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_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
  42 typedef enum {
  43         ptr_explicit,
  44         ptr_ext4_sb_info_offset,
  45         ptr_ext4_super_block_offset,
  46 } attr_ptr_t;
  47
  48 static const char proc_dirname[] = "fs/ext4";
  49 static struct proc_dir_entry *ext4_proc_root;
  50
  51 struct 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
  62 static 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
  71 static 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
  81 static 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
  98 static 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
 114 static 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
 130 static 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)                                      \
 139 static 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)       \
 149 static 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)     \
 159 static 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) \
 191 static 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
 202 EXT4_ATTR_FUNC(delayed_allocation_blocks, 0444);
 203 EXT4_ATTR_FUNC(session_write_kbytes, 0444);
 204 EXT4_ATTR_FUNC(lifetime_write_kbytes, 0444);
 205 EXT4_ATTR_FUNC(reserved_clusters, 0644);
 206 EXT4_ATTR_FUNC(sra_exceeded_retry_limit, 0444);
 207
 208 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, inode_readahead,
 209                  ext4_sb_info, s_inode_readahead_blks);
 210 EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
 211 EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
 212 EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
 213 EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
 214 EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
 215 EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
 216 EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
 217 EXT4_RW_ATTR_SBI_UI(mb_max_inode_prealloc, s_mb_max_inode_prealloc);
 218 EXT4_RW_ATTR_SBI_UI(mb_max_linear_groups, s_mb_max_linear_groups);
 219 EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb);
 220 EXT4_ATTR(trigger_fs_error, 0200, trigger_test_error);
 221 EXT4_RW_ATTR_SBI_UI(err_ratelimit_interval_ms, s_err_ratelimit_state.interval);
 222 EXT4_RW_ATTR_SBI_UI(err_ratelimit_burst, s_err_ratelimit_state.burst);
 223 EXT4_RW_ATTR_SBI_UI(warning_ratelimit_interval_ms, s_warning_ratelimit_state.interval);
 224 EXT4_RW_ATTR_SBI_UI(warning_ratelimit_burst, s_warning_ratelimit_state.burst);
 225 EXT4_RW_ATTR_SBI_UI(msg_ratelimit_interval_ms, s_msg_ratelimit_state.interval);
 226 EXT4_RW_ATTR_SBI_UI(msg_ratelimit_burst, s_msg_ratelimit_state.burst);
 227 #ifdef CONFIG_EXT4_DEBUG
 228 EXT4_RW_ATTR_SBI_UL(simulate_fail, s_simulate_fail);
 229 #endif
 230 EXT4_RO_ATTR_SBI_ATOMIC(warning_count, s_warning_count);
 231 EXT4_RO_ATTR_SBI_ATOMIC(msg_count, s_msg_count);
 232 EXT4_RO_ATTR_ES_UI(errors_count, s_error_count);
 233 EXT4_RO_ATTR_ES_U8(first_error_errcode, s_first_error_errcode);
 234 EXT4_RO_ATTR_ES_U8(last_error_errcode, s_last_error_errcode);
 235 EXT4_RO_ATTR_ES_UI(first_error_ino, s_first_error_ino);
 236 EXT4_RO_ATTR_ES_UI(last_error_ino, s_last_error_ino);
 237 EXT4_RO_ATTR_ES_U64(first_error_block, s_first_error_block);
 238 EXT4_RO_ATTR_ES_U64(last_error_block, s_last_error_block);
 239 EXT4_RO_ATTR_ES_UI(first_error_line, s_first_error_line);
 240 EXT4_RO_ATTR_ES_UI(last_error_line, s_last_error_line);
 241 EXT4_RO_ATTR_ES_STRING(first_error_func, s_first_error_func, 32);
 242 EXT4_RO_ATTR_ES_STRING(last_error_func, s_last_error_func, 32);
 243 EXT4_ATTR(first_error_time, 0444, first_error_time);
 244 EXT4_ATTR(last_error_time, 0444, last_error_time);
 245 EXT4_ATTR(journal_task, 0444, journal_task);
 246 EXT4_RW_ATTR_SBI_UI(mb_prefetch, s_mb_prefetch);
 247 EXT4_RW_ATTR_SBI_UI(mb_prefetch_limit, s_mb_prefetch_limit);
 248 EXT4_RW_ATTR_SBI_UL(last_trim_minblks, s_last_trim_minblks);
 249
 250 static unsigned int old_bump_val = 128;
 251 EXT4_ATTR_PTR(max_writeback_mb_bump, 0444, pointer_ui, &old_bump_val);
 252
 253 static 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_inode_prealloc),
 268         ATTR_LIST(mb_max_linear_groups),
 269         ATTR_LIST(max_writeback_mb_bump),
 270         ATTR_LIST(extent_max_zeroout_kb),
 271         ATTR_LIST(trigger_fs_error),
 272         ATTR_LIST(err_ratelimit_interval_ms),
 273         ATTR_LIST(err_ratelimit_burst),
 274         ATTR_LIST(warning_ratelimit_interval_ms),
 275         ATTR_LIST(warning_ratelimit_burst),
 276         ATTR_LIST(msg_ratelimit_interval_ms),
 277         ATTR_LIST(msg_ratelimit_burst),
 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 };
 302 ATTRIBUTE_GROUPS(ext4);
 303
 304 /* Features this copy of ext4 supports */
 305 EXT4_ATTR_FEATURE(lazy_itable_init);
 306 EXT4_ATTR_FEATURE(batched_discard);
 307 EXT4_ATTR_FEATURE(meta_bg_resize);
 308 #ifdef CONFIG_FS_ENCRYPTION
 309 EXT4_ATTR_FEATURE(encryption);
 310 EXT4_ATTR_FEATURE(test_dummy_encryption_v2);
 311 #endif
 312 #if IS_ENABLED(CONFIG_UNICODE)
 313 EXT4_ATTR_FEATURE(casefold);
 314 #endif
 315 #ifdef CONFIG_FS_VERITY
 316 EXT4_ATTR_FEATURE(verity);
 317 #endif
 318 EXT4_ATTR_FEATURE(metadata_csum_seed);
 319 EXT4_ATTR_FEATURE(fast_commit);
 320 #if IS_ENABLED(CONFIG_UNICODE) && defined(CONFIG_FS_ENCRYPTION)
 321 EXT4_ATTR_FEATURE(encrypted_casefold);
 322 #endif
 323
 324 static 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 };
 345 ATTRIBUTE_GROUPS(ext4_feat);
 346
 347 static 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
 360 static 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
 369 static 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
 446 static 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
 487 static 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
 494 static const struct sysfs_ops ext4_attr_ops = {
 495         .show   = ext4_attr_show,
 496         .store  = ext4_attr_store,
 497 };
 498
 499 static struct kobj_type ext4_sb_ktype = {
 500         .default_groups = ext4_groups,
 501         .sysfs_ops      = &ext4_attr_ops,
 502         .release        = ext4_sb_release,
 503 };
 504
 505 static struct kobj_type ext4_feat_ktype = {
 506         .default_groups = ext4_feat_groups,
 507         .sysfs_ops      = &ext4_attr_ops,
 508         .release        = (void (*)(struct kobject *))kfree,
 509 };
 510
 511 void ext4_notify_error_sysfs(struct ext4_sb_info *sbi)
 512 {
 513         sysfs_notify(&sbi->s_kobj, NULL, "errors_count");
 514 }
 515
 516 static struct kobject *ext4_root;
 517
 518 static struct kobject *ext4_feat;
 519
 520 int ext4_register_sysfs(struct super_block *sb)
 521 {
 522         struct ext4_sb_info *sbi = EXT4_SB(sb);
 523         int err;
 524
 525         init_completion(&sbi->s_kobj_unregister);
 526         err = kobject_init_and_add(&sbi->s_kobj, &ext4_sb_ktype, ext4_root,
 527                                    "%s", sb->s_id);
 528         if (err) {
 529                 kobject_put(&sbi->s_kobj);
 530                 wait_for_completion(&sbi->s_kobj_unregister);
 531                 return err;
 532         }
 533
 534         if (ext4_proc_root)
 535                 sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
 536         if (sbi->s_proc) {
 537                 proc_create_single_data("options", S_IRUGO, sbi->s_proc,
 538                                 ext4_seq_options_show, sb);
 539                 proc_create_single_data("es_shrinker_info", S_IRUGO,
 540                                 sbi->s_proc, ext4_seq_es_shrinker_info_show,
 541                                 sb);
 542                 proc_create_single_data("fc_info", 0444, sbi->s_proc,
 543                                         ext4_fc_info_show, sb);
 544                 proc_create_seq_data("mb_groups", S_IRUGO, sbi->s_proc,
 545                                 &ext4_mb_seq_groups_ops, sb);
 546                 proc_create_single_data("mb_stats", 0444, sbi->s_proc,
 547                                 ext4_seq_mb_stats_show, sb);
 548                 proc_create_seq_data("mb_structs_summary", 0444, sbi->s_proc,
 549                                 &ext4_mb_seq_structs_summary_ops, sb);
 550         }
 551         return 0;
 552 }
 553
 554 void ext4_unregister_sysfs(struct super_block *sb)
 555 {
 556         struct ext4_sb_info *sbi = EXT4_SB(sb);
 557
 558         if (sbi->s_proc)
 559                 remove_proc_subtree(sb->s_id, ext4_proc_root);
 560         kobject_del(&sbi->s_kobj);
 561 }
 562
 563 int __init ext4_init_sysfs(void)
 564 {
 565         int ret;
 566
 567         ext4_root = kobject_create_and_add("ext4", fs_kobj);
 568         if (!ext4_root)
 569                 return -ENOMEM;
 570
 571         ext4_feat = kzalloc(sizeof(*ext4_feat), GFP_KERNEL);
 572         if (!ext4_feat) {
 573                 ret = -ENOMEM;
 574                 goto root_err;
 575         }
 576
 577         ret = kobject_init_and_add(ext4_feat, &ext4_feat_ktype,
 578                                    ext4_root, "features");
 579         if (ret)
 580                 goto feat_err;
 581
 582         ext4_proc_root = proc_mkdir(proc_dirname, NULL);
 583         return ret;
 584
 585 feat_err:
 586         kobject_put(ext4_feat);
 587         ext4_feat = NULL;
 588 root_err:
 589         kobject_put(ext4_root);
 590         ext4_root = NULL;
 591         return ret;
 592 }
 593
 594 void ext4_exit_sysfs(void)
 595 {
 596         kobject_put(ext4_feat);
 597         ext4_feat = NULL;
 598         kobject_put(ext4_root);
 599         ext4_root = NULL;
 600         remove_proc_entry(proc_dirname, NULL);
 601         ext4_proc_root = NULL;
 602 }
 603