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dm persistent data: use DMERR_LIMIT for errors
[~shefty/rdma-dev.git] / drivers / md / persistent-data / dm-space-map-common.c
1 /*
2  * Copyright (C) 2011 Red Hat, Inc.
3  *
4  * This file is released under the GPL.
5  */
6
7 #include "dm-space-map-common.h"
8 #include "dm-transaction-manager.h"
9
10 #include <linux/bitops.h>
11 #include <linux/device-mapper.h>
12
13 #define DM_MSG_PREFIX "space map common"
14
15 /*----------------------------------------------------------------*/
16
17 /*
18  * Index validator.
19  */
20 #define INDEX_CSUM_XOR 160478
21
22 static void index_prepare_for_write(struct dm_block_validator *v,
23                                     struct dm_block *b,
24                                     size_t block_size)
25 {
26         struct disk_metadata_index *mi_le = dm_block_data(b);
27
28         mi_le->blocknr = cpu_to_le64(dm_block_location(b));
29         mi_le->csum = cpu_to_le32(dm_bm_checksum(&mi_le->padding,
30                                                  block_size - sizeof(__le32),
31                                                  INDEX_CSUM_XOR));
32 }
33
34 static int index_check(struct dm_block_validator *v,
35                        struct dm_block *b,
36                        size_t block_size)
37 {
38         struct disk_metadata_index *mi_le = dm_block_data(b);
39         __le32 csum_disk;
40
41         if (dm_block_location(b) != le64_to_cpu(mi_le->blocknr)) {
42                 DMERR_LIMIT("index_check failed: blocknr %llu != wanted %llu",
43                             le64_to_cpu(mi_le->blocknr), dm_block_location(b));
44                 return -ENOTBLK;
45         }
46
47         csum_disk = cpu_to_le32(dm_bm_checksum(&mi_le->padding,
48                                                block_size - sizeof(__le32),
49                                                INDEX_CSUM_XOR));
50         if (csum_disk != mi_le->csum) {
51                 DMERR_LIMIT("index_check failed: csum %u != wanted %u",
52                             le32_to_cpu(csum_disk), le32_to_cpu(mi_le->csum));
53                 return -EILSEQ;
54         }
55
56         return 0;
57 }
58
59 static struct dm_block_validator index_validator = {
60         .name = "index",
61         .prepare_for_write = index_prepare_for_write,
62         .check = index_check
63 };
64
65 /*----------------------------------------------------------------*/
66
67 /*
68  * Bitmap validator
69  */
70 #define BITMAP_CSUM_XOR 240779
71
72 static void bitmap_prepare_for_write(struct dm_block_validator *v,
73                                      struct dm_block *b,
74                                      size_t block_size)
75 {
76         struct disk_bitmap_header *disk_header = dm_block_data(b);
77
78         disk_header->blocknr = cpu_to_le64(dm_block_location(b));
79         disk_header->csum = cpu_to_le32(dm_bm_checksum(&disk_header->not_used,
80                                                        block_size - sizeof(__le32),
81                                                        BITMAP_CSUM_XOR));
82 }
83
84 static int bitmap_check(struct dm_block_validator *v,
85                         struct dm_block *b,
86                         size_t block_size)
87 {
88         struct disk_bitmap_header *disk_header = dm_block_data(b);
89         __le32 csum_disk;
90
91         if (dm_block_location(b) != le64_to_cpu(disk_header->blocknr)) {
92                 DMERR_LIMIT("bitmap check failed: blocknr %llu != wanted %llu",
93                             le64_to_cpu(disk_header->blocknr), dm_block_location(b));
94                 return -ENOTBLK;
95         }
96
97         csum_disk = cpu_to_le32(dm_bm_checksum(&disk_header->not_used,
98                                                block_size - sizeof(__le32),
99                                                BITMAP_CSUM_XOR));
100         if (csum_disk != disk_header->csum) {
101                 DMERR_LIMIT("bitmap check failed: csum %u != wanted %u",
102                             le32_to_cpu(csum_disk), le32_to_cpu(disk_header->csum));
103                 return -EILSEQ;
104         }
105
106         return 0;
107 }
108
109 static struct dm_block_validator dm_sm_bitmap_validator = {
110         .name = "sm_bitmap",
111         .prepare_for_write = bitmap_prepare_for_write,
112         .check = bitmap_check
113 };
114
115 /*----------------------------------------------------------------*/
116
117 #define ENTRIES_PER_WORD 32
118 #define ENTRIES_SHIFT   5
119
120 static void *dm_bitmap_data(struct dm_block *b)
121 {
122         return dm_block_data(b) + sizeof(struct disk_bitmap_header);
123 }
124
125 #define WORD_MASK_HIGH 0xAAAAAAAAAAAAAAAAULL
126
127 static unsigned bitmap_word_used(void *addr, unsigned b)
128 {
129         __le64 *words_le = addr;
130         __le64 *w_le = words_le + (b >> ENTRIES_SHIFT);
131
132         uint64_t bits = le64_to_cpu(*w_le);
133         uint64_t mask = (bits + WORD_MASK_HIGH + 1) & WORD_MASK_HIGH;
134
135         return !(~bits & mask);
136 }
137
138 static unsigned sm_lookup_bitmap(void *addr, unsigned b)
139 {
140         __le64 *words_le = addr;
141         __le64 *w_le = words_le + (b >> ENTRIES_SHIFT);
142         unsigned hi, lo;
143
144         b = (b & (ENTRIES_PER_WORD - 1)) << 1;
145         hi = !!test_bit_le(b, (void *) w_le);
146         lo = !!test_bit_le(b + 1, (void *) w_le);
147         return (hi << 1) | lo;
148 }
149
150 static void sm_set_bitmap(void *addr, unsigned b, unsigned val)
151 {
152         __le64 *words_le = addr;
153         __le64 *w_le = words_le + (b >> ENTRIES_SHIFT);
154
155         b = (b & (ENTRIES_PER_WORD - 1)) << 1;
156
157         if (val & 2)
158                 __set_bit_le(b, (void *) w_le);
159         else
160                 __clear_bit_le(b, (void *) w_le);
161
162         if (val & 1)
163                 __set_bit_le(b + 1, (void *) w_le);
164         else
165                 __clear_bit_le(b + 1, (void *) w_le);
166 }
167
168 static int sm_find_free(void *addr, unsigned begin, unsigned end,
169                         unsigned *result)
170 {
171         while (begin < end) {
172                 if (!(begin & (ENTRIES_PER_WORD - 1)) &&
173                     bitmap_word_used(addr, begin)) {
174                         begin += ENTRIES_PER_WORD;
175                         continue;
176                 }
177
178                 if (!sm_lookup_bitmap(addr, begin)) {
179                         *result = begin;
180                         return 0;
181                 }
182
183                 begin++;
184         }
185
186         return -ENOSPC;
187 }
188
189 /*----------------------------------------------------------------*/
190
191 static int sm_ll_init(struct ll_disk *ll, struct dm_transaction_manager *tm)
192 {
193         ll->tm = tm;
194
195         ll->bitmap_info.tm = tm;
196         ll->bitmap_info.levels = 1;
197
198         /*
199          * Because the new bitmap blocks are created via a shadow
200          * operation, the old entry has already had its reference count
201          * decremented and we don't need the btree to do any bookkeeping.
202          */
203         ll->bitmap_info.value_type.size = sizeof(struct disk_index_entry);
204         ll->bitmap_info.value_type.inc = NULL;
205         ll->bitmap_info.value_type.dec = NULL;
206         ll->bitmap_info.value_type.equal = NULL;
207
208         ll->ref_count_info.tm = tm;
209         ll->ref_count_info.levels = 1;
210         ll->ref_count_info.value_type.size = sizeof(uint32_t);
211         ll->ref_count_info.value_type.inc = NULL;
212         ll->ref_count_info.value_type.dec = NULL;
213         ll->ref_count_info.value_type.equal = NULL;
214
215         ll->block_size = dm_bm_block_size(dm_tm_get_bm(tm));
216
217         if (ll->block_size > (1 << 30)) {
218                 DMERR("block size too big to hold bitmaps");
219                 return -EINVAL;
220         }
221
222         ll->entries_per_block = (ll->block_size - sizeof(struct disk_bitmap_header)) *
223                 ENTRIES_PER_BYTE;
224         ll->nr_blocks = 0;
225         ll->bitmap_root = 0;
226         ll->ref_count_root = 0;
227         ll->bitmap_index_changed = false;
228
229         return 0;
230 }
231
232 int sm_ll_extend(struct ll_disk *ll, dm_block_t extra_blocks)
233 {
234         int r;
235         dm_block_t i, nr_blocks, nr_indexes;
236         unsigned old_blocks, blocks;
237
238         nr_blocks = ll->nr_blocks + extra_blocks;
239         old_blocks = dm_sector_div_up(ll->nr_blocks, ll->entries_per_block);
240         blocks = dm_sector_div_up(nr_blocks, ll->entries_per_block);
241
242         nr_indexes = dm_sector_div_up(nr_blocks, ll->entries_per_block);
243         if (nr_indexes > ll->max_entries(ll)) {
244                 DMERR("space map too large");
245                 return -EINVAL;
246         }
247
248         for (i = old_blocks; i < blocks; i++) {
249                 struct dm_block *b;
250                 struct disk_index_entry idx;
251
252                 r = dm_tm_new_block(ll->tm, &dm_sm_bitmap_validator, &b);
253                 if (r < 0)
254                         return r;
255                 idx.blocknr = cpu_to_le64(dm_block_location(b));
256
257                 r = dm_tm_unlock(ll->tm, b);
258                 if (r < 0)
259                         return r;
260
261                 idx.nr_free = cpu_to_le32(ll->entries_per_block);
262                 idx.none_free_before = 0;
263
264                 r = ll->save_ie(ll, i, &idx);
265                 if (r < 0)
266                         return r;
267         }
268
269         ll->nr_blocks = nr_blocks;
270         return 0;
271 }
272
273 int sm_ll_lookup_bitmap(struct ll_disk *ll, dm_block_t b, uint32_t *result)
274 {
275         int r;
276         dm_block_t index = b;
277         struct disk_index_entry ie_disk;
278         struct dm_block *blk;
279
280         b = do_div(index, ll->entries_per_block);
281         r = ll->load_ie(ll, index, &ie_disk);
282         if (r < 0)
283                 return r;
284
285         r = dm_tm_read_lock(ll->tm, le64_to_cpu(ie_disk.blocknr),
286                             &dm_sm_bitmap_validator, &blk);
287         if (r < 0)
288                 return r;
289
290         *result = sm_lookup_bitmap(dm_bitmap_data(blk), b);
291
292         return dm_tm_unlock(ll->tm, blk);
293 }
294
295 int sm_ll_lookup(struct ll_disk *ll, dm_block_t b, uint32_t *result)
296 {
297         __le32 le_rc;
298         int r = sm_ll_lookup_bitmap(ll, b, result);
299
300         if (r)
301                 return r;
302
303         if (*result != 3)
304                 return r;
305
306         r = dm_btree_lookup(&ll->ref_count_info, ll->ref_count_root, &b, &le_rc);
307         if (r < 0)
308                 return r;
309
310         *result = le32_to_cpu(le_rc);
311
312         return r;
313 }
314
315 int sm_ll_find_free_block(struct ll_disk *ll, dm_block_t begin,
316                           dm_block_t end, dm_block_t *result)
317 {
318         int r;
319         struct disk_index_entry ie_disk;
320         dm_block_t i, index_begin = begin;
321         dm_block_t index_end = dm_sector_div_up(end, ll->entries_per_block);
322
323         /*
324          * FIXME: Use shifts
325          */
326         begin = do_div(index_begin, ll->entries_per_block);
327         end = do_div(end, ll->entries_per_block);
328
329         for (i = index_begin; i < index_end; i++, begin = 0) {
330                 struct dm_block *blk;
331                 unsigned position;
332                 uint32_t bit_end;
333
334                 r = ll->load_ie(ll, i, &ie_disk);
335                 if (r < 0)
336                         return r;
337
338                 if (le32_to_cpu(ie_disk.nr_free) == 0)
339                         continue;
340
341                 r = dm_tm_read_lock(ll->tm, le64_to_cpu(ie_disk.blocknr),
342                                     &dm_sm_bitmap_validator, &blk);
343                 if (r < 0)
344                         return r;
345
346                 bit_end = (i == index_end - 1) ?  end : ll->entries_per_block;
347
348                 r = sm_find_free(dm_bitmap_data(blk),
349                                  max_t(unsigned, begin, le32_to_cpu(ie_disk.none_free_before)),
350                                  bit_end, &position);
351                 if (r == -ENOSPC) {
352                         /*
353                          * This might happen because we started searching
354                          * part way through the bitmap.
355                          */
356                         dm_tm_unlock(ll->tm, blk);
357                         continue;
358
359                 } else if (r < 0) {
360                         dm_tm_unlock(ll->tm, blk);
361                         return r;
362                 }
363
364                 r = dm_tm_unlock(ll->tm, blk);
365                 if (r < 0)
366                         return r;
367
368                 *result = i * ll->entries_per_block + (dm_block_t) position;
369                 return 0;
370         }
371
372         return -ENOSPC;
373 }
374
375 int sm_ll_insert(struct ll_disk *ll, dm_block_t b,
376                  uint32_t ref_count, enum allocation_event *ev)
377 {
378         int r;
379         uint32_t bit, old;
380         struct dm_block *nb;
381         dm_block_t index = b;
382         struct disk_index_entry ie_disk;
383         void *bm_le;
384         int inc;
385
386         bit = do_div(index, ll->entries_per_block);
387         r = ll->load_ie(ll, index, &ie_disk);
388         if (r < 0)
389                 return r;
390
391         r = dm_tm_shadow_block(ll->tm, le64_to_cpu(ie_disk.blocknr),
392                                &dm_sm_bitmap_validator, &nb, &inc);
393         if (r < 0) {
394                 DMERR("dm_tm_shadow_block() failed");
395                 return r;
396         }
397         ie_disk.blocknr = cpu_to_le64(dm_block_location(nb));
398
399         bm_le = dm_bitmap_data(nb);
400         old = sm_lookup_bitmap(bm_le, bit);
401
402         if (ref_count <= 2) {
403                 sm_set_bitmap(bm_le, bit, ref_count);
404
405                 r = dm_tm_unlock(ll->tm, nb);
406                 if (r < 0)
407                         return r;
408
409                 if (old > 2) {
410                         r = dm_btree_remove(&ll->ref_count_info,
411                                             ll->ref_count_root,
412                                             &b, &ll->ref_count_root);
413                         if (r)
414                                 return r;
415                 }
416
417         } else {
418                 __le32 le_rc = cpu_to_le32(ref_count);
419
420                 sm_set_bitmap(bm_le, bit, 3);
421                 r = dm_tm_unlock(ll->tm, nb);
422                 if (r < 0)
423                         return r;
424
425                 __dm_bless_for_disk(&le_rc);
426                 r = dm_btree_insert(&ll->ref_count_info, ll->ref_count_root,
427                                     &b, &le_rc, &ll->ref_count_root);
428                 if (r < 0) {
429                         DMERR("ref count insert failed");
430                         return r;
431                 }
432         }
433
434         if (ref_count && !old) {
435                 *ev = SM_ALLOC;
436                 ll->nr_allocated++;
437                 le32_add_cpu(&ie_disk.nr_free, -1);
438                 if (le32_to_cpu(ie_disk.none_free_before) == bit)
439                         ie_disk.none_free_before = cpu_to_le32(bit + 1);
440
441         } else if (old && !ref_count) {
442                 *ev = SM_FREE;
443                 ll->nr_allocated--;
444                 le32_add_cpu(&ie_disk.nr_free, 1);
445                 ie_disk.none_free_before = cpu_to_le32(min(le32_to_cpu(ie_disk.none_free_before), bit));
446         }
447
448         return ll->save_ie(ll, index, &ie_disk);
449 }
450
451 int sm_ll_inc(struct ll_disk *ll, dm_block_t b, enum allocation_event *ev)
452 {
453         int r;
454         uint32_t rc;
455
456         r = sm_ll_lookup(ll, b, &rc);
457         if (r)
458                 return r;
459
460         return sm_ll_insert(ll, b, rc + 1, ev);
461 }
462
463 int sm_ll_dec(struct ll_disk *ll, dm_block_t b, enum allocation_event *ev)
464 {
465         int r;
466         uint32_t rc;
467
468         r = sm_ll_lookup(ll, b, &rc);
469         if (r)
470                 return r;
471
472         if (!rc)
473                 return -EINVAL;
474
475         return sm_ll_insert(ll, b, rc - 1, ev);
476 }
477
478 int sm_ll_commit(struct ll_disk *ll)
479 {
480         int r = 0;
481
482         if (ll->bitmap_index_changed) {
483                 r = ll->commit(ll);
484                 if (!r)
485                         ll->bitmap_index_changed = false;
486         }
487
488         return r;
489 }
490
491 /*----------------------------------------------------------------*/
492
493 static int metadata_ll_load_ie(struct ll_disk *ll, dm_block_t index,
494                                struct disk_index_entry *ie)
495 {
496         memcpy(ie, ll->mi_le.index + index, sizeof(*ie));
497         return 0;
498 }
499
500 static int metadata_ll_save_ie(struct ll_disk *ll, dm_block_t index,
501                                struct disk_index_entry *ie)
502 {
503         ll->bitmap_index_changed = true;
504         memcpy(ll->mi_le.index + index, ie, sizeof(*ie));
505         return 0;
506 }
507
508 static int metadata_ll_init_index(struct ll_disk *ll)
509 {
510         int r;
511         struct dm_block *b;
512
513         r = dm_tm_new_block(ll->tm, &index_validator, &b);
514         if (r < 0)
515                 return r;
516
517         memcpy(dm_block_data(b), &ll->mi_le, sizeof(ll->mi_le));
518         ll->bitmap_root = dm_block_location(b);
519
520         return dm_tm_unlock(ll->tm, b);
521 }
522
523 static int metadata_ll_open(struct ll_disk *ll)
524 {
525         int r;
526         struct dm_block *block;
527
528         r = dm_tm_read_lock(ll->tm, ll->bitmap_root,
529                             &index_validator, &block);
530         if (r)
531                 return r;
532
533         memcpy(&ll->mi_le, dm_block_data(block), sizeof(ll->mi_le));
534         return dm_tm_unlock(ll->tm, block);
535 }
536
537 static dm_block_t metadata_ll_max_entries(struct ll_disk *ll)
538 {
539         return MAX_METADATA_BITMAPS;
540 }
541
542 static int metadata_ll_commit(struct ll_disk *ll)
543 {
544         int r, inc;
545         struct dm_block *b;
546
547         r = dm_tm_shadow_block(ll->tm, ll->bitmap_root, &index_validator, &b, &inc);
548         if (r)
549                 return r;
550
551         memcpy(dm_block_data(b), &ll->mi_le, sizeof(ll->mi_le));
552         ll->bitmap_root = dm_block_location(b);
553
554         return dm_tm_unlock(ll->tm, b);
555 }
556
557 int sm_ll_new_metadata(struct ll_disk *ll, struct dm_transaction_manager *tm)
558 {
559         int r;
560
561         r = sm_ll_init(ll, tm);
562         if (r < 0)
563                 return r;
564
565         ll->load_ie = metadata_ll_load_ie;
566         ll->save_ie = metadata_ll_save_ie;
567         ll->init_index = metadata_ll_init_index;
568         ll->open_index = metadata_ll_open;
569         ll->max_entries = metadata_ll_max_entries;
570         ll->commit = metadata_ll_commit;
571
572         ll->nr_blocks = 0;
573         ll->nr_allocated = 0;
574
575         r = ll->init_index(ll);
576         if (r < 0)
577                 return r;
578
579         r = dm_btree_empty(&ll->ref_count_info, &ll->ref_count_root);
580         if (r < 0)
581                 return r;
582
583         return 0;
584 }
585
586 int sm_ll_open_metadata(struct ll_disk *ll, struct dm_transaction_manager *tm,
587                         void *root_le, size_t len)
588 {
589         int r;
590         struct disk_sm_root *smr = root_le;
591
592         if (len < sizeof(struct disk_sm_root)) {
593                 DMERR("sm_metadata root too small");
594                 return -ENOMEM;
595         }
596
597         r = sm_ll_init(ll, tm);
598         if (r < 0)
599                 return r;
600
601         ll->load_ie = metadata_ll_load_ie;
602         ll->save_ie = metadata_ll_save_ie;
603         ll->init_index = metadata_ll_init_index;
604         ll->open_index = metadata_ll_open;
605         ll->max_entries = metadata_ll_max_entries;
606         ll->commit = metadata_ll_commit;
607
608         ll->nr_blocks = le64_to_cpu(smr->nr_blocks);
609         ll->nr_allocated = le64_to_cpu(smr->nr_allocated);
610         ll->bitmap_root = le64_to_cpu(smr->bitmap_root);
611         ll->ref_count_root = le64_to_cpu(smr->ref_count_root);
612
613         return ll->open_index(ll);
614 }
615
616 /*----------------------------------------------------------------*/
617
618 static int disk_ll_load_ie(struct ll_disk *ll, dm_block_t index,
619                            struct disk_index_entry *ie)
620 {
621         return dm_btree_lookup(&ll->bitmap_info, ll->bitmap_root, &index, ie);
622 }
623
624 static int disk_ll_save_ie(struct ll_disk *ll, dm_block_t index,
625                            struct disk_index_entry *ie)
626 {
627         __dm_bless_for_disk(ie);
628         return dm_btree_insert(&ll->bitmap_info, ll->bitmap_root,
629                                &index, ie, &ll->bitmap_root);
630 }
631
632 static int disk_ll_init_index(struct ll_disk *ll)
633 {
634         return dm_btree_empty(&ll->bitmap_info, &ll->bitmap_root);
635 }
636
637 static int disk_ll_open(struct ll_disk *ll)
638 {
639         /* nothing to do */
640         return 0;
641 }
642
643 static dm_block_t disk_ll_max_entries(struct ll_disk *ll)
644 {
645         return -1ULL;
646 }
647
648 static int disk_ll_commit(struct ll_disk *ll)
649 {
650         return 0;
651 }
652
653 int sm_ll_new_disk(struct ll_disk *ll, struct dm_transaction_manager *tm)
654 {
655         int r;
656
657         r = sm_ll_init(ll, tm);
658         if (r < 0)
659                 return r;
660
661         ll->load_ie = disk_ll_load_ie;
662         ll->save_ie = disk_ll_save_ie;
663         ll->init_index = disk_ll_init_index;
664         ll->open_index = disk_ll_open;
665         ll->max_entries = disk_ll_max_entries;
666         ll->commit = disk_ll_commit;
667
668         ll->nr_blocks = 0;
669         ll->nr_allocated = 0;
670
671         r = ll->init_index(ll);
672         if (r < 0)
673                 return r;
674
675         r = dm_btree_empty(&ll->ref_count_info, &ll->ref_count_root);
676         if (r < 0)
677                 return r;
678
679         return 0;
680 }
681
682 int sm_ll_open_disk(struct ll_disk *ll, struct dm_transaction_manager *tm,
683                     void *root_le, size_t len)
684 {
685         int r;
686         struct disk_sm_root *smr = root_le;
687
688         if (len < sizeof(struct disk_sm_root)) {
689                 DMERR("sm_metadata root too small");
690                 return -ENOMEM;
691         }
692
693         r = sm_ll_init(ll, tm);
694         if (r < 0)
695                 return r;
696
697         ll->load_ie = disk_ll_load_ie;
698         ll->save_ie = disk_ll_save_ie;
699         ll->init_index = disk_ll_init_index;
700         ll->open_index = disk_ll_open;
701         ll->max_entries = disk_ll_max_entries;
702         ll->commit = disk_ll_commit;
703
704         ll->nr_blocks = le64_to_cpu(smr->nr_blocks);
705         ll->nr_allocated = le64_to_cpu(smr->nr_allocated);
706         ll->bitmap_root = le64_to_cpu(smr->bitmap_root);
707         ll->ref_count_root = le64_to_cpu(smr->ref_count_root);
708
709         return ll->open_index(ll);
710 }
711
712 /*----------------------------------------------------------------*/