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[LogFS] Silence gcc
[linux-2.6-block.git] / fs / logfs / journal.c
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5db53f3e
JE		 1/*
2 * fs/logfs/journal.c - journal handling code
3 *
4 * As should be obvious for Linux kernel code, license is GPLv2
5 *
6 * Copyright (c) 2005-2008 Joern Engel <joern@logfs.org>
7 */
8#include "logfs.h"
9
10static void logfs_calc_free(struct super_block *sb)
11{
12 struct logfs_super *super = logfs_super(sb);
13 u64 reserve, no_segs = super->s_no_segs;
14 s64 free;
15 int i;
16
17 /* superblock segments */
18 no_segs -= 2;
19 super->s_no_journal_segs = 0;
20 /* journal */
21 journal_for_each(i)
22 if (super->s_journal_seg[i]) {
23 no_segs--;
24 super->s_no_journal_segs++;
25 }
26
27 /* open segments plus one extra per level for GC */
28 no_segs -= 2 * super->s_total_levels;
29
30 free = no_segs * (super->s_segsize - LOGFS_SEGMENT_RESERVE);
31 free -= super->s_used_bytes;
32 /* just a bit extra */
33 free -= super->s_total_levels * 4096;
34
35 /* Bad blocks are 'paid' for with speed reserve - the filesystem
36 * simply gets slower as bad blocks accumulate. Until the bad blocks
37 * exceed the speed reserve - then the filesystem gets smaller.
38 */
39 reserve = super->s_bad_segments + super->s_bad_seg_reserve;
40 reserve *= super->s_segsize - LOGFS_SEGMENT_RESERVE;
41 reserve = max(reserve, super->s_speed_reserve);
42 free -= reserve;
43 if (free < 0)
44 free = 0;
45
46 super->s_free_bytes = free;
47}
48
49static void reserve_sb_and_journal(struct super_block *sb)
50{
51 struct logfs_super *super = logfs_super(sb);
52 struct btree_head32 *head = &super->s_reserved_segments;
53 int i, err;
54
55 err = btree_insert32(head, seg_no(sb, super->s_sb_ofs[0]), (void *)1,
56 GFP_KERNEL);
57 BUG_ON(err);
58
59 err = btree_insert32(head, seg_no(sb, super->s_sb_ofs[1]), (void *)1,
60 GFP_KERNEL);
61 BUG_ON(err);
62
63 journal_for_each(i) {
64 if (!super->s_journal_seg[i])
65 continue;
66 err = btree_insert32(head, super->s_journal_seg[i], (void *)1,
67 GFP_KERNEL);
68 BUG_ON(err);
69 }
70}
71
72static void read_dynsb(struct super_block *sb,
73 struct logfs_je_dynsb *dynsb)
74{
75 struct logfs_super *super = logfs_super(sb);
76
77 super->s_gec = be64_to_cpu(dynsb->ds_gec);
78 super->s_sweeper = be64_to_cpu(dynsb->ds_sweeper);
79 super->s_victim_ino = be64_to_cpu(dynsb->ds_victim_ino);
80 super->s_rename_dir = be64_to_cpu(dynsb->ds_rename_dir);
81 super->s_rename_pos = be64_to_cpu(dynsb->ds_rename_pos);
82 super->s_used_bytes = be64_to_cpu(dynsb->ds_used_bytes);
83 super->s_generation = be32_to_cpu(dynsb->ds_generation);
84}
85
86static void read_anchor(struct super_block *sb,
87 struct logfs_je_anchor *da)
88{
89 struct logfs_super *super = logfs_super(sb);
90 struct inode *inode = super->s_master_inode;
91 struct logfs_inode *li = logfs_inode(inode);
92 int i;
93
94 super->s_last_ino = be64_to_cpu(da->da_last_ino);
95 li->li_flags = 0;
96 li->li_height = da->da_height;
97 i_size_write(inode, be64_to_cpu(da->da_size));
98 li->li_used_bytes = be64_to_cpu(da->da_used_bytes);
99
100 for (i = 0; i < LOGFS_EMBEDDED_FIELDS; i++)
101 li->li_data[i] = be64_to_cpu(da->da_data[i]);
102}
103
104static void read_erasecount(struct super_block *sb,
105 struct logfs_je_journal_ec *ec)
106{
107 struct logfs_super *super = logfs_super(sb);
108 int i;
109
110 journal_for_each(i)
111 super->s_journal_ec[i] = be32_to_cpu(ec->ec[i]);
112}
113
114static int read_area(struct super_block *sb, struct logfs_je_area *a)
115{
116 struct logfs_super *super = logfs_super(sb);
117 struct logfs_area *area = super->s_area[a->gc_level];
118 u64 ofs;
119 u32 writemask = ~(super->s_writesize - 1);
120
121 if (a->gc_level >= LOGFS_NO_AREAS)
122 return -EIO;
123 if (a->vim != VIM_DEFAULT)
124 return -EIO; /* TODO: close area and continue */
125
126 area->a_used_bytes = be32_to_cpu(a->used_bytes);
127 area->a_written_bytes = area->a_used_bytes & writemask;
128 area->a_segno = be32_to_cpu(a->segno);
129 if (area->a_segno)
130 area->a_is_open = 1;
131
132 ofs = dev_ofs(sb, area->a_segno, area->a_written_bytes);
133 if (super->s_writesize > 1)
134 logfs_buf_recover(area, ofs, a + 1, super->s_writesize);
135 else
136 logfs_buf_recover(area, ofs, NULL, 0);
137 return 0;
138}
139
140static void *unpack(void *from, void *to)
141{
142 struct logfs_journal_header *jh = from;
143 void *data = from + sizeof(struct logfs_journal_header);
144 int err;
145 size_t inlen, outlen;
146
147 inlen = be16_to_cpu(jh->h_len);
148 outlen = be16_to_cpu(jh->h_datalen);
149
150 if (jh->h_compr == COMPR_NONE)
151 memcpy(to, data, inlen);
152 else {
153 err = logfs_uncompress(data, to, inlen, outlen);
154 BUG_ON(err);
155 }
156 return to;
157}
158
159static int __read_je_header(struct super_block *sb, u64 ofs,
160 struct logfs_journal_header *jh)
161{
162 struct logfs_super *super = logfs_super(sb);
163 size_t bufsize = max_t(size_t, sb->s_blocksize, super->s_writesize)
164 + MAX_JOURNAL_HEADER;
165 u16 type, len, datalen;
166 int err;
167
168 /* read header only */
169 err = wbuf_read(sb, ofs, sizeof(*jh), jh);
170 if (err)
171 return err;
172 type = be16_to_cpu(jh->h_type);
173 len = be16_to_cpu(jh->h_len);
174 datalen = be16_to_cpu(jh->h_datalen);
175 if (len > sb->s_blocksize)
176 return -EIO;
177 if ((type < JE_FIRST) || (type > JE_LAST))
178 return -EIO;
179 if (datalen > bufsize)
180 return -EIO;
181 return 0;
182}
183
184static int __read_je_payload(struct super_block *sb, u64 ofs,
185 struct logfs_journal_header *jh)
186{
187 u16 len;
188 int err;
189
190 len = be16_to_cpu(jh->h_len);
191 err = wbuf_read(sb, ofs + sizeof(*jh), len, jh + 1);
192 if (err)
193 return err;
194 if (jh->h_crc != logfs_crc32(jh, len + sizeof(*jh), 4)) {
195 /* Old code was confused. It forgot about the header length
196 * and stopped calculating the crc 16 bytes before the end
197 * of data - ick!
198 * FIXME: Remove this hack once the old code is fixed.
199 */
200 if (jh->h_crc == logfs_crc32(jh, len, 4))
201 WARN_ON_ONCE(1);
202 else
203 return -EIO;
204 }
205 return 0;
206}
207
208/*
209 * jh needs to be large enough to hold the complete entry, not just the header
210 */
211static int __read_je(struct super_block *sb, u64 ofs,
212 struct logfs_journal_header *jh)
213{
214 int err;
215
216 err = __read_je_header(sb, ofs, jh);
217 if (err)
218 return err;
219 return __read_je_payload(sb, ofs, jh);
220}
221
222static int read_je(struct super_block *sb, u64 ofs)
223{
224 struct logfs_super *super = logfs_super(sb);
225 struct logfs_journal_header *jh = super->s_compressed_je;
226 void *scratch = super->s_je;
227 u16 type, datalen;
228 int err;
229
230 err = __read_je(sb, ofs, jh);
231 if (err)
232 return err;
233 type = be16_to_cpu(jh->h_type);
234 datalen = be16_to_cpu(jh->h_datalen);
235
236 switch (type) {
237 case JE_DYNSB:
238 read_dynsb(sb, unpack(jh, scratch));
239 break;
240 case JE_ANCHOR:
241 read_anchor(sb, unpack(jh, scratch));
242 break;
243 case JE_ERASECOUNT:
244 read_erasecount(sb, unpack(jh, scratch));
245 break;
246 case JE_AREA:
247 read_area(sb, unpack(jh, scratch));
248 break;
249 case JE_OBJ_ALIAS:
250 err = logfs_load_object_aliases(sb, unpack(jh, scratch),
251 datalen);
252 break;
253 default:
254 WARN_ON_ONCE(1);
255 return -EIO;
256 }
257 return err;
258}
259
260static int logfs_read_segment(struct super_block *sb, u32 segno)
261{
262 struct logfs_super *super = logfs_super(sb);
263 struct logfs_journal_header *jh = super->s_compressed_je;
264 u64 ofs, seg_ofs = dev_ofs(sb, segno, 0);
265 u32 h_ofs, last_ofs = 0;
5c564c2a 266 u16 len, datalen, last_len = 0;
5db53f3e
JE		 267 int i, err;
268
269 /* search for most recent commit */
270 for (h_ofs = 0; h_ofs < super->s_segsize; h_ofs += sizeof(*jh)) {
271 ofs = seg_ofs + h_ofs;
272 err = __read_je_header(sb, ofs, jh);
273 if (err)
274 continue;
275 if (jh->h_type != cpu_to_be16(JE_COMMIT))
276 continue;
277 err = __read_je_payload(sb, ofs, jh);
278 if (err)
279 continue;
280 len = be16_to_cpu(jh->h_len);
281 datalen = be16_to_cpu(jh->h_datalen);
282 if ((datalen > sizeof(super->s_je_array)) ||
283 (datalen % sizeof(__be64)))
284 continue;
285 last_ofs = h_ofs;
286 last_len = datalen;
287 h_ofs += ALIGN(len, sizeof(*jh)) - sizeof(*jh);
288 }
289 /* read commit */
290 if (last_ofs == 0)
291 return -ENOENT;
292 ofs = seg_ofs + last_ofs;
293 log_journal("Read commit from %llx\n", ofs);
294 err = __read_je(sb, ofs, jh);
295 BUG_ON(err); /* We should have caught it in the scan loop already */
296 if (err)
297 return err;
298 /* uncompress */
299 unpack(jh, super->s_je_array);
300 super->s_no_je = last_len / sizeof(__be64);
301 /* iterate over array */
302 for (i = 0; i < super->s_no_je; i++) {
303 err = read_je(sb, be64_to_cpu(super->s_je_array[i]));
304 if (err)
305 return err;
306 }
307 super->s_journal_area->a_segno = segno;
308 return 0;
309}
310
311static u64 read_gec(struct super_block *sb, u32 segno)
312{
313 struct logfs_segment_header sh;
314 __be32 crc;
315 int err;
316
317 if (!segno)
318 return 0;
319 err = wbuf_read(sb, dev_ofs(sb, segno, 0), sizeof(sh), &sh);
320 if (err)
321 return 0;
322 crc = logfs_crc32(&sh, sizeof(sh), 4);
323 if (crc != sh.crc) {
324 WARN_ON(sh.gec != cpu_to_be64(0xffffffffffffffffull));
325 /* Most likely it was just erased */
326 return 0;
327 }
328 return be64_to_cpu(sh.gec);
329}
330
331static int logfs_read_journal(struct super_block *sb)
332{
333 struct logfs_super *super = logfs_super(sb);
334 u64 gec[LOGFS_JOURNAL_SEGS], max;
335 u32 segno;
336 int i, max_i;
337
338 max = 0;
339 max_i = -1;
340 journal_for_each(i) {
341 segno = super->s_journal_seg[i];
342 gec[i] = read_gec(sb, super->s_journal_seg[i]);
343 if (gec[i] > max) {
344 max = gec[i];
345 max_i = i;
346 }
347 }
348 if (max_i == -1)
349 return -EIO;
350 /* FIXME: Try older segments in case of error */
351 return logfs_read_segment(sb, super->s_journal_seg[max_i]);
352}
353
354/*
355 * First search the current segment (outer loop), then pick the next segment
356 * in the array, skipping any zero entries (inner loop).
357 */
358static void journal_get_free_segment(struct logfs_area *area)
359{
360 struct logfs_super *super = logfs_super(area->a_sb);
361 int i;
362
363 journal_for_each(i) {
364 if (area->a_segno != super->s_journal_seg[i])
365 continue;
366
367 do {
368 i++;
369 if (i == LOGFS_JOURNAL_SEGS)
370 i = 0;
371 } while (!super->s_journal_seg[i]);
372
373 area->a_segno = super->s_journal_seg[i];
374 area->a_erase_count = ++(super->s_journal_ec[i]);
375 log_journal("Journal now at %x (ec %x)\n", area->a_segno,
376 area->a_erase_count);
377 return;
378 }
379 BUG();
380}
381
382static void journal_get_erase_count(struct logfs_area *area)
383{
384 /* erase count is stored globally and incremented in
385 * journal_get_free_segment() - nothing to do here */
386}
387
388static int journal_erase_segment(struct logfs_area *area)
389{
390 struct super_block *sb = area->a_sb;
391 struct logfs_segment_header sh;
392 u64 ofs;
393 int err;
394
395 err = logfs_erase_segment(sb, area->a_segno);
396 if (err)
397 return err;
398
399 sh.pad = 0;
400 sh.type = SEG_JOURNAL;
401 sh.level = 0;
402 sh.segno = cpu_to_be32(area->a_segno);
403 sh.ec = cpu_to_be32(area->a_erase_count);
404 sh.gec = cpu_to_be64(logfs_super(sb)->s_gec);
405 sh.crc = logfs_crc32(&sh, sizeof(sh), 4);
406
407 /* This causes a bug in segment.c. Not yet. */
408 //logfs_set_segment_erased(sb, area->a_segno, area->a_erase_count, 0);
409
410 ofs = dev_ofs(sb, area->a_segno, 0);
411 area->a_used_bytes = ALIGN(sizeof(sh), 16);
412 logfs_buf_write(area, ofs, &sh, sizeof(sh));
413 return 0;
414}
415
416static size_t __logfs_write_header(struct logfs_super *super,
417 struct logfs_journal_header *jh, size_t len, size_t datalen,
418 u16 type, u8 compr)
419{
420 jh->h_len = cpu_to_be16(len);
421 jh->h_type = cpu_to_be16(type);
422 jh->h_version = cpu_to_be16(++super->s_last_version);
423 jh->h_datalen = cpu_to_be16(datalen);
424 jh->h_compr = compr;
425 jh->h_pad[0] = 'H';
426 jh->h_pad[1] = 'A';
427 jh->h_pad[2] = 'T';
428 jh->h_crc = logfs_crc32(jh, len + sizeof(*jh), 4);
429 return ALIGN(len, 16) + sizeof(*jh);
430}
431
432static size_t logfs_write_header(struct logfs_super *super,
433 struct logfs_journal_header *jh, size_t datalen, u16 type)
434{
435 size_t len = datalen;
436
437 return __logfs_write_header(super, jh, len, datalen, type, COMPR_NONE);
438}
439
440static inline size_t logfs_journal_erasecount_size(struct logfs_super *super)
441{
442 return LOGFS_JOURNAL_SEGS * sizeof(__be32);
443}
444
445static void *logfs_write_erasecount(struct super_block *sb, void *_ec,
446 u16 *type, size_t *len)
447{
448 struct logfs_super *super = logfs_super(sb);
449 struct logfs_je_journal_ec *ec = _ec;
450 int i;
451
452 journal_for_each(i)
453 ec->ec[i] = cpu_to_be32(super->s_journal_ec[i]);
454 *type = JE_ERASECOUNT;
455 *len = logfs_journal_erasecount_size(super);
456 return ec;
457}
458
459static void account_shadow(void *_shadow, unsigned long _sb, u64 ignore,
460 size_t ignore2)
461{
462 struct logfs_shadow *shadow = _shadow;
463 struct super_block *sb = (void *)_sb;
464 struct logfs_super *super = logfs_super(sb);
465
466 /* consume new space */
467 super->s_free_bytes -= shadow->new_len;
468 super->s_used_bytes += shadow->new_len;
469 super->s_dirty_used_bytes -= shadow->new_len;
470
471 /* free up old space */
472 super->s_free_bytes += shadow->old_len;
473 super->s_used_bytes -= shadow->old_len;
474 super->s_dirty_free_bytes -= shadow->old_len;
475
476 logfs_set_segment_used(sb, shadow->old_ofs, -shadow->old_len);
477 logfs_set_segment_used(sb, shadow->new_ofs, shadow->new_len);
478
479 log_journal("account_shadow(%llx, %llx, %x) %llx->%llx %x->%x\n",
480 shadow->ino, shadow->bix, shadow->gc_level,
481 shadow->old_ofs, shadow->new_ofs,
482 shadow->old_len, shadow->new_len);
483 mempool_free(shadow, super->s_shadow_pool);
484}
485
486static void account_shadows(struct super_block *sb)
487{
488 struct logfs_super *super = logfs_super(sb);
489 struct inode *inode = super->s_master_inode;
490 struct logfs_inode *li = logfs_inode(inode);
491 struct shadow_tree *tree = &super->s_shadow_tree;
492
493 btree_grim_visitor64(&tree->new, (unsigned long)sb, account_shadow);
494 btree_grim_visitor64(&tree->old, (unsigned long)sb, account_shadow);
495
496 if (li->li_block) {
497 /*
498 * We never actually use the structure, when attached to the
499 * master inode. But it is easier to always free it here than
500 * to have checks in several places elsewhere when allocating
501 * it.
502 */
503 li->li_block->ops->free_block(sb, li->li_block);
504 }
505 BUG_ON((s64)li->li_used_bytes < 0);
506}
507
508static void *__logfs_write_anchor(struct super_block *sb, void *_da,
509 u16 *type, size_t *len)
510{
511 struct logfs_super *super = logfs_super(sb);
512 struct logfs_je_anchor *da = _da;
513 struct inode *inode = super->s_master_inode;
514 struct logfs_inode *li = logfs_inode(inode);
515 int i;
516
517 da->da_height = li->li_height;
518 da->da_last_ino = cpu_to_be64(super->s_last_ino);
519 da->da_size = cpu_to_be64(i_size_read(inode));
520 da->da_used_bytes = cpu_to_be64(li->li_used_bytes);
521 for (i = 0; i < LOGFS_EMBEDDED_FIELDS; i++)
522 da->da_data[i] = cpu_to_be64(li->li_data[i]);
523 *type = JE_ANCHOR;
524 *len = sizeof(*da);
525 return da;
526}
527
528static void *logfs_write_dynsb(struct super_block *sb, void *_dynsb,
529 u16 *type, size_t *len)
530{
531 struct logfs_super *super = logfs_super(sb);
532 struct logfs_je_dynsb *dynsb = _dynsb;
533
534 dynsb->ds_gec = cpu_to_be64(super->s_gec);
535 dynsb->ds_sweeper = cpu_to_be64(super->s_sweeper);
536 dynsb->ds_victim_ino = cpu_to_be64(super->s_victim_ino);
537 dynsb->ds_rename_dir = cpu_to_be64(super->s_rename_dir);
538 dynsb->ds_rename_pos = cpu_to_be64(super->s_rename_pos);
539 dynsb->ds_used_bytes = cpu_to_be64(super->s_used_bytes);
540 dynsb->ds_generation = cpu_to_be32(super->s_generation);
541 *type = JE_DYNSB;
542 *len = sizeof(*dynsb);
543 return dynsb;
544}
545
546static void write_wbuf(struct super_block *sb, struct logfs_area *area,
547 void *wbuf)
548{
549 struct logfs_super *super = logfs_super(sb);
550 struct address_space *mapping = super->s_mapping_inode->i_mapping;
551 u64 ofs;
552 pgoff_t index;
553 int page_ofs;
554 struct page *page;
555
556 ofs = dev_ofs(sb, area->a_segno,
557 area->a_used_bytes & ~(super->s_writesize - 1));
558 index = ofs >> PAGE_SHIFT;
559 page_ofs = ofs & (PAGE_SIZE - 1);
560
561 page = find_lock_page(mapping, index);
562 BUG_ON(!page);
563 memcpy(wbuf, page_address(page) + page_ofs, super->s_writesize);
564 unlock_page(page);
565}
566
567static void *logfs_write_area(struct super_block *sb, void *_a,
568 u16 *type, size_t *len)
569{
570 struct logfs_super *super = logfs_super(sb);
571 struct logfs_area *area = super->s_area[super->s_sum_index];
572 struct logfs_je_area *a = _a;
573
574 a->vim = VIM_DEFAULT;
575 a->gc_level = super->s_sum_index;
576 a->used_bytes = cpu_to_be32(area->a_used_bytes);
577 a->segno = cpu_to_be32(area->a_segno);
578 if (super->s_writesize > 1)
579 write_wbuf(sb, area, a + 1);
580
581 *type = JE_AREA;
582 *len = sizeof(*a) + super->s_writesize;
583 return a;
584}
585
586static void *logfs_write_commit(struct super_block *sb, void *h,
587 u16 *type, size_t *len)
588{
589 struct logfs_super *super = logfs_super(sb);
590
591 *type = JE_COMMIT;
592 *len = super->s_no_je * sizeof(__be64);
593 return super->s_je_array;
594}
595
596static size_t __logfs_write_je(struct super_block *sb, void *buf, u16 type,
597 size_t len)
598{
599 struct logfs_super *super = logfs_super(sb);
600 void *header = super->s_compressed_je;
601 void *data = header + sizeof(struct logfs_journal_header);
602 ssize_t compr_len, pad_len;
603 u8 compr = COMPR_ZLIB;
604
605 if (len == 0)
606 return logfs_write_header(super, header, 0, type);
607
608 compr_len = logfs_compress(buf, data, len, sb->s_blocksize);
609 if (compr_len < 0 || type == JE_ANCHOR) {
610 BUG_ON(len > sb->s_blocksize);
611 memcpy(data, buf, len);
612 compr_len = len;
613 compr = COMPR_NONE;
614 }
615
616 pad_len = ALIGN(compr_len, 16);
617 memset(data + compr_len, 0, pad_len - compr_len);
618
619 return __logfs_write_header(super, header, compr_len, len, type, compr);
620}
621
622static s64 logfs_get_free_bytes(struct logfs_area *area, size_t *bytes,
623 int must_pad)
624{
625 u32 writesize = logfs_super(area->a_sb)->s_writesize;
626 s32 ofs;
627 int ret;
628
629 ret = logfs_open_area(area, *bytes);
630 if (ret)
631 return -EAGAIN;
632
633 ofs = area->a_used_bytes;
634 area->a_used_bytes += *bytes;
635
636 if (must_pad) {
637 area->a_used_bytes = ALIGN(area->a_used_bytes, writesize);
638 *bytes = area->a_used_bytes - ofs;
639 }
640
641 return dev_ofs(area->a_sb, area->a_segno, ofs);
642}
643
644static int logfs_write_je_buf(struct super_block *sb, void *buf, u16 type,
645 size_t buf_len)
646{
647 struct logfs_super *super = logfs_super(sb);
648 struct logfs_area *area = super->s_journal_area;
649 struct logfs_journal_header *jh = super->s_compressed_je;
650 size_t len;
651 int must_pad = 0;
652 s64 ofs;
653
654 len = __logfs_write_je(sb, buf, type, buf_len);
655 if (jh->h_type == cpu_to_be16(JE_COMMIT))
656 must_pad = 1;
657
658 ofs = logfs_get_free_bytes(area, &len, must_pad);
659 if (ofs < 0)
660 return ofs;
661 logfs_buf_write(area, ofs, super->s_compressed_je, len);
662 super->s_je_array[super->s_no_je++] = cpu_to_be64(ofs);
663 return 0;
664}
665
666static int logfs_write_je(struct super_block *sb,
667 void* (*write)(struct super_block *sb, void *scratch,
668 u16 *type, size_t *len))
669{
670 void *buf;
671 size_t len;
672 u16 type;
673
674 buf = write(sb, logfs_super(sb)->s_je, &type, &len);
675 return logfs_write_je_buf(sb, buf, type, len);
676}
677
678int write_alias_journal(struct super_block *sb, u64 ino, u64 bix,
679 level_t level, int child_no, __be64 val)
680{
681 struct logfs_super *super = logfs_super(sb);
682 struct logfs_obj_alias *oa = super->s_je;
683 int err = 0, fill = super->s_je_fill;
684
685 log_aliases("logfs_write_obj_aliases #%x(%llx, %llx, %x, %x) %llx\n",
686 fill, ino, bix, level, child_no, be64_to_cpu(val));
687 oa[fill].ino = cpu_to_be64(ino);
688 oa[fill].bix = cpu_to_be64(bix);
689 oa[fill].val = val;
690 oa[fill].level = (__force u8)level;
691 oa[fill].child_no = cpu_to_be16(child_no);
692 fill++;
693 if (fill >= sb->s_blocksize / sizeof(*oa)) {
694 err = logfs_write_je_buf(sb, oa, JE_OBJ_ALIAS, sb->s_blocksize);
695 fill = 0;
696 }
697
698 super->s_je_fill = fill;
699 return err;
700}
701
702static int logfs_write_obj_aliases(struct super_block *sb)
703{
704 struct logfs_super *super = logfs_super(sb);
705 int err;
706
707 log_journal("logfs_write_obj_aliases: %d aliases to write\n",
708 super->s_no_object_aliases);
709 super->s_je_fill = 0;
710 err = logfs_write_obj_aliases_pagecache(sb);
711 if (err)
712 return err;
713
714 if (super->s_je_fill)
715 err = logfs_write_je_buf(sb, super->s_je, JE_OBJ_ALIAS,
716 super->s_je_fill
717 * sizeof(struct logfs_obj_alias));
718 return err;
719}
720
721/*
722 * Write all journal entries. The goto logic ensures that all journal entries
723 * are written whenever a new segment is used. It is ugly and potentially a
724 * bit wasteful, but robustness is more important. With this we can *always*
725 * erase all journal segments except the one containing the most recent commit.
726 */
727void logfs_write_anchor(struct inode *inode)
728{
729 struct super_block *sb = inode->i_sb;
730 struct logfs_super *super = logfs_super(sb);
731 struct logfs_area *area = super->s_journal_area;
732 int i, err;
733
734 BUG_ON(logfs_super(sb)->s_flags & LOGFS_SB_FLAG_SHUTDOWN);
735 mutex_lock(&super->s_journal_mutex);
736
737 /* Do this first or suffer corruption */
738 logfs_sync_segments(sb);
739 account_shadows(sb);
740
741again:
742 super->s_no_je = 0;
743 for_each_area(i) {
744 if (!super->s_area[i]->a_is_open)
745 continue;
746 super->s_sum_index = i;
747 err = logfs_write_je(sb, logfs_write_area);
748 if (err)
749 goto again;
750 }
751 err = logfs_write_obj_aliases(sb);
752 if (err)
753 goto again;
754 err = logfs_write_je(sb, logfs_write_erasecount);
755 if (err)
756 goto again;
757 err = logfs_write_je(sb, __logfs_write_anchor);
758 if (err)
759 goto again;
760 err = logfs_write_je(sb, logfs_write_dynsb);
761 if (err)
762 goto again;
763 /*
764 * Order is imperative. First we sync all writes, including the
765 * non-committed journal writes. Then we write the final commit and
766 * sync the current journal segment.
767 * There is a theoretical bug here. Syncing the journal segment will
768 * write a number of journal entries and the final commit. All these
769 * are written in a single operation. If the device layer writes the
770 * data back-to-front, the commit will precede the other journal
771 * entries, leaving a race window.
772 * Two fixes are possible. Preferred is to fix the device layer to
773 * ensure writes happen front-to-back. Alternatively we can insert
774 * another logfs_sync_area() super->s_devops->sync() combo before
775 * writing the commit.
776 */
777 /*
778 * On another subject, super->s_devops->sync is usually not necessary.
779 * Unless called from sys_sync or friends, a barrier would suffice.
780 */
781 super->s_devops->sync(sb);
782 err = logfs_write_je(sb, logfs_write_commit);
783 if (err)
784 goto again;
785 log_journal("Write commit to %llx\n",
786 be64_to_cpu(super->s_je_array[super->s_no_je - 1]));
787 logfs_sync_area(area);
788 BUG_ON(area->a_used_bytes != area->a_written_bytes);
789 super->s_devops->sync(sb);
790
791 mutex_unlock(&super->s_journal_mutex);
792 return;
793}
794
795void do_logfs_journal_wl_pass(struct super_block *sb)
796{
797 struct logfs_super *super = logfs_super(sb);
798 struct logfs_area *area = super->s_journal_area;
799 u32 segno, ec;
800 int i, err;
801
802 log_journal("Journal requires wear-leveling.\n");
803 /* Drop old segments */
804 journal_for_each(i)
805 if (super->s_journal_seg[i]) {
806 logfs_set_segment_unreserved(sb,
807 super->s_journal_seg[i],
808 super->s_journal_ec[i]);
809 super->s_journal_seg[i] = 0;
810 super->s_journal_ec[i] = 0;
811 }
812 /* Get new segments */
813 for (i = 0; i < super->s_no_journal_segs; i++) {
814 segno = get_best_cand(sb, &super->s_reserve_list, &ec);
815 super->s_journal_seg[i] = segno;
816 super->s_journal_ec[i] = ec;
817 logfs_set_segment_reserved(sb, segno);
818 }
819 /* Manually move journal_area */
820 area->a_segno = super->s_journal_seg[0];
821 area->a_is_open = 0;
822 area->a_used_bytes = 0;
823 /* Write journal */
824 logfs_write_anchor(super->s_master_inode);
825 /* Write superblocks */
826 err = logfs_write_sb(sb);
827 BUG_ON(err);
828}
829
830static const struct logfs_area_ops journal_area_ops = {
831 .get_free_segment = journal_get_free_segment,
832 .get_erase_count = journal_get_erase_count,
833 .erase_segment = journal_erase_segment,
834};
835
836int logfs_init_journal(struct super_block *sb)
837{
838 struct logfs_super *super = logfs_super(sb);
839 size_t bufsize = max_t(size_t, sb->s_blocksize, super->s_writesize)
840 + MAX_JOURNAL_HEADER;
841 int ret = -ENOMEM;
842
843 mutex_init(&super->s_journal_mutex);
844 btree_init_mempool32(&super->s_reserved_segments, super->s_btree_pool);
845
846 super->s_je = kzalloc(bufsize, GFP_KERNEL);
847 if (!super->s_je)
848 return ret;
849
850 super->s_compressed_je = kzalloc(bufsize, GFP_KERNEL);
851 if (!super->s_compressed_je)
852 return ret;
853
854 super->s_master_inode = logfs_new_meta_inode(sb, LOGFS_INO_MASTER);
855 if (IS_ERR(super->s_master_inode))
856 return PTR_ERR(super->s_master_inode);
857
858 ret = logfs_read_journal(sb);
859 if (ret)
860 return -EIO;
861
862 reserve_sb_and_journal(sb);
863 logfs_calc_free(sb);
864
865 super->s_journal_area->a_ops = &journal_area_ops;
866 return 0;
867}
868
869void logfs_cleanup_journal(struct super_block *sb)
870{
871 struct logfs_super *super = logfs_super(sb);
872
873 btree_grim_visitor32(&super->s_reserved_segments, 0, NULL);
874 destroy_meta_inode(super->s_master_inode);
875 super->s_master_inode = NULL;
876
877 kfree(super->s_compressed_je);
878 kfree(super->s_je);
879}
Linux 6.x block layer and io_uring tree(s)