fs/ext4/sysfs.c

   1 /*
   2  *  linux/fs/ext4/sysfs.c
   3  *
   4  * Copyright (C) 1992, 1993, 1994, 1995
   5  * Remy Card (card@masi.ibp.fr)
   6  * Theodore Ts'o (tytso@mit.edu)
   7  *
   8  */
   9
  10 #include <linux/time.h>
  11 #include <linux/fs.h>
  12 #include <linux/seq_file.h>
  13 #include <linux/proc_fs.h>
  14
  15 #include "ext4.h"
  16 #include "ext4_jbd2.h"
  17
  18 typedef enum {
  19         attr_noop,
  20         attr_delayed_allocation_blocks,
  21         attr_session_write_kbytes,
  22         attr_lifetime_write_kbytes,
  23         attr_reserved_clusters,
  24         attr_inode_readahead,
  25         attr_trigger_test_error,
  26         attr_feature,
  27         attr_pointer_ui,
  28         attr_pointer_atomic,
  29 } attr_id_t;
  30
  31 typedef enum {
  32         ptr_explicit,
  33         ptr_ext4_sb_info_offset,
  34         ptr_ext4_super_block_offset,
  35 } attr_ptr_t;
  36
  37 static const char *proc_dirname = "fs/ext4";
  38 static struct proc_dir_entry *ext4_proc_root;
  39
  40 struct ext4_attr {
  41         struct attribute attr;
  42         short attr_id;
  43         short attr_ptr;
  44         union {
  45                 int offset;
  46                 void *explicit_ptr;
  47         } u;
  48 };
  49
  50 static ssize_t session_write_kbytes_show(struct ext4_attr *a,
  51                                          struct ext4_sb_info *sbi, char *buf)
  52 {
  53         struct super_block *sb = sbi->s_buddy_cache->i_sb;
  54
  55         if (!sb->s_bdev->bd_part)
  56                 return snprintf(buf, PAGE_SIZE, "0\n");
  57         return snprintf(buf, PAGE_SIZE, "%lu\n",
  58                         (part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
  59                          sbi->s_sectors_written_start) >> 1);
  60 }
  61
  62 static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
  63                                           struct ext4_sb_info *sbi, char *buf)
  64 {
  65         struct super_block *sb = sbi->s_buddy_cache->i_sb;
  66
  67         if (!sb->s_bdev->bd_part)
  68                 return snprintf(buf, PAGE_SIZE, "0\n");
  69         return snprintf(buf, PAGE_SIZE, "%llu\n",
  70                         (unsigned long long)(sbi->s_kbytes_written +
  71                         ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
  72                           EXT4_SB(sb)->s_sectors_written_start) >> 1)));
  73 }
  74
  75 static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
  76                                           struct ext4_sb_info *sbi,
  77                                           const char *buf, size_t count)
  78 {
  79         unsigned long t;
  80         int ret;
  81
  82         ret = kstrtoul(skip_spaces(buf), 0, &t);
  83         if (ret)
  84                 return ret;
  85
  86         if (t && (!is_power_of_2(t) || t > 0x40000000))
  87                 return -EINVAL;
  88
  89         sbi->s_inode_readahead_blks = t;
  90         return count;
  91 }
  92
  93 static ssize_t reserved_clusters_store(struct ext4_attr *a,
  94                                    struct ext4_sb_info *sbi,
  95                                    const char *buf, size_t count)
  96 {
  97         unsigned long long val;
  98         ext4_fsblk_t clusters = (ext4_blocks_count(sbi->s_es) >>
  99                                  sbi->s_cluster_bits);
 100         int ret;
 101
 102         ret = kstrtoull(skip_spaces(buf), 0, &val);
 103         if (ret || val >= clusters)
 104                 return -EINVAL;
 105
 106         atomic64_set(&sbi->s_resv_clusters, val);
 107         return count;
 108 }
 109
 110 static ssize_t trigger_test_error(struct ext4_attr *a,
 111                                   struct ext4_sb_info *sbi,
 112                                   const char *buf, size_t count)
 113 {
 114         int len = count;
 115
 116         if (!capable(CAP_SYS_ADMIN))
 117                 return -EPERM;
 118
 119         if (len && buf[len-1] == '\n')
 120                 len--;
 121
 122         if (len)
 123                 ext4_error(sbi->s_sb, "%.*s", len, buf);
 124         return count;
 125 }
 126
 127 #define EXT4_ATTR(_name,_mode,_id)                                      \
 128 static struct ext4_attr ext4_attr_##_name = {                           \
 129         .attr = {.name = __stringify(_name), .mode = _mode },           \
 130         .attr_id = attr_##_id,                                          \
 131 }
 132
 133 #define EXT4_ATTR_FUNC(_name,_mode)  EXT4_ATTR(_name,_mode,_name)
 134
 135 #define EXT4_ATTR_FEATURE(_name)   EXT4_ATTR(_name, 0444, feature)
 136
 137 #define EXT4_ATTR_OFFSET(_name,_mode,_id,_struct,_elname)       \
 138 static struct ext4_attr ext4_attr_##_name = {                   \
 139         .attr = {.name = __stringify(_name), .mode = _mode },   \
 140         .attr_id = attr_##_id,                                  \
 141         .attr_ptr = ptr_##_struct##_offset,                     \
 142         .u = {                                                  \
 143                 .offset = offsetof(struct _struct, _elname),\
 144         },                                                      \
 145 }
 146
 147 #define EXT4_RO_ATTR_ES_UI(_name,_elname)                               \
 148         EXT4_ATTR_OFFSET(_name, 0444, pointer_ui, ext4_super_block, _elname)
 149
 150 #define EXT4_RW_ATTR_SBI_UI(_name,_elname)      \
 151         EXT4_ATTR_OFFSET(_name, 0644, pointer_ui, ext4_sb_info, _elname)
 152
 153 #define EXT4_ATTR_PTR(_name,_mode,_id,_ptr) \
 154 static struct ext4_attr ext4_attr_##_name = {                   \
 155         .attr = {.name = __stringify(_name), .mode = _mode },   \
 156         .attr_id = attr_##_id,                                  \
 157         .attr_ptr = ptr_explicit,                               \
 158         .u = {                                                  \
 159                 .explicit_ptr = _ptr,                           \
 160         },                                                      \
 161 }
 162
 163 #define ATTR_LIST(name) &ext4_attr_##name.attr
 164
 165 EXT4_ATTR_FUNC(delayed_allocation_blocks, 0444);
 166 EXT4_ATTR_FUNC(session_write_kbytes, 0444);
 167 EXT4_ATTR_FUNC(lifetime_write_kbytes, 0444);
 168 EXT4_ATTR_FUNC(reserved_clusters, 0644);
 169
 170 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, inode_readahead,
 171                  ext4_sb_info, s_inode_readahead_blks);
 172 EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
 173 EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
 174 EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
 175 EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
 176 EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
 177 EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
 178 EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
 179 EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb);
 180 EXT4_ATTR(trigger_fs_error, 0200, trigger_test_error);
 181 EXT4_RW_ATTR_SBI_UI(err_ratelimit_interval_ms, s_err_ratelimit_state.interval);
 182 EXT4_RW_ATTR_SBI_UI(err_ratelimit_burst, s_err_ratelimit_state.burst);
 183 EXT4_RW_ATTR_SBI_UI(warning_ratelimit_interval_ms, s_warning_ratelimit_state.interval);
 184 EXT4_RW_ATTR_SBI_UI(warning_ratelimit_burst, s_warning_ratelimit_state.burst);
 185 EXT4_RW_ATTR_SBI_UI(msg_ratelimit_interval_ms, s_msg_ratelimit_state.interval);
 186 EXT4_RW_ATTR_SBI_UI(msg_ratelimit_burst, s_msg_ratelimit_state.burst);
 187 EXT4_RO_ATTR_ES_UI(errors_count, s_error_count);
 188 EXT4_RO_ATTR_ES_UI(first_error_time, s_first_error_time);
 189 EXT4_RO_ATTR_ES_UI(last_error_time, s_last_error_time);
 190
 191 static unsigned int old_bump_val = 128;
 192 EXT4_ATTR_PTR(max_writeback_mb_bump, 0444, pointer_ui, &old_bump_val);
 193
 194 static struct attribute *ext4_attrs[] = {
 195         ATTR_LIST(delayed_allocation_blocks),
 196         ATTR_LIST(session_write_kbytes),
 197         ATTR_LIST(lifetime_write_kbytes),
 198         ATTR_LIST(reserved_clusters),
 199         ATTR_LIST(inode_readahead_blks),
 200         ATTR_LIST(inode_goal),
 201         ATTR_LIST(mb_stats),
 202         ATTR_LIST(mb_max_to_scan),
 203         ATTR_LIST(mb_min_to_scan),
 204         ATTR_LIST(mb_order2_req),
 205         ATTR_LIST(mb_stream_req),
 206         ATTR_LIST(mb_group_prealloc),
 207         ATTR_LIST(max_writeback_mb_bump),
 208         ATTR_LIST(extent_max_zeroout_kb),
 209         ATTR_LIST(trigger_fs_error),
 210         ATTR_LIST(err_ratelimit_interval_ms),
 211         ATTR_LIST(err_ratelimit_burst),
 212         ATTR_LIST(warning_ratelimit_interval_ms),
 213         ATTR_LIST(warning_ratelimit_burst),
 214         ATTR_LIST(msg_ratelimit_interval_ms),
 215         ATTR_LIST(msg_ratelimit_burst),
 216         ATTR_LIST(errors_count),
 217         ATTR_LIST(first_error_time),
 218         ATTR_LIST(last_error_time),
 219         NULL,
 220 };
 221
 222 /* Features this copy of ext4 supports */
 223 EXT4_ATTR_FEATURE(lazy_itable_init);
 224 EXT4_ATTR_FEATURE(batched_discard);
 225 EXT4_ATTR_FEATURE(meta_bg_resize);
 226 #ifdef CONFIG_EXT4_FS_ENCRYPTION
 227 EXT4_ATTR_FEATURE(encryption);
 228 #endif
 229 EXT4_ATTR_FEATURE(metadata_csum_seed);
 230
 231 static struct attribute *ext4_feat_attrs[] = {
 232         ATTR_LIST(lazy_itable_init),
 233         ATTR_LIST(batched_discard),
 234         ATTR_LIST(meta_bg_resize),
 235 #ifdef CONFIG_EXT4_FS_ENCRYPTION
 236         ATTR_LIST(encryption),
 237 #endif
 238         ATTR_LIST(metadata_csum_seed),
 239         NULL,
 240 };
 241
 242 static void *calc_ptr(struct ext4_attr *a, struct ext4_sb_info *sbi)
 243 {
 244         switch (a->attr_ptr) {
 245         case ptr_explicit:
 246                 return a->u.explicit_ptr;
 247         case ptr_ext4_sb_info_offset:
 248                 return (void *) (((char *) sbi) + a->u.offset);
 249         case ptr_ext4_super_block_offset:
 250                 return (void *) (((char *) sbi->s_es) + a->u.offset);
 251         }
 252         return NULL;
 253 }
 254
 255 static ssize_t ext4_attr_show(struct kobject *kobj,
 256                               struct attribute *attr, char *buf)
 257 {
 258         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
 259                                                 s_kobj);
 260         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
 261         void *ptr = calc_ptr(a, sbi);
 262
 263         switch (a->attr_id) {
 264         case attr_delayed_allocation_blocks:
 265                 return snprintf(buf, PAGE_SIZE, "%llu\n",
 266                                 (s64) EXT4_C2B(sbi,
 267                        percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
 268         case attr_session_write_kbytes:
 269                 return session_write_kbytes_show(a, sbi, buf);
 270         case attr_lifetime_write_kbytes:
 271                 return lifetime_write_kbytes_show(a, sbi, buf);
 272         case attr_reserved_clusters:
 273                 return snprintf(buf, PAGE_SIZE, "%llu\n",
 274                                 (unsigned long long)
 275                                 atomic64_read(&sbi->s_resv_clusters));
 276         case attr_inode_readahead:
 277         case attr_pointer_ui:
 278                 if (!ptr)
 279                         return 0;
 280                 if (a->attr_ptr == ptr_ext4_super_block_offset)
 281                         return snprintf(buf, PAGE_SIZE, "%u\n",
 282                                         le32_to_cpup(ptr));
 283                 else
 284                         return snprintf(buf, PAGE_SIZE, "%u\n",
 285                                         *((unsigned int *) ptr));
 286         case attr_pointer_atomic:
 287                 if (!ptr)
 288                         return 0;
 289                 return snprintf(buf, PAGE_SIZE, "%d\n",
 290                                 atomic_read((atomic_t *) ptr));
 291         case attr_feature:
 292                 return snprintf(buf, PAGE_SIZE, "supported\n");
 293         }
 294
 295         return 0;
 296 }
 297
 298 static ssize_t ext4_attr_store(struct kobject *kobj,
 299                                struct attribute *attr,
 300                                const char *buf, size_t len)
 301 {
 302         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
 303                                                 s_kobj);
 304         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
 305         void *ptr = calc_ptr(a, sbi);
 306         unsigned long t;
 307         int ret;
 308
 309         switch (a->attr_id) {
 310         case attr_reserved_clusters:
 311                 return reserved_clusters_store(a, sbi, buf, len);
 312         case attr_pointer_ui:
 313                 if (!ptr)
 314                         return 0;
 315                 ret = kstrtoul(skip_spaces(buf), 0, &t);
 316                 if (ret)
 317                         return ret;
 318                 if (a->attr_ptr == ptr_ext4_super_block_offset)
 319                         *((__le32 *) ptr) = cpu_to_le32(t);
 320                 else
 321                         *((unsigned int *) ptr) = t;
 322                 return len;
 323         case attr_inode_readahead:
 324                 return inode_readahead_blks_store(a, sbi, buf, len);
 325         case attr_trigger_test_error:
 326                 return trigger_test_error(a, sbi, buf, len);
 327         }
 328         return 0;
 329 }
 330
 331 static void ext4_sb_release(struct kobject *kobj)
 332 {
 333         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
 334                                                 s_kobj);
 335         complete(&sbi->s_kobj_unregister);
 336 }
 337
 338 static const struct sysfs_ops ext4_attr_ops = {
 339         .show   = ext4_attr_show,
 340         .store  = ext4_attr_store,
 341 };
 342
 343 static struct kobj_type ext4_sb_ktype = {
 344         .default_attrs  = ext4_attrs,
 345         .sysfs_ops      = &ext4_attr_ops,
 346         .release        = ext4_sb_release,
 347 };
 348
 349 static struct kobj_type ext4_ktype = {
 350         .sysfs_ops      = &ext4_attr_ops,
 351 };
 352
 353 static struct kset ext4_kset = {
 354         .kobj   = {.ktype = &ext4_ktype},
 355 };
 356
 357 static struct kobj_type ext4_feat_ktype = {
 358         .default_attrs  = ext4_feat_attrs,
 359         .sysfs_ops      = &ext4_attr_ops,
 360 };
 361
 362 static struct kobject ext4_feat = {
 363         .kset   = &ext4_kset,
 364 };
 365
 366 #define PROC_FILE_SHOW_DEFN(name) \
 367 static int name##_open(struct inode *inode, struct file *file) \
 368 { \
 369         return single_open(file, ext4_seq_##name##_show, PDE_DATA(inode)); \
 370 } \
 371 \
 372 static const struct file_operations ext4_seq_##name##_fops = { \
 373         .open           = name##_open, \
 374         .read           = seq_read, \
 375         .llseek         = seq_lseek, \
 376         .release        = single_release, \
 377 }
 378
 379 #define PROC_FILE_LIST(name) \
 380         { __stringify(name), &ext4_seq_##name##_fops }
 381
 382 PROC_FILE_SHOW_DEFN(es_shrinker_info);
 383 PROC_FILE_SHOW_DEFN(options);
 384
 385 static struct ext4_proc_files {
 386         const char *name;
 387         const struct file_operations *fops;
 388 } proc_files[] = {
 389         PROC_FILE_LIST(options),
 390         PROC_FILE_LIST(es_shrinker_info),
 391         PROC_FILE_LIST(mb_groups),
 392         { NULL, NULL },
 393 };
 394
 395 int ext4_register_sysfs(struct super_block *sb)
 396 {
 397         struct ext4_sb_info *sbi = EXT4_SB(sb);
 398         struct ext4_proc_files *p;
 399         int err;
 400
 401         sbi->s_kobj.kset = &ext4_kset;
 402         init_completion(&sbi->s_kobj_unregister);
 403         err = kobject_init_and_add(&sbi->s_kobj, &ext4_sb_ktype, NULL,
 404                                    "%s", sb->s_id);
 405         if (err)
 406                 return err;
 407
 408         if (ext4_proc_root)
 409                 sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
 410
 411         if (sbi->s_proc) {
 412                 for (p = proc_files; p->name; p++)
 413                         proc_create_data(p->name, S_IRUGO, sbi->s_proc,
 414                                          p->fops, sb);
 415         }
 416         return 0;
 417 }
 418
 419 void ext4_unregister_sysfs(struct super_block *sb)
 420 {
 421         struct ext4_sb_info *sbi = EXT4_SB(sb);
 422         struct ext4_proc_files *p;
 423
 424         if (sbi->s_proc) {
 425                 for (p = proc_files; p->name; p++)
 426                         remove_proc_entry(p->name, sbi->s_proc);
 427                 remove_proc_entry(sb->s_id, ext4_proc_root);
 428         }
 429         kobject_del(&sbi->s_kobj);
 430 }
 431
 432 int __init ext4_init_sysfs(void)
 433 {
 434         int ret;
 435
 436         kobject_set_name(&ext4_kset.kobj, "ext4");
 437         ext4_kset.kobj.parent = fs_kobj;
 438         ret = kset_register(&ext4_kset);
 439         if (ret)
 440                 return ret;
 441
 442         ret = kobject_init_and_add(&ext4_feat, &ext4_feat_ktype,
 443                                    NULL, "features");
 444         if (ret)
 445                 kset_unregister(&ext4_kset);
 446         else
 447                 ext4_proc_root = proc_mkdir(proc_dirname, NULL);
 448         return ret;
 449 }
 450
 451 void ext4_exit_sysfs(void)
 452 {
 453         kobject_put(&ext4_feat);
 454         kset_unregister(&ext4_kset);
 455         remove_proc_entry(proc_dirname, NULL);
 456         ext4_proc_root = NULL;
 457 }
 458