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