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Merge remote-tracking branch 'slab/for-next'
[linux-2.6/next.git] / fs / logfs / journal.c
blob9da29706f91cd74772169e6391333ae877a1fa05
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 return logfs_buf_recover(area, ofs, a + 1, super->s_writesize);
136 else
137 return logfs_buf_recover(area, ofs, NULL, 0);
138 }
139
140 static 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
159 static 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
184 static 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 */
211 static 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
222 static 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 err = 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
260 static 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;
266 u16 len, datalen, last_len = 0;
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
311 static 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
331 static 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 */
358 static 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
382 static 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
388 static int journal_erase_segment(struct logfs_area *area)
389 {
390 struct super_block *sb = area->a_sb;
391 union {
392 struct logfs_segment_header sh;
393 unsigned char c[ALIGN(sizeof(struct logfs_segment_header), 16)];
394 } u;
395 u64 ofs;
396 int err;
397
398 err = logfs_erase_segment(sb, area->a_segno, 1);
399 if (err)
400 return err;
401
402 memset(&u, 0, sizeof(u));
403 u.sh.pad = 0;
404 u.sh.type = SEG_JOURNAL;
405 u.sh.level = 0;
406 u.sh.segno = cpu_to_be32(area->a_segno);
407 u.sh.ec = cpu_to_be32(area->a_erase_count);
408 u.sh.gec = cpu_to_be64(logfs_super(sb)->s_gec);
409 u.sh.crc = logfs_crc32(&u.sh, sizeof(u.sh), 4);
410
411 /* This causes a bug in segment.c. Not yet. */
412 //logfs_set_segment_erased(sb, area->a_segno, area->a_erase_count, 0);
413
414 ofs = dev_ofs(sb, area->a_segno, 0);
415 area->a_used_bytes = sizeof(u);
416 logfs_buf_write(area, ofs, &u, sizeof(u));
417 return 0;
418 }
419
420 static size_t __logfs_write_header(struct logfs_super *super,
421 struct logfs_journal_header *jh, size_t len, size_t datalen,
422 u16 type, u8 compr)
423 {
424 jh->h_len = cpu_to_be16(len);
425 jh->h_type = cpu_to_be16(type);
426 jh->h_datalen = cpu_to_be16(datalen);
427 jh->h_compr = compr;
428 jh->h_pad[0] = 'H';
429 jh->h_pad[1] = 'E';
430 jh->h_pad[2] = 'A';
431 jh->h_pad[3] = 'D';
432 jh->h_pad[4] = 'R';
433 jh->h_crc = logfs_crc32(jh, len + sizeof(*jh), 4);
434 return ALIGN(len, 16) + sizeof(*jh);
435 }
436
437 static size_t logfs_write_header(struct logfs_super *super,
438 struct logfs_journal_header *jh, size_t datalen, u16 type)
439 {
440 size_t len = datalen;
441
442 return __logfs_write_header(super, jh, len, datalen, type, COMPR_NONE);
443 }
444
445 static inline size_t logfs_journal_erasecount_size(struct logfs_super *super)
446 {
447 return LOGFS_JOURNAL_SEGS * sizeof(__be32);
448 }
449
450 static void *logfs_write_erasecount(struct super_block *sb, void *_ec,
451 u16 *type, size_t *len)
452 {
453 struct logfs_super *super = logfs_super(sb);
454 struct logfs_je_journal_ec *ec = _ec;
455 int i;
456
457 journal_for_each(i)
458 ec->ec[i] = cpu_to_be32(super->s_journal_ec[i]);
459 *type = JE_ERASECOUNT;
460 *len = logfs_journal_erasecount_size(super);
461 return ec;
462 }
463
464 static void account_shadow(void *_shadow, unsigned long _sb, u64 ignore,
465 size_t ignore2)
466 {
467 struct logfs_shadow *shadow = _shadow;
468 struct super_block *sb = (void *)_sb;
469 struct logfs_super *super = logfs_super(sb);
470
471 /* consume new space */
472 super->s_free_bytes -= shadow->new_len;
473 super->s_used_bytes += shadow->new_len;
474 super->s_dirty_used_bytes -= shadow->new_len;
475
476 /* free up old space */
477 super->s_free_bytes += shadow->old_len;
478 super->s_used_bytes -= shadow->old_len;
479 super->s_dirty_free_bytes -= shadow->old_len;
480
481 logfs_set_segment_used(sb, shadow->old_ofs, -shadow->old_len);
482 logfs_set_segment_used(sb, shadow->new_ofs, shadow->new_len);
483
484 log_journal("account_shadow(%llx, %llx, %x) %llx->%llx %x->%x\n",
485 shadow->ino, shadow->bix, shadow->gc_level,
486 shadow->old_ofs, shadow->new_ofs,
487 shadow->old_len, shadow->new_len);
488 mempool_free(shadow, super->s_shadow_pool);
489 }
490
491 static void account_shadows(struct super_block *sb)
492 {
493 struct logfs_super *super = logfs_super(sb);
494 struct inode *inode = super->s_master_inode;
495 struct logfs_inode *li = logfs_inode(inode);
496 struct shadow_tree *tree = &super->s_shadow_tree;
497
498 btree_grim_visitor64(&tree->new, (unsigned long)sb, account_shadow);
499 btree_grim_visitor64(&tree->old, (unsigned long)sb, account_shadow);
500 btree_grim_visitor32(&tree->segment_map, 0, NULL);
501 tree->no_shadowed_segments = 0;
502
503 if (li->li_block) {
504 /*
505 * We never actually use the structure, when attached to the
506 * master inode. But it is easier to always free it here than
507 * to have checks in several places elsewhere when allocating
508 * it.
509 */
510 li->li_block->ops->free_block(sb, li->li_block);
511 }
512 BUG_ON((s64)li->li_used_bytes < 0);
513 }
514
515 static void *__logfs_write_anchor(struct super_block *sb, void *_da,
516 u16 *type, size_t *len)
517 {
518 struct logfs_super *super = logfs_super(sb);
519 struct logfs_je_anchor *da = _da;
520 struct inode *inode = super->s_master_inode;
521 struct logfs_inode *li = logfs_inode(inode);
522 int i;
523
524 da->da_height = li->li_height;
525 da->da_last_ino = cpu_to_be64(super->s_last_ino);
526 da->da_size = cpu_to_be64(i_size_read(inode));
527 da->da_used_bytes = cpu_to_be64(li->li_used_bytes);
528 for (i = 0; i < LOGFS_EMBEDDED_FIELDS; i++)
529 da->da_data[i] = cpu_to_be64(li->li_data[i]);
530 *type = JE_ANCHOR;
531 *len = sizeof(*da);
532 return da;
533 }
534
535 static void *logfs_write_dynsb(struct super_block *sb, void *_dynsb,
536 u16 *type, size_t *len)
537 {
538 struct logfs_super *super = logfs_super(sb);
539 struct logfs_je_dynsb *dynsb = _dynsb;
540
541 dynsb->ds_gec = cpu_to_be64(super->s_gec);
542 dynsb->ds_sweeper = cpu_to_be64(super->s_sweeper);
543 dynsb->ds_victim_ino = cpu_to_be64(super->s_victim_ino);
544 dynsb->ds_rename_dir = cpu_to_be64(super->s_rename_dir);
545 dynsb->ds_rename_pos = cpu_to_be64(super->s_rename_pos);
546 dynsb->ds_used_bytes = cpu_to_be64(super->s_used_bytes);
547 dynsb->ds_generation = cpu_to_be32(super->s_generation);
548 *type = JE_DYNSB;
549 *len = sizeof(*dynsb);
550 return dynsb;
551 }
552
553 static void write_wbuf(struct super_block *sb, struct logfs_area *area,
554 void *wbuf)
555 {
556 struct logfs_super *super = logfs_super(sb);
557 struct address_space *mapping = super->s_mapping_inode->i_mapping;
558 u64 ofs;
559 pgoff_t index;
560 int page_ofs;
561 struct page *page;
562
563 ofs = dev_ofs(sb, area->a_segno,
564 area->a_used_bytes & ~(super->s_writesize - 1));
565 index = ofs >> PAGE_SHIFT;
566 page_ofs = ofs & (PAGE_SIZE - 1);
567
568 page = find_lock_page(mapping, index);
569 BUG_ON(!page);
570 memcpy(wbuf, page_address(page) + page_ofs, super->s_writesize);
571 unlock_page(page);
572 }
573
574 static void *logfs_write_area(struct super_block *sb, void *_a,
575 u16 *type, size_t *len)
576 {
577 struct logfs_super *super = logfs_super(sb);
578 struct logfs_area *area = super->s_area[super->s_sum_index];
579 struct logfs_je_area *a = _a;
580
581 a->vim = VIM_DEFAULT;
582 a->gc_level = super->s_sum_index;
583 a->used_bytes = cpu_to_be32(area->a_used_bytes);
584 a->segno = cpu_to_be32(area->a_segno);
585 if (super->s_writesize > 1)
586 write_wbuf(sb, area, a + 1);
587
588 *type = JE_AREA;
589 *len = sizeof(*a) + super->s_writesize;
590 return a;
591 }
592
593 static void *logfs_write_commit(struct super_block *sb, void *h,
594 u16 *type, size_t *len)
595 {
596 struct logfs_super *super = logfs_super(sb);
597
598 *type = JE_COMMIT;
599 *len = super->s_no_je * sizeof(__be64);
600 return super->s_je_array;
601 }
602
603 static size_t __logfs_write_je(struct super_block *sb, void *buf, u16 type,
604 size_t len)
605 {
606 struct logfs_super *super = logfs_super(sb);
607 void *header = super->s_compressed_je;
608 void *data = header + sizeof(struct logfs_journal_header);
609 ssize_t compr_len, pad_len;
610 u8 compr = COMPR_ZLIB;
611
612 if (len == 0)
613 return logfs_write_header(super, header, 0, type);
614
615 BUG_ON(len > sb->s_blocksize);
616 compr_len = logfs_compress(buf, data, len, sb->s_blocksize);
617 if (compr_len < 0 || type == JE_ANCHOR) {
618 memcpy(data, buf, len);
619 compr_len = len;
620 compr = COMPR_NONE;
621 }
622
623 pad_len = ALIGN(compr_len, 16);
624 memset(data + compr_len, 0, pad_len - compr_len);
625
626 return __logfs_write_header(super, header, compr_len, len, type, compr);
627 }
628
629 static s64 logfs_get_free_bytes(struct logfs_area *area, size_t *bytes,
630 int must_pad)
631 {
632 u32 writesize = logfs_super(area->a_sb)->s_writesize;
633 s32 ofs;
634 int ret;
635
636 ret = logfs_open_area(area, *bytes);
637 if (ret)
638 return -EAGAIN;
639
640 ofs = area->a_used_bytes;
641 area->a_used_bytes += *bytes;
642
643 if (must_pad) {
644 area->a_used_bytes = ALIGN(area->a_used_bytes, writesize);
645 *bytes = area->a_used_bytes - ofs;
646 }
647
648 return dev_ofs(area->a_sb, area->a_segno, ofs);
649 }
650
651 static int logfs_write_je_buf(struct super_block *sb, void *buf, u16 type,
652 size_t buf_len)
653 {
654 struct logfs_super *super = logfs_super(sb);
655 struct logfs_area *area = super->s_journal_area;
656 struct logfs_journal_header *jh = super->s_compressed_je;
657 size_t len;
658 int must_pad = 0;
659 s64 ofs;
660
661 len = __logfs_write_je(sb, buf, type, buf_len);
662 if (jh->h_type == cpu_to_be16(JE_COMMIT))
663 must_pad = 1;
664
665 ofs = logfs_get_free_bytes(area, &len, must_pad);
666 if (ofs < 0)
667 return ofs;
668 logfs_buf_write(area, ofs, super->s_compressed_je, len);
669 BUG_ON(super->s_no_je >= MAX_JOURNAL_ENTRIES);
670 super->s_je_array[super->s_no_je++] = cpu_to_be64(ofs);
671 return 0;
672 }
673
674 static int logfs_write_je(struct super_block *sb,
675 void* (*write)(struct super_block *sb, void *scratch,
676 u16 *type, size_t *len))
677 {
678 void *buf;
679 size_t len;
680 u16 type;
681
682 buf = write(sb, logfs_super(sb)->s_je, &type, &len);
683 return logfs_write_je_buf(sb, buf, type, len);
684 }
685
686 int write_alias_journal(struct super_block *sb, u64 ino, u64 bix,
687 level_t level, int child_no, __be64 val)
688 {
689 struct logfs_super *super = logfs_super(sb);
690 struct logfs_obj_alias *oa = super->s_je;
691 int err = 0, fill = super->s_je_fill;
692
693 log_aliases("logfs_write_obj_aliases #%x(%llx, %llx, %x, %x) %llx\n",
694 fill, ino, bix, level, child_no, be64_to_cpu(val));
695 oa[fill].ino = cpu_to_be64(ino);
696 oa[fill].bix = cpu_to_be64(bix);
697 oa[fill].val = val;
698 oa[fill].level = (__force u8)level;
699 oa[fill].child_no = cpu_to_be16(child_no);
700 fill++;
701 if (fill >= sb->s_blocksize / sizeof(*oa)) {
702 err = logfs_write_je_buf(sb, oa, JE_OBJ_ALIAS, sb->s_blocksize);
703 fill = 0;
704 }
705
706 super->s_je_fill = fill;
707 return err;
708 }
709
710 static int logfs_write_obj_aliases(struct super_block *sb)
711 {
712 struct logfs_super *super = logfs_super(sb);
713 int err;
714
715 log_journal("logfs_write_obj_aliases: %d aliases to write\n",
716 super->s_no_object_aliases);
717 super->s_je_fill = 0;
718 err = logfs_write_obj_aliases_pagecache(sb);
719 if (err)
720 return err;
721
722 if (super->s_je_fill)
723 err = logfs_write_je_buf(sb, super->s_je, JE_OBJ_ALIAS,
724 super->s_je_fill
725 * sizeof(struct logfs_obj_alias));
726 return err;
727 }
728
729 /*
730 * Write all journal entries. The goto logic ensures that all journal entries
731 * are written whenever a new segment is used. It is ugly and potentially a
732 * bit wasteful, but robustness is more important. With this we can *always*
733 * erase all journal segments except the one containing the most recent commit.
734 */
735 void logfs_write_anchor(struct super_block *sb)
736 {
737 struct logfs_super *super = logfs_super(sb);
738 struct logfs_area *area = super->s_journal_area;
739 int i, err;
740
741 if (!(super->s_flags & LOGFS_SB_FLAG_DIRTY))
742 return;
743 super->s_flags &= ~LOGFS_SB_FLAG_DIRTY;
744
745 BUG_ON(super->s_flags & LOGFS_SB_FLAG_SHUTDOWN);
746 mutex_lock(&super->s_journal_mutex);
747
748 /* Do this first or suffer corruption */
749 logfs_sync_segments(sb);
750 account_shadows(sb);
751
752 again:
753 super->s_no_je = 0;
754 for_each_area(i) {
755 if (!super->s_area[i]->a_is_open)
756 continue;
757 super->s_sum_index = i;
758 err = logfs_write_je(sb, logfs_write_area);
759 if (err)
760 goto again;
761 }
762 err = logfs_write_obj_aliases(sb);
763 if (err)
764 goto again;
765 err = logfs_write_je(sb, logfs_write_erasecount);
766 if (err)
767 goto again;
768 err = logfs_write_je(sb, __logfs_write_anchor);
769 if (err)
770 goto again;
771 err = logfs_write_je(sb, logfs_write_dynsb);
772 if (err)
773 goto again;
774 /*
775 * Order is imperative. First we sync all writes, including the
776 * non-committed journal writes. Then we write the final commit and
777 * sync the current journal segment.
778 * There is a theoretical bug here. Syncing the journal segment will
779 * write a number of journal entries and the final commit. All these
780 * are written in a single operation. If the device layer writes the
781 * data back-to-front, the commit will precede the other journal
782 * entries, leaving a race window.
783 * Two fixes are possible. Preferred is to fix the device layer to
784 * ensure writes happen front-to-back. Alternatively we can insert
785 * another logfs_sync_area() super->s_devops->sync() combo before
786 * writing the commit.
787 */
788 /*
789 * On another subject, super->s_devops->sync is usually not necessary.
790 * Unless called from sys_sync or friends, a barrier would suffice.
791 */
792 super->s_devops->sync(sb);
793 err = logfs_write_je(sb, logfs_write_commit);
794 if (err)
795 goto again;
796 log_journal("Write commit to %llx\n",
797 be64_to_cpu(super->s_je_array[super->s_no_je - 1]));
798 logfs_sync_area(area);
799 BUG_ON(area->a_used_bytes != area->a_written_bytes);
800 super->s_devops->sync(sb);
801
802 mutex_unlock(&super->s_journal_mutex);
803 return;
804 }
805
806 void do_logfs_journal_wl_pass(struct super_block *sb)
807 {
808 struct logfs_super *super = logfs_super(sb);
809 struct logfs_area *area = super->s_journal_area;
810 struct btree_head32 *head = &super->s_reserved_segments;
811 u32 segno, ec;
812 int i, err;
813
814 log_journal("Journal requires wear-leveling.\n");
815 /* Drop old segments */
816 journal_for_each(i)
817 if (super->s_journal_seg[i]) {
818 btree_remove32(head, super->s_journal_seg[i]);
819 logfs_set_segment_unreserved(sb,
820 super->s_journal_seg[i],
821 super->s_journal_ec[i]);
822 super->s_journal_seg[i] = 0;
823 super->s_journal_ec[i] = 0;
824 }
825 /* Get new segments */
826 for (i = 0; i < super->s_no_journal_segs; i++) {
827 segno = get_best_cand(sb, &super->s_reserve_list, &ec);
828 super->s_journal_seg[i] = segno;
829 super->s_journal_ec[i] = ec;
830 logfs_set_segment_reserved(sb, segno);
831 err = btree_insert32(head, segno, (void *)1, GFP_NOFS);
832 BUG_ON(err); /* mempool should prevent this */
833 err = logfs_erase_segment(sb, segno, 1);
834 BUG_ON(err); /* FIXME: remount-ro would be nicer */
835 }
836 /* Manually move journal_area */
837 freeseg(sb, area->a_segno);
838 area->a_segno = super->s_journal_seg[0];
839 area->a_is_open = 0;
840 area->a_used_bytes = 0;
841 /* Write journal */
842 logfs_write_anchor(sb);
843 /* Write superblocks */
844 err = logfs_write_sb(sb);
845 BUG_ON(err);
846 }
847
848 static const struct logfs_area_ops journal_area_ops = {
849 .get_free_segment = journal_get_free_segment,
850 .get_erase_count = journal_get_erase_count,
851 .erase_segment = journal_erase_segment,
852 };
853
854 int logfs_init_journal(struct super_block *sb)
855 {
856 struct logfs_super *super = logfs_super(sb);
857 size_t bufsize = max_t(size_t, sb->s_blocksize, super->s_writesize)
858 + MAX_JOURNAL_HEADER;
859 int ret = -ENOMEM;
860
861 mutex_init(&super->s_journal_mutex);
862 btree_init_mempool32(&super->s_reserved_segments, super->s_btree_pool);
863
864 super->s_je = kzalloc(bufsize, GFP_KERNEL);
865 if (!super->s_je)
866 return ret;
867
868 super->s_compressed_je = kzalloc(bufsize, GFP_KERNEL);
869 if (!super->s_compressed_je)
870 return ret;
871
872 super->s_master_inode = logfs_new_meta_inode(sb, LOGFS_INO_MASTER);
873 if (IS_ERR(super->s_master_inode))
874 return PTR_ERR(super->s_master_inode);
875
876 ret = logfs_read_journal(sb);
877 if (ret)
878 return -EIO;
879
880 reserve_sb_and_journal(sb);
881 logfs_calc_free(sb);
882
883 super->s_journal_area->a_ops = &journal_area_ops;
884 return 0;
885 }
886
887 void logfs_cleanup_journal(struct super_block *sb)
888 {
889 struct logfs_super *super = logfs_super(sb);
890
891 btree_grim_visitor32(&super->s_reserved_segments, 0, NULL);
892
893 kfree(super->s_compressed_je);
894 kfree(super->s_je);
895 }
linux-next