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-rw-r--r--fs/logfs/gc.c730
1 files changed, 730 insertions, 0 deletions
diff --git a/fs/logfs/gc.c b/fs/logfs/gc.c
new file mode 100644
index 000000000000..92949f95a901
--- /dev/null
+++ b/fs/logfs/gc.c
@@ -0,0 +1,730 @@
1/*
2 * fs/logfs/gc.c - garbage collection 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/sched.h>
10
11/*
12 * Wear leveling needs to kick in when the difference between low erase
13 * counts and high erase counts gets too big. A good value for "too big"
14 * may be somewhat below 10% of maximum erase count for the device.
15 * Why not 397, to pick a nice round number with no specific meaning? :)
16 *
17 * WL_RATELIMIT is the minimum time between two wear level events. A huge
18 * number of segments may fulfil the requirements for wear leveling at the
19 * same time. If that happens we don't want to cause a latency from hell,
20 * but just gently pick one segment every so often and minimize overhead.
21 */
22#define WL_DELTA 397
23#define WL_RATELIMIT 100
24#define MAX_OBJ_ALIASES 2600
25#define SCAN_RATIO 512 /* number of scanned segments per gc'd segment */
26#define LIST_SIZE 64 /* base size of candidate lists */
27#define SCAN_ROUNDS 128 /* maximum number of complete medium scans */
28#define SCAN_ROUNDS_HIGH 4 /* maximum number of higher-level scans */
29
30static int no_free_segments(struct super_block *sb)
31{
32 struct logfs_super *super = logfs_super(sb);
33
34 return super->s_free_list.count;
35}
36
37/* journal has distance -1, top-most ifile layer distance 0 */
38static u8 root_distance(struct super_block *sb, gc_level_t __gc_level)
39{
40 struct logfs_super *super = logfs_super(sb);
41 u8 gc_level = (__force u8)__gc_level;
42
43 switch (gc_level) {
44 case 0: /* fall through */
45 case 1: /* fall through */
46 case 2: /* fall through */
47 case 3:
48 /* file data or indirect blocks */
49 return super->s_ifile_levels + super->s_iblock_levels - gc_level;
50 case 6: /* fall through */
51 case 7: /* fall through */
52 case 8: /* fall through */
53 case 9:
54 /* inode file data or indirect blocks */
55 return super->s_ifile_levels - (gc_level - 6);
56 default:
57 printk(KERN_ERR"LOGFS: segment of unknown level %x found\n",
58 gc_level);
59 WARN_ON(1);
60 return super->s_ifile_levels + super->s_iblock_levels;
61 }
62}
63
64static int segment_is_reserved(struct super_block *sb, u32 segno)
65{
66 struct logfs_super *super = logfs_super(sb);
67 struct logfs_area *area;
68 void *reserved;
69 int i;
70
71 /* Some segments are reserved. Just pretend they were all valid */
72 reserved = btree_lookup32(&super->s_reserved_segments, segno);
73 if (reserved)
74 return 1;
75
76 /* Currently open segments */
77 for_each_area(i) {
78 area = super->s_area[i];
79 if (area->a_is_open && area->a_segno == segno)
80 return 1;
81 }
82
83 return 0;
84}
85
86static void logfs_mark_segment_bad(struct super_block *sb, u32 segno)
87{
88 BUG();
89}
90
91/*
92 * Returns the bytes consumed by valid objects in this segment. Object headers
93 * are counted, the segment header is not.
94 */
95static u32 logfs_valid_bytes(struct super_block *sb, u32 segno, u32 *ec,
96 gc_level_t *gc_level)
97{
98 struct logfs_segment_entry se;
99 u32 ec_level;
100
101 logfs_get_segment_entry(sb, segno, &se);
102 if (se.ec_level == cpu_to_be32(BADSEG) ||
103 se.valid == cpu_to_be32(RESERVED))
104 return RESERVED;
105
106 ec_level = be32_to_cpu(se.ec_level);
107 *ec = ec_level >> 4;
108 *gc_level = GC_LEVEL(ec_level & 0xf);
109 return be32_to_cpu(se.valid);
110}
111
112static void logfs_cleanse_block(struct super_block *sb, u64 ofs, u64 ino,
113 u64 bix, gc_level_t gc_level)
114{
115 struct inode *inode;
116 int err, cookie;
117
118 inode = logfs_safe_iget(sb, ino, &cookie);
119 err = logfs_rewrite_block(inode, bix, ofs, gc_level, 0);
120 BUG_ON(err);
121 logfs_safe_iput(inode, cookie);
122}
123
124static u32 logfs_gc_segment(struct super_block *sb, u32 segno, u8 dist)
125{
126 struct logfs_super *super = logfs_super(sb);
127 struct logfs_segment_header sh;
128 struct logfs_object_header oh;
129 u64 ofs, ino, bix;
130 u32 seg_ofs, logical_segno, cleaned = 0;
131 int err, len, valid;
132 gc_level_t gc_level;
133
134 LOGFS_BUG_ON(segment_is_reserved(sb, segno), sb);
135
136 btree_insert32(&super->s_reserved_segments, segno, (void *)1, GFP_NOFS);
137 err = wbuf_read(sb, dev_ofs(sb, segno, 0), sizeof(sh), &sh);
138 BUG_ON(err);
139 gc_level = GC_LEVEL(sh.level);
140 logical_segno = be32_to_cpu(sh.segno);
141 if (sh.crc != logfs_crc32(&sh, sizeof(sh), 4)) {
142 logfs_mark_segment_bad(sb, segno);
143 cleaned = -1;
144 goto out;
145 }
146
147 for (seg_ofs = LOGFS_SEGMENT_HEADERSIZE;
148 seg_ofs + sizeof(oh) < super->s_segsize; ) {
149 ofs = dev_ofs(sb, logical_segno, seg_ofs);
150 err = wbuf_read(sb, dev_ofs(sb, segno, seg_ofs), sizeof(oh),
151 &oh);
152 BUG_ON(err);
153
154 if (!memchr_inv(&oh, 0xff, sizeof(oh)))
155 break;
156
157 if (oh.crc != logfs_crc32(&oh, sizeof(oh) - 4, 4)) {
158 logfs_mark_segment_bad(sb, segno);
159 cleaned = super->s_segsize - 1;
160 goto out;
161 }
162
163 ino = be64_to_cpu(oh.ino);
164 bix = be64_to_cpu(oh.bix);
165 len = sizeof(oh) + be16_to_cpu(oh.len);
166 valid = logfs_is_valid_block(sb, ofs, ino, bix, gc_level);
167 if (valid == 1) {
168 logfs_cleanse_block(sb, ofs, ino, bix, gc_level);
169 cleaned += len;
170 } else if (valid == 2) {
171 /* Will be invalid upon journal commit */
172 cleaned += len;
173 }
174 seg_ofs += len;
175 }
176out:
177 btree_remove32(&super->s_reserved_segments, segno);
178 return cleaned;
179}
180
181static struct gc_candidate *add_list(struct gc_candidate *cand,
182 struct candidate_list *list)
183{
184 struct rb_node **p = &list->rb_tree.rb_node;
185 struct rb_node *parent = NULL;
186 struct gc_candidate *cur;
187 int comp;
188
189 cand->list = list;
190 while (*p) {
191 parent = *p;
192 cur = rb_entry(parent, struct gc_candidate, rb_node);
193
194 if (list->sort_by_ec)
195 comp = cand->erase_count < cur->erase_count;
196 else
197 comp = cand->valid < cur->valid;
198
199 if (comp)
200 p = &parent->rb_left;
201 else
202 p = &parent->rb_right;
203 }
204 rb_link_node(&cand->rb_node, parent, p);
205 rb_insert_color(&cand->rb_node, &list->rb_tree);
206
207 if (list->count <= list->maxcount) {
208 list->count++;
209 return NULL;
210 }
211 cand = rb_entry(rb_last(&list->rb_tree), struct gc_candidate, rb_node);
212 rb_erase(&cand->rb_node, &list->rb_tree);
213 cand->list = NULL;
214 return cand;
215}
216
217static void remove_from_list(struct gc_candidate *cand)
218{
219 struct candidate_list *list = cand->list;
220
221 rb_erase(&cand->rb_node, &list->rb_tree);
222 list->count--;
223}
224
225static void free_candidate(struct super_block *sb, struct gc_candidate *cand)
226{
227 struct logfs_super *super = logfs_super(sb);
228
229 btree_remove32(&super->s_cand_tree, cand->segno);
230 kfree(cand);
231}
232
233u32 get_best_cand(struct super_block *sb, struct candidate_list *list, u32 *ec)
234{
235 struct gc_candidate *cand;
236 u32 segno;
237
238 BUG_ON(list->count == 0);
239
240 cand = rb_entry(rb_first(&list->rb_tree), struct gc_candidate, rb_node);
241 remove_from_list(cand);
242 segno = cand->segno;
243 if (ec)
244 *ec = cand->erase_count;
245 free_candidate(sb, cand);
246 return segno;
247}
248
249/*
250 * We have several lists to manage segments with. The reserve_list is used to
251 * deal with bad blocks. We try to keep the best (lowest ec) segments on this
252 * list.
253 * The free_list contains free segments for normal usage. It usually gets the
254 * second pick after the reserve_list. But when the free_list is running short
255 * it is more important to keep the free_list full than to keep a reserve.
256 *
257 * Segments that are not free are put onto a per-level low_list. If we have
258 * to run garbage collection, we pick a candidate from there. All segments on
259 * those lists should have at least some free space so GC will make progress.
260 *
261 * And last we have the ec_list, which is used to pick segments for wear
262 * leveling.
263 *
264 * If all appropriate lists are full, we simply free the candidate and forget
265 * about that segment for a while. We have better candidates for each purpose.
266 */
267static void __add_candidate(struct super_block *sb, struct gc_candidate *cand)
268{
269 struct logfs_super *super = logfs_super(sb);
270 u32 full = super->s_segsize - LOGFS_SEGMENT_RESERVE;
271
272 if (cand->valid == 0) {
273 /* 100% free segments */
274 log_gc_noisy("add reserve segment %x (ec %x) at %llx\n",
275 cand->segno, cand->erase_count,
276 dev_ofs(sb, cand->segno, 0));
277 cand = add_list(cand, &super->s_reserve_list);
278 if (cand) {
279 log_gc_noisy("add free segment %x (ec %x) at %llx\n",
280 cand->segno, cand->erase_count,
281 dev_ofs(sb, cand->segno, 0));
282 cand = add_list(cand, &super->s_free_list);
283 }
284 } else {
285 /* good candidates for Garbage Collection */
286 if (cand->valid < full)
287 cand = add_list(cand, &super->s_low_list[cand->dist]);
288 /* good candidates for wear leveling,
289 * segments that were recently written get ignored */
290 if (cand)
291 cand = add_list(cand, &super->s_ec_list);
292 }
293 if (cand)
294 free_candidate(sb, cand);
295}
296
297static int add_candidate(struct super_block *sb, u32 segno, u32 valid, u32 ec,
298 u8 dist)
299{
300 struct logfs_super *super = logfs_super(sb);
301 struct gc_candidate *cand;
302
303 cand = kmalloc(sizeof(*cand), GFP_NOFS);
304 if (!cand)
305 return -ENOMEM;
306
307 cand->segno = segno;
308 cand->valid = valid;
309 cand->erase_count = ec;
310 cand->dist = dist;
311
312 btree_insert32(&super->s_cand_tree, segno, cand, GFP_NOFS);
313 __add_candidate(sb, cand);
314 return 0;
315}
316
317static void remove_segment_from_lists(struct super_block *sb, u32 segno)
318{
319 struct logfs_super *super = logfs_super(sb);
320 struct gc_candidate *cand;
321
322 cand = btree_lookup32(&super->s_cand_tree, segno);
323 if (cand) {
324 remove_from_list(cand);
325 free_candidate(sb, cand);
326 }
327}
328
329static void scan_segment(struct super_block *sb, u32 segno)
330{
331 u32 valid, ec = 0;
332 gc_level_t gc_level = 0;
333 u8 dist;
334
335 if (segment_is_reserved(sb, segno))
336 return;
337
338 remove_segment_from_lists(sb, segno);
339 valid = logfs_valid_bytes(sb, segno, &ec, &gc_level);
340 if (valid == RESERVED)
341 return;
342
343 dist = root_distance(sb, gc_level);
344 add_candidate(sb, segno, valid, ec, dist);
345}
346
347static struct gc_candidate *first_in_list(struct candidate_list *list)
348{
349 if (list->count == 0)
350 return NULL;
351 return rb_entry(rb_first(&list->rb_tree), struct gc_candidate, rb_node);
352}
353
354/*
355 * Find the best segment for garbage collection. Main criterion is
356 * the segment requiring the least effort to clean. Secondary
357 * criterion is to GC on the lowest level available.
358 *
359 * So we search the least effort segment on the lowest level first,
360 * then move up and pick another segment iff is requires significantly
361 * less effort. Hence the LOGFS_MAX_OBJECTSIZE in the comparison.
362 */
363static struct gc_candidate *get_candidate(struct super_block *sb)
364{
365 struct logfs_super *super = logfs_super(sb);
366 int i, max_dist;
367 struct gc_candidate *cand = NULL, *this;
368
369 max_dist = min(no_free_segments(sb), LOGFS_NO_AREAS);
370
371 for (i = max_dist; i >= 0; i--) {
372 this = first_in_list(&super->s_low_list[i]);
373 if (!this)
374 continue;
375 if (!cand)
376 cand = this;
377 if (this->valid + LOGFS_MAX_OBJECTSIZE <= cand->valid)
378 cand = this;
379 }
380 return cand;
381}
382
383static int __logfs_gc_once(struct super_block *sb, struct gc_candidate *cand)
384{
385 struct logfs_super *super = logfs_super(sb);
386 gc_level_t gc_level;
387 u32 cleaned, valid, segno, ec;
388 u8 dist;
389
390 if (!cand) {
391 log_gc("GC attempted, but no candidate found\n");
392 return 0;
393 }
394
395 segno = cand->segno;
396 dist = cand->dist;
397 valid = logfs_valid_bytes(sb, segno, &ec, &gc_level);
398 free_candidate(sb, cand);
399 log_gc("GC segment #%02x at %llx, %x required, %x free, %x valid, %llx free\n",
400 segno, (u64)segno << super->s_segshift,
401 dist, no_free_segments(sb), valid,
402 super->s_free_bytes);
403 cleaned = logfs_gc_segment(sb, segno, dist);
404 log_gc("GC segment #%02x complete - now %x valid\n", segno,
405 valid - cleaned);
406 BUG_ON(cleaned != valid);
407 return 1;
408}
409
410static int logfs_gc_once(struct super_block *sb)
411{
412 struct gc_candidate *cand;
413
414 cand = get_candidate(sb);
415 if (cand)
416 remove_from_list(cand);
417 return __logfs_gc_once(sb, cand);
418}
419
420/* returns 1 if a wrap occurs, 0 otherwise */
421static int logfs_scan_some(struct super_block *sb)
422{
423 struct logfs_super *super = logfs_super(sb);
424 u32 segno;
425 int i, ret = 0;
426
427 segno = super->s_sweeper;
428 for (i = SCAN_RATIO; i > 0; i--) {
429 segno++;
430 if (segno >= super->s_no_segs) {
431 segno = 0;
432 ret = 1;
433 /* Break out of the loop. We want to read a single
434 * block from the segment size on next invocation if
435 * SCAN_RATIO is set to match block size
436 */
437 break;
438 }
439
440 scan_segment(sb, segno);
441 }
442 super->s_sweeper = segno;
443 return ret;
444}
445
446/*
447 * In principle, this function should loop forever, looking for GC candidates
448 * and moving data. LogFS is designed in such a way that this loop is
449 * guaranteed to terminate.
450 *
451 * Limiting the loop to some iterations serves purely to catch cases when
452 * these guarantees have failed. An actual endless loop is an obvious bug
453 * and should be reported as such.
454 */
455static void __logfs_gc_pass(struct super_block *sb, int target)
456{
457 struct logfs_super *super = logfs_super(sb);
458 struct logfs_block *block;
459 int round, progress, last_progress = 0;
460
461 if (no_free_segments(sb) >= target &&
462 super->s_no_object_aliases < MAX_OBJ_ALIASES)
463 return;
464
465 log_gc("__logfs_gc_pass(%x)\n", target);
466 for (round = 0; round < SCAN_ROUNDS; ) {
467 if (no_free_segments(sb) >= target)
468 goto write_alias;
469
470 /* Sync in-memory state with on-medium state in case they
471 * diverged */
472 logfs_write_anchor(sb);
473 round += logfs_scan_some(sb);
474 if (no_free_segments(sb) >= target)
475 goto write_alias;
476 progress = logfs_gc_once(sb);
477 if (progress)
478 last_progress = round;
479 else if (round - last_progress > 2)
480 break;
481 continue;
482
483 /*
484 * The goto logic is nasty, I just don't know a better way to
485 * code it. GC is supposed to ensure two things:
486 * 1. Enough free segments are available.
487 * 2. The number of aliases is bounded.
488 * When 1. is achieved, we take a look at 2. and write back
489 * some alias-containing blocks, if necessary. However, after
490 * each such write we need to go back to 1., as writes can
491 * consume free segments.
492 */
493write_alias:
494 if (super->s_no_object_aliases < MAX_OBJ_ALIASES)
495 return;
496 if (list_empty(&super->s_object_alias)) {
497 /* All aliases are still in btree */
498 return;
499 }
500 log_gc("Write back one alias\n");
501 block = list_entry(super->s_object_alias.next,
502 struct logfs_block, alias_list);
503 block->ops->write_block(block);
504 /*
505 * To round off the nasty goto logic, we reset round here. It
506 * is a safety-net for GC not making any progress and limited
507 * to something reasonably small. If incremented it for every
508 * single alias, the loop could terminate rather quickly.
509 */
510 round = 0;
511 }
512 LOGFS_BUG(sb);
513}
514
515static int wl_ratelimit(struct super_block *sb, u64 *next_event)
516{
517 struct logfs_super *super = logfs_super(sb);
518
519 if (*next_event < super->s_gec) {
520 *next_event = super->s_gec + WL_RATELIMIT;
521 return 0;
522 }
523 return 1;
524}
525
526static void logfs_wl_pass(struct super_block *sb)
527{
528 struct logfs_super *super = logfs_super(sb);
529 struct gc_candidate *wl_cand, *free_cand;
530
531 if (wl_ratelimit(sb, &super->s_wl_gec_ostore))
532 return;
533
534 wl_cand = first_in_list(&super->s_ec_list);
535 if (!wl_cand)
536 return;
537 free_cand = first_in_list(&super->s_free_list);
538 if (!free_cand)
539 return;
540
541 if (wl_cand->erase_count < free_cand->erase_count + WL_DELTA) {
542 remove_from_list(wl_cand);
543 __logfs_gc_once(sb, wl_cand);
544 }
545}
546
547/*
548 * The journal needs wear leveling as well. But moving the journal is an
549 * expensive operation so we try to avoid it as much as possible. And if we
550 * have to do it, we move the whole journal, not individual segments.
551 *
552 * Ratelimiting is not strictly necessary here, it mainly serves to avoid the
553 * calculations. First we check whether moving the journal would be a
554 * significant improvement. That means that a) the current journal segments
555 * have more wear than the future journal segments and b) the current journal
556 * segments have more wear than normal ostore segments.
557 * Rationale for b) is that we don't have to move the journal if it is aging
558 * less than the ostore, even if the reserve segments age even less (they are
559 * excluded from wear leveling, after all).
560 * Next we check that the superblocks have less wear than the journal. Since
561 * moving the journal requires writing the superblocks, we have to protect the
562 * superblocks even more than the journal.
563 *
564 * Also we double the acceptable wear difference, compared to ostore wear
565 * leveling. Journal data is read and rewritten rapidly, comparatively. So
566 * soft errors have much less time to accumulate and we allow the journal to
567 * be a bit worse than the ostore.
568 */
569static void logfs_journal_wl_pass(struct super_block *sb)
570{
571 struct logfs_super *super = logfs_super(sb);
572 struct gc_candidate *cand;
573 u32 min_journal_ec = -1, max_reserve_ec = 0;
574 int i;
575
576 if (wl_ratelimit(sb, &super->s_wl_gec_journal))
577 return;
578
579 if (super->s_reserve_list.count < super->s_no_journal_segs) {
580 /* Reserve is not full enough to move complete journal */
581 return;
582 }
583
584 journal_for_each(i)
585 if (super->s_journal_seg[i])
586 min_journal_ec = min(min_journal_ec,
587 super->s_journal_ec[i]);
588 cand = rb_entry(rb_first(&super->s_free_list.rb_tree),
589 struct gc_candidate, rb_node);
590 max_reserve_ec = cand->erase_count;
591 for (i = 0; i < 2; i++) {
592 struct logfs_segment_entry se;
593 u32 segno = seg_no(sb, super->s_sb_ofs[i]);
594 u32 ec;
595
596 logfs_get_segment_entry(sb, segno, &se);
597 ec = be32_to_cpu(se.ec_level) >> 4;
598 max_reserve_ec = max(max_reserve_ec, ec);
599 }
600
601 if (min_journal_ec > max_reserve_ec + 2 * WL_DELTA) {
602 do_logfs_journal_wl_pass(sb);
603 }
604}
605
606void logfs_gc_pass(struct super_block *sb)
607{
608 struct logfs_super *super = logfs_super(sb);
609
610 //BUG_ON(mutex_trylock(&logfs_super(sb)->s_w_mutex));
611 /* Write journal before free space is getting saturated with dirty
612 * objects.
613 */
614 if (super->s_dirty_used_bytes + super->s_dirty_free_bytes
615 + LOGFS_MAX_OBJECTSIZE >= super->s_free_bytes)
616 logfs_write_anchor(sb);
617 __logfs_gc_pass(sb, super->s_total_levels);
618 logfs_wl_pass(sb);
619 logfs_journal_wl_pass(sb);
620}
621
622static int check_area(struct super_block *sb, int i)
623{
624 struct logfs_super *super = logfs_super(sb);
625 struct logfs_area *area = super->s_area[i];
626 struct logfs_object_header oh;
627 u32 segno = area->a_segno;
628 u32 ofs = area->a_used_bytes;
629 __be32 crc;
630 int err;
631
632 if (!area->a_is_open)
633 return 0;
634
635 for (ofs = area->a_used_bytes;
636 ofs <= super->s_segsize - sizeof(oh);
637 ofs += (u32)be16_to_cpu(oh.len) + sizeof(oh)) {
638 err = wbuf_read(sb, dev_ofs(sb, segno, ofs), sizeof(oh), &oh);
639 if (err)
640 return err;
641
642 if (!memchr_inv(&oh, 0xff, sizeof(oh)))
643 break;
644
645 crc = logfs_crc32(&oh, sizeof(oh) - 4, 4);
646 if (crc != oh.crc) {
647 printk(KERN_INFO "interrupted header at %llx\n",
648 dev_ofs(sb, segno, ofs));
649 return 0;
650 }
651 }
652 if (ofs != area->a_used_bytes) {
653 printk(KERN_INFO "%x bytes unaccounted data found at %llx\n",
654 ofs - area->a_used_bytes,
655 dev_ofs(sb, segno, area->a_used_bytes));
656 area->a_used_bytes = ofs;
657 }
658 return 0;
659}
660
661int logfs_check_areas(struct super_block *sb)
662{
663 int i, err;
664
665 for_each_area(i) {
666 err = check_area(sb, i);
667 if (err)
668 return err;
669 }
670 return 0;
671}
672
673static void logfs_init_candlist(struct candidate_list *list, int maxcount,
674 int sort_by_ec)
675{
676 list->count = 0;
677 list->maxcount = maxcount;
678 list->sort_by_ec = sort_by_ec;
679 list->rb_tree = RB_ROOT;
680}
681
682int logfs_init_gc(struct super_block *sb)
683{
684 struct logfs_super *super = logfs_super(sb);
685 int i;
686
687 btree_init_mempool32(&super->s_cand_tree, super->s_btree_pool);
688 logfs_init_candlist(&super->s_free_list, LIST_SIZE + SCAN_RATIO, 1);
689 logfs_init_candlist(&super->s_reserve_list,
690 super->s_bad_seg_reserve, 1);
691 for_each_area(i)
692 logfs_init_candlist(&super->s_low_list[i], LIST_SIZE, 0);
693 logfs_init_candlist(&super->s_ec_list, LIST_SIZE, 1);
694 return 0;
695}
696
697static void logfs_cleanup_list(struct super_block *sb,
698 struct candidate_list *list)
699{
700 struct gc_candidate *cand;
701
702 while (list->count) {
703 cand = rb_entry(list->rb_tree.rb_node, struct gc_candidate,
704 rb_node);
705 remove_from_list(cand);
706 free_candidate(sb, cand);
707 }
708 BUG_ON(list->rb_tree.rb_node);
709}
710
711void logfs_cleanup_gc(struct super_block *sb)
712{
713 struct logfs_super *super = logfs_super(sb);
714 int i;
715
716 if (!super->s_free_list.count)
717 return;
718
719 /*
720 * FIXME: The btree may still contain a single empty node. So we
721 * call the grim visitor to clean up that mess. Btree code should
722 * do it for us, really.
723 */
724 btree_grim_visitor32(&super->s_cand_tree, 0, NULL);
725 logfs_cleanup_list(sb, &super->s_free_list);
726 logfs_cleanup_list(sb, &super->s_reserve_list);
727 for_each_area(i)
728 logfs_cleanup_list(sb, &super->s_low_list[i]);
729 logfs_cleanup_list(sb, &super->s_ec_list);
730}
generated by cgit v1.2.2 (git 2.25.0) at 2025-10-31 10:42:04 -0400