blob: 94b8a0c4845358ab34dd16b02b9ce12147f04fac [file] [log] [blame]
Jaegeuk Kim0a8165d2012-11-29 13:28:09 +09001/*
Jaegeuk Kim7bc09002012-11-02 17:13:01 +09002 * fs/f2fs/gc.c
3 *
4 * Copyright (c) 2012 Samsung Electronics Co., Ltd.
5 * http://www.samsung.com/
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 */
11#include <linux/fs.h>
12#include <linux/module.h>
13#include <linux/backing-dev.h>
14#include <linux/proc_fs.h>
15#include <linux/init.h>
16#include <linux/f2fs_fs.h>
17#include <linux/kthread.h>
18#include <linux/delay.h>
19#include <linux/freezer.h>
20#include <linux/blkdev.h>
21
22#include "f2fs.h"
23#include "node.h"
24#include "segment.h"
25#include "gc.h"
26
27static struct kmem_cache *winode_slab;
28
29static int gc_thread_func(void *data)
30{
31 struct f2fs_sb_info *sbi = data;
32 wait_queue_head_t *wq = &sbi->gc_thread->gc_wait_queue_head;
33 long wait_ms;
34
35 wait_ms = GC_THREAD_MIN_SLEEP_TIME;
36
37 do {
38 if (try_to_freeze())
39 continue;
40 else
41 wait_event_interruptible_timeout(*wq,
42 kthread_should_stop(),
43 msecs_to_jiffies(wait_ms));
44 if (kthread_should_stop())
45 break;
46
Changman Leed6212a52013-01-29 18:30:07 +090047 if (sbi->sb->s_writers.frozen >= SB_FREEZE_WRITE) {
48 wait_ms = GC_THREAD_MAX_SLEEP_TIME;
49 continue;
50 }
51
Jaegeuk Kim7bc09002012-11-02 17:13:01 +090052 /*
53 * [GC triggering condition]
54 * 0. GC is not conducted currently.
55 * 1. There are enough dirty segments.
56 * 2. IO subsystem is idle by checking the # of writeback pages.
57 * 3. IO subsystem is idle by checking the # of requests in
58 * bdev's request list.
59 *
60 * Note) We have to avoid triggering GCs too much frequently.
61 * Because it is possible that some segments can be
62 * invalidated soon after by user update or deletion.
63 * So, I'd like to wait some time to collect dirty segments.
64 */
65 if (!mutex_trylock(&sbi->gc_mutex))
66 continue;
67
68 if (!is_idle(sbi)) {
69 wait_ms = increase_sleep_time(wait_ms);
70 mutex_unlock(&sbi->gc_mutex);
71 continue;
72 }
73
74 if (has_enough_invalid_blocks(sbi))
75 wait_ms = decrease_sleep_time(wait_ms);
76 else
77 wait_ms = increase_sleep_time(wait_ms);
78
79 sbi->bg_gc++;
80
Jaegeuk Kim43727522013-02-04 15:11:17 +090081 /* if return value is not zero, no victim was selected */
82 if (f2fs_gc(sbi))
Jaegeuk Kim7bc09002012-11-02 17:13:01 +090083 wait_ms = GC_THREAD_NOGC_SLEEP_TIME;
84 else if (wait_ms == GC_THREAD_NOGC_SLEEP_TIME)
85 wait_ms = GC_THREAD_MAX_SLEEP_TIME;
86
87 } while (!kthread_should_stop());
88 return 0;
89}
90
91int start_gc_thread(struct f2fs_sb_info *sbi)
92{
Namjae Jeon1042d602012-12-01 10:56:13 +090093 struct f2fs_gc_kthread *gc_th;
Namjae Jeonec7b1f22013-02-02 23:52:28 +090094 dev_t dev = sbi->sb->s_bdev->bd_dev;
Jaegeuk Kim7bc09002012-11-02 17:13:01 +090095
Changman Lee48600e42013-02-04 10:05:09 +090096 if (!test_opt(sbi, BG_GC))
97 return 0;
Jaegeuk Kim7bc09002012-11-02 17:13:01 +090098 gc_th = kmalloc(sizeof(struct f2fs_gc_kthread), GFP_KERNEL);
99 if (!gc_th)
100 return -ENOMEM;
101
102 sbi->gc_thread = gc_th;
103 init_waitqueue_head(&sbi->gc_thread->gc_wait_queue_head);
104 sbi->gc_thread->f2fs_gc_task = kthread_run(gc_thread_func, sbi,
Namjae Jeonec7b1f22013-02-02 23:52:28 +0900105 "f2fs_gc-%u:%u", MAJOR(dev), MINOR(dev));
Jaegeuk Kim7bc09002012-11-02 17:13:01 +0900106 if (IS_ERR(gc_th->f2fs_gc_task)) {
107 kfree(gc_th);
Namjae Jeon25718422013-02-02 23:52:42 +0900108 sbi->gc_thread = NULL;
Jaegeuk Kim7bc09002012-11-02 17:13:01 +0900109 return -ENOMEM;
110 }
111 return 0;
112}
113
114void stop_gc_thread(struct f2fs_sb_info *sbi)
115{
116 struct f2fs_gc_kthread *gc_th = sbi->gc_thread;
117 if (!gc_th)
118 return;
119 kthread_stop(gc_th->f2fs_gc_task);
120 kfree(gc_th);
121 sbi->gc_thread = NULL;
122}
123
124static int select_gc_type(int gc_type)
125{
126 return (gc_type == BG_GC) ? GC_CB : GC_GREEDY;
127}
128
129static void select_policy(struct f2fs_sb_info *sbi, int gc_type,
130 int type, struct victim_sel_policy *p)
131{
132 struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
133
134 if (p->alloc_mode) {
135 p->gc_mode = GC_GREEDY;
136 p->dirty_segmap = dirty_i->dirty_segmap[type];
137 p->ofs_unit = 1;
138 } else {
139 p->gc_mode = select_gc_type(gc_type);
140 p->dirty_segmap = dirty_i->dirty_segmap[DIRTY];
141 p->ofs_unit = sbi->segs_per_sec;
142 }
143 p->offset = sbi->last_victim[p->gc_mode];
144}
145
146static unsigned int get_max_cost(struct f2fs_sb_info *sbi,
147 struct victim_sel_policy *p)
148{
Jaegeuk Kimb7250d22013-02-05 13:19:28 +0900149 /* SSR allocates in a segment unit */
150 if (p->alloc_mode == SSR)
151 return 1 << sbi->log_blocks_per_seg;
Jaegeuk Kim7bc09002012-11-02 17:13:01 +0900152 if (p->gc_mode == GC_GREEDY)
153 return (1 << sbi->log_blocks_per_seg) * p->ofs_unit;
154 else if (p->gc_mode == GC_CB)
155 return UINT_MAX;
156 else /* No other gc_mode */
157 return 0;
158}
159
160static unsigned int check_bg_victims(struct f2fs_sb_info *sbi)
161{
162 struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
163 unsigned int segno;
164
165 /*
166 * If the gc_type is FG_GC, we can select victim segments
167 * selected by background GC before.
168 * Those segments guarantee they have small valid blocks.
169 */
170 segno = find_next_bit(dirty_i->victim_segmap[BG_GC],
171 TOTAL_SEGS(sbi), 0);
172 if (segno < TOTAL_SEGS(sbi)) {
173 clear_bit(segno, dirty_i->victim_segmap[BG_GC]);
174 return segno;
175 }
176 return NULL_SEGNO;
177}
178
179static unsigned int get_cb_cost(struct f2fs_sb_info *sbi, unsigned int segno)
180{
181 struct sit_info *sit_i = SIT_I(sbi);
182 unsigned int secno = GET_SECNO(sbi, segno);
183 unsigned int start = secno * sbi->segs_per_sec;
184 unsigned long long mtime = 0;
185 unsigned int vblocks;
186 unsigned char age = 0;
187 unsigned char u;
188 unsigned int i;
189
190 for (i = 0; i < sbi->segs_per_sec; i++)
191 mtime += get_seg_entry(sbi, start + i)->mtime;
192 vblocks = get_valid_blocks(sbi, segno, sbi->segs_per_sec);
193
194 mtime = div_u64(mtime, sbi->segs_per_sec);
195 vblocks = div_u64(vblocks, sbi->segs_per_sec);
196
197 u = (vblocks * 100) >> sbi->log_blocks_per_seg;
198
199 /* Handle if the system time is changed by user */
200 if (mtime < sit_i->min_mtime)
201 sit_i->min_mtime = mtime;
202 if (mtime > sit_i->max_mtime)
203 sit_i->max_mtime = mtime;
204 if (sit_i->max_mtime != sit_i->min_mtime)
205 age = 100 - div64_u64(100 * (mtime - sit_i->min_mtime),
206 sit_i->max_mtime - sit_i->min_mtime);
207
208 return UINT_MAX - ((100 * (100 - u) * age) / (100 + u));
209}
210
211static unsigned int get_gc_cost(struct f2fs_sb_info *sbi, unsigned int segno,
212 struct victim_sel_policy *p)
213{
214 if (p->alloc_mode == SSR)
215 return get_seg_entry(sbi, segno)->ckpt_valid_blocks;
216
217 /* alloc_mode == LFS */
218 if (p->gc_mode == GC_GREEDY)
219 return get_valid_blocks(sbi, segno, sbi->segs_per_sec);
220 else
221 return get_cb_cost(sbi, segno);
222}
223
Jaegeuk Kim0a8165d2012-11-29 13:28:09 +0900224/*
Jaegeuk Kim7bc09002012-11-02 17:13:01 +0900225 * This function is called from two pathes.
226 * One is garbage collection and the other is SSR segment selection.
227 * When it is called during GC, it just gets a victim segment
228 * and it does not remove it from dirty seglist.
229 * When it is called from SSR segment selection, it finds a segment
230 * which has minimum valid blocks and removes it from dirty seglist.
231 */
232static int get_victim_by_default(struct f2fs_sb_info *sbi,
233 unsigned int *result, int gc_type, int type, char alloc_mode)
234{
235 struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
236 struct victim_sel_policy p;
237 unsigned int segno;
238 int nsearched = 0;
239
240 p.alloc_mode = alloc_mode;
241 select_policy(sbi, gc_type, type, &p);
242
243 p.min_segno = NULL_SEGNO;
244 p.min_cost = get_max_cost(sbi, &p);
245
246 mutex_lock(&dirty_i->seglist_lock);
247
248 if (p.alloc_mode == LFS && gc_type == FG_GC) {
249 p.min_segno = check_bg_victims(sbi);
250 if (p.min_segno != NULL_SEGNO)
251 goto got_it;
252 }
253
254 while (1) {
255 unsigned long cost;
256
257 segno = find_next_bit(p.dirty_segmap,
258 TOTAL_SEGS(sbi), p.offset);
259 if (segno >= TOTAL_SEGS(sbi)) {
260 if (sbi->last_victim[p.gc_mode]) {
261 sbi->last_victim[p.gc_mode] = 0;
262 p.offset = 0;
263 continue;
264 }
265 break;
266 }
267 p.offset = ((segno / p.ofs_unit) * p.ofs_unit) + p.ofs_unit;
268
269 if (test_bit(segno, dirty_i->victim_segmap[FG_GC]))
270 continue;
271 if (gc_type == BG_GC &&
272 test_bit(segno, dirty_i->victim_segmap[BG_GC]))
273 continue;
274 if (IS_CURSEC(sbi, GET_SECNO(sbi, segno)))
275 continue;
276
277 cost = get_gc_cost(sbi, segno, &p);
278
279 if (p.min_cost > cost) {
280 p.min_segno = segno;
281 p.min_cost = cost;
282 }
283
284 if (cost == get_max_cost(sbi, &p))
285 continue;
286
287 if (nsearched++ >= MAX_VICTIM_SEARCH) {
288 sbi->last_victim[p.gc_mode] = segno;
289 break;
290 }
291 }
292got_it:
293 if (p.min_segno != NULL_SEGNO) {
294 *result = (p.min_segno / p.ofs_unit) * p.ofs_unit;
295 if (p.alloc_mode == LFS) {
296 int i;
297 for (i = 0; i < p.ofs_unit; i++)
298 set_bit(*result + i,
299 dirty_i->victim_segmap[gc_type]);
300 }
301 }
302 mutex_unlock(&dirty_i->seglist_lock);
303
304 return (p.min_segno == NULL_SEGNO) ? 0 : 1;
305}
306
307static const struct victim_selection default_v_ops = {
308 .get_victim = get_victim_by_default,
309};
310
311static struct inode *find_gc_inode(nid_t ino, struct list_head *ilist)
312{
313 struct list_head *this;
314 struct inode_entry *ie;
315
316 list_for_each(this, ilist) {
317 ie = list_entry(this, struct inode_entry, list);
318 if (ie->inode->i_ino == ino)
319 return ie->inode;
320 }
321 return NULL;
322}
323
324static void add_gc_inode(struct inode *inode, struct list_head *ilist)
325{
326 struct list_head *this;
327 struct inode_entry *new_ie, *ie;
328
329 list_for_each(this, ilist) {
330 ie = list_entry(this, struct inode_entry, list);
331 if (ie->inode == inode) {
332 iput(inode);
333 return;
334 }
335 }
336repeat:
337 new_ie = kmem_cache_alloc(winode_slab, GFP_NOFS);
338 if (!new_ie) {
339 cond_resched();
340 goto repeat;
341 }
342 new_ie->inode = inode;
343 list_add_tail(&new_ie->list, ilist);
344}
345
346static void put_gc_inode(struct list_head *ilist)
347{
348 struct inode_entry *ie, *next_ie;
349 list_for_each_entry_safe(ie, next_ie, ilist, list) {
350 iput(ie->inode);
351 list_del(&ie->list);
352 kmem_cache_free(winode_slab, ie);
353 }
354}
355
356static int check_valid_map(struct f2fs_sb_info *sbi,
357 unsigned int segno, int offset)
358{
359 struct sit_info *sit_i = SIT_I(sbi);
360 struct seg_entry *sentry;
361 int ret;
362
363 mutex_lock(&sit_i->sentry_lock);
364 sentry = get_seg_entry(sbi, segno);
365 ret = f2fs_test_bit(offset, sentry->cur_valid_map);
366 mutex_unlock(&sit_i->sentry_lock);
Jaegeuk Kim43727522013-02-04 15:11:17 +0900367 return ret;
Jaegeuk Kim7bc09002012-11-02 17:13:01 +0900368}
369
Jaegeuk Kim0a8165d2012-11-29 13:28:09 +0900370/*
Jaegeuk Kim7bc09002012-11-02 17:13:01 +0900371 * This function compares node address got in summary with that in NAT.
372 * On validity, copy that node with cold status, otherwise (invalid node)
373 * ignore that.
374 */
Jaegeuk Kim43727522013-02-04 15:11:17 +0900375static void gc_node_segment(struct f2fs_sb_info *sbi,
Jaegeuk Kim7bc09002012-11-02 17:13:01 +0900376 struct f2fs_summary *sum, unsigned int segno, int gc_type)
377{
378 bool initial = true;
379 struct f2fs_summary *entry;
380 int off;
381
382next_step:
383 entry = sum;
384 for (off = 0; off < sbi->blocks_per_seg; off++, entry++) {
385 nid_t nid = le32_to_cpu(entry->nid);
386 struct page *node_page;
Jaegeuk Kim7bc09002012-11-02 17:13:01 +0900387
Jaegeuk Kim43727522013-02-04 15:11:17 +0900388 /* stop BG_GC if there is not enough free sections. */
389 if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0))
390 return;
Jaegeuk Kim7bc09002012-11-02 17:13:01 +0900391
Jaegeuk Kim43727522013-02-04 15:11:17 +0900392 if (check_valid_map(sbi, segno, off) == 0)
Jaegeuk Kim7bc09002012-11-02 17:13:01 +0900393 continue;
394
395 if (initial) {
396 ra_node_page(sbi, nid);
397 continue;
398 }
399 node_page = get_node_page(sbi, nid);
400 if (IS_ERR(node_page))
401 continue;
402
403 /* set page dirty and write it */
404 if (!PageWriteback(node_page))
405 set_page_dirty(node_page);
406 f2fs_put_page(node_page, 1);
407 stat_inc_node_blk_count(sbi, 1);
408 }
409 if (initial) {
410 initial = false;
411 goto next_step;
412 }
413
414 if (gc_type == FG_GC) {
415 struct writeback_control wbc = {
416 .sync_mode = WB_SYNC_ALL,
417 .nr_to_write = LONG_MAX,
418 .for_reclaim = 0,
419 };
420 sync_node_pages(sbi, 0, &wbc);
421 }
Jaegeuk Kim7bc09002012-11-02 17:13:01 +0900422}
423
Jaegeuk Kim0a8165d2012-11-29 13:28:09 +0900424/*
Jaegeuk Kim9af45ef2013-01-21 17:34:21 +0900425 * Calculate start block index indicating the given node offset.
426 * Be careful, caller should give this node offset only indicating direct node
427 * blocks. If any node offsets, which point the other types of node blocks such
428 * as indirect or double indirect node blocks, are given, it must be a caller's
429 * bug.
Jaegeuk Kim7bc09002012-11-02 17:13:01 +0900430 */
431block_t start_bidx_of_node(unsigned int node_ofs)
432{
Jaegeuk Kimce19a5d2012-12-26 12:03:22 +0900433 unsigned int indirect_blks = 2 * NIDS_PER_BLOCK + 4;
434 unsigned int bidx;
Jaegeuk Kim7bc09002012-11-02 17:13:01 +0900435
Jaegeuk Kimce19a5d2012-12-26 12:03:22 +0900436 if (node_ofs == 0)
437 return 0;
Jaegeuk Kim7bc09002012-11-02 17:13:01 +0900438
Jaegeuk Kimce19a5d2012-12-26 12:03:22 +0900439 if (node_ofs <= 2) {
Jaegeuk Kim7bc09002012-11-02 17:13:01 +0900440 bidx = node_ofs - 1;
441 } else if (node_ofs <= indirect_blks) {
Jaegeuk Kimce19a5d2012-12-26 12:03:22 +0900442 int dec = (node_ofs - 4) / (NIDS_PER_BLOCK + 1);
Jaegeuk Kim7bc09002012-11-02 17:13:01 +0900443 bidx = node_ofs - 2 - dec;
444 } else {
Jaegeuk Kimce19a5d2012-12-26 12:03:22 +0900445 int dec = (node_ofs - indirect_blks - 3) / (NIDS_PER_BLOCK + 1);
Jaegeuk Kim7bc09002012-11-02 17:13:01 +0900446 bidx = node_ofs - 5 - dec;
447 }
Jaegeuk Kimce19a5d2012-12-26 12:03:22 +0900448 return bidx * ADDRS_PER_BLOCK + ADDRS_PER_INODE;
Jaegeuk Kim7bc09002012-11-02 17:13:01 +0900449}
450
451static int check_dnode(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
452 struct node_info *dni, block_t blkaddr, unsigned int *nofs)
453{
454 struct page *node_page;
455 nid_t nid;
456 unsigned int ofs_in_node;
457 block_t source_blkaddr;
458
459 nid = le32_to_cpu(sum->nid);
460 ofs_in_node = le16_to_cpu(sum->ofs_in_node);
461
462 node_page = get_node_page(sbi, nid);
463 if (IS_ERR(node_page))
Jaegeuk Kim43727522013-02-04 15:11:17 +0900464 return 0;
Jaegeuk Kim7bc09002012-11-02 17:13:01 +0900465
466 get_node_info(sbi, nid, dni);
467
468 if (sum->version != dni->version) {
469 f2fs_put_page(node_page, 1);
Jaegeuk Kim43727522013-02-04 15:11:17 +0900470 return 0;
Jaegeuk Kim7bc09002012-11-02 17:13:01 +0900471 }
472
473 *nofs = ofs_of_node(node_page);
474 source_blkaddr = datablock_addr(node_page, ofs_in_node);
475 f2fs_put_page(node_page, 1);
476
477 if (source_blkaddr != blkaddr)
Jaegeuk Kim43727522013-02-04 15:11:17 +0900478 return 0;
479 return 1;
Jaegeuk Kim7bc09002012-11-02 17:13:01 +0900480}
481
482static void move_data_page(struct inode *inode, struct page *page, int gc_type)
483{
484 if (page->mapping != inode->i_mapping)
485 goto out;
486
487 if (inode != page->mapping->host)
488 goto out;
489
490 if (PageWriteback(page))
491 goto out;
492
493 if (gc_type == BG_GC) {
494 set_page_dirty(page);
495 set_cold_data(page);
496 } else {
497 struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
498 mutex_lock_op(sbi, DATA_WRITE);
499 if (clear_page_dirty_for_io(page) &&
500 S_ISDIR(inode->i_mode)) {
501 dec_page_count(sbi, F2FS_DIRTY_DENTS);
502 inode_dec_dirty_dents(inode);
503 }
504 set_cold_data(page);
505 do_write_data_page(page);
506 mutex_unlock_op(sbi, DATA_WRITE);
507 clear_cold_data(page);
508 }
509out:
510 f2fs_put_page(page, 1);
511}
512
Jaegeuk Kim0a8165d2012-11-29 13:28:09 +0900513/*
Jaegeuk Kim7bc09002012-11-02 17:13:01 +0900514 * This function tries to get parent node of victim data block, and identifies
515 * data block validity. If the block is valid, copy that with cold status and
516 * modify parent node.
517 * If the parent node is not valid or the data block address is different,
518 * the victim data block is ignored.
519 */
Jaegeuk Kim43727522013-02-04 15:11:17 +0900520static void gc_data_segment(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
Jaegeuk Kim7bc09002012-11-02 17:13:01 +0900521 struct list_head *ilist, unsigned int segno, int gc_type)
522{
523 struct super_block *sb = sbi->sb;
524 struct f2fs_summary *entry;
525 block_t start_addr;
Jaegeuk Kim43727522013-02-04 15:11:17 +0900526 int off;
Jaegeuk Kim7bc09002012-11-02 17:13:01 +0900527 int phase = 0;
528
529 start_addr = START_BLOCK(sbi, segno);
530
531next_step:
532 entry = sum;
533 for (off = 0; off < sbi->blocks_per_seg; off++, entry++) {
534 struct page *data_page;
535 struct inode *inode;
536 struct node_info dni; /* dnode info for the data */
537 unsigned int ofs_in_node, nofs;
538 block_t start_bidx;
539
Jaegeuk Kim43727522013-02-04 15:11:17 +0900540 /* stop BG_GC if there is not enough free sections. */
541 if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0))
542 return;
Jaegeuk Kim7bc09002012-11-02 17:13:01 +0900543
Jaegeuk Kim43727522013-02-04 15:11:17 +0900544 if (check_valid_map(sbi, segno, off) == 0)
Jaegeuk Kim7bc09002012-11-02 17:13:01 +0900545 continue;
546
547 if (phase == 0) {
548 ra_node_page(sbi, le32_to_cpu(entry->nid));
549 continue;
550 }
551
552 /* Get an inode by ino with checking validity */
Jaegeuk Kim43727522013-02-04 15:11:17 +0900553 if (check_dnode(sbi, entry, &dni, start_addr + off, &nofs) == 0)
Jaegeuk Kim7bc09002012-11-02 17:13:01 +0900554 continue;
555
556 if (phase == 1) {
557 ra_node_page(sbi, dni.ino);
558 continue;
559 }
560
561 start_bidx = start_bidx_of_node(nofs);
562 ofs_in_node = le16_to_cpu(entry->ofs_in_node);
563
564 if (phase == 2) {
Jaegeuk Kimd4686d562013-01-31 15:36:04 +0900565 inode = f2fs_iget(sb, dni.ino);
Jaegeuk Kim7bc09002012-11-02 17:13:01 +0900566 if (IS_ERR(inode))
567 continue;
568
569 data_page = find_data_page(inode,
570 start_bidx + ofs_in_node);
571 if (IS_ERR(data_page))
572 goto next_iput;
573
574 f2fs_put_page(data_page, 0);
575 add_gc_inode(inode, ilist);
576 } else {
577 inode = find_gc_inode(dni.ino, ilist);
578 if (inode) {
579 data_page = get_lock_data_page(inode,
580 start_bidx + ofs_in_node);
581 if (IS_ERR(data_page))
582 continue;
583 move_data_page(inode, data_page, gc_type);
584 stat_inc_data_blk_count(sbi, 1);
585 }
586 }
587 continue;
588next_iput:
589 iput(inode);
590 }
591 if (++phase < 4)
592 goto next_step;
Jaegeuk Kim43727522013-02-04 15:11:17 +0900593
Jaegeuk Kim7bc09002012-11-02 17:13:01 +0900594 if (gc_type == FG_GC)
595 f2fs_submit_bio(sbi, DATA, true);
Jaegeuk Kim7bc09002012-11-02 17:13:01 +0900596}
597
598static int __get_victim(struct f2fs_sb_info *sbi, unsigned int *victim,
599 int gc_type, int type)
600{
601 struct sit_info *sit_i = SIT_I(sbi);
602 int ret;
603 mutex_lock(&sit_i->sentry_lock);
604 ret = DIRTY_I(sbi)->v_ops->get_victim(sbi, victim, gc_type, type, LFS);
605 mutex_unlock(&sit_i->sentry_lock);
606 return ret;
607}
608
Jaegeuk Kim43727522013-02-04 15:11:17 +0900609static void do_garbage_collect(struct f2fs_sb_info *sbi, unsigned int segno,
Jaegeuk Kim7bc09002012-11-02 17:13:01 +0900610 struct list_head *ilist, int gc_type)
611{
612 struct page *sum_page;
613 struct f2fs_summary_block *sum;
Jaegeuk Kim7bc09002012-11-02 17:13:01 +0900614
615 /* read segment summary of victim */
616 sum_page = get_sum_page(sbi, segno);
617 if (IS_ERR(sum_page))
Jaegeuk Kim43727522013-02-04 15:11:17 +0900618 return;
Jaegeuk Kim7bc09002012-11-02 17:13:01 +0900619
620 /*
621 * CP needs to lock sum_page. In this time, we don't need
622 * to lock this page, because this summary page is not gone anywhere.
623 * Also, this page is not gonna be updated before GC is done.
624 */
625 unlock_page(sum_page);
626 sum = page_address(sum_page);
627
628 switch (GET_SUM_TYPE((&sum->footer))) {
629 case SUM_TYPE_NODE:
Jaegeuk Kim43727522013-02-04 15:11:17 +0900630 gc_node_segment(sbi, sum->entries, segno, gc_type);
Jaegeuk Kim7bc09002012-11-02 17:13:01 +0900631 break;
632 case SUM_TYPE_DATA:
Jaegeuk Kim43727522013-02-04 15:11:17 +0900633 gc_data_segment(sbi, sum->entries, ilist, segno, gc_type);
Jaegeuk Kim7bc09002012-11-02 17:13:01 +0900634 break;
635 }
636 stat_inc_seg_count(sbi, GET_SUM_TYPE((&sum->footer)));
637 stat_inc_call_count(sbi->stat_info);
638
639 f2fs_put_page(sum_page, 0);
Jaegeuk Kim7bc09002012-11-02 17:13:01 +0900640}
641
Jaegeuk Kim408e9372013-01-03 17:55:52 +0900642int f2fs_gc(struct f2fs_sb_info *sbi)
Jaegeuk Kim7bc09002012-11-02 17:13:01 +0900643{
Jaegeuk Kim7bc09002012-11-02 17:13:01 +0900644 struct list_head ilist;
Jaegeuk Kim408e9372013-01-03 17:55:52 +0900645 unsigned int segno, i;
Jaegeuk Kim7bc09002012-11-02 17:13:01 +0900646 int gc_type = BG_GC;
Jaegeuk Kim43727522013-02-04 15:11:17 +0900647 int nfree = 0;
648 int ret = -1;
Jaegeuk Kim7bc09002012-11-02 17:13:01 +0900649
650 INIT_LIST_HEAD(&ilist);
651gc_more:
Jaegeuk Kim408e9372013-01-03 17:55:52 +0900652 if (!(sbi->sb->s_flags & MS_ACTIVE))
653 goto stop;
Jaegeuk Kim7bc09002012-11-02 17:13:01 +0900654
Jaegeuk Kim43727522013-02-04 15:11:17 +0900655 if (gc_type == BG_GC && has_not_enough_free_secs(sbi, nfree))
Jaegeuk Kim408e9372013-01-03 17:55:52 +0900656 gc_type = FG_GC;
Jaegeuk Kim7bc09002012-11-02 17:13:01 +0900657
Jaegeuk Kim408e9372013-01-03 17:55:52 +0900658 if (!__get_victim(sbi, &segno, gc_type, NO_CHECK_TYPE))
659 goto stop;
Jaegeuk Kim43727522013-02-04 15:11:17 +0900660 ret = 0;
Jaegeuk Kim7bc09002012-11-02 17:13:01 +0900661
Jaegeuk Kim43727522013-02-04 15:11:17 +0900662 for (i = 0; i < sbi->segs_per_sec; i++)
663 do_garbage_collect(sbi, segno + i, &ilist, gc_type);
664
665 if (gc_type == FG_GC &&
666 get_valid_blocks(sbi, segno, sbi->segs_per_sec) == 0)
667 nfree++;
668
669 if (has_not_enough_free_secs(sbi, nfree))
670 goto gc_more;
671
672 if (gc_type == FG_GC)
673 write_checkpoint(sbi, false);
Jaegeuk Kim408e9372013-01-03 17:55:52 +0900674stop:
Jaegeuk Kim7bc09002012-11-02 17:13:01 +0900675 mutex_unlock(&sbi->gc_mutex);
676
677 put_gc_inode(&ilist);
Jaegeuk Kim43727522013-02-04 15:11:17 +0900678 return ret;
Jaegeuk Kim7bc09002012-11-02 17:13:01 +0900679}
680
681void build_gc_manager(struct f2fs_sb_info *sbi)
682{
683 DIRTY_I(sbi)->v_ops = &default_v_ops;
684}
685
Namjae Jeon6e6093a2013-01-17 00:08:30 +0900686int __init create_gc_caches(void)
Jaegeuk Kim7bc09002012-11-02 17:13:01 +0900687{
688 winode_slab = f2fs_kmem_cache_create("f2fs_gc_inodes",
689 sizeof(struct inode_entry), NULL);
690 if (!winode_slab)
691 return -ENOMEM;
692 return 0;
693}
694
695void destroy_gc_caches(void)
696{
697 kmem_cache_destroy(winode_slab);
698}