1// SPDX-License-Identifier: GPL-2.0 2/* 3 * linux/fs/ext4/sysfs.c 4 * 5 * Copyright (C) 1992, 1993, 1994, 1995 6 * Remy Card (card@masi.ibp.fr) 7 * Theodore Ts'o (tytso@mit.edu) 8 * 9 */ 10 11#include <linux/time.h> 12#include <linux/fs.h> 13#include <linux/seq_file.h> 14#include <linux/slab.h> 15#include <linux/proc_fs.h> 16#include <linux/part_stat.h> 17 18#include "ext4.h" 19#include "ext4_jbd2.h" 20 21typedef enum { 22 attr_noop, 23 attr_delayed_allocation_blocks, 24 attr_session_write_kbytes, 25 attr_lifetime_write_kbytes, 26 attr_reserved_clusters, 27 attr_sra_exceeded_retry_limit, 28 attr_inode_readahead, 29 attr_trigger_test_error, 30 attr_first_error_time, 31 attr_last_error_time, 32 attr_feature, 33 attr_pointer_ui, 34 attr_pointer_ul, 35 attr_pointer_u64, 36 attr_pointer_u8, 37 attr_pointer_string, 38 attr_pointer_atomic, 39 attr_journal_task, 40} attr_id_t; 41 42typedef enum { 43 ptr_explicit, 44 ptr_ext4_sb_info_offset, 45 ptr_ext4_super_block_offset, 46} attr_ptr_t; 47 48static const char proc_dirname[] = "fs/ext4"; 49static struct proc_dir_entry *ext4_proc_root; 50 51struct ext4_attr { 52 struct attribute attr; 53 short attr_id; 54 short attr_ptr; 55 unsigned short attr_size; 56 union { 57 int offset; 58 void *explicit_ptr; 59 } u; 60}; 61 62static ssize_t session_write_kbytes_show(struct ext4_sb_info *sbi, char *buf) 63{ 64 struct super_block *sb = sbi->s_buddy_cache->i_sb; 65 66 return sysfs_emit(buf, "%lu\n", 67 (part_stat_read(sb->s_bdev, sectors[STAT_WRITE]) - 68 sbi->s_sectors_written_start) >> 1); 69} 70 71static ssize_t lifetime_write_kbytes_show(struct ext4_sb_info *sbi, char *buf) 72{ 73 struct super_block *sb = sbi->s_buddy_cache->i_sb; 74 75 return sysfs_emit(buf, "%llu\n", 76 (unsigned long long)(sbi->s_kbytes_written + 77 ((part_stat_read(sb->s_bdev, sectors[STAT_WRITE]) - 78 EXT4_SB(sb)->s_sectors_written_start) >> 1))); 79} 80 81static ssize_t inode_readahead_blks_store(struct ext4_sb_info *sbi, 82 const char *buf, size_t count) 83{ 84 unsigned long t; 85 int ret; 86 87 ret = kstrtoul(skip_spaces(buf), 0, &t); 88 if (ret) 89 return ret; 90 91 if (t && (!is_power_of_2(t) || t > 0x40000000)) 92 return -EINVAL; 93 94 sbi->s_inode_readahead_blks = t; 95 return count; 96} 97 98static ssize_t reserved_clusters_store(struct ext4_sb_info *sbi, 99 const char *buf, size_t count) 100{ 101 unsigned long long val; 102 ext4_fsblk_t clusters = (ext4_blocks_count(sbi->s_es) >> 103 sbi->s_cluster_bits); 104 int ret; 105 106 ret = kstrtoull(skip_spaces(buf), 0, &val); 107 if (ret || val >= clusters) 108 return -EINVAL; 109 110 atomic64_set(&sbi->s_resv_clusters, val); 111 return count; 112} 113 114static ssize_t trigger_test_error(struct ext4_sb_info *sbi, 115 const char *buf, size_t count) 116{ 117 int len = count; 118 119 if (!capable(CAP_SYS_ADMIN)) 120 return -EPERM; 121 122 if (len && buf[len-1] == '\n') 123 len--; 124 125 if (len) 126 ext4_error(sbi->s_sb, "%.*s", len, buf); 127 return count; 128} 129 130static ssize_t journal_task_show(struct ext4_sb_info *sbi, char *buf) 131{ 132 if (!sbi->s_journal) 133 return sysfs_emit(buf, "<none>\n"); 134 return sysfs_emit(buf, "%d\n", 135 task_pid_vnr(sbi->s_journal->j_task)); 136} 137 138#define EXT4_ATTR(_name,_mode,_id) \ 139static struct ext4_attr ext4_attr_##_name = { \ 140 .attr = {.name = __stringify(_name), .mode = _mode }, \ 141 .attr_id = attr_##_id, \ 142} 143 144#define EXT4_ATTR_FUNC(_name,_mode) EXT4_ATTR(_name,_mode,_name) 145 146#define EXT4_ATTR_FEATURE(_name) EXT4_ATTR(_name, 0444, feature) 147 148#define EXT4_ATTR_OFFSET(_name,_mode,_id,_struct,_elname) \ 149static struct ext4_attr ext4_attr_##_name = { \ 150 .attr = {.name = __stringify(_name), .mode = _mode }, \ 151 .attr_id = attr_##_id, \ 152 .attr_ptr = ptr_##_struct##_offset, \ 153 .u = { \ 154 .offset = offsetof(struct _struct, _elname),\ 155 }, \ 156} 157 158#define EXT4_ATTR_STRING(_name,_mode,_size,_struct,_elname) \ 159static struct ext4_attr ext4_attr_##_name = { \ 160 .attr = {.name = __stringify(_name), .mode = _mode }, \ 161 .attr_id = attr_pointer_string, \ 162 .attr_size = _size, \ 163 .attr_ptr = ptr_##_struct##_offset, \ 164 .u = { \ 165 .offset = offsetof(struct _struct, _elname),\ 166 }, \ 167} 168 169#define EXT4_RO_ATTR_ES_UI(_name,_elname) \ 170 EXT4_ATTR_OFFSET(_name, 0444, pointer_ui, ext4_super_block, _elname) 171 172#define EXT4_RO_ATTR_ES_U8(_name,_elname) \ 173 EXT4_ATTR_OFFSET(_name, 0444, pointer_u8, ext4_super_block, _elname) 174 175#define EXT4_RO_ATTR_ES_U64(_name,_elname) \ 176 EXT4_ATTR_OFFSET(_name, 0444, pointer_u64, ext4_super_block, _elname) 177 178#define EXT4_RO_ATTR_ES_STRING(_name,_elname,_size) \ 179 EXT4_ATTR_STRING(_name, 0444, _size, ext4_super_block, _elname) 180 181#define EXT4_RW_ATTR_SBI_UI(_name,_elname) \ 182 EXT4_ATTR_OFFSET(_name, 0644, pointer_ui, ext4_sb_info, _elname) 183 184#define EXT4_RW_ATTR_SBI_UL(_name,_elname) \ 185 EXT4_ATTR_OFFSET(_name, 0644, pointer_ul, ext4_sb_info, _elname) 186 187#define EXT4_RO_ATTR_SBI_ATOMIC(_name,_elname) \ 188 EXT4_ATTR_OFFSET(_name, 0444, pointer_atomic, ext4_sb_info, _elname) 189 190#define EXT4_ATTR_PTR(_name,_mode,_id,_ptr) \ 191static struct ext4_attr ext4_attr_##_name = { \ 192 .attr = {.name = __stringify(_name), .mode = _mode }, \ 193 .attr_id = attr_##_id, \ 194 .attr_ptr = ptr_explicit, \ 195 .u = { \ 196 .explicit_ptr = _ptr, \ 197 }, \ 198} 199 200#define ATTR_LIST(name) &ext4_attr_##name.attr 201 202EXT4_ATTR_FUNC(delayed_allocation_blocks, 0444); 203EXT4_ATTR_FUNC(session_write_kbytes, 0444); 204EXT4_ATTR_FUNC(lifetime_write_kbytes, 0444); 205EXT4_ATTR_FUNC(reserved_clusters, 0644); 206EXT4_ATTR_FUNC(sra_exceeded_retry_limit, 0444); 207 208EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, inode_readahead, 209 ext4_sb_info, s_inode_readahead_blks); 210EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal); 211EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats); 212EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan); 213EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan); 214EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs); 215EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request); 216EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc); 217EXT4_RW_ATTR_SBI_UI(mb_max_linear_groups, s_mb_max_linear_groups); 218EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb); 219EXT4_ATTR(trigger_fs_error, 0200, trigger_test_error); 220EXT4_RW_ATTR_SBI_UI(err_ratelimit_interval_ms, s_err_ratelimit_state.interval); 221EXT4_RW_ATTR_SBI_UI(err_ratelimit_burst, s_err_ratelimit_state.burst); 222EXT4_RW_ATTR_SBI_UI(warning_ratelimit_interval_ms, s_warning_ratelimit_state.interval); 223EXT4_RW_ATTR_SBI_UI(warning_ratelimit_burst, s_warning_ratelimit_state.burst); 224EXT4_RW_ATTR_SBI_UI(msg_ratelimit_interval_ms, s_msg_ratelimit_state.interval); 225EXT4_RW_ATTR_SBI_UI(msg_ratelimit_burst, s_msg_ratelimit_state.burst); 226EXT4_RW_ATTR_SBI_UI(mb_best_avail_max_trim_order, s_mb_best_avail_max_trim_order); 227#ifdef CONFIG_EXT4_DEBUG 228EXT4_RW_ATTR_SBI_UL(simulate_fail, s_simulate_fail); 229#endif 230EXT4_RO_ATTR_SBI_ATOMIC(warning_count, s_warning_count); 231EXT4_RO_ATTR_SBI_ATOMIC(msg_count, s_msg_count); 232EXT4_RO_ATTR_ES_UI(errors_count, s_error_count); 233EXT4_RO_ATTR_ES_U8(first_error_errcode, s_first_error_errcode); 234EXT4_RO_ATTR_ES_U8(last_error_errcode, s_last_error_errcode); 235EXT4_RO_ATTR_ES_UI(first_error_ino, s_first_error_ino); 236EXT4_RO_ATTR_ES_UI(last_error_ino, s_last_error_ino); 237EXT4_RO_ATTR_ES_U64(first_error_block, s_first_error_block); 238EXT4_RO_ATTR_ES_U64(last_error_block, s_last_error_block); 239EXT4_RO_ATTR_ES_UI(first_error_line, s_first_error_line); 240EXT4_RO_ATTR_ES_UI(last_error_line, s_last_error_line); 241EXT4_RO_ATTR_ES_STRING(first_error_func, s_first_error_func, 32); 242EXT4_RO_ATTR_ES_STRING(last_error_func, s_last_error_func, 32); 243EXT4_ATTR(first_error_time, 0444, first_error_time); 244EXT4_ATTR(last_error_time, 0444, last_error_time); 245EXT4_ATTR(journal_task, 0444, journal_task); 246EXT4_RW_ATTR_SBI_UI(mb_prefetch, s_mb_prefetch); 247EXT4_RW_ATTR_SBI_UI(mb_prefetch_limit, s_mb_prefetch_limit); 248EXT4_RW_ATTR_SBI_UL(last_trim_minblks, s_last_trim_minblks); 249 250static unsigned int old_bump_val = 128; 251EXT4_ATTR_PTR(max_writeback_mb_bump, 0444, pointer_ui, &old_bump_val); 252 253static struct attribute *ext4_attrs[] = { 254 ATTR_LIST(delayed_allocation_blocks), 255 ATTR_LIST(session_write_kbytes), 256 ATTR_LIST(lifetime_write_kbytes), 257 ATTR_LIST(reserved_clusters), 258 ATTR_LIST(sra_exceeded_retry_limit), 259 ATTR_LIST(inode_readahead_blks), 260 ATTR_LIST(inode_goal), 261 ATTR_LIST(mb_stats), 262 ATTR_LIST(mb_max_to_scan), 263 ATTR_LIST(mb_min_to_scan), 264 ATTR_LIST(mb_order2_req), 265 ATTR_LIST(mb_stream_req), 266 ATTR_LIST(mb_group_prealloc), 267 ATTR_LIST(mb_max_linear_groups), 268 ATTR_LIST(max_writeback_mb_bump), 269 ATTR_LIST(extent_max_zeroout_kb), 270 ATTR_LIST(trigger_fs_error), 271 ATTR_LIST(err_ratelimit_interval_ms), 272 ATTR_LIST(err_ratelimit_burst), 273 ATTR_LIST(warning_ratelimit_interval_ms), 274 ATTR_LIST(warning_ratelimit_burst), 275 ATTR_LIST(msg_ratelimit_interval_ms), 276 ATTR_LIST(msg_ratelimit_burst), 277 ATTR_LIST(mb_best_avail_max_trim_order), 278 ATTR_LIST(errors_count), 279 ATTR_LIST(warning_count), 280 ATTR_LIST(msg_count), 281 ATTR_LIST(first_error_ino), 282 ATTR_LIST(last_error_ino), 283 ATTR_LIST(first_error_block), 284 ATTR_LIST(last_error_block), 285 ATTR_LIST(first_error_line), 286 ATTR_LIST(last_error_line), 287 ATTR_LIST(first_error_func), 288 ATTR_LIST(last_error_func), 289 ATTR_LIST(first_error_errcode), 290 ATTR_LIST(last_error_errcode), 291 ATTR_LIST(first_error_time), 292 ATTR_LIST(last_error_time), 293 ATTR_LIST(journal_task), 294#ifdef CONFIG_EXT4_DEBUG 295 ATTR_LIST(simulate_fail), 296#endif 297 ATTR_LIST(mb_prefetch), 298 ATTR_LIST(mb_prefetch_limit), 299 ATTR_LIST(last_trim_minblks), 300 NULL, 301}; 302ATTRIBUTE_GROUPS(ext4); 303 304/* Features this copy of ext4 supports */ 305EXT4_ATTR_FEATURE(lazy_itable_init); 306EXT4_ATTR_FEATURE(batched_discard); 307EXT4_ATTR_FEATURE(meta_bg_resize); 308#ifdef CONFIG_FS_ENCRYPTION 309EXT4_ATTR_FEATURE(encryption); 310EXT4_ATTR_FEATURE(test_dummy_encryption_v2); 311#endif 312#if IS_ENABLED(CONFIG_UNICODE) 313EXT4_ATTR_FEATURE(casefold); 314#endif 315#ifdef CONFIG_FS_VERITY 316EXT4_ATTR_FEATURE(verity); 317#endif 318EXT4_ATTR_FEATURE(metadata_csum_seed); 319EXT4_ATTR_FEATURE(fast_commit); 320#if IS_ENABLED(CONFIG_UNICODE) && defined(CONFIG_FS_ENCRYPTION) 321EXT4_ATTR_FEATURE(encrypted_casefold); 322#endif 323 324static struct attribute *ext4_feat_attrs[] = { 325 ATTR_LIST(lazy_itable_init), 326 ATTR_LIST(batched_discard), 327 ATTR_LIST(meta_bg_resize), 328#ifdef CONFIG_FS_ENCRYPTION 329 ATTR_LIST(encryption), 330 ATTR_LIST(test_dummy_encryption_v2), 331#endif 332#if IS_ENABLED(CONFIG_UNICODE) 333 ATTR_LIST(casefold), 334#endif 335#ifdef CONFIG_FS_VERITY 336 ATTR_LIST(verity), 337#endif 338 ATTR_LIST(metadata_csum_seed), 339 ATTR_LIST(fast_commit), 340#if IS_ENABLED(CONFIG_UNICODE) && defined(CONFIG_FS_ENCRYPTION) 341 ATTR_LIST(encrypted_casefold), 342#endif 343 NULL, 344}; 345ATTRIBUTE_GROUPS(ext4_feat); 346 347static void *calc_ptr(struct ext4_attr *a, struct ext4_sb_info *sbi) 348{ 349 switch (a->attr_ptr) { 350 case ptr_explicit: 351 return a->u.explicit_ptr; 352 case ptr_ext4_sb_info_offset: 353 return (void *) (((char *) sbi) + a->u.offset); 354 case ptr_ext4_super_block_offset: 355 return (void *) (((char *) sbi->s_es) + a->u.offset); 356 } 357 return NULL; 358} 359 360static ssize_t __print_tstamp(char *buf, __le32 lo, __u8 hi) 361{ 362 return sysfs_emit(buf, "%lld\n", 363 ((time64_t)hi << 32) + le32_to_cpu(lo)); 364} 365 366#define print_tstamp(buf, es, tstamp) \ 367 __print_tstamp(buf, (es)->tstamp, (es)->tstamp ## _hi) 368 369static ssize_t ext4_attr_show(struct kobject *kobj, 370 struct attribute *attr, char *buf) 371{ 372 struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info, 373 s_kobj); 374 struct ext4_attr *a = container_of(attr, struct ext4_attr, attr); 375 void *ptr = calc_ptr(a, sbi); 376 377 switch (a->attr_id) { 378 case attr_delayed_allocation_blocks: 379 return sysfs_emit(buf, "%llu\n", 380 (s64) EXT4_C2B(sbi, 381 percpu_counter_sum(&sbi->s_dirtyclusters_counter))); 382 case attr_session_write_kbytes: 383 return session_write_kbytes_show(sbi, buf); 384 case attr_lifetime_write_kbytes: 385 return lifetime_write_kbytes_show(sbi, buf); 386 case attr_reserved_clusters: 387 return sysfs_emit(buf, "%llu\n", 388 (unsigned long long) 389 atomic64_read(&sbi->s_resv_clusters)); 390 case attr_sra_exceeded_retry_limit: 391 return sysfs_emit(buf, "%llu\n", 392 (unsigned long long) 393 percpu_counter_sum(&sbi->s_sra_exceeded_retry_limit)); 394 case attr_inode_readahead: 395 case attr_pointer_ui: 396 if (!ptr) 397 return 0; 398 if (a->attr_ptr == ptr_ext4_super_block_offset) 399 return sysfs_emit(buf, "%u\n", 400 le32_to_cpup(ptr)); 401 else 402 return sysfs_emit(buf, "%u\n", 403 *((unsigned int *) ptr)); 404 case attr_pointer_ul: 405 if (!ptr) 406 return 0; 407 return sysfs_emit(buf, "%lu\n", 408 *((unsigned long *) ptr)); 409 case attr_pointer_u8: 410 if (!ptr) 411 return 0; 412 return sysfs_emit(buf, "%u\n", 413 *((unsigned char *) ptr)); 414 case attr_pointer_u64: 415 if (!ptr) 416 return 0; 417 if (a->attr_ptr == ptr_ext4_super_block_offset) 418 return sysfs_emit(buf, "%llu\n", 419 le64_to_cpup(ptr)); 420 else 421 return sysfs_emit(buf, "%llu\n", 422 *((unsigned long long *) ptr)); 423 case attr_pointer_string: 424 if (!ptr) 425 return 0; 426 return sysfs_emit(buf, "%.*s\n", a->attr_size, 427 (char *) ptr); 428 case attr_pointer_atomic: 429 if (!ptr) 430 return 0; 431 return sysfs_emit(buf, "%d\n", 432 atomic_read((atomic_t *) ptr)); 433 case attr_feature: 434 return sysfs_emit(buf, "supported\n"); 435 case attr_first_error_time: 436 return print_tstamp(buf, sbi->s_es, s_first_error_time); 437 case attr_last_error_time: 438 return print_tstamp(buf, sbi->s_es, s_last_error_time); 439 case attr_journal_task: 440 return journal_task_show(sbi, buf); 441 } 442 443 return 0; 444} 445 446static ssize_t ext4_attr_store(struct kobject *kobj, 447 struct attribute *attr, 448 const char *buf, size_t len) 449{ 450 struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info, 451 s_kobj); 452 struct ext4_attr *a = container_of(attr, struct ext4_attr, attr); 453 void *ptr = calc_ptr(a, sbi); 454 unsigned long t; 455 int ret; 456 457 switch (a->attr_id) { 458 case attr_reserved_clusters: 459 return reserved_clusters_store(sbi, buf, len); 460 case attr_pointer_ui: 461 if (!ptr) 462 return 0; 463 ret = kstrtoul(skip_spaces(buf), 0, &t); 464 if (ret) 465 return ret; 466 if (a->attr_ptr == ptr_ext4_super_block_offset) 467 *((__le32 *) ptr) = cpu_to_le32(t); 468 else 469 *((unsigned int *) ptr) = t; 470 return len; 471 case attr_pointer_ul: 472 if (!ptr) 473 return 0; 474 ret = kstrtoul(skip_spaces(buf), 0, &t); 475 if (ret) 476 return ret; 477 *((unsigned long *) ptr) = t; 478 return len; 479 case attr_inode_readahead: 480 return inode_readahead_blks_store(sbi, buf, len); 481 case attr_trigger_test_error: 482 return trigger_test_error(sbi, buf, len); 483 } 484 return 0; 485} 486 487static void ext4_sb_release(struct kobject *kobj) 488{ 489 struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info, 490 s_kobj); 491 complete(&sbi->s_kobj_unregister); 492} 493 494static void ext4_feat_release(struct kobject *kobj) 495{ 496 kfree(kobj); 497} 498 499static const struct sysfs_ops ext4_attr_ops = { 500 .show = ext4_attr_show, 501 .store = ext4_attr_store, 502}; 503 504static const struct kobj_type ext4_sb_ktype = { 505 .default_groups = ext4_groups, 506 .sysfs_ops = &ext4_attr_ops, 507 .release = ext4_sb_release, 508}; 509 510static const struct kobj_type ext4_feat_ktype = { 511 .default_groups = ext4_feat_groups, 512 .sysfs_ops = &ext4_attr_ops, 513 .release = ext4_feat_release, 514}; 515 516void ext4_notify_error_sysfs(struct ext4_sb_info *sbi) 517{ 518 sysfs_notify(&sbi->s_kobj, NULL, "errors_count"); 519} 520 521static struct kobject *ext4_root; 522 523static struct kobject *ext4_feat; 524 525int ext4_register_sysfs(struct super_block *sb) 526{ 527 struct ext4_sb_info *sbi = EXT4_SB(sb); 528 int err; 529 530 init_completion(&sbi->s_kobj_unregister); 531 err = kobject_init_and_add(&sbi->s_kobj, &ext4_sb_ktype, ext4_root, 532 "%s", sb->s_id); 533 if (err) { 534 kobject_put(&sbi->s_kobj); 535 wait_for_completion(&sbi->s_kobj_unregister); 536 return err; 537 } 538 539 if (ext4_proc_root) 540 sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root); 541 if (sbi->s_proc) { 542 proc_create_single_data("options", S_IRUGO, sbi->s_proc, 543 ext4_seq_options_show, sb); 544 proc_create_single_data("es_shrinker_info", S_IRUGO, 545 sbi->s_proc, ext4_seq_es_shrinker_info_show, 546 sb); 547 proc_create_single_data("fc_info", 0444, sbi->s_proc, 548 ext4_fc_info_show, sb); 549 proc_create_seq_data("mb_groups", S_IRUGO, sbi->s_proc, 550 &ext4_mb_seq_groups_ops, sb); 551 proc_create_single_data("mb_stats", 0444, sbi->s_proc, 552 ext4_seq_mb_stats_show, sb); 553 proc_create_seq_data("mb_structs_summary", 0444, sbi->s_proc, 554 &ext4_mb_seq_structs_summary_ops, sb); 555 } 556 return 0; 557} 558 559void ext4_unregister_sysfs(struct super_block *sb) 560{ 561 struct ext4_sb_info *sbi = EXT4_SB(sb); 562 563 if (sbi->s_proc) 564 remove_proc_subtree(sb->s_id, ext4_proc_root); 565 kobject_del(&sbi->s_kobj); 566} 567 568int __init ext4_init_sysfs(void) 569{ 570 int ret; 571 572 ext4_root = kobject_create_and_add("ext4", fs_kobj); 573 if (!ext4_root) 574 return -ENOMEM; 575 576 ext4_feat = kzalloc(sizeof(*ext4_feat), GFP_KERNEL); 577 if (!ext4_feat) { 578 ret = -ENOMEM; 579 goto root_err; 580 } 581 582 ret = kobject_init_and_add(ext4_feat, &ext4_feat_ktype, 583 ext4_root, "features"); 584 if (ret) 585 goto feat_err; 586 587 ext4_proc_root = proc_mkdir(proc_dirname, NULL); 588 return ret; 589 590feat_err: 591 kobject_put(ext4_feat); 592 ext4_feat = NULL; 593root_err: 594 kobject_put(ext4_root); 595 ext4_root = NULL; 596 return ret; 597} 598 599void ext4_exit_sysfs(void) 600{ 601 kobject_put(ext4_feat); 602 ext4_feat = NULL; 603 kobject_put(ext4_root); 604 ext4_root = NULL; 605 remove_proc_entry(proc_dirname, NULL); 606 ext4_proc_root = NULL; 607} 608 609