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Staging: rtl8192su: led update
[linux/fpc-iii.git] / fs / logfs / journal.c
blobfb0a613f885b768c12a49ef52f1ab0fac42e12be
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 #include <linux/slab.h>
10
11 static void logfs_calc_free(struct super_block *sb)
12 {
13 struct logfs_super *super = logfs_super(sb);
14 u64 reserve, no_segs = super->s_no_segs;
15 s64 free;
16 int i;
17
18 /* superblock segments */
19 no_segs -= 2;
20 super->s_no_journal_segs = 0;
21 /* journal */
22 journal_for_each(i)
23 if (super->s_journal_seg[i]) {
24 no_segs--;
25 super->s_no_journal_segs++;
26 }
27
28 /* open segments plus one extra per level for GC */
29 no_segs -= 2 * super->s_total_levels;
30
31 free = no_segs * (super->s_segsize - LOGFS_SEGMENT_RESERVE);
32 free -= super->s_used_bytes;
33 /* just a bit extra */
34 free -= super->s_total_levels * 4096;
35
36 /* Bad blocks are 'paid' for with speed reserve - the filesystem
37 * simply gets slower as bad blocks accumulate. Until the bad blocks
38 * exceed the speed reserve - then the filesystem gets smaller.
39 */
40 reserve = super->s_bad_segments + super->s_bad_seg_reserve;
41 reserve *= super->s_segsize - LOGFS_SEGMENT_RESERVE;
42 reserve = max(reserve, super->s_speed_reserve);
43 free -= reserve;
44 if (free < 0)
45 free = 0;
46
47 super->s_free_bytes = free;
48 }
49
50 static void reserve_sb_and_journal(struct super_block *sb)
51 {
52 struct logfs_super *super = logfs_super(sb);
53 struct btree_head32 *head = &super->s_reserved_segments;
54 int i, err;
55
56 err = btree_insert32(head, seg_no(sb, super->s_sb_ofs[0]), (void *)1,
57 GFP_KERNEL);
58 BUG_ON(err);
59
60 err = btree_insert32(head, seg_no(sb, super->s_sb_ofs[1]), (void *)1,
61 GFP_KERNEL);
62 BUG_ON(err);
63
64 journal_for_each(i) {
65 if (!super->s_journal_seg[i])
66 continue;
67 err = btree_insert32(head, super->s_journal_seg[i], (void *)1,
68 GFP_KERNEL);
69 BUG_ON(err);
70 }
71 }
72
73 static void read_dynsb(struct super_block *sb,
74 struct logfs_je_dynsb *dynsb)
75 {
76 struct logfs_super *super = logfs_super(sb);
77
78 super->s_gec = be64_to_cpu(dynsb->ds_gec);
79 super->s_sweeper = be64_to_cpu(dynsb->ds_sweeper);
80 super->s_victim_ino = be64_to_cpu(dynsb->ds_victim_ino);
81 super->s_rename_dir = be64_to_cpu(dynsb->ds_rename_dir);
82 super->s_rename_pos = be64_to_cpu(dynsb->ds_rename_pos);
83 super->s_used_bytes = be64_to_cpu(dynsb->ds_used_bytes);
84 super->s_generation = be32_to_cpu(dynsb->ds_generation);
85 }
86
87 static void read_anchor(struct super_block *sb,
88 struct logfs_je_anchor *da)
89 {
90 struct logfs_super *super = logfs_super(sb);
91 struct inode *inode = super->s_master_inode;
92 struct logfs_inode *li = logfs_inode(inode);
93 int i;
94
95 super->s_last_ino = be64_to_cpu(da->da_last_ino);
96 li->li_flags = 0;
97 li->li_height = da->da_height;
98 i_size_write(inode, be64_to_cpu(da->da_size));
99 li->li_used_bytes = be64_to_cpu(da->da_used_bytes);
100
101 for (i = 0; i < LOGFS_EMBEDDED_FIELDS; i++)
102 li->li_data[i] = be64_to_cpu(da->da_data[i]);
103 }
104
105 static void read_erasecount(struct super_block *sb,
106 struct logfs_je_journal_ec *ec)
107 {
108 struct logfs_super *super = logfs_super(sb);
109 int i;
110
111 journal_for_each(i)
112 super->s_journal_ec[i] = be32_to_cpu(ec->ec[i]);
113 }
114
115 static int read_area(struct super_block *sb, struct logfs_je_area *a)
116 {
117 struct logfs_super *super = logfs_super(sb);
118 struct logfs_area *area = super->s_area[a->gc_level];
119 u64 ofs;
120 u32 writemask = ~(super->s_writesize - 1);
121
122 if (a->gc_level >= LOGFS_NO_AREAS)
123 return -EIO;
124 if (a->vim != VIM_DEFAULT)
125 return -EIO; /* TODO: close area and continue */
126
127 area->a_used_bytes = be32_to_cpu(a->used_bytes);
128 area->a_written_bytes = area->a_used_bytes & writemask;
129 area->a_segno = be32_to_cpu(a->segno);
130 if (area->a_segno)
131 area->a_is_open = 1;
132
133 ofs = dev_ofs(sb, area->a_segno, area->a_written_bytes);
134 if (super->s_writesize > 1)
135 logfs_buf_recover(area, ofs, a + 1, super->s_writesize);
136 else
137 logfs_buf_recover(area, ofs, NULL, 0);
138 return 0;
139 }
140
141 static void *unpack(void *from, void *to)
142 {
143 struct logfs_journal_header *jh = from;
144 void *data = from + sizeof(struct logfs_journal_header);
145 int err;
146 size_t inlen, outlen;
147
148 inlen = be16_to_cpu(jh->h_len);
149 outlen = be16_to_cpu(jh->h_datalen);
150
151 if (jh->h_compr == COMPR_NONE)
152 memcpy(to, data, inlen);
153 else {
154 err = logfs_uncompress(data, to, inlen, outlen);
155 BUG_ON(err);
156 }
157 return to;
158 }
159
160 static int __read_je_header(struct super_block *sb, u64 ofs,
161 struct logfs_journal_header *jh)
162 {
163 struct logfs_super *super = logfs_super(sb);
164 size_t bufsize = max_t(size_t, sb->s_blocksize, super->s_writesize)
165 + MAX_JOURNAL_HEADER;
166 u16 type, len, datalen;
167 int err;
168
169 /* read header only */
170 err = wbuf_read(sb, ofs, sizeof(*jh), jh);
171 if (err)
172 return err;
173 type = be16_to_cpu(jh->h_type);
174 len = be16_to_cpu(jh->h_len);
175 datalen = be16_to_cpu(jh->h_datalen);
176 if (len > sb->s_blocksize)
177 return -EIO;
178 if ((type < JE_FIRST) || (type > JE_LAST))
179 return -EIO;
180 if (datalen > bufsize)
181 return -EIO;
182 return 0;
183 }
184
185 static int __read_je_payload(struct super_block *sb, u64 ofs,
186 struct logfs_journal_header *jh)
187 {
188 u16 len;
189 int err;
190
191 len = be16_to_cpu(jh->h_len);
192 err = wbuf_read(sb, ofs + sizeof(*jh), len, jh + 1);
193 if (err)
194 return err;
195 if (jh->h_crc != logfs_crc32(jh, len + sizeof(*jh), 4)) {
196 /* Old code was confused. It forgot about the header length
197 * and stopped calculating the crc 16 bytes before the end
198 * of data - ick!
199 * FIXME: Remove this hack once the old code is fixed.
200 */
201 if (jh->h_crc == logfs_crc32(jh, len, 4))
202 WARN_ON_ONCE(1);
203 else
204 return -EIO;
205 }
206 return 0;
207 }
208
209 /*
210 * jh needs to be large enough to hold the complete entry, not just the header
211 */
212 static int __read_je(struct super_block *sb, u64 ofs,
213 struct logfs_journal_header *jh)
214 {
215 int err;
216
217 err = __read_je_header(sb, ofs, jh);
218 if (err)
219 return err;
220 return __read_je_payload(sb, ofs, jh);
221 }
222
223 static int read_je(struct super_block *sb, u64 ofs)
224 {
225 struct logfs_super *super = logfs_super(sb);
226 struct logfs_journal_header *jh = super->s_compressed_je;
227 void *scratch = super->s_je;
228 u16 type, datalen;
229 int err;
230
231 err = __read_je(sb, ofs, jh);
232 if (err)
233 return err;
234 type = be16_to_cpu(jh->h_type);
235 datalen = be16_to_cpu(jh->h_datalen);
236
237 switch (type) {
238 case JE_DYNSB:
239 read_dynsb(sb, unpack(jh, scratch));
240 break;
241 case JE_ANCHOR:
242 read_anchor(sb, unpack(jh, scratch));
243 break;
244 case JE_ERASECOUNT:
245 read_erasecount(sb, unpack(jh, scratch));
246 break;
247 case JE_AREA:
248 read_area(sb, unpack(jh, scratch));
249 break;
250 case JE_OBJ_ALIAS:
251 err = logfs_load_object_aliases(sb, unpack(jh, scratch),
252 datalen);
253 break;
254 default:
255 WARN_ON_ONCE(1);
256 return -EIO;
257 }
258 return err;
259 }
260
261 static int logfs_read_segment(struct super_block *sb, u32 segno)
262 {
263 struct logfs_super *super = logfs_super(sb);
264 struct logfs_journal_header *jh = super->s_compressed_je;
265 u64 ofs, seg_ofs = dev_ofs(sb, segno, 0);
266 u32 h_ofs, last_ofs = 0;
267 u16 len, datalen, last_len = 0;
268 int i, err;
269
270 /* search for most recent commit */
271 for (h_ofs = 0; h_ofs < super->s_segsize; h_ofs += sizeof(*jh)) {
272 ofs = seg_ofs + h_ofs;
273 err = __read_je_header(sb, ofs, jh);
274 if (err)
275 continue;
276 if (jh->h_type != cpu_to_be16(JE_COMMIT))
277 continue;
278 err = __read_je_payload(sb, ofs, jh);
279 if (err)
280 continue;
281 len = be16_to_cpu(jh->h_len);
282 datalen = be16_to_cpu(jh->h_datalen);
283 if ((datalen > sizeof(super->s_je_array)) ||
284 (datalen % sizeof(__be64)))
285 continue;
286 last_ofs = h_ofs;
287 last_len = datalen;
288 h_ofs += ALIGN(len, sizeof(*jh)) - sizeof(*jh);
289 }
290 /* read commit */
291 if (last_ofs == 0)
292 return -ENOENT;
293 ofs = seg_ofs + last_ofs;
294 log_journal("Read commit from %llx\n", ofs);
295 err = __read_je(sb, ofs, jh);
296 BUG_ON(err); /* We should have caught it in the scan loop already */
297 if (err)
298 return err;
299 /* uncompress */
300 unpack(jh, super->s_je_array);
301 super->s_no_je = last_len / sizeof(__be64);
302 /* iterate over array */
303 for (i = 0; i < super->s_no_je; i++) {
304 err = read_je(sb, be64_to_cpu(super->s_je_array[i]));
305 if (err)
306 return err;
307 }
308 super->s_journal_area->a_segno = segno;
309 return 0;
310 }
311
312 static u64 read_gec(struct super_block *sb, u32 segno)
313 {
314 struct logfs_segment_header sh;
315 __be32 crc;
316 int err;
317
318 if (!segno)
319 return 0;
320 err = wbuf_read(sb, dev_ofs(sb, segno, 0), sizeof(sh), &sh);
321 if (err)
322 return 0;
323 crc = logfs_crc32(&sh, sizeof(sh), 4);
324 if (crc != sh.crc) {
325 WARN_ON(sh.gec != cpu_to_be64(0xffffffffffffffffull));
326 /* Most likely it was just erased */
327 return 0;
328 }
329 return be64_to_cpu(sh.gec);
330 }
331
332 static int logfs_read_journal(struct super_block *sb)
333 {
334 struct logfs_super *super = logfs_super(sb);
335 u64 gec[LOGFS_JOURNAL_SEGS], max;
336 u32 segno;
337 int i, max_i;
338
339 max = 0;
340 max_i = -1;
341 journal_for_each(i) {
342 segno = super->s_journal_seg[i];
343 gec[i] = read_gec(sb, super->s_journal_seg[i]);
344 if (gec[i] > max) {
345 max = gec[i];
346 max_i = i;
347 }
348 }
349 if (max_i == -1)
350 return -EIO;
351 /* FIXME: Try older segments in case of error */
352 return logfs_read_segment(sb, super->s_journal_seg[max_i]);
353 }
354
355 /*
356 * First search the current segment (outer loop), then pick the next segment
357 * in the array, skipping any zero entries (inner loop).
358 */
359 static void journal_get_free_segment(struct logfs_area *area)
360 {
361 struct logfs_super *super = logfs_super(area->a_sb);
362 int i;
363
364 journal_for_each(i) {
365 if (area->a_segno != super->s_journal_seg[i])
366 continue;
367
368 do {
369 i++;
370 if (i == LOGFS_JOURNAL_SEGS)
371 i = 0;
372 } while (!super->s_journal_seg[i]);
373
374 area->a_segno = super->s_journal_seg[i];
375 area->a_erase_count = ++(super->s_journal_ec[i]);
376 log_journal("Journal now at %x (ec %x)\n", area->a_segno,
377 area->a_erase_count);
378 return;
379 }
380 BUG();
381 }
382
383 static void journal_get_erase_count(struct logfs_area *area)
384 {
385 /* erase count is stored globally and incremented in
386 * journal_get_free_segment() - nothing to do here */
387 }
388
389 static int journal_erase_segment(struct logfs_area *area)
390 {
391 struct super_block *sb = area->a_sb;
392 union {
393 struct logfs_segment_header sh;
394 unsigned char c[ALIGN(sizeof(struct logfs_segment_header), 16)];
395 } u;
396 u64 ofs;
397 int err;
398
399 err = logfs_erase_segment(sb, area->a_segno, 1);
400 if (err)
401 return err;
402
403 memset(&u, 0, sizeof(u));
404 u.sh.pad = 0;
405 u.sh.type = SEG_JOURNAL;
406 u.sh.level = 0;
407 u.sh.segno = cpu_to_be32(area->a_segno);
408 u.sh.ec = cpu_to_be32(area->a_erase_count);
409 u.sh.gec = cpu_to_be64(logfs_super(sb)->s_gec);
410 u.sh.crc = logfs_crc32(&u.sh, sizeof(u.sh), 4);
411
412 /* This causes a bug in segment.c. Not yet. */
413 //logfs_set_segment_erased(sb, area->a_segno, area->a_erase_count, 0);
414
415 ofs = dev_ofs(sb, area->a_segno, 0);
416 area->a_used_bytes = sizeof(u);
417 logfs_buf_write(area, ofs, &u, sizeof(u));
418 return 0;
419 }
420
421 static size_t __logfs_write_header(struct logfs_super *super,
422 struct logfs_journal_header *jh, size_t len, size_t datalen,
423 u16 type, u8 compr)
424 {
425 jh->h_len = cpu_to_be16(len);
426 jh->h_type = cpu_to_be16(type);
427 jh->h_datalen = cpu_to_be16(datalen);
428 jh->h_compr = compr;
429 jh->h_pad[0] = 'H';
430 jh->h_pad[1] = 'E';
431 jh->h_pad[2] = 'A';
432 jh->h_pad[3] = 'D';
433 jh->h_pad[4] = 'R';
434 jh->h_crc = logfs_crc32(jh, len + sizeof(*jh), 4);
435 return ALIGN(len, 16) + sizeof(*jh);
436 }
437
438 static size_t logfs_write_header(struct logfs_super *super,
439 struct logfs_journal_header *jh, size_t datalen, u16 type)
440 {
441 size_t len = datalen;
442
443 return __logfs_write_header(super, jh, len, datalen, type, COMPR_NONE);
444 }
445
446 static inline size_t logfs_journal_erasecount_size(struct logfs_super *super)
447 {
448 return LOGFS_JOURNAL_SEGS * sizeof(__be32);
449 }
450
451 static void *logfs_write_erasecount(struct super_block *sb, void *_ec,
452 u16 *type, size_t *len)
453 {
454 struct logfs_super *super = logfs_super(sb);
455 struct logfs_je_journal_ec *ec = _ec;
456 int i;
457
458 journal_for_each(i)
459 ec->ec[i] = cpu_to_be32(super->s_journal_ec[i]);
460 *type = JE_ERASECOUNT;
461 *len = logfs_journal_erasecount_size(super);
462 return ec;
463 }
464
465 static void account_shadow(void *_shadow, unsigned long _sb, u64 ignore,
466 size_t ignore2)
467 {
468 struct logfs_shadow *shadow = _shadow;
469 struct super_block *sb = (void *)_sb;
470 struct logfs_super *super = logfs_super(sb);
471
472 /* consume new space */
473 super->s_free_bytes -= shadow->new_len;
474 super->s_used_bytes += shadow->new_len;
475 super->s_dirty_used_bytes -= shadow->new_len;
476
477 /* free up old space */
478 super->s_free_bytes += shadow->old_len;
479 super->s_used_bytes -= shadow->old_len;
480 super->s_dirty_free_bytes -= shadow->old_len;
481
482 logfs_set_segment_used(sb, shadow->old_ofs, -shadow->old_len);
483 logfs_set_segment_used(sb, shadow->new_ofs, shadow->new_len);
484
485 log_journal("account_shadow(%llx, %llx, %x) %llx->%llx %x->%x\n",
486 shadow->ino, shadow->bix, shadow->gc_level,
487 shadow->old_ofs, shadow->new_ofs,
488 shadow->old_len, shadow->new_len);
489 mempool_free(shadow, super->s_shadow_pool);
490 }
491
492 static void account_shadows(struct super_block *sb)
493 {
494 struct logfs_super *super = logfs_super(sb);
495 struct inode *inode = super->s_master_inode;
496 struct logfs_inode *li = logfs_inode(inode);
497 struct shadow_tree *tree = &super->s_shadow_tree;
498
499 btree_grim_visitor64(&tree->new, (unsigned long)sb, account_shadow);
500 btree_grim_visitor64(&tree->old, (unsigned long)sb, account_shadow);
501 btree_grim_visitor32(&tree->segment_map, 0, NULL);
502 tree->no_shadowed_segments = 0;
503
504 if (li->li_block) {
505 /*
506 * We never actually use the structure, when attached to the
507 * master inode. But it is easier to always free it here than
508 * to have checks in several places elsewhere when allocating
509 * it.
510 */
511 li->li_block->ops->free_block(sb, li->li_block);
512 }
513 BUG_ON((s64)li->li_used_bytes < 0);
514 }
515
516 static void *__logfs_write_anchor(struct super_block *sb, void *_da,
517 u16 *type, size_t *len)
518 {
519 struct logfs_super *super = logfs_super(sb);
520 struct logfs_je_anchor *da = _da;
521 struct inode *inode = super->s_master_inode;
522 struct logfs_inode *li = logfs_inode(inode);
523 int i;
524
525 da->da_height = li->li_height;
526 da->da_last_ino = cpu_to_be64(super->s_last_ino);
527 da->da_size = cpu_to_be64(i_size_read(inode));
528 da->da_used_bytes = cpu_to_be64(li->li_used_bytes);
529 for (i = 0; i < LOGFS_EMBEDDED_FIELDS; i++)
530 da->da_data[i] = cpu_to_be64(li->li_data[i]);
531 *type = JE_ANCHOR;
532 *len = sizeof(*da);
533 return da;
534 }
535
536 static void *logfs_write_dynsb(struct super_block *sb, void *_dynsb,
537 u16 *type, size_t *len)
538 {
539 struct logfs_super *super = logfs_super(sb);
540 struct logfs_je_dynsb *dynsb = _dynsb;
541
542 dynsb->ds_gec = cpu_to_be64(super->s_gec);
543 dynsb->ds_sweeper = cpu_to_be64(super->s_sweeper);
544 dynsb->ds_victim_ino = cpu_to_be64(super->s_victim_ino);
545 dynsb->ds_rename_dir = cpu_to_be64(super->s_rename_dir);
546 dynsb->ds_rename_pos = cpu_to_be64(super->s_rename_pos);
547 dynsb->ds_used_bytes = cpu_to_be64(super->s_used_bytes);
548 dynsb->ds_generation = cpu_to_be32(super->s_generation);
549 *type = JE_DYNSB;
550 *len = sizeof(*dynsb);
551 return dynsb;
552 }
553
554 static void write_wbuf(struct super_block *sb, struct logfs_area *area,
555 void *wbuf)
556 {
557 struct logfs_super *super = logfs_super(sb);
558 struct address_space *mapping = super->s_mapping_inode->i_mapping;
559 u64 ofs;
560 pgoff_t index;
561 int page_ofs;
562 struct page *page;
563
564 ofs = dev_ofs(sb, area->a_segno,
565 area->a_used_bytes & ~(super->s_writesize - 1));
566 index = ofs >> PAGE_SHIFT;
567 page_ofs = ofs & (PAGE_SIZE - 1);
568
569 page = find_lock_page(mapping, index);
570 BUG_ON(!page);
571 memcpy(wbuf, page_address(page) + page_ofs, super->s_writesize);
572 unlock_page(page);
573 }
574
575 static void *logfs_write_area(struct super_block *sb, void *_a,
576 u16 *type, size_t *len)
577 {
578 struct logfs_super *super = logfs_super(sb);
579 struct logfs_area *area = super->s_area[super->s_sum_index];
580 struct logfs_je_area *a = _a;
581
582 a->vim = VIM_DEFAULT;
583 a->gc_level = super->s_sum_index;
584 a->used_bytes = cpu_to_be32(area->a_used_bytes);
585 a->segno = cpu_to_be32(area->a_segno);
586 if (super->s_writesize > 1)
587 write_wbuf(sb, area, a + 1);
588
589 *type = JE_AREA;
590 *len = sizeof(*a) + super->s_writesize;
591 return a;
592 }
593
594 static void *logfs_write_commit(struct super_block *sb, void *h,
595 u16 *type, size_t *len)
596 {
597 struct logfs_super *super = logfs_super(sb);
598
599 *type = JE_COMMIT;
600 *len = super->s_no_je * sizeof(__be64);
601 return super->s_je_array;
602 }
603
604 static size_t __logfs_write_je(struct super_block *sb, void *buf, u16 type,
605 size_t len)
606 {
607 struct logfs_super *super = logfs_super(sb);
608 void *header = super->s_compressed_je;
609 void *data = header + sizeof(struct logfs_journal_header);
610 ssize_t compr_len, pad_len;
611 u8 compr = COMPR_ZLIB;
612
613 if (len == 0)
614 return logfs_write_header(super, header, 0, type);
615
616 BUG_ON(len > sb->s_blocksize);
617 compr_len = logfs_compress(buf, data, len, sb->s_blocksize);
618 if (compr_len < 0 || type == JE_ANCHOR) {
619 memcpy(data, buf, len);
620 compr_len = len;
621 compr = COMPR_NONE;
622 }
623
624 pad_len = ALIGN(compr_len, 16);
625 memset(data + compr_len, 0, pad_len - compr_len);
626
627 return __logfs_write_header(super, header, compr_len, len, type, compr);
628 }
629
630 static s64 logfs_get_free_bytes(struct logfs_area *area, size_t *bytes,
631 int must_pad)
632 {
633 u32 writesize = logfs_super(area->a_sb)->s_writesize;
634 s32 ofs;
635 int ret;
636
637 ret = logfs_open_area(area, *bytes);
638 if (ret)
639 return -EAGAIN;
640
641 ofs = area->a_used_bytes;
642 area->a_used_bytes += *bytes;
643
644 if (must_pad) {
645 area->a_used_bytes = ALIGN(area->a_used_bytes, writesize);
646 *bytes = area->a_used_bytes - ofs;
647 }
648
649 return dev_ofs(area->a_sb, area->a_segno, ofs);
650 }
651
652 static int logfs_write_je_buf(struct super_block *sb, void *buf, u16 type,
653 size_t buf_len)
654 {
655 struct logfs_super *super = logfs_super(sb);
656 struct logfs_area *area = super->s_journal_area;
657 struct logfs_journal_header *jh = super->s_compressed_je;
658 size_t len;
659 int must_pad = 0;
660 s64 ofs;
661
662 len = __logfs_write_je(sb, buf, type, buf_len);
663 if (jh->h_type == cpu_to_be16(JE_COMMIT))
664 must_pad = 1;
665
666 ofs = logfs_get_free_bytes(area, &len, must_pad);
667 if (ofs < 0)
668 return ofs;
669 logfs_buf_write(area, ofs, super->s_compressed_je, len);
670 BUG_ON(super->s_no_je >= MAX_JOURNAL_ENTRIES);
671 super->s_je_array[super->s_no_je++] = cpu_to_be64(ofs);
672 return 0;
673 }
674
675 static int logfs_write_je(struct super_block *sb,
676 void* (*write)(struct super_block *sb, void *scratch,
677 u16 *type, size_t *len))
678 {
679 void *buf;
680 size_t len;
681 u16 type;
682
683 buf = write(sb, logfs_super(sb)->s_je, &type, &len);
684 return logfs_write_je_buf(sb, buf, type, len);
685 }
686
687 int write_alias_journal(struct super_block *sb, u64 ino, u64 bix,
688 level_t level, int child_no, __be64 val)
689 {
690 struct logfs_super *super = logfs_super(sb);
691 struct logfs_obj_alias *oa = super->s_je;
692 int err = 0, fill = super->s_je_fill;
693
694 log_aliases("logfs_write_obj_aliases #%x(%llx, %llx, %x, %x) %llx\n",
695 fill, ino, bix, level, child_no, be64_to_cpu(val));
696 oa[fill].ino = cpu_to_be64(ino);
697 oa[fill].bix = cpu_to_be64(bix);
698 oa[fill].val = val;
699 oa[fill].level = (__force u8)level;
700 oa[fill].child_no = cpu_to_be16(child_no);
701 fill++;
702 if (fill >= sb->s_blocksize / sizeof(*oa)) {
703 err = logfs_write_je_buf(sb, oa, JE_OBJ_ALIAS, sb->s_blocksize);
704 fill = 0;
705 }
706
707 super->s_je_fill = fill;
708 return err;
709 }
710
711 static int logfs_write_obj_aliases(struct super_block *sb)
712 {
713 struct logfs_super *super = logfs_super(sb);
714 int err;
715
716 log_journal("logfs_write_obj_aliases: %d aliases to write\n",
717 super->s_no_object_aliases);
718 super->s_je_fill = 0;
719 err = logfs_write_obj_aliases_pagecache(sb);
720 if (err)
721 return err;
722
723 if (super->s_je_fill)
724 err = logfs_write_je_buf(sb, super->s_je, JE_OBJ_ALIAS,
725 super->s_je_fill
726 * sizeof(struct logfs_obj_alias));
727 return err;
728 }
729
730 /*
731 * Write all journal entries. The goto logic ensures that all journal entries
732 * are written whenever a new segment is used. It is ugly and potentially a
733 * bit wasteful, but robustness is more important. With this we can *always*
734 * erase all journal segments except the one containing the most recent commit.
735 */
736 void logfs_write_anchor(struct super_block *sb)
737 {
738 struct logfs_super *super = logfs_super(sb);
739 struct logfs_area *area = super->s_journal_area;
740 int i, err;
741
742 if (!(super->s_flags & LOGFS_SB_FLAG_DIRTY))
743 return;
744 super->s_flags &= ~LOGFS_SB_FLAG_DIRTY;
745
746 BUG_ON(super->s_flags & LOGFS_SB_FLAG_SHUTDOWN);
747 mutex_lock(&super->s_journal_mutex);
748
749 /* Do this first or suffer corruption */
750 logfs_sync_segments(sb);
751 account_shadows(sb);
752
753 again:
754 super->s_no_je = 0;
755 for_each_area(i) {
756 if (!super->s_area[i]->a_is_open)
757 continue;
758 super->s_sum_index = i;
759 err = logfs_write_je(sb, logfs_write_area);
760 if (err)
761 goto again;
762 }
763 err = logfs_write_obj_aliases(sb);
764 if (err)
765 goto again;
766 err = logfs_write_je(sb, logfs_write_erasecount);
767 if (err)
768 goto again;
769 err = logfs_write_je(sb, __logfs_write_anchor);
770 if (err)
771 goto again;
772 err = logfs_write_je(sb, logfs_write_dynsb);
773 if (err)
774 goto again;
775 /*
776 * Order is imperative. First we sync all writes, including the
777 * non-committed journal writes. Then we write the final commit and
778 * sync the current journal segment.
779 * There is a theoretical bug here. Syncing the journal segment will
780 * write a number of journal entries and the final commit. All these
781 * are written in a single operation. If the device layer writes the
782 * data back-to-front, the commit will precede the other journal
783 * entries, leaving a race window.
784 * Two fixes are possible. Preferred is to fix the device layer to
785 * ensure writes happen front-to-back. Alternatively we can insert
786 * another logfs_sync_area() super->s_devops->sync() combo before
787 * writing the commit.
788 */
789 /*
790 * On another subject, super->s_devops->sync is usually not necessary.
791 * Unless called from sys_sync or friends, a barrier would suffice.
792 */
793 super->s_devops->sync(sb);
794 err = logfs_write_je(sb, logfs_write_commit);
795 if (err)
796 goto again;
797 log_journal("Write commit to %llx\n",
798 be64_to_cpu(super->s_je_array[super->s_no_je - 1]));
799 logfs_sync_area(area);
800 BUG_ON(area->a_used_bytes != area->a_written_bytes);
801 super->s_devops->sync(sb);
802
803 mutex_unlock(&super->s_journal_mutex);
804 return;
805 }
806
807 void do_logfs_journal_wl_pass(struct super_block *sb)
808 {
809 struct logfs_super *super = logfs_super(sb);
810 struct logfs_area *area = super->s_journal_area;
811 struct btree_head32 *head = &super->s_reserved_segments;
812 u32 segno, ec;
813 int i, err;
814
815 log_journal("Journal requires wear-leveling.\n");
816 /* Drop old segments */
817 journal_for_each(i)
818 if (super->s_journal_seg[i]) {
819 btree_remove32(head, super->s_journal_seg[i]);
820 logfs_set_segment_unreserved(sb,
821 super->s_journal_seg[i],
822 super->s_journal_ec[i]);
823 super->s_journal_seg[i] = 0;
824 super->s_journal_ec[i] = 0;
825 }
826 /* Get new segments */
827 for (i = 0; i < super->s_no_journal_segs; i++) {
828 segno = get_best_cand(sb, &super->s_reserve_list, &ec);
829 super->s_journal_seg[i] = segno;
830 super->s_journal_ec[i] = ec;
831 logfs_set_segment_reserved(sb, segno);
832 err = btree_insert32(head, segno, (void *)1, GFP_KERNEL);
833 BUG_ON(err); /* mempool should prevent this */
834 err = logfs_erase_segment(sb, segno, 1);
835 BUG_ON(err); /* FIXME: remount-ro would be nicer */
836 }
837 /* Manually move journal_area */
838 freeseg(sb, area->a_segno);
839 area->a_segno = super->s_journal_seg[0];
840 area->a_is_open = 0;
841 area->a_used_bytes = 0;
842 /* Write journal */
843 logfs_write_anchor(sb);
844 /* Write superblocks */
845 err = logfs_write_sb(sb);
846 BUG_ON(err);
847 }
848
849 static const struct logfs_area_ops journal_area_ops = {
850 .get_free_segment = journal_get_free_segment,
851 .get_erase_count = journal_get_erase_count,
852 .erase_segment = journal_erase_segment,
853 };
854
855 int logfs_init_journal(struct super_block *sb)
856 {
857 struct logfs_super *super = logfs_super(sb);
858 size_t bufsize = max_t(size_t, sb->s_blocksize, super->s_writesize)
859 + MAX_JOURNAL_HEADER;
860 int ret = -ENOMEM;
861
862 mutex_init(&super->s_journal_mutex);
863 btree_init_mempool32(&super->s_reserved_segments, super->s_btree_pool);
864
865 super->s_je = kzalloc(bufsize, GFP_KERNEL);
866 if (!super->s_je)
867 return ret;
868
869 super->s_compressed_je = kzalloc(bufsize, GFP_KERNEL);
870 if (!super->s_compressed_je)
871 return ret;
872
873 super->s_master_inode = logfs_new_meta_inode(sb, LOGFS_INO_MASTER);
874 if (IS_ERR(super->s_master_inode))
875 return PTR_ERR(super->s_master_inode);
876
877 ret = logfs_read_journal(sb);
878 if (ret)
879 return -EIO;
880
881 reserve_sb_and_journal(sb);
882 logfs_calc_free(sb);
883
884 super->s_journal_area->a_ops = &journal_area_ops;
885 return 0;
886 }
887
888 void logfs_cleanup_journal(struct super_block *sb)
889 {
890 struct logfs_super *super = logfs_super(sb);
891
892 btree_grim_visitor32(&super->s_reserved_segments, 0, NULL);
893 destroy_meta_inode(super->s_master_inode);
894 super->s_master_inode = NULL;
895
896 kfree(super->s_compressed_je);
897 kfree(super->s_je);
898 }
Linux with added FPC-III support