continue;
883 }
884
885 update_parity = true;
886
887 /* map raid sector to member disk */
888 sector = raid5_compute_sector(conf, r_sector, 0,
889 &dd_idx, NULL);
890 pr_debug("%s:%*s processing array sector %llu => data member disk %d, sector %llu\n",
891 __func__, indent, "",
892 (unsigned long long)r_sector, dd_idx,
893 (unsigned long long)sector);
894
895 rdev = conf->disks[dd_idx].rdev;
896 if (!rdev || (!test_bit(In_sync, &rdev->flags) &&
897 sector >= rdev->recovery_offset)) {
898 pr_debug("%s:%*s data member disk %d missing\n",
899 __func__, indent, "", dd_idx);
900 update_parity = false;
901 break;
902 }
903
904 pr_debug("%s:%*s reading data member disk %s sector %llu\n",
905 __func__, indent, "", bdevname(rdev->bdev, b),
906 (unsigned long long)sector);
907 if (!sync_page_io(rdev, sector, block_size, page2,
908 REQ_OP_READ, 0, false)) {
909 md_error(mddev, rdev);
910 pr_debug("%s:%*s read failed!\n", __func__,
911 indent, "");
912 ret = -EIO;
913 goto out;
914 }
915
916 ppl_xor(block_size, page1, page2);
917
918 indent -= 2;
919 }
920
921 if (!update_parity)
922 continue;
923
924 if (pp_size > 0) {
925 pr_debug("%s:%*s reading pp disk sector %llu\n",
926 __func__, indent, "",
927 (unsigned long long)(ppl_sector + i));
928 if (!sync_page_io(log->rdev,
929 ppl_sector - log->rdev->data_offset + i,
930 block_size, page2, REQ_OP_READ, 0,
931 false)) {
932 pr_debug("%s:%*s read failed!\n", __func__,
933 indent, "");
934 md_error(mddev, log->rdev);
935 ret = -EIO;
936 goto out;
937 }
938
939 ppl_xor(block_size, page1, page2);
940 }
941
942 /* map raid sector to parity disk */
943 parity_sector = raid5_compute_sector(conf, r_sector_first + i,
944 0, &disk, &sh);
945 BUG_ON(sh.pd_idx != le32_to_cpu(e->parity_disk));
946 parity_rdev = conf->disks[sh.pd_idx].rdev;
947
948 BUG_ON(parity_rdev->bdev->bd_dev != log->rdev->bdev->bd_dev);
949 pr_debug("%s:%*s write parity at sector %llu, disk %s\n",
950 __func__, indent, "",
951 (unsigned long long)parity_sector,
952 bdevname(parity_rdev->bdev, b));
953 if (!sync_page_io(parity_rdev, parity_sector, block_size,
954 page1, REQ_OP_WRITE, 0, false)) {
955 pr_debug("%s:%*s parity write error!\n", __func__,
956 indent, "");
957 md_error(mddev, parity_rdev);
958 ret = -EIO;
959 goto out;
960 }
961 }
962 out:
963 if (page1)
964 __free_page(page1);
965 if (page2)
966 __free_page(page2);
967 return ret;
968 }
969
ppl_recover(struct ppl_log * log,struct ppl_header * pplhdr,sector_t offset)970 static int ppl_recover(struct ppl_log *log, struct ppl_header *pplhdr,
971 sector_t offset)
972 {
973 struct ppl_conf *ppl_conf = log->ppl_conf;
974 struct md_rdev *rdev = log->rdev;
975 struct mddev *mddev = rdev->mddev;
976 sector_t ppl_sector = rdev->ppl.sector + offset +
977 (PPL_HEADER_SIZE >> 9);
978 struct page *page;
979 int i;
980 int ret = 0;
981
982 page = alloc_page(GFP_KERNEL);
983 if (!page)
984 return -ENOMEM;
985
986 /* iterate through all PPL entries saved */
987 for (i = 0; i < le32_to_cpu(pplhdr->entries_count); i++) {
988 struct ppl_header_entry *e = &pplhdr->entries[i];
989 u32 pp_size = le32_to_cpu(e->pp_size);
990 sector_t sector = ppl_sector;
991 int ppl_entry_sectors = pp_size >> 9;
992 u32 crc, crc_stored;
993
994 pr_debug("%s: disk: %d entry: %d ppl_sector: %llu pp_size: %u\n",
995 __func__, rdev->raid_disk, i,
996 (unsigned long long)ppl_sector, pp_size);
997
998 crc = ~0;
999 crc_stored = le32_to_cpu(e->checksum);
1000
1001 /* read parial parity for this entry and calculate its checksum */
1002 while (pp_size) {
1003 int s = pp_size > PAGE_SIZE ? PAGE_SIZE : pp_size;
1004
1005 if (!sync_page_io(rdev, sector - rdev->data_offset,
1006 s, page, REQ_OP_READ, 0, false)) {
1007 md_error(mddev, rdev);
1008 ret = -EIO;
1009 goto out;
1010 }
1011
1012 crc = crc32c_le(crc, page_address(page), s);
1013
1014 pp_size -= s;
1015 sector += s >> 9;
1016 }
1017
1018 crc = ~crc;
1019
1020 if (crc != crc_stored) {
1021 /*
1022 * Don't recover this entry if the checksum does not
1023 * match, but keep going and try to recover other
1024 * entries.
1025 */
1026 pr_debug("%s: ppl entry crc does not match: stored: 0x%x calculated: 0x%x\n",
1027 __func__, crc_stored, crc);
1028 ppl_conf->mismatch_count++;
1029 } else {
1030 ret = ppl_recover_entry(log, e, ppl_sector);
1031 if (ret)
1032 goto out;
1033 ppl_conf->recovered_entries++;
1034 }
1035
1036 ppl_sector += ppl_entry_sectors;
1037 }
1038
1039 /* flush the disk cache after recovery if necessary */
1040 ret = blkdev_issue_flush(rdev->bdev);
1041 out:
1042 __free_page(page);
1043 return ret;
1044 }
1045
ppl_write_empty_header(struct ppl_log * log)1046 static int ppl_write_empty_header(struct ppl_log *log)
1047 {
1048 struct page *page;
1049 struct ppl_header *pplhdr;
1050 struct md_rdev *rdev = log->rdev;
1051 int ret = 0;
1052
1053 pr_debug("%s: disk: %d ppl_sector: %llu\n", __func__,
1054 rdev->raid_disk, (unsigned long long)rdev->ppl.sector);
1055
1056 page = alloc_page(GFP_NOIO | __GFP_ZERO);
1057 if (!page)
1058 return -ENOMEM;
1059
1060 pplhdr = page_address(page);
1061 /* zero out PPL space to avoid collision with old PPLs */
1062 blkdev_issue_zeroout(rdev->bdev, rdev->ppl.sector,
1063 log->rdev->ppl.size, GFP_NOIO, 0);
1064 memset(pplhdr->reserved, 0xff, PPL_HDR_RESERVED);
1065 pplhdr->signature = cpu_to_le32(log->ppl_conf->signature);
1066 pplhdr->checksum = cpu_to_le32(~crc32c_le(~0, pplhdr, PAGE_SIZE));
1067
1068 if (!sync_page_io(rdev, rdev->ppl.sector - rdev->data_offset,
1069 PPL_HEADER_SIZE, page, REQ_OP_WRITE | REQ_SYNC |
1070 REQ_FUA, 0, false)) {
1071 md_error(rdev->mddev, rdev);
1072 ret = -EIO;
1073 }
1074
1075 __free_page(page);
1076 return ret;
1077 }
1078
ppl_load_distributed(struct ppl_log * log)1079 static int ppl_load_distributed(struct ppl_log *log)
1080 {
1081 struct ppl_conf *ppl_conf = log->ppl_conf;
1082 struct md_rdev *rdev = log->rdev;
1083 struct mddev *mddev = rdev->mddev;
1084 struct page *page, *page2, *tmp;
1085 struct ppl_header *pplhdr = NULL, *prev_pplhdr = NULL;
1086 u32 crc, crc_stored;
1087 u32 signature;
1088 int ret = 0, i;
1089 sector_t pplhdr_offset = 0, prev_pplhdr_offset = 0;
1090
1091 pr_debug("%s: disk: %d\n", __func__, rdev->raid_disk);
1092 /* read PPL headers, find the recent one */
1093 page = alloc_page(GFP_KERNEL);
1094 if (!page)
1095 return -ENOMEM;
1096
1097 page2 = alloc_page(GFP_KERNEL);
1098 if (!page2) {
1099 __free_page(page);
1100 return -ENOMEM;
1101 }
1102
1103 /* searching ppl area for latest ppl */
1104 while (pplhdr_offset < rdev->ppl.size - (PPL_HEADER_SIZE >> 9)) {
1105 if (!sync_page_io(rdev,
1106 rdev->ppl.sector - rdev->data_offset +
1107 pplhdr_offset, PAGE_SIZE, page, REQ_OP_READ,
1108 0, false)) {
1109 md_error(mddev, rdev);
1110 ret = -EIO;
1111 /* if not able to read - don't recover any PPL */
1112 pplhdr = NULL;
1113 break;
1114 }
1115 pplhdr = page_address(page);
1116
1117 /* check header validity */
1118 crc_stored = le32_to_cpu(pplhdr->checksum);
1119 pplhdr->checksum = 0;
1120 crc = ~crc32c_le(~0, pplhdr, PAGE_SIZE);
1121
1122 if (crc_stored != crc) {
1123 pr_debug("%s: ppl header crc does not match: stored: 0x%x calculated: 0x%x (offset: %llu)\n",
1124 __func__, crc_stored, crc,
1125 (unsigned long long)pplhdr_offset);
1126 pplhdr = prev_pplhdr;
1127 pplhdr_offset = prev_pplhdr_offset;
1128 break;
1129 }
1130
1131 signature = le32_to_cpu(pplhdr->signature);
1132
1133 if (mddev->external) {
1134 /*
1135 * For external metadata the header signature is set and
1136 * validated in userspace.
1137 */
1138 ppl_conf->signature = signature;
1139 } else if (ppl_conf->signature != signature) {
1140 pr_debug("%s: ppl header signature does not match: stored: 0x%x configured: 0x%x (offset: %llu)\n",
1141 __func__, signature, ppl_conf->signature,
1142 (unsigned long long)pplhdr_offset);
1143 pplhdr = prev_pplhdr;
1144 pplhdr_offset = prev_pplhdr_offset;
1145 break;
1146 }
1147
1148 if (prev_pplhdr && le64_to_cpu(prev_pplhdr->generation) >
1149 le64_to_cpu(pplhdr->generation)) {
1150 /* previous was newest */
1151 pplhdr = prev_pplhdr;
1152 pplhdr_offset = prev_pplhdr_offset;
1153 break;
1154 }
1155
1156 prev_pplhdr_offset = pplhdr_offset;
1157 prev_pplhdr = pplhdr;
1158
1159 tmp = page;
1160 page = page2;
1161 page2 = tmp;
1162
1163 /* calculate next potential ppl offset */
1164 for (i = 0; i < le32_to_cpu(pplhdr->entries_count); i++)
1165 pplhdr_offset +=
1166 le32_to_cpu(pplhdr->entries[i].pp_size) >> 9;
1167 pplhdr_offset += PPL_HEADER_SIZE >> 9;
1168 }
1169
1170 /* no valid ppl found */
1171 if (!pplhdr)
1172 ppl_conf->mismatch_count++;
1173 else
1174 pr_debug("%s: latest PPL found at offset: %llu, with generation: %llu\n",
1175 __func__, (unsigned long long)pplhdr_offset,
1176 le64_to_cpu(pplhdr->generation));
1177
1178 /* attempt to recover from log if we are starting a dirty array */
1179 if (pplhdr && !mddev->pers && mddev->recovery_cp != MaxSector)
1180 ret = ppl_recover(log, pplhdr, pplhdr_offset);
1181
1182 /* write empty header if we are starting the array */
1183 if (!ret && !mddev->pers)
1184 ret = ppl_write_empty_header(log);
1185
1186 __free_page(page);
1187 __free_page(page2);
1188
1189 pr_debug("%s: return: %d mismatch_count: %d recovered_entries: %d\n",
1190 __func__, ret, ppl_conf->mismatch_count,
1191 ppl_conf->recovered_entries);
1192 return ret;
1193 }
1194
ppl_load(struct ppl_conf * ppl_conf)1195 static int ppl_load(struct ppl_conf *ppl_conf)
1196 {
1197 int ret = 0;
1198 u32 signature = 0;
1199 bool signature_set = false;
1200 int i;
1201
1202 for (i = 0; i < ppl_conf->count; i++) {
1203 struct ppl_log *log = &ppl_conf->child_logs[i];
1204
1205 /* skip missing drive */
1206 if (!log->rdev)
1207 continue;
1208
1209 ret = ppl_load_distributed(log);
1210 if (ret)
1211 break;
1212
1213 /*
1214 * For external metadata we can't check if the signature is
1215 * correct on a single drive, but we can check if it is the same
1216 * on all drives.
1217 */
1218 if (ppl_conf->mddev->external) {
1219 if (!signature_set) {
1220 signature = ppl_conf->signature;
1221 signature_set = true;
1222 } else if (signature != ppl_conf->signature) {
1223 pr_warn("md/raid:%s: PPL header signature does not match on all member drives\n",
1224 mdname(ppl_conf->mddev));
1225 ret = -EINVAL;
1226 break;
1227 }
1228 }
1229 }
1230
1231 pr_debug("%s: return: %d mismatch_count: %d recovered_entries: %d\n",
1232 __func__, ret, ppl_conf->mismatch_count,
1233 ppl_conf->recovered_entries);
1234 return ret;
1235 }
1236
__ppl_exit_log(struct ppl_conf * ppl_conf)1237 static void __ppl_exit_log(struct ppl_conf *ppl_conf)
1238 {
1239 clear_bit(MD_HAS_PPL, &ppl_conf->mddev->flags);
1240 clear_bit(MD_HAS_MULTIPLE_PPLS, &ppl_conf->mddev->flags);
1241
1242 kfree(ppl_conf->child_logs);
1243
1244 bioset_exit(&ppl_conf->bs);
1245 bioset_exit(&ppl_conf->flush_bs);
1246 mempool_exit(&ppl_conf->io_pool);
1247 kmem_cache_destroy(ppl_conf->io_kc);
1248
1249 kfree(ppl_conf);
1250 }
1251
ppl_exit_log(struct r5conf * conf)1252 void ppl_exit_log(struct r5conf *conf)
1253 {
1254 struct ppl_conf *ppl_conf = conf->log_private;
1255
1256 if (ppl_conf) {
1257 __ppl_exit_log(ppl_conf);
1258 conf->log_private = NULL;
1259 }
1260 }
1261
ppl_validate_rdev(struct md_rdev * rdev)1262 static int ppl_validate_rdev(struct md_rdev *rdev)
1263 {
1264 char b[BDEVNAME_SIZE];
1265 int ppl_data_sectors;
1266 int ppl_size_new;
1267
1268 /*
1269 * The configured PPL size must be enough to store
1270 * the header and (at the very least) partial parity
1271 * for one stripe. Round it down to ensure the data
1272 * space is cleanly divisible by stripe size.
1273 */
1274 ppl_data_sectors = rdev->ppl.size - (PPL_HEADER_SIZE >> 9);
1275
1276 if (ppl_data_sectors > 0)
1277 ppl_data_sectors = rounddown(ppl_data_sectors,
1278 RAID5_STRIPE_SECTORS((struct r5conf *)rdev->mddev->private));
1279
1280 if (ppl_data_sectors <= 0) {
1281 pr_warn("md/raid:%s: PPL space too small on %s\n",
1282 mdname(rdev->mddev), bdevname(rdev->bdev, b));
1283 return -ENOSPC;
1284 }
1285
1286 ppl_size_new = ppl_data_sectors + (PPL_HEADER_SIZE >> 9);
1287
1288 if ((rdev->ppl.sector < rdev->data_offset &&
1289 rdev->ppl.sector + ppl_size_new > rdev->data_offset) ||
1290 (rdev->ppl.sector >= rdev->data_offset &&
1291 rdev->data_offset + rdev->sectors > rdev->ppl.sector)) {
1292 pr_warn("md/raid:%s: PPL space overlaps with data on %s\n",
1293 mdname(rdev->mddev), bdevname(rdev->bdev, b));
1294 return -EINVAL;
1295 }
1296
1297 if (!rdev->mddev->external &&
1298 ((rdev->ppl.offset > 0 && rdev->ppl.offset < (rdev->sb_size >> 9)) ||
1299 (rdev->ppl.offset <= 0 && rdev->ppl.offset + ppl_size_new > 0))) {
1300 pr_warn("md/raid:%s: PPL space overlaps with superblock on %s\n",
1301 mdname(rdev->mddev), bdevname(rdev->bdev, b));
1302 return -EINVAL;
1303 }
1304
1305 rdev->ppl.size = ppl_size_new;
1306
1307 return 0;
1308 }
1309
ppl_init_child_log(struct ppl_log * log,struct md_rdev * rdev)1310 static void ppl_init_child_log(struct ppl_log *log, struct md_rdev *rdev)
1311 {
1312 struct request_queue *q;
1313
1314 if ((rdev->ppl.size << 9) >= (PPL_SPACE_SIZE +
1315 PPL_HEADER_SIZE) * 2) {
1316 log->use_multippl = true;
1317 set_bit(MD_HAS_MULTIPLE_PPLS,
1318 &log->ppl_conf->mddev->flags);
1319 log->entry_space = PPL_SPACE_SIZE;
1320 } else {
1321 log->use_multippl = false;
1322 log->entry_space = (log->rdev->ppl.size << 9) -
1323 PPL_HEADER_SIZE;
1324 }
1325 log->next_io_sector = rdev->ppl.sector;
1326
1327 q = bdev_get_queue(rdev->bdev);
1328 if (test_bit(QUEUE_FLAG_WC, &q->queue_flags))
1329 log->wb_cache_on = true;
1330 }
1331
ppl_init_log(struct r5conf * conf)1332 int ppl_init_log(struct r5conf *conf)
1333 {
1334 struct ppl_conf *ppl_conf;
1335 struct mddev *mddev = conf->mddev;
1336 int ret = 0;
1337 int max_disks;
1338 int i;
1339
1340 pr_debug("md/raid:%s: enabling distributed Partial Parity Log\n",
1341 mdname(conf->mddev));
1342
1343 if (PAGE_SIZE != 4096)
1344 return -EINVAL;
1345
1346 if (mddev->level != 5) {
1347 pr_warn("md/raid:%s PPL is not compatible with raid level %d\n",
1348 mdname(mddev), mddev->level);
1349 return -EINVAL;
1350 }
1351
1352 if (mddev->bitmap_info.file || mddev->bitmap_info.offset) {
1353 pr_warn("md/raid:%s PPL is not compatible with bitmap\n",
1354 mdname(mddev));
1355 return -EINVAL;
1356 }
1357
1358 if (test_bit(MD_HAS_JOURNAL, &mddev->flags)) {
1359 pr_warn("md/raid:%s PPL is not compatible with journal\n",
1360 mdname(mddev));
1361 return -EINVAL;
1362 }
1363
1364 max_disks = sizeof_field(struct ppl_log, disk_flush_bitmap) *
1365 BITS_PER_BYTE;
1366 if (conf->raid_disks > max_disks) {
1367 pr_warn("md/raid:%s PPL doesn't support over %d disks in the array\n",
1368 mdname(mddev), max_disks);
1369 return -EINVAL;
1370 }
1371
1372 ppl_conf = kzalloc(sizeof(struct ppl_conf), GFP_KERNEL);
1373 if (!ppl_conf)
1374 return -ENOMEM;
1375
1376 ppl_conf->mddev = mddev;
1377
1378 ppl_conf->io_kc = KMEM_CACHE(ppl_io_unit, 0);
1379 if (!ppl_conf->io_kc) {
1380 ret = -ENOMEM;
1381 goto err;
1382 }
1383
1384 ret = mempool_init(&ppl_conf->io_pool, conf->raid_disks, ppl_io_pool_alloc,
1385 ppl_io_pool_free, ppl_conf->io_kc);
1386 if (ret)
1387 goto err;
1388
1389 ret = bioset_init(&ppl_conf->bs, conf->raid_disks, 0, BIOSET_NEED_BVECS);
1390 if (ret)
1391 goto err;
1392
1393 ret = bioset_init(&ppl_conf->flush_bs, conf->raid_disks, 0, 0);
1394 if (ret)
1395 goto err;
1396
1397 ppl_conf->count = conf->raid_disks;
1398 ppl_conf->child_logs = kcalloc(ppl_conf->count, sizeof(struct ppl_log),
1399 GFP_KERNEL);
1400 if (!ppl_conf->child_logs) {
1401 ret = -ENOMEM;
1402 goto err;
1403 }
1404
1405 atomic64_set(&ppl_conf->seq, 0);
1406 INIT_LIST_HEAD(&ppl_conf->no_mem_stripes);
1407 spin_lock_init(&ppl_conf->no_mem_stripes_lock);
1408 ppl_conf->write_hint = RWH_WRITE_LIFE_NOT_SET;
1409
1410 if (!mddev->external) {
1411 ppl_conf->signature = ~crc32c_le(~0, mddev->uuid, sizeof(mddev->uuid));
1412 ppl_conf->block_size = 512;
1413 } else {
1414 ppl_conf->block_size = queue_logical_block_size(mddev->queue);
1415 }
1416
1417 for (i = 0; i < ppl_conf->count; i++) {
1418 struct ppl_log *log = &ppl_conf->child_logs[i];
1419 struct md_rdev *rdev = conf->disks[i].rdev;
1420
1421 mutex_init(&log->io_mutex);
1422 spin_lock_init(&log->io_list_lock);
1423 INIT_LIST_HEAD(&log->io_list);
1424
1425 log->ppl_conf = ppl_conf;
1426 log->rdev = rdev;
1427
1428 if (rdev) {
1429 ret = ppl_validate_rdev(rdev);
1430 if (ret)
1431 goto err;
1432
1433 ppl_init_child_log(log, rdev);
1434 }
1435 }
1436
1437 /* load and possibly recover the logs from the member disks */
1438 ret = ppl_load(ppl_conf);
1439
1440 if (ret) {
1441 goto err;
1442 } else if (!mddev->pers && mddev->recovery_cp == 0 &&
1443 ppl_conf->recovered_entries > 0 &&
1444 ppl_conf->mismatch_count == 0) {
1445 /*
1446 * If we are starting a dirty array and the recovery succeeds
1447 * without any issues, set the array as clean.
1448 */
1449 mddev->recovery_cp = MaxSector;
1450 set_bit(MD_SB_CHANGE_CLEAN, &mddev->sb_flags);
1451 } else if (mddev->pers && ppl_conf->mismatch_count > 0) {
1452 /* no mismatch allowed when enabling PPL for a running array */
1453 ret = -EINVAL;
1454 goto err;
1455 }
1456
1457 conf->log_private = ppl_conf;
1458 set_bit(MD_HAS_PPL, &ppl_conf->mddev->flags);
1459
1460 return 0;
1461 err:
1462 __ppl_exit_log(ppl_conf);
1463 return ret;
1464 }
1465
ppl_modify_log(struct r5conf * conf,struct md_rdev * rdev,bool add)1466 int ppl_modify_log(struct r5conf *conf, struct md_rdev *rdev, bool add)
1467 {
1468 struct ppl_conf *ppl_conf = conf->log_private;
1469 struct ppl_log *log;
1470 int ret = 0;
1471 char b[BDEVNAME_SIZE];
1472
1473 if (!rdev)
1474 return -EINVAL;
1475
1476 pr_debug("%s: disk: %d operation: %s dev: %s\n",
1477 __func__, rdev->raid_disk, add ? "add" : "remove",
1478 bdevname(rdev->bdev, b));
1479
1480 if (rdev->raid_disk < 0)
1481 return 0;
1482
1483 if (rdev->raid_disk >= ppl_conf->count)
1484 return -ENODEV;
1485
1486 log = &ppl_conf->child_logs[rdev->raid_disk];
1487
1488 mutex_lock(&log->io_mutex);
1489 if (add) {
1490 ret = ppl_validate_rdev(rdev);
1491 if (!ret) {
1492 log->rdev = rdev;
1493 ret = ppl_write_empty_header(log);
1494 ppl_init_child_log(log, rdev);
1495 }
1496 } else {
1497 log->rdev = NULL;
1498 }
1499 mutex_unlock(&log->io_mutex);
1500
1501 return ret;
1502 }
1503
1504 static ssize_t
ppl_write_hint_show(struct mddev * mddev,char * buf)1505 ppl_write_hint_show(struct mddev *mddev, char *buf)
1506 {
1507 size_t ret = 0;
1508 struct r5conf *conf;
1509 struct ppl_conf *ppl_conf = NULL;
1510
1511 spin_lock(&mddev->lock);
1512 conf = mddev->private;
1513 if (conf && raid5_has_ppl(conf))
1514 ppl_conf = conf->log_private;
1515 ret = sprintf(buf, "%d\n", ppl_conf ? ppl_conf->write_hint : 0);
1516 spin_unlock(&mddev->lock);
1517
1518 return ret;
1519 }
1520
1521 static ssize_t
ppl_write_hint_store(struct mddev * mddev,const char * page,size_t len)1522 ppl_write_hint_store(struct mddev *mddev, const char *page, size_t len)
1523 {
1524 struct r5conf *conf;
1525 struct ppl_conf *ppl_conf;
1526 int err = 0;
1527 unsigned short new;
1528
1529 if (len >= PAGE_SIZE)
1530 return -EINVAL;
1531 if (kstrtou16(page, 10, &new))
1532 return -EINVAL;
1533
1534 err = mddev_lock(mddev);
1535 if (err)
1536 return err;
1537
1538 conf = mddev->private;
1539 if (!conf) {
1540 err = -ENODEV;
1541 } else if (raid5_has_ppl(conf)) {
1542 ppl_conf = conf->log_private;
1543 if (!ppl_conf)
1544 err = -EINVAL;
1545 else
1546 ppl_conf->write_hint = new;
1547 } else {
1548 err = -EINVAL;
1549 }
1550
1551 mddev_unlock(mddev);
1552
1553 return err ?: len;
1554 }
1555
1556 struct md_sysfs_entry
1557 ppl_write_hint = __ATTR(ppl_write_hint, S_IRUGO | S_IWUSR,
1558 ppl_write_hint_show,
1559 ppl_write_hint_store);
1560