1 // SPDX-License-Identifier: GPL-2.0
3 * f2fs debugging statistics
5 * Copyright (c) 2012 Samsung Electronics Co., Ltd.
6 * http://www.samsung.com/
7 * Copyright (c) 2012 Linux Foundation
12 #include <linux/backing-dev.h>
13 #include <linux/f2fs_fs.h>
14 #include <linux/blkdev.h>
15 #include <linux/debugfs.h>
16 #include <linux/seq_file.h>
23 static LIST_HEAD(f2fs_stat_list);
24 static struct dentry *f2fs_debugfs_root;
25 static DEFINE_MUTEX(f2fs_stat_mutex);
27 static void update_general_status(struct f2fs_sb_info *sbi)
29 struct f2fs_stat_info *si = F2FS_STAT(sbi);
32 /* validation check of the segment numbers */
33 si->hit_largest = atomic64_read(&sbi->read_hit_largest);
34 si->hit_cached = atomic64_read(&sbi->read_hit_cached);
35 si->hit_rbtree = atomic64_read(&sbi->read_hit_rbtree);
36 si->hit_total = si->hit_largest + si->hit_cached + si->hit_rbtree;
37 si->total_ext = atomic64_read(&sbi->total_hit_ext);
38 si->ext_tree = atomic_read(&sbi->total_ext_tree);
39 si->zombie_tree = atomic_read(&sbi->total_zombie_tree);
40 si->ext_node = atomic_read(&sbi->total_ext_node);
41 si->ndirty_node = get_pages(sbi, F2FS_DIRTY_NODES);
42 si->ndirty_dent = get_pages(sbi, F2FS_DIRTY_DENTS);
43 si->ndirty_meta = get_pages(sbi, F2FS_DIRTY_META);
44 si->ndirty_data = get_pages(sbi, F2FS_DIRTY_DATA);
45 si->ndirty_qdata = get_pages(sbi, F2FS_DIRTY_QDATA);
46 si->ndirty_imeta = get_pages(sbi, F2FS_DIRTY_IMETA);
47 si->ndirty_dirs = sbi->ndirty_inode[DIR_INODE];
48 si->ndirty_files = sbi->ndirty_inode[FILE_INODE];
49 si->nquota_files = sbi->nquota_files;
50 si->ndirty_all = sbi->ndirty_inode[DIRTY_META];
51 si->inmem_pages = get_pages(sbi, F2FS_INMEM_PAGES);
52 si->aw_cnt = atomic_read(&sbi->aw_cnt);
53 si->vw_cnt = atomic_read(&sbi->vw_cnt);
54 si->max_aw_cnt = atomic_read(&sbi->max_aw_cnt);
55 si->max_vw_cnt = atomic_read(&sbi->max_vw_cnt);
56 si->nr_dio_read = get_pages(sbi, F2FS_DIO_READ);
57 si->nr_dio_write = get_pages(sbi, F2FS_DIO_WRITE);
58 si->nr_wb_cp_data = get_pages(sbi, F2FS_WB_CP_DATA);
59 si->nr_wb_data = get_pages(sbi, F2FS_WB_DATA);
60 si->nr_rd_data = get_pages(sbi, F2FS_RD_DATA);
61 si->nr_rd_node = get_pages(sbi, F2FS_RD_NODE);
62 si->nr_rd_meta = get_pages(sbi, F2FS_RD_META);
63 if (SM_I(sbi) && SM_I(sbi)->fcc_info) {
65 atomic_read(&SM_I(sbi)->fcc_info->issued_flush);
67 atomic_read(&SM_I(sbi)->fcc_info->queued_flush);
68 si->flush_list_empty =
69 llist_empty(&SM_I(sbi)->fcc_info->issue_list);
71 if (SM_I(sbi) && SM_I(sbi)->dcc_info) {
73 atomic_read(&SM_I(sbi)->dcc_info->issued_discard);
75 atomic_read(&SM_I(sbi)->dcc_info->queued_discard);
77 atomic_read(&SM_I(sbi)->dcc_info->discard_cmd_cnt);
78 si->undiscard_blks = SM_I(sbi)->dcc_info->undiscard_blks;
80 si->total_count = (int)sbi->user_block_count / sbi->blocks_per_seg;
81 si->rsvd_segs = reserved_segments(sbi);
82 si->overp_segs = overprovision_segments(sbi);
83 si->valid_count = valid_user_blocks(sbi);
84 si->discard_blks = discard_blocks(sbi);
85 si->valid_node_count = valid_node_count(sbi);
86 si->valid_inode_count = valid_inode_count(sbi);
87 si->inline_xattr = atomic_read(&sbi->inline_xattr);
88 si->inline_inode = atomic_read(&sbi->inline_inode);
89 si->inline_dir = atomic_read(&sbi->inline_dir);
90 si->append = sbi->im[APPEND_INO].ino_num;
91 si->update = sbi->im[UPDATE_INO].ino_num;
92 si->orphans = sbi->im[ORPHAN_INO].ino_num;
93 si->utilization = utilization(sbi);
95 si->free_segs = free_segments(sbi);
96 si->free_secs = free_sections(sbi);
97 si->prefree_count = prefree_segments(sbi);
98 si->dirty_count = dirty_segments(sbi);
99 si->node_pages = NODE_MAPPING(sbi)->nrpages;
100 si->meta_pages = META_MAPPING(sbi)->nrpages;
101 si->nats = NM_I(sbi)->nat_cnt;
102 si->dirty_nats = NM_I(sbi)->dirty_nat_cnt;
103 si->sits = MAIN_SEGS(sbi);
104 si->dirty_sits = SIT_I(sbi)->dirty_sentries;
105 si->free_nids = NM_I(sbi)->nid_cnt[FREE_NID];
106 si->avail_nids = NM_I(sbi)->available_nids;
107 si->alloc_nids = NM_I(sbi)->nid_cnt[PREALLOC_NID];
108 si->bg_gc = sbi->bg_gc;
109 si->io_skip_bggc = sbi->io_skip_bggc;
110 si->other_skip_bggc = sbi->other_skip_bggc;
111 si->skipped_atomic_files[BG_GC] = sbi->skipped_atomic_files[BG_GC];
112 si->skipped_atomic_files[FG_GC] = sbi->skipped_atomic_files[FG_GC];
113 si->util_free = (int)(free_user_blocks(sbi) >> sbi->log_blocks_per_seg)
114 * 100 / (int)(sbi->user_block_count >> sbi->log_blocks_per_seg)
116 si->util_valid = (int)(written_block_count(sbi) >>
117 sbi->log_blocks_per_seg)
118 * 100 / (int)(sbi->user_block_count >> sbi->log_blocks_per_seg)
120 si->util_invalid = 50 - si->util_free - si->util_valid;
121 for (i = CURSEG_HOT_DATA; i <= CURSEG_COLD_NODE; i++) {
122 struct curseg_info *curseg = CURSEG_I(sbi, i);
123 si->curseg[i] = curseg->segno;
124 si->cursec[i] = GET_SEC_FROM_SEG(sbi, curseg->segno);
125 si->curzone[i] = GET_ZONE_FROM_SEC(sbi, si->cursec[i]);
128 for (i = META_CP; i < META_MAX; i++)
129 si->meta_count[i] = atomic_read(&sbi->meta_count[i]);
131 for (i = 0; i < 2; i++) {
132 si->segment_count[i] = sbi->segment_count[i];
133 si->block_count[i] = sbi->block_count[i];
136 si->inplace_count = atomic_read(&sbi->inplace_count);
140 * This function calculates BDF of every segments
142 static void update_sit_info(struct f2fs_sb_info *sbi)
144 struct f2fs_stat_info *si = F2FS_STAT(sbi);
145 unsigned long long blks_per_sec, hblks_per_sec, total_vblocks;
146 unsigned long long bimodal, dist;
147 unsigned int segno, vblocks;
152 blks_per_sec = BLKS_PER_SEC(sbi);
153 hblks_per_sec = blks_per_sec / 2;
154 for (segno = 0; segno < MAIN_SEGS(sbi); segno += sbi->segs_per_sec) {
155 vblocks = get_valid_blocks(sbi, segno, true);
156 dist = abs(vblocks - hblks_per_sec);
157 bimodal += dist * dist;
159 if (vblocks > 0 && vblocks < blks_per_sec) {
160 total_vblocks += vblocks;
164 dist = div_u64(MAIN_SECS(sbi) * hblks_per_sec * hblks_per_sec, 100);
165 si->bimodal = div64_u64(bimodal, dist);
167 si->avg_vblocks = div_u64(total_vblocks, ndirty);
173 * This function calculates memory footprint.
175 static void update_mem_info(struct f2fs_sb_info *sbi)
177 struct f2fs_stat_info *si = F2FS_STAT(sbi);
185 si->base_mem = sizeof(struct f2fs_stat_info);
187 /* build superblock */
188 si->base_mem += sizeof(struct f2fs_sb_info) + sbi->sb->s_blocksize;
189 si->base_mem += 2 * sizeof(struct f2fs_inode_info);
190 si->base_mem += sizeof(*sbi->ckpt);
193 si->base_mem += sizeof(struct f2fs_sm_info);
196 si->base_mem += sizeof(struct sit_info);
197 si->base_mem += MAIN_SEGS(sbi) * sizeof(struct seg_entry);
198 si->base_mem += f2fs_bitmap_size(MAIN_SEGS(sbi));
199 si->base_mem += 2 * SIT_VBLOCK_MAP_SIZE * MAIN_SEGS(sbi);
200 si->base_mem += SIT_VBLOCK_MAP_SIZE * MAIN_SEGS(sbi);
201 si->base_mem += SIT_VBLOCK_MAP_SIZE;
202 if (__is_large_section(sbi))
203 si->base_mem += MAIN_SECS(sbi) * sizeof(struct sec_entry);
204 si->base_mem += __bitmap_size(sbi, SIT_BITMAP);
206 /* build free segmap */
207 si->base_mem += sizeof(struct free_segmap_info);
208 si->base_mem += f2fs_bitmap_size(MAIN_SEGS(sbi));
209 si->base_mem += f2fs_bitmap_size(MAIN_SECS(sbi));
212 si->base_mem += sizeof(struct curseg_info) * NR_CURSEG_TYPE;
213 si->base_mem += PAGE_SIZE * NR_CURSEG_TYPE;
215 /* build dirty segmap */
216 si->base_mem += sizeof(struct dirty_seglist_info);
217 si->base_mem += NR_DIRTY_TYPE * f2fs_bitmap_size(MAIN_SEGS(sbi));
218 si->base_mem += f2fs_bitmap_size(MAIN_SECS(sbi));
221 si->base_mem += sizeof(struct f2fs_nm_info);
222 si->base_mem += __bitmap_size(sbi, NAT_BITMAP);
223 si->base_mem += (NM_I(sbi)->nat_bits_blocks << F2FS_BLKSIZE_BITS);
224 si->base_mem += NM_I(sbi)->nat_blocks *
225 f2fs_bitmap_size(NAT_ENTRY_PER_BLOCK);
226 si->base_mem += NM_I(sbi)->nat_blocks / 8;
227 si->base_mem += NM_I(sbi)->nat_blocks * sizeof(unsigned short);
234 si->cache_mem += sizeof(struct f2fs_gc_kthread);
236 /* build merge flush thread */
237 if (SM_I(sbi)->fcc_info)
238 si->cache_mem += sizeof(struct flush_cmd_control);
239 if (SM_I(sbi)->dcc_info) {
240 si->cache_mem += sizeof(struct discard_cmd_control);
241 si->cache_mem += sizeof(struct discard_cmd) *
242 atomic_read(&SM_I(sbi)->dcc_info->discard_cmd_cnt);
246 si->cache_mem += (NM_I(sbi)->nid_cnt[FREE_NID] +
247 NM_I(sbi)->nid_cnt[PREALLOC_NID]) *
248 sizeof(struct free_nid);
249 si->cache_mem += NM_I(sbi)->nat_cnt * sizeof(struct nat_entry);
250 si->cache_mem += NM_I(sbi)->dirty_nat_cnt *
251 sizeof(struct nat_entry_set);
252 si->cache_mem += si->inmem_pages * sizeof(struct inmem_pages);
253 for (i = 0; i < MAX_INO_ENTRY; i++)
254 si->cache_mem += sbi->im[i].ino_num * sizeof(struct ino_entry);
255 si->cache_mem += atomic_read(&sbi->total_ext_tree) *
256 sizeof(struct extent_tree);
257 si->cache_mem += atomic_read(&sbi->total_ext_node) *
258 sizeof(struct extent_node);
261 npages = NODE_MAPPING(sbi)->nrpages;
262 si->page_mem += (unsigned long long)npages << PAGE_SHIFT;
263 npages = META_MAPPING(sbi)->nrpages;
264 si->page_mem += (unsigned long long)npages << PAGE_SHIFT;
267 static int stat_show(struct seq_file *s, void *v)
269 struct f2fs_stat_info *si;
273 mutex_lock(&f2fs_stat_mutex);
274 list_for_each_entry(si, &f2fs_stat_list, stat_list) {
275 update_general_status(si->sbi);
277 seq_printf(s, "\n=====[ partition info(%pg). #%d, %s, CP: %s]=====\n",
278 si->sbi->sb->s_bdev, i++,
279 f2fs_readonly(si->sbi->sb) ? "RO": "RW",
280 is_set_ckpt_flags(si->sbi, CP_DISABLED_FLAG) ?
281 "Disabled": (f2fs_cp_error(si->sbi) ? "Error": "Good"));
282 seq_printf(s, "[SB: 1] [CP: 2] [SIT: %d] [NAT: %d] ",
283 si->sit_area_segs, si->nat_area_segs);
284 seq_printf(s, "[SSA: %d] [MAIN: %d",
285 si->ssa_area_segs, si->main_area_segs);
286 seq_printf(s, "(OverProv:%d Resv:%d)]\n\n",
287 si->overp_segs, si->rsvd_segs);
288 if (test_opt(si->sbi, DISCARD))
289 seq_printf(s, "Utilization: %u%% (%u valid blocks, %u discard blocks)\n",
290 si->utilization, si->valid_count, si->discard_blks);
292 seq_printf(s, "Utilization: %u%% (%u valid blocks)\n",
293 si->utilization, si->valid_count);
295 seq_printf(s, " - Node: %u (Inode: %u, ",
296 si->valid_node_count, si->valid_inode_count);
297 seq_printf(s, "Other: %u)\n - Data: %u\n",
298 si->valid_node_count - si->valid_inode_count,
299 si->valid_count - si->valid_node_count);
300 seq_printf(s, " - Inline_xattr Inode: %u\n",
302 seq_printf(s, " - Inline_data Inode: %u\n",
304 seq_printf(s, " - Inline_dentry Inode: %u\n",
306 seq_printf(s, " - Orphan/Append/Update Inode: %u, %u, %u\n",
307 si->orphans, si->append, si->update);
308 seq_printf(s, "\nMain area: %d segs, %d secs %d zones\n",
309 si->main_area_segs, si->main_area_sections,
310 si->main_area_zones);
311 seq_printf(s, " - COLD data: %d, %d, %d\n",
312 si->curseg[CURSEG_COLD_DATA],
313 si->cursec[CURSEG_COLD_DATA],
314 si->curzone[CURSEG_COLD_DATA]);
315 seq_printf(s, " - WARM data: %d, %d, %d\n",
316 si->curseg[CURSEG_WARM_DATA],
317 si->cursec[CURSEG_WARM_DATA],
318 si->curzone[CURSEG_WARM_DATA]);
319 seq_printf(s, " - HOT data: %d, %d, %d\n",
320 si->curseg[CURSEG_HOT_DATA],
321 si->cursec[CURSEG_HOT_DATA],
322 si->curzone[CURSEG_HOT_DATA]);
323 seq_printf(s, " - Dir dnode: %d, %d, %d\n",
324 si->curseg[CURSEG_HOT_NODE],
325 si->cursec[CURSEG_HOT_NODE],
326 si->curzone[CURSEG_HOT_NODE]);
327 seq_printf(s, " - File dnode: %d, %d, %d\n",
328 si->curseg[CURSEG_WARM_NODE],
329 si->cursec[CURSEG_WARM_NODE],
330 si->curzone[CURSEG_WARM_NODE]);
331 seq_printf(s, " - Indir nodes: %d, %d, %d\n",
332 si->curseg[CURSEG_COLD_NODE],
333 si->cursec[CURSEG_COLD_NODE],
334 si->curzone[CURSEG_COLD_NODE]);
335 seq_printf(s, "\n - Valid: %d\n - Dirty: %d\n",
336 si->main_area_segs - si->dirty_count -
337 si->prefree_count - si->free_segs,
339 seq_printf(s, " - Prefree: %d\n - Free: %d (%d)\n\n",
340 si->prefree_count, si->free_segs, si->free_secs);
341 seq_printf(s, "CP calls: %d (BG: %d)\n",
342 si->cp_count, si->bg_cp_count);
343 seq_printf(s, " - cp blocks : %u\n", si->meta_count[META_CP]);
344 seq_printf(s, " - sit blocks : %u\n",
345 si->meta_count[META_SIT]);
346 seq_printf(s, " - nat blocks : %u\n",
347 si->meta_count[META_NAT]);
348 seq_printf(s, " - ssa blocks : %u\n",
349 si->meta_count[META_SSA]);
350 seq_printf(s, "GC calls: %d (BG: %d)\n",
351 si->call_count, si->bg_gc);
352 seq_printf(s, " - data segments : %d (%d)\n",
353 si->data_segs, si->bg_data_segs);
354 seq_printf(s, " - node segments : %d (%d)\n",
355 si->node_segs, si->bg_node_segs);
356 seq_printf(s, "Try to move %d blocks (BG: %d)\n", si->tot_blks,
357 si->bg_data_blks + si->bg_node_blks);
358 seq_printf(s, " - data blocks : %d (%d)\n", si->data_blks,
360 seq_printf(s, " - node blocks : %d (%d)\n", si->node_blks,
362 seq_printf(s, "Skipped : atomic write %llu (%llu)\n",
363 si->skipped_atomic_files[BG_GC] +
364 si->skipped_atomic_files[FG_GC],
365 si->skipped_atomic_files[BG_GC]);
366 seq_printf(s, "BG skip : IO: %u, Other: %u\n",
367 si->io_skip_bggc, si->other_skip_bggc);
368 seq_puts(s, "\nExtent Cache:\n");
369 seq_printf(s, " - Hit Count: L1-1:%llu L1-2:%llu L2:%llu\n",
370 si->hit_largest, si->hit_cached,
372 seq_printf(s, " - Hit Ratio: %llu%% (%llu / %llu)\n",
374 div64_u64(si->hit_total * 100, si->total_ext),
375 si->hit_total, si->total_ext);
376 seq_printf(s, " - Inner Struct Count: tree: %d(%d), node: %d\n",
377 si->ext_tree, si->zombie_tree, si->ext_node);
378 seq_puts(s, "\nBalancing F2FS Async:\n");
379 seq_printf(s, " - DIO (R: %4d, W: %4d)\n",
380 si->nr_dio_read, si->nr_dio_write);
381 seq_printf(s, " - IO_R (Data: %4d, Node: %4d, Meta: %4d\n",
382 si->nr_rd_data, si->nr_rd_node, si->nr_rd_meta);
383 seq_printf(s, " - IO_W (CP: %4d, Data: %4d, Flush: (%4d %4d %4d), "
384 "Discard: (%4d %4d)) cmd: %4d undiscard:%4u\n",
385 si->nr_wb_cp_data, si->nr_wb_data,
386 si->nr_flushing, si->nr_flushed,
387 si->flush_list_empty,
388 si->nr_discarding, si->nr_discarded,
389 si->nr_discard_cmd, si->undiscard_blks);
390 seq_printf(s, " - inmem: %4d, atomic IO: %4d (Max. %4d), "
391 "volatile IO: %4d (Max. %4d)\n",
392 si->inmem_pages, si->aw_cnt, si->max_aw_cnt,
393 si->vw_cnt, si->max_vw_cnt);
394 seq_printf(s, " - nodes: %4d in %4d\n",
395 si->ndirty_node, si->node_pages);
396 seq_printf(s, " - dents: %4d in dirs:%4d (%4d)\n",
397 si->ndirty_dent, si->ndirty_dirs, si->ndirty_all);
398 seq_printf(s, " - datas: %4d in files:%4d\n",
399 si->ndirty_data, si->ndirty_files);
400 seq_printf(s, " - quota datas: %4d in quota files:%4d\n",
401 si->ndirty_qdata, si->nquota_files);
402 seq_printf(s, " - meta: %4d in %4d\n",
403 si->ndirty_meta, si->meta_pages);
404 seq_printf(s, " - imeta: %4d\n",
406 seq_printf(s, " - NATs: %9d/%9d\n - SITs: %9d/%9d\n",
407 si->dirty_nats, si->nats, si->dirty_sits, si->sits);
408 seq_printf(s, " - free_nids: %9d/%9d\n - alloc_nids: %9d\n",
409 si->free_nids, si->avail_nids, si->alloc_nids);
410 seq_puts(s, "\nDistribution of User Blocks:");
411 seq_puts(s, " [ valid | invalid | free ]\n");
414 for (j = 0; j < si->util_valid; j++)
418 for (j = 0; j < si->util_invalid; j++)
422 for (j = 0; j < si->util_free; j++)
424 seq_puts(s, "]\n\n");
425 seq_printf(s, "IPU: %u blocks\n", si->inplace_count);
426 seq_printf(s, "SSR: %u blocks in %u segments\n",
427 si->block_count[SSR], si->segment_count[SSR]);
428 seq_printf(s, "LFS: %u blocks in %u segments\n",
429 si->block_count[LFS], si->segment_count[LFS]);
431 /* segment usage info */
432 update_sit_info(si->sbi);
433 seq_printf(s, "\nBDF: %u, avg. vblocks: %u\n",
434 si->bimodal, si->avg_vblocks);
436 /* memory footprint */
437 update_mem_info(si->sbi);
438 seq_printf(s, "\nMemory: %llu KB\n",
439 (si->base_mem + si->cache_mem + si->page_mem) >> 10);
440 seq_printf(s, " - static: %llu KB\n",
442 seq_printf(s, " - cached: %llu KB\n",
443 si->cache_mem >> 10);
444 seq_printf(s, " - paged : %llu KB\n",
447 mutex_unlock(&f2fs_stat_mutex);
451 DEFINE_SHOW_ATTRIBUTE(stat);
453 int f2fs_build_stats(struct f2fs_sb_info *sbi)
455 struct f2fs_super_block *raw_super = F2FS_RAW_SUPER(sbi);
456 struct f2fs_stat_info *si;
459 si = f2fs_kzalloc(sbi, sizeof(struct f2fs_stat_info), GFP_KERNEL);
463 si->all_area_segs = le32_to_cpu(raw_super->segment_count);
464 si->sit_area_segs = le32_to_cpu(raw_super->segment_count_sit);
465 si->nat_area_segs = le32_to_cpu(raw_super->segment_count_nat);
466 si->ssa_area_segs = le32_to_cpu(raw_super->segment_count_ssa);
467 si->main_area_segs = le32_to_cpu(raw_super->segment_count_main);
468 si->main_area_sections = le32_to_cpu(raw_super->section_count);
469 si->main_area_zones = si->main_area_sections /
470 le32_to_cpu(raw_super->secs_per_zone);
474 atomic64_set(&sbi->total_hit_ext, 0);
475 atomic64_set(&sbi->read_hit_rbtree, 0);
476 atomic64_set(&sbi->read_hit_largest, 0);
477 atomic64_set(&sbi->read_hit_cached, 0);
479 atomic_set(&sbi->inline_xattr, 0);
480 atomic_set(&sbi->inline_inode, 0);
481 atomic_set(&sbi->inline_dir, 0);
482 atomic_set(&sbi->inplace_count, 0);
483 for (i = META_CP; i < META_MAX; i++)
484 atomic_set(&sbi->meta_count[i], 0);
486 atomic_set(&sbi->aw_cnt, 0);
487 atomic_set(&sbi->vw_cnt, 0);
488 atomic_set(&sbi->max_aw_cnt, 0);
489 atomic_set(&sbi->max_vw_cnt, 0);
491 mutex_lock(&f2fs_stat_mutex);
492 list_add_tail(&si->stat_list, &f2fs_stat_list);
493 mutex_unlock(&f2fs_stat_mutex);
498 void f2fs_destroy_stats(struct f2fs_sb_info *sbi)
500 struct f2fs_stat_info *si = F2FS_STAT(sbi);
502 mutex_lock(&f2fs_stat_mutex);
503 list_del(&si->stat_list);
504 mutex_unlock(&f2fs_stat_mutex);
509 void __init f2fs_create_root_stats(void)
511 f2fs_debugfs_root = debugfs_create_dir("f2fs", NULL);
513 debugfs_create_file("status", S_IRUGO, f2fs_debugfs_root, NULL,
517 void f2fs_destroy_root_stats(void)
519 debugfs_remove_recursive(f2fs_debugfs_root);
520 f2fs_debugfs_root = NULL;