1 /* 2 * f2fs debugging statistics 3 * 4 * Copyright (c) 2012 Samsung Electronics Co., Ltd. 5 * http://www.samsung.com/ 6 * Copyright (c) 2012 Linux Foundation 7 * Copyright (c) 2012 Greg Kroah-Hartman <gregkh@linuxfoundation.org> 8 * 9 * This program is free software; you can redistribute it and/or modify 10 * it under the terms of the GNU General Public License version 2 as 11 * published by the Free Software Foundation. 12 */ 13 14 #include <linux/fs.h> 15 #include <linux/backing-dev.h> 16 #include <linux/f2fs_fs.h> 17 #include <linux/blkdev.h> 18 #include <linux/debugfs.h> 19 #include <linux/seq_file.h> 20 21 #include "f2fs.h" 22 #include "node.h" 23 #include "segment.h" 24 #include "gc.h" 25 26 static LIST_HEAD(f2fs_stat_list); 27 static struct dentry *f2fs_debugfs_root; 28 static DEFINE_MUTEX(f2fs_stat_mutex); 29 30 static void update_general_status(struct f2fs_sb_info *sbi) 31 { 32 struct f2fs_stat_info *si = F2FS_STAT(sbi); 33 int i; 34 35 /* validation check of the segment numbers */ 36 si->hit_largest = atomic64_read(&sbi->read_hit_largest); 37 si->hit_cached = atomic64_read(&sbi->read_hit_cached); 38 si->hit_rbtree = atomic64_read(&sbi->read_hit_rbtree); 39 si->hit_total = si->hit_largest + si->hit_cached + si->hit_rbtree; 40 si->total_ext = atomic64_read(&sbi->total_hit_ext); 41 si->ext_tree = atomic_read(&sbi->total_ext_tree); 42 si->zombie_tree = atomic_read(&sbi->total_zombie_tree); 43 si->ext_node = atomic_read(&sbi->total_ext_node); 44 si->ndirty_node = get_pages(sbi, F2FS_DIRTY_NODES); 45 si->ndirty_dent = get_pages(sbi, F2FS_DIRTY_DENTS); 46 si->ndirty_meta = get_pages(sbi, F2FS_DIRTY_META); 47 si->ndirty_data = get_pages(sbi, F2FS_DIRTY_DATA); 48 si->ndirty_imeta = get_pages(sbi, F2FS_DIRTY_IMETA); 49 si->ndirty_dirs = sbi->ndirty_inode[DIR_INODE]; 50 si->ndirty_files = sbi->ndirty_inode[FILE_INODE]; 51 si->ndirty_all = sbi->ndirty_inode[DIRTY_META]; 52 si->inmem_pages = get_pages(sbi, F2FS_INMEM_PAGES); 53 si->aw_cnt = atomic_read(&sbi->aw_cnt); 54 si->vw_cnt = atomic_read(&sbi->vw_cnt); 55 si->max_aw_cnt = atomic_read(&sbi->max_aw_cnt); 56 si->max_vw_cnt = atomic_read(&sbi->max_vw_cnt); 57 si->nr_wb_cp_data = get_pages(sbi, F2FS_WB_CP_DATA); 58 si->nr_wb_data = get_pages(sbi, F2FS_WB_DATA); 59 if (SM_I(sbi) && SM_I(sbi)->fcc_info) { 60 si->nr_flushed = 61 atomic_read(&SM_I(sbi)->fcc_info->issued_flush); 62 si->nr_flushing = 63 atomic_read(&SM_I(sbi)->fcc_info->issing_flush); 64 } 65 if (SM_I(sbi) && SM_I(sbi)->dcc_info) { 66 si->nr_discarded = 67 atomic_read(&SM_I(sbi)->dcc_info->issued_discard); 68 si->nr_discarding = 69 atomic_read(&SM_I(sbi)->dcc_info->issing_discard); 70 } 71 si->total_count = (int)sbi->user_block_count / sbi->blocks_per_seg; 72 si->rsvd_segs = reserved_segments(sbi); 73 si->overp_segs = overprovision_segments(sbi); 74 si->valid_count = valid_user_blocks(sbi); 75 si->discard_blks = discard_blocks(sbi); 76 si->valid_node_count = valid_node_count(sbi); 77 si->valid_inode_count = valid_inode_count(sbi); 78 si->inline_xattr = atomic_read(&sbi->inline_xattr); 79 si->inline_inode = atomic_read(&sbi->inline_inode); 80 si->inline_dir = atomic_read(&sbi->inline_dir); 81 si->append = sbi->im[APPEND_INO].ino_num; 82 si->update = sbi->im[UPDATE_INO].ino_num; 83 si->orphans = sbi->im[ORPHAN_INO].ino_num; 84 si->utilization = utilization(sbi); 85 86 si->free_segs = free_segments(sbi); 87 si->free_secs = free_sections(sbi); 88 si->prefree_count = prefree_segments(sbi); 89 si->dirty_count = dirty_segments(sbi); 90 si->node_pages = NODE_MAPPING(sbi)->nrpages; 91 si->meta_pages = META_MAPPING(sbi)->nrpages; 92 si->nats = NM_I(sbi)->nat_cnt; 93 si->dirty_nats = NM_I(sbi)->dirty_nat_cnt; 94 si->sits = MAIN_SEGS(sbi); 95 si->dirty_sits = SIT_I(sbi)->dirty_sentries; 96 si->free_nids = NM_I(sbi)->nid_cnt[FREE_NID_LIST]; 97 si->alloc_nids = NM_I(sbi)->nid_cnt[ALLOC_NID_LIST]; 98 si->bg_gc = sbi->bg_gc; 99 si->util_free = (int)(free_user_blocks(sbi) >> sbi->log_blocks_per_seg) 100 * 100 / (int)(sbi->user_block_count >> sbi->log_blocks_per_seg) 101 / 2; 102 si->util_valid = (int)(written_block_count(sbi) >> 103 sbi->log_blocks_per_seg) 104 * 100 / (int)(sbi->user_block_count >> sbi->log_blocks_per_seg) 105 / 2; 106 si->util_invalid = 50 - si->util_free - si->util_valid; 107 for (i = CURSEG_HOT_DATA; i <= CURSEG_COLD_NODE; i++) { 108 struct curseg_info *curseg = CURSEG_I(sbi, i); 109 si->curseg[i] = curseg->segno; 110 si->cursec[i] = curseg->segno / sbi->segs_per_sec; 111 si->curzone[i] = si->cursec[i] / sbi->secs_per_zone; 112 } 113 114 for (i = 0; i < 2; i++) { 115 si->segment_count[i] = sbi->segment_count[i]; 116 si->block_count[i] = sbi->block_count[i]; 117 } 118 119 si->inplace_count = atomic_read(&sbi->inplace_count); 120 } 121 122 /* 123 * This function calculates BDF of every segments 124 */ 125 static void update_sit_info(struct f2fs_sb_info *sbi) 126 { 127 struct f2fs_stat_info *si = F2FS_STAT(sbi); 128 unsigned long long blks_per_sec, hblks_per_sec, total_vblocks; 129 unsigned long long bimodal, dist; 130 unsigned int segno, vblocks; 131 int ndirty = 0; 132 133 bimodal = 0; 134 total_vblocks = 0; 135 blks_per_sec = sbi->segs_per_sec * sbi->blocks_per_seg; 136 hblks_per_sec = blks_per_sec / 2; 137 for (segno = 0; segno < MAIN_SEGS(sbi); segno += sbi->segs_per_sec) { 138 vblocks = get_valid_blocks(sbi, segno, sbi->segs_per_sec); 139 dist = abs(vblocks - hblks_per_sec); 140 bimodal += dist * dist; 141 142 if (vblocks > 0 && vblocks < blks_per_sec) { 143 total_vblocks += vblocks; 144 ndirty++; 145 } 146 } 147 dist = div_u64(MAIN_SECS(sbi) * hblks_per_sec * hblks_per_sec, 100); 148 si->bimodal = div64_u64(bimodal, dist); 149 if (si->dirty_count) 150 si->avg_vblocks = div_u64(total_vblocks, ndirty); 151 else 152 si->avg_vblocks = 0; 153 } 154 155 /* 156 * This function calculates memory footprint. 157 */ 158 static void update_mem_info(struct f2fs_sb_info *sbi) 159 { 160 struct f2fs_stat_info *si = F2FS_STAT(sbi); 161 unsigned npages; 162 int i; 163 164 if (si->base_mem) 165 goto get_cache; 166 167 /* build stat */ 168 si->base_mem = sizeof(struct f2fs_stat_info); 169 170 /* build superblock */ 171 si->base_mem += sizeof(struct f2fs_sb_info) + sbi->sb->s_blocksize; 172 si->base_mem += 2 * sizeof(struct f2fs_inode_info); 173 si->base_mem += sizeof(*sbi->ckpt); 174 si->base_mem += sizeof(struct percpu_counter) * NR_COUNT_TYPE; 175 176 /* build sm */ 177 si->base_mem += sizeof(struct f2fs_sm_info); 178 179 /* build sit */ 180 si->base_mem += sizeof(struct sit_info); 181 si->base_mem += MAIN_SEGS(sbi) * sizeof(struct seg_entry); 182 si->base_mem += f2fs_bitmap_size(MAIN_SEGS(sbi)); 183 si->base_mem += 2 * SIT_VBLOCK_MAP_SIZE * MAIN_SEGS(sbi); 184 if (f2fs_discard_en(sbi)) 185 si->base_mem += SIT_VBLOCK_MAP_SIZE * MAIN_SEGS(sbi); 186 si->base_mem += SIT_VBLOCK_MAP_SIZE; 187 if (sbi->segs_per_sec > 1) 188 si->base_mem += MAIN_SECS(sbi) * sizeof(struct sec_entry); 189 si->base_mem += __bitmap_size(sbi, SIT_BITMAP); 190 191 /* build free segmap */ 192 si->base_mem += sizeof(struct free_segmap_info); 193 si->base_mem += f2fs_bitmap_size(MAIN_SEGS(sbi)); 194 si->base_mem += f2fs_bitmap_size(MAIN_SECS(sbi)); 195 196 /* build curseg */ 197 si->base_mem += sizeof(struct curseg_info) * NR_CURSEG_TYPE; 198 si->base_mem += PAGE_SIZE * NR_CURSEG_TYPE; 199 200 /* build dirty segmap */ 201 si->base_mem += sizeof(struct dirty_seglist_info); 202 si->base_mem += NR_DIRTY_TYPE * f2fs_bitmap_size(MAIN_SEGS(sbi)); 203 si->base_mem += f2fs_bitmap_size(MAIN_SECS(sbi)); 204 205 /* build nm */ 206 si->base_mem += sizeof(struct f2fs_nm_info); 207 si->base_mem += __bitmap_size(sbi, NAT_BITMAP); 208 si->base_mem += (NM_I(sbi)->nat_bits_blocks << F2FS_BLKSIZE_BITS); 209 si->base_mem += NM_I(sbi)->nat_blocks * NAT_ENTRY_BITMAP_SIZE; 210 si->base_mem += NM_I(sbi)->nat_blocks / 8; 211 si->base_mem += NM_I(sbi)->nat_blocks * sizeof(unsigned short); 212 213 get_cache: 214 si->cache_mem = 0; 215 216 /* build gc */ 217 if (sbi->gc_thread) 218 si->cache_mem += sizeof(struct f2fs_gc_kthread); 219 220 /* build merge flush thread */ 221 if (SM_I(sbi)->fcc_info) 222 si->cache_mem += sizeof(struct flush_cmd_control); 223 if (SM_I(sbi)->dcc_info) 224 si->cache_mem += sizeof(struct discard_cmd_control); 225 226 /* free nids */ 227 si->cache_mem += (NM_I(sbi)->nid_cnt[FREE_NID_LIST] + 228 NM_I(sbi)->nid_cnt[ALLOC_NID_LIST]) * 229 sizeof(struct free_nid); 230 si->cache_mem += NM_I(sbi)->nat_cnt * sizeof(struct nat_entry); 231 si->cache_mem += NM_I(sbi)->dirty_nat_cnt * 232 sizeof(struct nat_entry_set); 233 si->cache_mem += si->inmem_pages * sizeof(struct inmem_pages); 234 for (i = 0; i <= ORPHAN_INO; i++) 235 si->cache_mem += sbi->im[i].ino_num * sizeof(struct ino_entry); 236 si->cache_mem += atomic_read(&sbi->total_ext_tree) * 237 sizeof(struct extent_tree); 238 si->cache_mem += atomic_read(&sbi->total_ext_node) * 239 sizeof(struct extent_node); 240 241 si->page_mem = 0; 242 npages = NODE_MAPPING(sbi)->nrpages; 243 si->page_mem += (unsigned long long)npages << PAGE_SHIFT; 244 npages = META_MAPPING(sbi)->nrpages; 245 si->page_mem += (unsigned long long)npages << PAGE_SHIFT; 246 } 247 248 static int stat_show(struct seq_file *s, void *v) 249 { 250 struct f2fs_stat_info *si; 251 int i = 0; 252 int j; 253 254 mutex_lock(&f2fs_stat_mutex); 255 list_for_each_entry(si, &f2fs_stat_list, stat_list) { 256 update_general_status(si->sbi); 257 258 seq_printf(s, "\n=====[ partition info(%pg). #%d, %s]=====\n", 259 si->sbi->sb->s_bdev, i++, 260 f2fs_readonly(si->sbi->sb) ? "RO": "RW"); 261 seq_printf(s, "[SB: 1] [CP: 2] [SIT: %d] [NAT: %d] ", 262 si->sit_area_segs, si->nat_area_segs); 263 seq_printf(s, "[SSA: %d] [MAIN: %d", 264 si->ssa_area_segs, si->main_area_segs); 265 seq_printf(s, "(OverProv:%d Resv:%d)]\n\n", 266 si->overp_segs, si->rsvd_segs); 267 if (test_opt(si->sbi, DISCARD)) 268 seq_printf(s, "Utilization: %u%% (%u valid blocks, %u discard blocks)\n", 269 si->utilization, si->valid_count, si->discard_blks); 270 else 271 seq_printf(s, "Utilization: %u%% (%u valid blocks)\n", 272 si->utilization, si->valid_count); 273 274 seq_printf(s, " - Node: %u (Inode: %u, ", 275 si->valid_node_count, si->valid_inode_count); 276 seq_printf(s, "Other: %u)\n - Data: %u\n", 277 si->valid_node_count - si->valid_inode_count, 278 si->valid_count - si->valid_node_count); 279 seq_printf(s, " - Inline_xattr Inode: %u\n", 280 si->inline_xattr); 281 seq_printf(s, " - Inline_data Inode: %u\n", 282 si->inline_inode); 283 seq_printf(s, " - Inline_dentry Inode: %u\n", 284 si->inline_dir); 285 seq_printf(s, " - Orphan/Append/Update Inode: %u, %u, %u\n", 286 si->orphans, si->append, si->update); 287 seq_printf(s, "\nMain area: %d segs, %d secs %d zones\n", 288 si->main_area_segs, si->main_area_sections, 289 si->main_area_zones); 290 seq_printf(s, " - COLD data: %d, %d, %d\n", 291 si->curseg[CURSEG_COLD_DATA], 292 si->cursec[CURSEG_COLD_DATA], 293 si->curzone[CURSEG_COLD_DATA]); 294 seq_printf(s, " - WARM data: %d, %d, %d\n", 295 si->curseg[CURSEG_WARM_DATA], 296 si->cursec[CURSEG_WARM_DATA], 297 si->curzone[CURSEG_WARM_DATA]); 298 seq_printf(s, " - HOT data: %d, %d, %d\n", 299 si->curseg[CURSEG_HOT_DATA], 300 si->cursec[CURSEG_HOT_DATA], 301 si->curzone[CURSEG_HOT_DATA]); 302 seq_printf(s, " - Dir dnode: %d, %d, %d\n", 303 si->curseg[CURSEG_HOT_NODE], 304 si->cursec[CURSEG_HOT_NODE], 305 si->curzone[CURSEG_HOT_NODE]); 306 seq_printf(s, " - File dnode: %d, %d, %d\n", 307 si->curseg[CURSEG_WARM_NODE], 308 si->cursec[CURSEG_WARM_NODE], 309 si->curzone[CURSEG_WARM_NODE]); 310 seq_printf(s, " - Indir nodes: %d, %d, %d\n", 311 si->curseg[CURSEG_COLD_NODE], 312 si->cursec[CURSEG_COLD_NODE], 313 si->curzone[CURSEG_COLD_NODE]); 314 seq_printf(s, "\n - Valid: %d\n - Dirty: %d\n", 315 si->main_area_segs - si->dirty_count - 316 si->prefree_count - si->free_segs, 317 si->dirty_count); 318 seq_printf(s, " - Prefree: %d\n - Free: %d (%d)\n\n", 319 si->prefree_count, si->free_segs, si->free_secs); 320 seq_printf(s, "CP calls: %d (BG: %d)\n", 321 si->cp_count, si->bg_cp_count); 322 seq_printf(s, "GC calls: %d (BG: %d)\n", 323 si->call_count, si->bg_gc); 324 seq_printf(s, " - data segments : %d (%d)\n", 325 si->data_segs, si->bg_data_segs); 326 seq_printf(s, " - node segments : %d (%d)\n", 327 si->node_segs, si->bg_node_segs); 328 seq_printf(s, "Try to move %d blocks (BG: %d)\n", si->tot_blks, 329 si->bg_data_blks + si->bg_node_blks); 330 seq_printf(s, " - data blocks : %d (%d)\n", si->data_blks, 331 si->bg_data_blks); 332 seq_printf(s, " - node blocks : %d (%d)\n", si->node_blks, 333 si->bg_node_blks); 334 seq_puts(s, "\nExtent Cache:\n"); 335 seq_printf(s, " - Hit Count: L1-1:%llu L1-2:%llu L2:%llu\n", 336 si->hit_largest, si->hit_cached, 337 si->hit_rbtree); 338 seq_printf(s, " - Hit Ratio: %llu%% (%llu / %llu)\n", 339 !si->total_ext ? 0 : 340 div64_u64(si->hit_total * 100, si->total_ext), 341 si->hit_total, si->total_ext); 342 seq_printf(s, " - Inner Struct Count: tree: %d(%d), node: %d\n", 343 si->ext_tree, si->zombie_tree, si->ext_node); 344 seq_puts(s, "\nBalancing F2FS Async:\n"); 345 seq_printf(s, " - IO (CP: %4d, Data: %4d, Flush: (%4d %4d), " 346 "Discard: (%4d %4d))\n", 347 si->nr_wb_cp_data, si->nr_wb_data, 348 si->nr_flushing, si->nr_flushed, 349 si->nr_discarding, si->nr_discarded); 350 seq_printf(s, " - inmem: %4d, atomic IO: %4d (Max. %4d), " 351 "volatile IO: %4d (Max. %4d)\n", 352 si->inmem_pages, si->aw_cnt, si->max_aw_cnt, 353 si->vw_cnt, si->max_vw_cnt); 354 seq_printf(s, " - nodes: %4d in %4d\n", 355 si->ndirty_node, si->node_pages); 356 seq_printf(s, " - dents: %4d in dirs:%4d (%4d)\n", 357 si->ndirty_dent, si->ndirty_dirs, si->ndirty_all); 358 seq_printf(s, " - datas: %4d in files:%4d\n", 359 si->ndirty_data, si->ndirty_files); 360 seq_printf(s, " - meta: %4d in %4d\n", 361 si->ndirty_meta, si->meta_pages); 362 seq_printf(s, " - imeta: %4d\n", 363 si->ndirty_imeta); 364 seq_printf(s, " - NATs: %9d/%9d\n - SITs: %9d/%9d\n", 365 si->dirty_nats, si->nats, si->dirty_sits, si->sits); 366 seq_printf(s, " - free_nids: %9d, alloc_nids: %9d\n", 367 si->free_nids, si->alloc_nids); 368 seq_puts(s, "\nDistribution of User Blocks:"); 369 seq_puts(s, " [ valid | invalid | free ]\n"); 370 seq_puts(s, " ["); 371 372 for (j = 0; j < si->util_valid; j++) 373 seq_putc(s, '-'); 374 seq_putc(s, '|'); 375 376 for (j = 0; j < si->util_invalid; j++) 377 seq_putc(s, '-'); 378 seq_putc(s, '|'); 379 380 for (j = 0; j < si->util_free; j++) 381 seq_putc(s, '-'); 382 seq_puts(s, "]\n\n"); 383 seq_printf(s, "IPU: %u blocks\n", si->inplace_count); 384 seq_printf(s, "SSR: %u blocks in %u segments\n", 385 si->block_count[SSR], si->segment_count[SSR]); 386 seq_printf(s, "LFS: %u blocks in %u segments\n", 387 si->block_count[LFS], si->segment_count[LFS]); 388 389 /* segment usage info */ 390 update_sit_info(si->sbi); 391 seq_printf(s, "\nBDF: %u, avg. vblocks: %u\n", 392 si->bimodal, si->avg_vblocks); 393 394 /* memory footprint */ 395 update_mem_info(si->sbi); 396 seq_printf(s, "\nMemory: %llu KB\n", 397 (si->base_mem + si->cache_mem + si->page_mem) >> 10); 398 seq_printf(s, " - static: %llu KB\n", 399 si->base_mem >> 10); 400 seq_printf(s, " - cached: %llu KB\n", 401 si->cache_mem >> 10); 402 seq_printf(s, " - paged : %llu KB\n", 403 si->page_mem >> 10); 404 } 405 mutex_unlock(&f2fs_stat_mutex); 406 return 0; 407 } 408 409 static int stat_open(struct inode *inode, struct file *file) 410 { 411 return single_open(file, stat_show, inode->i_private); 412 } 413 414 static const struct file_operations stat_fops = { 415 .owner = THIS_MODULE, 416 .open = stat_open, 417 .read = seq_read, 418 .llseek = seq_lseek, 419 .release = single_release, 420 }; 421 422 int f2fs_build_stats(struct f2fs_sb_info *sbi) 423 { 424 struct f2fs_super_block *raw_super = F2FS_RAW_SUPER(sbi); 425 struct f2fs_stat_info *si; 426 427 si = kzalloc(sizeof(struct f2fs_stat_info), GFP_KERNEL); 428 if (!si) 429 return -ENOMEM; 430 431 si->all_area_segs = le32_to_cpu(raw_super->segment_count); 432 si->sit_area_segs = le32_to_cpu(raw_super->segment_count_sit); 433 si->nat_area_segs = le32_to_cpu(raw_super->segment_count_nat); 434 si->ssa_area_segs = le32_to_cpu(raw_super->segment_count_ssa); 435 si->main_area_segs = le32_to_cpu(raw_super->segment_count_main); 436 si->main_area_sections = le32_to_cpu(raw_super->section_count); 437 si->main_area_zones = si->main_area_sections / 438 le32_to_cpu(raw_super->secs_per_zone); 439 si->sbi = sbi; 440 sbi->stat_info = si; 441 442 atomic64_set(&sbi->total_hit_ext, 0); 443 atomic64_set(&sbi->read_hit_rbtree, 0); 444 atomic64_set(&sbi->read_hit_largest, 0); 445 atomic64_set(&sbi->read_hit_cached, 0); 446 447 atomic_set(&sbi->inline_xattr, 0); 448 atomic_set(&sbi->inline_inode, 0); 449 atomic_set(&sbi->inline_dir, 0); 450 atomic_set(&sbi->inplace_count, 0); 451 452 atomic_set(&sbi->aw_cnt, 0); 453 atomic_set(&sbi->vw_cnt, 0); 454 atomic_set(&sbi->max_aw_cnt, 0); 455 atomic_set(&sbi->max_vw_cnt, 0); 456 457 mutex_lock(&f2fs_stat_mutex); 458 list_add_tail(&si->stat_list, &f2fs_stat_list); 459 mutex_unlock(&f2fs_stat_mutex); 460 461 return 0; 462 } 463 464 void f2fs_destroy_stats(struct f2fs_sb_info *sbi) 465 { 466 struct f2fs_stat_info *si = F2FS_STAT(sbi); 467 468 mutex_lock(&f2fs_stat_mutex); 469 list_del(&si->stat_list); 470 mutex_unlock(&f2fs_stat_mutex); 471 472 kfree(si); 473 } 474 475 int __init f2fs_create_root_stats(void) 476 { 477 struct dentry *file; 478 479 f2fs_debugfs_root = debugfs_create_dir("f2fs", NULL); 480 if (!f2fs_debugfs_root) 481 return -ENOMEM; 482 483 file = debugfs_create_file("status", S_IRUGO, f2fs_debugfs_root, 484 NULL, &stat_fops); 485 if (!file) { 486 debugfs_remove(f2fs_debugfs_root); 487 f2fs_debugfs_root = NULL; 488 return -ENOMEM; 489 } 490 491 return 0; 492 } 493 494 void f2fs_destroy_root_stats(void) 495 { 496 if (!f2fs_debugfs_root) 497 return; 498 499 debugfs_remove_recursive(f2fs_debugfs_root); 500 f2fs_debugfs_root = NULL; 501 } 502