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