fs/ext4/sysfs.c

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