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/proc_fs.h>
  15
  16 #include "ext4.h"
  17 #include "ext4_jbd2.h"
  18
  19 typedef enum {
  20         attr_noop,
  21         attr_delayed_allocation_blocks,
  22         attr_session_write_kbytes,
  23         attr_lifetime_write_kbytes,
  24         attr_reserved_clusters,
  25         attr_inode_readahead,
  26         attr_trigger_test_error,
  27         attr_feature,
  28         attr_pointer_ui,
  29         attr_pointer_atomic,
  30 } attr_id_t;
  31
  32 typedef enum {
  33         ptr_explicit,
  34         ptr_ext4_sb_info_offset,
  35         ptr_ext4_super_block_offset,
  36 } attr_ptr_t;
  37
  38 static const char proc_dirname[] = "fs/ext4";
  39 static struct proc_dir_entry *ext4_proc_root;
  40
  41 struct ext4_attr {
  42         struct attribute attr;
  43         short attr_id;
  44         short attr_ptr;
  45         union {
  46                 int offset;
  47                 void *explicit_ptr;
  48         } u;
  49 };
  50
  51 static ssize_t session_write_kbytes_show(struct ext4_attr *a,
  52                                          struct ext4_sb_info *sbi, char *buf)
  53 {
  54         struct super_block *sb = sbi->s_buddy_cache->i_sb;
  55
  56         if (!sb->s_bdev->bd_part)
  57                 return snprintf(buf, PAGE_SIZE, "0\n");
  58         return snprintf(buf, PAGE_SIZE, "%lu\n",
  59                         (part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
  60                          sbi->s_sectors_written_start) >> 1);
  61 }
  62
  63 static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
  64                                           struct ext4_sb_info *sbi, char *buf)
  65 {
  66         struct super_block *sb = sbi->s_buddy_cache->i_sb;
  67
  68         if (!sb->s_bdev->bd_part)
  69                 return snprintf(buf, PAGE_SIZE, "0\n");
  70         return snprintf(buf, PAGE_SIZE, "%llu\n",
  71                         (unsigned long long)(sbi->s_kbytes_written +
  72                         ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
  73                           EXT4_SB(sb)->s_sectors_written_start) >> 1)));
  74 }
  75
  76 static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
  77                                           struct ext4_sb_info *sbi,
  78                                           const char *buf, size_t count)
  79 {
  80         unsigned long t;
  81         int ret;
  82
  83         ret = kstrtoul(skip_spaces(buf), 0, &t);
  84         if (ret)
  85                 return ret;
  86
  87         if (t && (!is_power_of_2(t) || t > 0x40000000))
  88                 return -EINVAL;
  89
  90         sbi->s_inode_readahead_blks = t;
  91         return count;
  92 }
  93
  94 static ssize_t reserved_clusters_store(struct ext4_attr *a,
  95                                    struct ext4_sb_info *sbi,
  96                                    const char *buf, size_t count)
  97 {
  98         unsigned long long val;
  99         ext4_fsblk_t clusters = (ext4_blocks_count(sbi->s_es) >>
 100                                  sbi->s_cluster_bits);
 101         int ret;
 102
 103         ret = kstrtoull(skip_spaces(buf), 0, &val);
 104         if (ret || val >= clusters)
 105                 return -EINVAL;
 106
 107         atomic64_set(&sbi->s_resv_clusters, val);
 108         return count;
 109 }
 110
 111 static ssize_t trigger_test_error(struct ext4_attr *a,
 112                                   struct ext4_sb_info *sbi,
 113                                   const char *buf, size_t count)
 114 {
 115         int len = count;
 116
 117         if (!capable(CAP_SYS_ADMIN))
 118                 return -EPERM;
 119
 120         if (len && buf[len-1] == '\n')
 121                 len--;
 122
 123         if (len)
 124                 ext4_error(sbi->s_sb, "%.*s", len, buf);
 125         return count;
 126 }
 127
 128 #define EXT4_ATTR(_name,_mode,_id)                                      \
 129 static struct ext4_attr ext4_attr_##_name = {                           \
 130         .attr = {.name = __stringify(_name), .mode = _mode },           \
 131         .attr_id = attr_##_id,                                          \
 132 }
 133
 134 #define EXT4_ATTR_FUNC(_name,_mode)  EXT4_ATTR(_name,_mode,_name)
 135
 136 #define EXT4_ATTR_FEATURE(_name)   EXT4_ATTR(_name, 0444, feature)
 137
 138 #define EXT4_ATTR_OFFSET(_name,_mode,_id,_struct,_elname)       \
 139 static struct ext4_attr ext4_attr_##_name = {                   \
 140         .attr = {.name = __stringify(_name), .mode = _mode },   \
 141         .attr_id = attr_##_id,                                  \
 142         .attr_ptr = ptr_##_struct##_offset,                     \
 143         .u = {                                                  \
 144                 .offset = offsetof(struct _struct, _elname),\
 145         },                                                      \
 146 }
 147
 148 #define EXT4_RO_ATTR_ES_UI(_name,_elname)                               \
 149         EXT4_ATTR_OFFSET(_name, 0444, pointer_ui, ext4_super_block, _elname)
 150
 151 #define EXT4_RW_ATTR_SBI_UI(_name,_elname)      \
 152         EXT4_ATTR_OFFSET(_name, 0644, pointer_ui, ext4_sb_info, _elname)
 153
 154 #define EXT4_ATTR_PTR(_name,_mode,_id,_ptr) \
 155 static struct ext4_attr ext4_attr_##_name = {                   \
 156         .attr = {.name = __stringify(_name), .mode = _mode },   \
 157         .attr_id = attr_##_id,                                  \
 158         .attr_ptr = ptr_explicit,                               \
 159         .u = {                                                  \
 160                 .explicit_ptr = _ptr,                           \
 161         },                                                      \
 162 }
 163
 164 #define ATTR_LIST(name) &ext4_attr_##name.attr
 165
 166 EXT4_ATTR_FUNC(delayed_allocation_blocks, 0444);
 167 EXT4_ATTR_FUNC(session_write_kbytes, 0444);
 168 EXT4_ATTR_FUNC(lifetime_write_kbytes, 0444);
 169 EXT4_ATTR_FUNC(reserved_clusters, 0644);
 170
 171 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, inode_readahead,
 172                  ext4_sb_info, s_inode_readahead_blks);
 173 EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
 174 EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
 175 EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
 176 EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
 177 EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
 178 EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
 179 EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
 180 EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb);
 181 EXT4_ATTR(trigger_fs_error, 0200, trigger_test_error);
 182 EXT4_RW_ATTR_SBI_UI(err_ratelimit_interval_ms, s_err_ratelimit_state.interval);
 183 EXT4_RW_ATTR_SBI_UI(err_ratelimit_burst, s_err_ratelimit_state.burst);
 184 EXT4_RW_ATTR_SBI_UI(warning_ratelimit_interval_ms, s_warning_ratelimit_state.interval);
 185 EXT4_RW_ATTR_SBI_UI(warning_ratelimit_burst, s_warning_ratelimit_state.burst);
 186 EXT4_RW_ATTR_SBI_UI(msg_ratelimit_interval_ms, s_msg_ratelimit_state.interval);
 187 EXT4_RW_ATTR_SBI_UI(msg_ratelimit_burst, s_msg_ratelimit_state.burst);
 188 EXT4_RO_ATTR_ES_UI(errors_count, s_error_count);
 189 EXT4_RO_ATTR_ES_UI(first_error_time, s_first_error_time);
 190 EXT4_RO_ATTR_ES_UI(last_error_time, s_last_error_time);
 191
 192 static unsigned int old_bump_val = 128;
 193 EXT4_ATTR_PTR(max_writeback_mb_bump, 0444, pointer_ui, &old_bump_val);
 194
 195 static struct attribute *ext4_attrs[] = {
 196         ATTR_LIST(delayed_allocation_blocks),
 197         ATTR_LIST(session_write_kbytes),
 198         ATTR_LIST(lifetime_write_kbytes),
 199         ATTR_LIST(reserved_clusters),
 200         ATTR_LIST(inode_readahead_blks),
 201         ATTR_LIST(inode_goal),
 202         ATTR_LIST(mb_stats),
 203         ATTR_LIST(mb_max_to_scan),
 204         ATTR_LIST(mb_min_to_scan),
 205         ATTR_LIST(mb_order2_req),
 206         ATTR_LIST(mb_stream_req),
 207         ATTR_LIST(mb_group_prealloc),
 208         ATTR_LIST(max_writeback_mb_bump),
 209         ATTR_LIST(extent_max_zeroout_kb),
 210         ATTR_LIST(trigger_fs_error),
 211         ATTR_LIST(err_ratelimit_interval_ms),
 212         ATTR_LIST(err_ratelimit_burst),
 213         ATTR_LIST(warning_ratelimit_interval_ms),
 214         ATTR_LIST(warning_ratelimit_burst),
 215         ATTR_LIST(msg_ratelimit_interval_ms),
 216         ATTR_LIST(msg_ratelimit_burst),
 217         ATTR_LIST(errors_count),
 218         ATTR_LIST(first_error_time),
 219         ATTR_LIST(last_error_time),
 220         NULL,
 221 };
 222
 223 /* Features this copy of ext4 supports */
 224 EXT4_ATTR_FEATURE(lazy_itable_init);
 225 EXT4_ATTR_FEATURE(batched_discard);
 226 EXT4_ATTR_FEATURE(meta_bg_resize);
 227 #ifdef CONFIG_EXT4_FS_ENCRYPTION
 228 EXT4_ATTR_FEATURE(encryption);
 229 #endif
 230 EXT4_ATTR_FEATURE(metadata_csum_seed);
 231
 232 static struct attribute *ext4_feat_attrs[] = {
 233         ATTR_LIST(lazy_itable_init),
 234         ATTR_LIST(batched_discard),
 235         ATTR_LIST(meta_bg_resize),
 236 #ifdef CONFIG_EXT4_FS_ENCRYPTION
 237         ATTR_LIST(encryption),
 238 #endif
 239         ATTR_LIST(metadata_csum_seed),
 240         NULL,
 241 };
 242
 243 static void *calc_ptr(struct ext4_attr *a, struct ext4_sb_info *sbi)
 244 {
 245         switch (a->attr_ptr) {
 246         case ptr_explicit:
 247                 return a->u.explicit_ptr;
 248         case ptr_ext4_sb_info_offset:
 249                 return (void *) (((char *) sbi) + a->u.offset);
 250         case ptr_ext4_super_block_offset:
 251                 return (void *) (((char *) sbi->s_es) + a->u.offset);
 252         }
 253         return NULL;
 254 }
 255
 256 static ssize_t ext4_attr_show(struct kobject *kobj,
 257                               struct attribute *attr, char *buf)
 258 {
 259         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
 260                                                 s_kobj);
 261         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
 262         void *ptr = calc_ptr(a, sbi);
 263
 264         switch (a->attr_id) {
 265         case attr_delayed_allocation_blocks:
 266                 return snprintf(buf, PAGE_SIZE, "%llu\n",
 267                                 (s64) EXT4_C2B(sbi,
 268                        percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
 269         case attr_session_write_kbytes:
 270                 return session_write_kbytes_show(a, sbi, buf);
 271         case attr_lifetime_write_kbytes:
 272                 return lifetime_write_kbytes_show(a, sbi, buf);
 273         case attr_reserved_clusters:
 274                 return snprintf(buf, PAGE_SIZE, "%llu\n",
 275                                 (unsigned long long)
 276                                 atomic64_read(&sbi->s_resv_clusters));
 277         case attr_inode_readahead:
 278         case attr_pointer_ui:
 279                 if (!ptr)
 280                         return 0;
 281                 if (a->attr_ptr == ptr_ext4_super_block_offset)
 282                         return snprintf(buf, PAGE_SIZE, "%u\n",
 283                                         le32_to_cpup(ptr));
 284                 else
 285                         return snprintf(buf, PAGE_SIZE, "%u\n",
 286                                         *((unsigned int *) ptr));
 287         case attr_pointer_atomic:
 288                 if (!ptr)
 289                         return 0;
 290                 return snprintf(buf, PAGE_SIZE, "%d\n",
 291                                 atomic_read((atomic_t *) ptr));
 292         case attr_feature:
 293                 return snprintf(buf, PAGE_SIZE, "supported\n");
 294         }
 295
 296         return 0;
 297 }
 298
 299 static ssize_t ext4_attr_store(struct kobject *kobj,
 300                                struct attribute *attr,
 301                                const char *buf, size_t len)
 302 {
 303         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
 304                                                 s_kobj);
 305         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
 306         void *ptr = calc_ptr(a, sbi);
 307         unsigned long t;
 308         int ret;
 309
 310         switch (a->attr_id) {
 311         case attr_reserved_clusters:
 312                 return reserved_clusters_store(a, sbi, buf, len);
 313         case attr_pointer_ui:
 314                 if (!ptr)
 315                         return 0;
 316                 ret = kstrtoul(skip_spaces(buf), 0, &t);
 317                 if (ret)
 318                         return ret;
 319                 if (a->attr_ptr == ptr_ext4_super_block_offset)
 320                         *((__le32 *) ptr) = cpu_to_le32(t);
 321                 else
 322                         *((unsigned int *) ptr) = t;
 323                 return len;
 324         case attr_inode_readahead:
 325                 return inode_readahead_blks_store(a, sbi, buf, len);
 326         case attr_trigger_test_error:
 327                 return trigger_test_error(a, sbi, buf, len);
 328         }
 329         return 0;
 330 }
 331
 332 static void ext4_sb_release(struct kobject *kobj)
 333 {
 334         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
 335                                                 s_kobj);
 336         complete(&sbi->s_kobj_unregister);
 337 }
 338
 339 static const struct sysfs_ops ext4_attr_ops = {
 340         .show   = ext4_attr_show,
 341         .store  = ext4_attr_store,
 342 };
 343
 344 static struct kobj_type ext4_sb_ktype = {
 345         .default_attrs  = ext4_attrs,
 346         .sysfs_ops      = &ext4_attr_ops,
 347         .release        = ext4_sb_release,
 348 };
 349
 350 static struct kobj_type ext4_ktype = {
 351         .sysfs_ops      = &ext4_attr_ops,
 352 };
 353
 354 static struct kset ext4_kset = {
 355         .kobj   = {.ktype = &ext4_ktype},
 356 };
 357
 358 static struct kobj_type ext4_feat_ktype = {
 359         .default_attrs  = ext4_feat_attrs,
 360         .sysfs_ops      = &ext4_attr_ops,
 361 };
 362
 363 static struct kobject ext4_feat = {
 364         .kset   = &ext4_kset,
 365 };
 366
 367 #define PROC_FILE_SHOW_DEFN(name) \
 368 static int name##_open(struct inode *inode, struct file *file) \
 369 { \
 370         return single_open(file, ext4_seq_##name##_show, PDE_DATA(inode)); \
 371 } \
 372 \
 373 static const struct file_operations ext4_seq_##name##_fops = { \
 374         .open           = name##_open, \
 375         .read           = seq_read, \
 376         .llseek         = seq_lseek, \
 377         .release        = single_release, \
 378 }
 379
 380 #define PROC_FILE_LIST(name) \
 381         { __stringify(name), &ext4_seq_##name##_fops }
 382
 383 PROC_FILE_SHOW_DEFN(es_shrinker_info);
 384 PROC_FILE_SHOW_DEFN(options);
 385
 386 static const struct ext4_proc_files {
 387         const char *name;
 388         const struct file_operations *fops;
 389 } proc_files[] = {
 390         PROC_FILE_LIST(options),
 391         PROC_FILE_LIST(es_shrinker_info),
 392         PROC_FILE_LIST(mb_groups),
 393         { NULL, NULL },
 394 };
 395
 396 int ext4_register_sysfs(struct super_block *sb)
 397 {
 398         struct ext4_sb_info *sbi = EXT4_SB(sb);
 399         const struct ext4_proc_files *p;
 400         int err;
 401
 402         sbi->s_kobj.kset = &ext4_kset;
 403         init_completion(&sbi->s_kobj_unregister);
 404         err = kobject_init_and_add(&sbi->s_kobj, &ext4_sb_ktype, NULL,
 405                                    "%s", sb->s_id);
 406         if (err)
 407                 return err;
 408
 409         if (ext4_proc_root)
 410                 sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
 411
 412         if (sbi->s_proc) {
 413                 for (p = proc_files; p->name; p++)
 414                         proc_create_data(p->name, S_IRUGO, sbi->s_proc,
 415                                          p->fops, sb);
 416         }
 417         return 0;
 418 }
 419
 420 void ext4_unregister_sysfs(struct super_block *sb)
 421 {
 422         struct ext4_sb_info *sbi = EXT4_SB(sb);
 423         const struct ext4_proc_files *p;
 424
 425         if (sbi->s_proc) {
 426                 for (p = proc_files; p->name; p++)
 427                         remove_proc_entry(p->name, sbi->s_proc);
 428                 remove_proc_entry(sb->s_id, ext4_proc_root);
 429         }
 430         kobject_del(&sbi->s_kobj);
 431 }
 432
 433 int __init ext4_init_sysfs(void)
 434 {
 435         int ret;
 436
 437         kobject_set_name(&ext4_kset.kobj, "ext4");
 438         ext4_kset.kobj.parent = fs_kobj;
 439         ret = kset_register(&ext4_kset);
 440         if (ret)
 441                 return ret;
 442
 443         ret = kobject_init_and_add(&ext4_feat, &ext4_feat_ktype,
 444                                    NULL, "features");
 445         if (ret)
 446                 kset_unregister(&ext4_kset);
 447         else
 448                 ext4_proc_root = proc_mkdir(proc_dirname, NULL);
 449         return ret;
 450 }
 451
 452 void ext4_exit_sysfs(void)
 453 {
 454         kobject_put(&ext4_feat);
 455         kset_unregister(&ext4_kset);
 456         remove_proc_entry(proc_dirname, NULL);
 457         ext4_proc_root = NULL;
 458 }
 459