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