xref: /openbmc/linux/fs/f2fs/debug.c (revision 274bd9ba39425610fdb9a6827602197a5cd27cd8)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * f2fs debugging statistics
4  *
5  * Copyright (c) 2012 Samsung Electronics Co., Ltd.
6  *             http://www.samsung.com/
7  * Copyright (c) 2012 Linux Foundation
8  * Copyright (c) 2012 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
9  */
10 
11 #include <linux/fs.h>
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>
17 
18 #include "f2fs.h"
19 #include "node.h"
20 #include "segment.h"
21 #include "gc.h"
22 
23 static LIST_HEAD(f2fs_stat_list);
24 static struct dentry *f2fs_debugfs_root;
25 static DEFINE_MUTEX(f2fs_stat_mutex);
26 
27 static void update_general_status(struct f2fs_sb_info *sbi)
28 {
29 	struct f2fs_stat_info *si = F2FS_STAT(sbi);
30 	int i;
31 
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_wb_cp_data = get_pages(sbi, F2FS_WB_CP_DATA);
57 	si->nr_wb_data = get_pages(sbi, F2FS_WB_DATA);
58 	if (SM_I(sbi) && SM_I(sbi)->fcc_info) {
59 		si->nr_flushed =
60 			atomic_read(&SM_I(sbi)->fcc_info->issued_flush);
61 		si->nr_flushing =
62 			atomic_read(&SM_I(sbi)->fcc_info->issing_flush);
63 		si->flush_list_empty =
64 			llist_empty(&SM_I(sbi)->fcc_info->issue_list);
65 	}
66 	if (SM_I(sbi) && SM_I(sbi)->dcc_info) {
67 		si->nr_discarded =
68 			atomic_read(&SM_I(sbi)->dcc_info->issued_discard);
69 		si->nr_discarding =
70 			atomic_read(&SM_I(sbi)->dcc_info->issing_discard);
71 		si->nr_discard_cmd =
72 			atomic_read(&SM_I(sbi)->dcc_info->discard_cmd_cnt);
73 		si->undiscard_blks = SM_I(sbi)->dcc_info->undiscard_blks;
74 	}
75 	si->total_count = (int)sbi->user_block_count / sbi->blocks_per_seg;
76 	si->rsvd_segs = reserved_segments(sbi);
77 	si->overp_segs = overprovision_segments(sbi);
78 	si->valid_count = valid_user_blocks(sbi);
79 	si->discard_blks = discard_blocks(sbi);
80 	si->valid_node_count = valid_node_count(sbi);
81 	si->valid_inode_count = valid_inode_count(sbi);
82 	si->inline_xattr = atomic_read(&sbi->inline_xattr);
83 	si->inline_inode = atomic_read(&sbi->inline_inode);
84 	si->inline_dir = atomic_read(&sbi->inline_dir);
85 	si->append = sbi->im[APPEND_INO].ino_num;
86 	si->update = sbi->im[UPDATE_INO].ino_num;
87 	si->orphans = sbi->im[ORPHAN_INO].ino_num;
88 	si->utilization = utilization(sbi);
89 
90 	si->free_segs = free_segments(sbi);
91 	si->free_secs = free_sections(sbi);
92 	si->prefree_count = prefree_segments(sbi);
93 	si->dirty_count = dirty_segments(sbi);
94 	si->node_pages = NODE_MAPPING(sbi)->nrpages;
95 	si->meta_pages = META_MAPPING(sbi)->nrpages;
96 	si->nats = NM_I(sbi)->nat_cnt;
97 	si->dirty_nats = NM_I(sbi)->dirty_nat_cnt;
98 	si->sits = MAIN_SEGS(sbi);
99 	si->dirty_sits = SIT_I(sbi)->dirty_sentries;
100 	si->free_nids = NM_I(sbi)->nid_cnt[FREE_NID];
101 	si->avail_nids = NM_I(sbi)->available_nids;
102 	si->alloc_nids = NM_I(sbi)->nid_cnt[PREALLOC_NID];
103 	si->bg_gc = sbi->bg_gc;
104 	si->io_skip_bggc = sbi->io_skip_bggc;
105 	si->other_skip_bggc = sbi->other_skip_bggc;
106 	si->skipped_atomic_files[BG_GC] = sbi->skipped_atomic_files[BG_GC];
107 	si->skipped_atomic_files[FG_GC] = sbi->skipped_atomic_files[FG_GC];
108 	si->util_free = (int)(free_user_blocks(sbi) >> sbi->log_blocks_per_seg)
109 		* 100 / (int)(sbi->user_block_count >> sbi->log_blocks_per_seg)
110 		/ 2;
111 	si->util_valid = (int)(written_block_count(sbi) >>
112 						sbi->log_blocks_per_seg)
113 		* 100 / (int)(sbi->user_block_count >> sbi->log_blocks_per_seg)
114 		/ 2;
115 	si->util_invalid = 50 - si->util_free - si->util_valid;
116 	for (i = CURSEG_HOT_DATA; i <= CURSEG_COLD_NODE; i++) {
117 		struct curseg_info *curseg = CURSEG_I(sbi, i);
118 		si->curseg[i] = curseg->segno;
119 		si->cursec[i] = GET_SEC_FROM_SEG(sbi, curseg->segno);
120 		si->curzone[i] = GET_ZONE_FROM_SEC(sbi, si->cursec[i]);
121 	}
122 
123 	for (i = META_CP; i < META_MAX; i++)
124 		si->meta_count[i] = atomic_read(&sbi->meta_count[i]);
125 
126 	for (i = 0; i < 2; i++) {
127 		si->segment_count[i] = sbi->segment_count[i];
128 		si->block_count[i] = sbi->block_count[i];
129 	}
130 
131 	si->inplace_count = atomic_read(&sbi->inplace_count);
132 }
133 
134 /*
135  * This function calculates BDF of every segments
136  */
137 static void update_sit_info(struct f2fs_sb_info *sbi)
138 {
139 	struct f2fs_stat_info *si = F2FS_STAT(sbi);
140 	unsigned long long blks_per_sec, hblks_per_sec, total_vblocks;
141 	unsigned long long bimodal, dist;
142 	unsigned int segno, vblocks;
143 	int ndirty = 0;
144 
145 	bimodal = 0;
146 	total_vblocks = 0;
147 	blks_per_sec = BLKS_PER_SEC(sbi);
148 	hblks_per_sec = blks_per_sec / 2;
149 	for (segno = 0; segno < MAIN_SEGS(sbi); segno += sbi->segs_per_sec) {
150 		vblocks = get_valid_blocks(sbi, segno, true);
151 		dist = abs(vblocks - hblks_per_sec);
152 		bimodal += dist * dist;
153 
154 		if (vblocks > 0 && vblocks < blks_per_sec) {
155 			total_vblocks += vblocks;
156 			ndirty++;
157 		}
158 	}
159 	dist = div_u64(MAIN_SECS(sbi) * hblks_per_sec * hblks_per_sec, 100);
160 	si->bimodal = div64_u64(bimodal, dist);
161 	if (si->dirty_count)
162 		si->avg_vblocks = div_u64(total_vblocks, ndirty);
163 	else
164 		si->avg_vblocks = 0;
165 }
166 
167 /*
168  * This function calculates memory footprint.
169  */
170 static void update_mem_info(struct f2fs_sb_info *sbi)
171 {
172 	struct f2fs_stat_info *si = F2FS_STAT(sbi);
173 	unsigned npages;
174 	int i;
175 
176 	if (si->base_mem)
177 		goto get_cache;
178 
179 	/* build stat */
180 	si->base_mem = sizeof(struct f2fs_stat_info);
181 
182 	/* build superblock */
183 	si->base_mem += sizeof(struct f2fs_sb_info) + sbi->sb->s_blocksize;
184 	si->base_mem += 2 * sizeof(struct f2fs_inode_info);
185 	si->base_mem += sizeof(*sbi->ckpt);
186 
187 	/* build sm */
188 	si->base_mem += sizeof(struct f2fs_sm_info);
189 
190 	/* build sit */
191 	si->base_mem += sizeof(struct sit_info);
192 	si->base_mem += MAIN_SEGS(sbi) * sizeof(struct seg_entry);
193 	si->base_mem += f2fs_bitmap_size(MAIN_SEGS(sbi));
194 	si->base_mem += 2 * SIT_VBLOCK_MAP_SIZE * MAIN_SEGS(sbi);
195 	si->base_mem += SIT_VBLOCK_MAP_SIZE * MAIN_SEGS(sbi);
196 	si->base_mem += SIT_VBLOCK_MAP_SIZE;
197 	if (sbi->segs_per_sec > 1)
198 		si->base_mem += MAIN_SECS(sbi) * sizeof(struct sec_entry);
199 	si->base_mem += __bitmap_size(sbi, SIT_BITMAP);
200 
201 	/* build free segmap */
202 	si->base_mem += sizeof(struct free_segmap_info);
203 	si->base_mem += f2fs_bitmap_size(MAIN_SEGS(sbi));
204 	si->base_mem += f2fs_bitmap_size(MAIN_SECS(sbi));
205 
206 	/* build curseg */
207 	si->base_mem += sizeof(struct curseg_info) * NR_CURSEG_TYPE;
208 	si->base_mem += PAGE_SIZE * NR_CURSEG_TYPE;
209 
210 	/* build dirty segmap */
211 	si->base_mem += sizeof(struct dirty_seglist_info);
212 	si->base_mem += NR_DIRTY_TYPE * f2fs_bitmap_size(MAIN_SEGS(sbi));
213 	si->base_mem += f2fs_bitmap_size(MAIN_SECS(sbi));
214 
215 	/* build nm */
216 	si->base_mem += sizeof(struct f2fs_nm_info);
217 	si->base_mem += __bitmap_size(sbi, NAT_BITMAP);
218 	si->base_mem += (NM_I(sbi)->nat_bits_blocks << F2FS_BLKSIZE_BITS);
219 	si->base_mem += NM_I(sbi)->nat_blocks *
220 				f2fs_bitmap_size(NAT_ENTRY_PER_BLOCK);
221 	si->base_mem += NM_I(sbi)->nat_blocks / 8;
222 	si->base_mem += NM_I(sbi)->nat_blocks * sizeof(unsigned short);
223 
224 get_cache:
225 	si->cache_mem = 0;
226 
227 	/* build gc */
228 	if (sbi->gc_thread)
229 		si->cache_mem += sizeof(struct f2fs_gc_kthread);
230 
231 	/* build merge flush thread */
232 	if (SM_I(sbi)->fcc_info)
233 		si->cache_mem += sizeof(struct flush_cmd_control);
234 	if (SM_I(sbi)->dcc_info) {
235 		si->cache_mem += sizeof(struct discard_cmd_control);
236 		si->cache_mem += sizeof(struct discard_cmd) *
237 			atomic_read(&SM_I(sbi)->dcc_info->discard_cmd_cnt);
238 	}
239 
240 	/* free nids */
241 	si->cache_mem += (NM_I(sbi)->nid_cnt[FREE_NID] +
242 				NM_I(sbi)->nid_cnt[PREALLOC_NID]) *
243 				sizeof(struct free_nid);
244 	si->cache_mem += NM_I(sbi)->nat_cnt * sizeof(struct nat_entry);
245 	si->cache_mem += NM_I(sbi)->dirty_nat_cnt *
246 					sizeof(struct nat_entry_set);
247 	si->cache_mem += si->inmem_pages * sizeof(struct inmem_pages);
248 	for (i = 0; i < MAX_INO_ENTRY; i++)
249 		si->cache_mem += sbi->im[i].ino_num * sizeof(struct ino_entry);
250 	si->cache_mem += atomic_read(&sbi->total_ext_tree) *
251 						sizeof(struct extent_tree);
252 	si->cache_mem += atomic_read(&sbi->total_ext_node) *
253 						sizeof(struct extent_node);
254 
255 	si->page_mem = 0;
256 	npages = NODE_MAPPING(sbi)->nrpages;
257 	si->page_mem += (unsigned long long)npages << PAGE_SHIFT;
258 	npages = META_MAPPING(sbi)->nrpages;
259 	si->page_mem += (unsigned long long)npages << PAGE_SHIFT;
260 }
261 
262 static int stat_show(struct seq_file *s, void *v)
263 {
264 	struct f2fs_stat_info *si;
265 	int i = 0;
266 	int j;
267 
268 	mutex_lock(&f2fs_stat_mutex);
269 	list_for_each_entry(si, &f2fs_stat_list, stat_list) {
270 		update_general_status(si->sbi);
271 
272 		seq_printf(s, "\n=====[ partition info(%pg). #%d, %s, CP: %s]=====\n",
273 			si->sbi->sb->s_bdev, i++,
274 			f2fs_readonly(si->sbi->sb) ? "RO": "RW",
275 			f2fs_cp_error(si->sbi) ? "Error": "Good");
276 		seq_printf(s, "[SB: 1] [CP: 2] [SIT: %d] [NAT: %d] ",
277 			   si->sit_area_segs, si->nat_area_segs);
278 		seq_printf(s, "[SSA: %d] [MAIN: %d",
279 			   si->ssa_area_segs, si->main_area_segs);
280 		seq_printf(s, "(OverProv:%d Resv:%d)]\n\n",
281 			   si->overp_segs, si->rsvd_segs);
282 		if (test_opt(si->sbi, DISCARD))
283 			seq_printf(s, "Utilization: %u%% (%u valid blocks, %u discard blocks)\n",
284 				si->utilization, si->valid_count, si->discard_blks);
285 		else
286 			seq_printf(s, "Utilization: %u%% (%u valid blocks)\n",
287 				si->utilization, si->valid_count);
288 
289 		seq_printf(s, "  - Node: %u (Inode: %u, ",
290 			   si->valid_node_count, si->valid_inode_count);
291 		seq_printf(s, "Other: %u)\n  - Data: %u\n",
292 			   si->valid_node_count - si->valid_inode_count,
293 			   si->valid_count - si->valid_node_count);
294 		seq_printf(s, "  - Inline_xattr Inode: %u\n",
295 			   si->inline_xattr);
296 		seq_printf(s, "  - Inline_data Inode: %u\n",
297 			   si->inline_inode);
298 		seq_printf(s, "  - Inline_dentry Inode: %u\n",
299 			   si->inline_dir);
300 		seq_printf(s, "  - Orphan/Append/Update Inode: %u, %u, %u\n",
301 			   si->orphans, si->append, si->update);
302 		seq_printf(s, "\nMain area: %d segs, %d secs %d zones\n",
303 			   si->main_area_segs, si->main_area_sections,
304 			   si->main_area_zones);
305 		seq_printf(s, "  - COLD  data: %d, %d, %d\n",
306 			   si->curseg[CURSEG_COLD_DATA],
307 			   si->cursec[CURSEG_COLD_DATA],
308 			   si->curzone[CURSEG_COLD_DATA]);
309 		seq_printf(s, "  - WARM  data: %d, %d, %d\n",
310 			   si->curseg[CURSEG_WARM_DATA],
311 			   si->cursec[CURSEG_WARM_DATA],
312 			   si->curzone[CURSEG_WARM_DATA]);
313 		seq_printf(s, "  - HOT   data: %d, %d, %d\n",
314 			   si->curseg[CURSEG_HOT_DATA],
315 			   si->cursec[CURSEG_HOT_DATA],
316 			   si->curzone[CURSEG_HOT_DATA]);
317 		seq_printf(s, "  - Dir   dnode: %d, %d, %d\n",
318 			   si->curseg[CURSEG_HOT_NODE],
319 			   si->cursec[CURSEG_HOT_NODE],
320 			   si->curzone[CURSEG_HOT_NODE]);
321 		seq_printf(s, "  - File   dnode: %d, %d, %d\n",
322 			   si->curseg[CURSEG_WARM_NODE],
323 			   si->cursec[CURSEG_WARM_NODE],
324 			   si->curzone[CURSEG_WARM_NODE]);
325 		seq_printf(s, "  - Indir nodes: %d, %d, %d\n",
326 			   si->curseg[CURSEG_COLD_NODE],
327 			   si->cursec[CURSEG_COLD_NODE],
328 			   si->curzone[CURSEG_COLD_NODE]);
329 		seq_printf(s, "\n  - Valid: %d\n  - Dirty: %d\n",
330 			   si->main_area_segs - si->dirty_count -
331 			   si->prefree_count - si->free_segs,
332 			   si->dirty_count);
333 		seq_printf(s, "  - Prefree: %d\n  - Free: %d (%d)\n\n",
334 			   si->prefree_count, si->free_segs, si->free_secs);
335 		seq_printf(s, "CP calls: %d (BG: %d)\n",
336 				si->cp_count, si->bg_cp_count);
337 		seq_printf(s, "  - cp blocks : %u\n", si->meta_count[META_CP]);
338 		seq_printf(s, "  - sit blocks : %u\n",
339 				si->meta_count[META_SIT]);
340 		seq_printf(s, "  - nat blocks : %u\n",
341 				si->meta_count[META_NAT]);
342 		seq_printf(s, "  - ssa blocks : %u\n",
343 				si->meta_count[META_SSA]);
344 		seq_printf(s, "GC calls: %d (BG: %d)\n",
345 			   si->call_count, si->bg_gc);
346 		seq_printf(s, "  - data segments : %d (%d)\n",
347 				si->data_segs, si->bg_data_segs);
348 		seq_printf(s, "  - node segments : %d (%d)\n",
349 				si->node_segs, si->bg_node_segs);
350 		seq_printf(s, "Try to move %d blocks (BG: %d)\n", si->tot_blks,
351 				si->bg_data_blks + si->bg_node_blks);
352 		seq_printf(s, "  - data blocks : %d (%d)\n", si->data_blks,
353 				si->bg_data_blks);
354 		seq_printf(s, "  - node blocks : %d (%d)\n", si->node_blks,
355 				si->bg_node_blks);
356 		seq_printf(s, "Skipped : atomic write %llu (%llu)\n",
357 				si->skipped_atomic_files[BG_GC] +
358 				si->skipped_atomic_files[FG_GC],
359 				si->skipped_atomic_files[BG_GC]);
360 		seq_printf(s, "BG skip : IO: %u, Other: %u\n",
361 				si->io_skip_bggc, si->other_skip_bggc);
362 		seq_puts(s, "\nExtent Cache:\n");
363 		seq_printf(s, "  - Hit Count: L1-1:%llu L1-2:%llu L2:%llu\n",
364 				si->hit_largest, si->hit_cached,
365 				si->hit_rbtree);
366 		seq_printf(s, "  - Hit Ratio: %llu%% (%llu / %llu)\n",
367 				!si->total_ext ? 0 :
368 				div64_u64(si->hit_total * 100, si->total_ext),
369 				si->hit_total, si->total_ext);
370 		seq_printf(s, "  - Inner Struct Count: tree: %d(%d), node: %d\n",
371 				si->ext_tree, si->zombie_tree, si->ext_node);
372 		seq_puts(s, "\nBalancing F2FS Async:\n");
373 		seq_printf(s, "  - IO (CP: %4d, Data: %4d, Flush: (%4d %4d %4d), "
374 			"Discard: (%4d %4d)) cmd: %4d undiscard:%4u\n",
375 			   si->nr_wb_cp_data, si->nr_wb_data,
376 			   si->nr_flushing, si->nr_flushed,
377 			   si->flush_list_empty,
378 			   si->nr_discarding, si->nr_discarded,
379 			   si->nr_discard_cmd, si->undiscard_blks);
380 		seq_printf(s, "  - inmem: %4d, atomic IO: %4d (Max. %4d), "
381 			"volatile IO: %4d (Max. %4d)\n",
382 			   si->inmem_pages, si->aw_cnt, si->max_aw_cnt,
383 			   si->vw_cnt, si->max_vw_cnt);
384 		seq_printf(s, "  - nodes: %4d in %4d\n",
385 			   si->ndirty_node, si->node_pages);
386 		seq_printf(s, "  - dents: %4d in dirs:%4d (%4d)\n",
387 			   si->ndirty_dent, si->ndirty_dirs, si->ndirty_all);
388 		seq_printf(s, "  - datas: %4d in files:%4d\n",
389 			   si->ndirty_data, si->ndirty_files);
390 		seq_printf(s, "  - quota datas: %4d in quota files:%4d\n",
391 			   si->ndirty_qdata, si->nquota_files);
392 		seq_printf(s, "  - meta: %4d in %4d\n",
393 			   si->ndirty_meta, si->meta_pages);
394 		seq_printf(s, "  - imeta: %4d\n",
395 			   si->ndirty_imeta);
396 		seq_printf(s, "  - NATs: %9d/%9d\n  - SITs: %9d/%9d\n",
397 			   si->dirty_nats, si->nats, si->dirty_sits, si->sits);
398 		seq_printf(s, "  - free_nids: %9d/%9d\n  - alloc_nids: %9d\n",
399 			   si->free_nids, si->avail_nids, si->alloc_nids);
400 		seq_puts(s, "\nDistribution of User Blocks:");
401 		seq_puts(s, " [ valid | invalid | free ]\n");
402 		seq_puts(s, "  [");
403 
404 		for (j = 0; j < si->util_valid; j++)
405 			seq_putc(s, '-');
406 		seq_putc(s, '|');
407 
408 		for (j = 0; j < si->util_invalid; j++)
409 			seq_putc(s, '-');
410 		seq_putc(s, '|');
411 
412 		for (j = 0; j < si->util_free; j++)
413 			seq_putc(s, '-');
414 		seq_puts(s, "]\n\n");
415 		seq_printf(s, "IPU: %u blocks\n", si->inplace_count);
416 		seq_printf(s, "SSR: %u blocks in %u segments\n",
417 			   si->block_count[SSR], si->segment_count[SSR]);
418 		seq_printf(s, "LFS: %u blocks in %u segments\n",
419 			   si->block_count[LFS], si->segment_count[LFS]);
420 
421 		/* segment usage info */
422 		update_sit_info(si->sbi);
423 		seq_printf(s, "\nBDF: %u, avg. vblocks: %u\n",
424 			   si->bimodal, si->avg_vblocks);
425 
426 		/* memory footprint */
427 		update_mem_info(si->sbi);
428 		seq_printf(s, "\nMemory: %llu KB\n",
429 			(si->base_mem + si->cache_mem + si->page_mem) >> 10);
430 		seq_printf(s, "  - static: %llu KB\n",
431 				si->base_mem >> 10);
432 		seq_printf(s, "  - cached: %llu KB\n",
433 				si->cache_mem >> 10);
434 		seq_printf(s, "  - paged : %llu KB\n",
435 				si->page_mem >> 10);
436 	}
437 	mutex_unlock(&f2fs_stat_mutex);
438 	return 0;
439 }
440 
441 static int stat_open(struct inode *inode, struct file *file)
442 {
443 	return single_open(file, stat_show, inode->i_private);
444 }
445 
446 static const struct file_operations stat_fops = {
447 	.owner = THIS_MODULE,
448 	.open = stat_open,
449 	.read = seq_read,
450 	.llseek = seq_lseek,
451 	.release = single_release,
452 };
453 
454 int f2fs_build_stats(struct f2fs_sb_info *sbi)
455 {
456 	struct f2fs_super_block *raw_super = F2FS_RAW_SUPER(sbi);
457 	struct f2fs_stat_info *si;
458 	int i;
459 
460 	si = f2fs_kzalloc(sbi, sizeof(struct f2fs_stat_info), GFP_KERNEL);
461 	if (!si)
462 		return -ENOMEM;
463 
464 	si->all_area_segs = le32_to_cpu(raw_super->segment_count);
465 	si->sit_area_segs = le32_to_cpu(raw_super->segment_count_sit);
466 	si->nat_area_segs = le32_to_cpu(raw_super->segment_count_nat);
467 	si->ssa_area_segs = le32_to_cpu(raw_super->segment_count_ssa);
468 	si->main_area_segs = le32_to_cpu(raw_super->segment_count_main);
469 	si->main_area_sections = le32_to_cpu(raw_super->section_count);
470 	si->main_area_zones = si->main_area_sections /
471 				le32_to_cpu(raw_super->secs_per_zone);
472 	si->sbi = sbi;
473 	sbi->stat_info = si;
474 
475 	atomic64_set(&sbi->total_hit_ext, 0);
476 	atomic64_set(&sbi->read_hit_rbtree, 0);
477 	atomic64_set(&sbi->read_hit_largest, 0);
478 	atomic64_set(&sbi->read_hit_cached, 0);
479 
480 	atomic_set(&sbi->inline_xattr, 0);
481 	atomic_set(&sbi->inline_inode, 0);
482 	atomic_set(&sbi->inline_dir, 0);
483 	atomic_set(&sbi->inplace_count, 0);
484 	for (i = META_CP; i < META_MAX; i++)
485 		atomic_set(&sbi->meta_count[i], 0);
486 
487 	atomic_set(&sbi->aw_cnt, 0);
488 	atomic_set(&sbi->vw_cnt, 0);
489 	atomic_set(&sbi->max_aw_cnt, 0);
490 	atomic_set(&sbi->max_vw_cnt, 0);
491 
492 	mutex_lock(&f2fs_stat_mutex);
493 	list_add_tail(&si->stat_list, &f2fs_stat_list);
494 	mutex_unlock(&f2fs_stat_mutex);
495 
496 	return 0;
497 }
498 
499 void f2fs_destroy_stats(struct f2fs_sb_info *sbi)
500 {
501 	struct f2fs_stat_info *si = F2FS_STAT(sbi);
502 
503 	mutex_lock(&f2fs_stat_mutex);
504 	list_del(&si->stat_list);
505 	mutex_unlock(&f2fs_stat_mutex);
506 
507 	kfree(si);
508 }
509 
510 int __init f2fs_create_root_stats(void)
511 {
512 	struct dentry *file;
513 
514 	f2fs_debugfs_root = debugfs_create_dir("f2fs", NULL);
515 	if (!f2fs_debugfs_root)
516 		return -ENOMEM;
517 
518 	file = debugfs_create_file("status", S_IRUGO, f2fs_debugfs_root,
519 			NULL, &stat_fops);
520 	if (!file) {
521 		debugfs_remove(f2fs_debugfs_root);
522 		f2fs_debugfs_root = NULL;
523 		return -ENOMEM;
524 	}
525 
526 	return 0;
527 }
528 
529 void f2fs_destroy_root_stats(void)
530 {
531 	if (!f2fs_debugfs_root)
532 		return;
533 
534 	debugfs_remove_recursive(f2fs_debugfs_root);
535 	f2fs_debugfs_root = NULL;
536 }
537