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 EXT4_ATTR_FEATURE(encryption);
 227 EXT4_ATTR_FEATURE(metadata_csum_seed);
 228
 229 static struct attribute *ext4_feat_attrs[] = {
 230         ATTR_LIST(lazy_itable_init),
 231         ATTR_LIST(batched_discard),
 232         ATTR_LIST(meta_bg_resize),
 233         ATTR_LIST(encryption),
 234         ATTR_LIST(metadata_csum_seed),
 235         NULL,
 236 };
 237
 238 static void *calc_ptr(struct ext4_attr *a, struct ext4_sb_info *sbi)
 239 {
 240         switch (a->attr_ptr) {
 241         case ptr_explicit:
 242                 return a->u.explicit_ptr;
 243         case ptr_ext4_sb_info_offset:
 244                 return (void *) (((char *) sbi) + a->u.offset);
 245         case ptr_ext4_super_block_offset:
 246                 return (void *) (((char *) sbi->s_es) + a->u.offset);
 247         }
 248         return NULL;
 249 }
 250
 251 static ssize_t ext4_attr_show(struct kobject *kobj,
 252                               struct attribute *attr, char *buf)
 253 {
 254         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
 255                                                 s_kobj);
 256         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
 257         void *ptr = calc_ptr(a, sbi);
 258
 259         switch (a->attr_id) {
 260         case attr_delayed_allocation_blocks:
 261                 return snprintf(buf, PAGE_SIZE, "%llu\n",
 262                                 (s64) EXT4_C2B(sbi,
 263                        percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
 264         case attr_session_write_kbytes:
 265                 return session_write_kbytes_show(a, sbi, buf);
 266         case attr_lifetime_write_kbytes:
 267                 return lifetime_write_kbytes_show(a, sbi, buf);
 268         case attr_reserved_clusters:
 269                 return snprintf(buf, PAGE_SIZE, "%llu\n",
 270                                 (unsigned long long)
 271                                 atomic64_read(&sbi->s_resv_clusters));
 272         case attr_inode_readahead:
 273         case attr_pointer_ui:
 274                 if (!ptr)
 275                         return 0;
 276                 return snprintf(buf, PAGE_SIZE, "%u\n",
 277                                 *((unsigned int *) ptr));
 278         case attr_pointer_atomic:
 279                 if (!ptr)
 280                         return 0;
 281                 return snprintf(buf, PAGE_SIZE, "%d\n",
 282                                 atomic_read((atomic_t *) ptr));
 283         case attr_feature:
 284                 return snprintf(buf, PAGE_SIZE, "supported\n");
 285         }
 286
 287         return 0;
 288 }
 289
 290 static ssize_t ext4_attr_store(struct kobject *kobj,
 291                                struct attribute *attr,
 292                                const char *buf, size_t len)
 293 {
 294         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
 295                                                 s_kobj);
 296         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
 297         void *ptr = calc_ptr(a, sbi);
 298         unsigned long t;
 299         int ret;
 300
 301         switch (a->attr_id) {
 302         case attr_reserved_clusters:
 303                 return reserved_clusters_store(a, sbi, buf, len);
 304         case attr_pointer_ui:
 305                 if (!ptr)
 306                         return 0;
 307                 ret = kstrtoul(skip_spaces(buf), 0, &t);
 308                 if (ret)
 309                         return ret;
 310                 *((unsigned int *) ptr) = t;
 311                 return len;
 312         case attr_inode_readahead:
 313                 return inode_readahead_blks_store(a, sbi, buf, len);
 314         case attr_trigger_test_error:
 315                 return trigger_test_error(a, sbi, buf, len);
 316         }
 317         return 0;
 318 }
 319
 320 static void ext4_sb_release(struct kobject *kobj)
 321 {
 322         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
 323                                                 s_kobj);
 324         complete(&sbi->s_kobj_unregister);
 325 }
 326
 327 static const struct sysfs_ops ext4_attr_ops = {
 328         .show   = ext4_attr_show,
 329         .store  = ext4_attr_store,
 330 };
 331
 332 static struct kobj_type ext4_sb_ktype = {
 333         .default_attrs  = ext4_attrs,
 334         .sysfs_ops      = &ext4_attr_ops,
 335         .release        = ext4_sb_release,
 336 };
 337
 338 static struct kobj_type ext4_ktype = {
 339         .sysfs_ops      = &ext4_attr_ops,
 340 };
 341
 342 static struct kset ext4_kset = {
 343         .kobj   = {.ktype = &ext4_ktype},
 344 };
 345
 346 static struct kobj_type ext4_feat_ktype = {
 347         .default_attrs  = ext4_feat_attrs,
 348         .sysfs_ops      = &ext4_attr_ops,
 349 };
 350
 351 static struct kobject ext4_feat = {
 352         .kset   = &ext4_kset,
 353 };
 354
 355 #define PROC_FILE_SHOW_DEFN(name) \
 356 static int name##_open(struct inode *inode, struct file *file) \
 357 { \
 358         return single_open(file, ext4_seq_##name##_show, PDE_DATA(inode)); \
 359 } \
 360 \
 361 static const struct file_operations ext4_seq_##name##_fops = { \
 362         .owner          = THIS_MODULE, \
 363         .open           = name##_open, \
 364         .read           = seq_read, \
 365         .llseek         = seq_lseek, \
 366         .release        = single_release, \
 367 }
 368
 369 #define PROC_FILE_LIST(name) \
 370         { __stringify(name), &ext4_seq_##name##_fops }
 371
 372 PROC_FILE_SHOW_DEFN(es_shrinker_info);
 373 PROC_FILE_SHOW_DEFN(options);
 374
 375 static struct ext4_proc_files {
 376         const char *name;
 377         const struct file_operations *fops;
 378 } proc_files[] = {
 379         PROC_FILE_LIST(options),
 380         PROC_FILE_LIST(es_shrinker_info),
 381         PROC_FILE_LIST(mb_groups),
 382         { NULL, NULL },
 383 };
 384
 385 int ext4_register_sysfs(struct super_block *sb)
 386 {
 387         struct ext4_sb_info *sbi = EXT4_SB(sb);
 388         struct ext4_proc_files *p;
 389         int err;
 390
 391         sbi->s_kobj.kset = &ext4_kset;
 392         init_completion(&sbi->s_kobj_unregister);
 393         err = kobject_init_and_add(&sbi->s_kobj, &ext4_sb_ktype, NULL,
 394                                    "%s", sb->s_id);
 395         if (err)
 396                 return err;
 397
 398         if (ext4_proc_root)
 399                 sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
 400
 401         if (sbi->s_proc) {
 402                 for (p = proc_files; p->name; p++)
 403                         proc_create_data(p->name, S_IRUGO, sbi->s_proc,
 404                                          p->fops, sb);
 405         }
 406         return 0;
 407 }
 408
 409 void ext4_unregister_sysfs(struct super_block *sb)
 410 {
 411         struct ext4_sb_info *sbi = EXT4_SB(sb);
 412         struct ext4_proc_files *p;
 413
 414         if (sbi->s_proc) {
 415                 for (p = proc_files; p->name; p++)
 416                         remove_proc_entry(p->name, sbi->s_proc);
 417                 remove_proc_entry(sb->s_id, ext4_proc_root);
 418         }
 419         kobject_del(&sbi->s_kobj);
 420 }
 421
 422 int __init ext4_init_sysfs(void)
 423 {
 424         int ret;
 425
 426         kobject_set_name(&ext4_kset.kobj, "ext4");
 427         ext4_kset.kobj.parent = fs_kobj;
 428         ret = kset_register(&ext4_kset);
 429         if (ret)
 430                 return ret;
 431
 432         ret = kobject_init_and_add(&ext4_feat, &ext4_feat_ktype,
 433                                    NULL, "features");
 434         if (ret)
 435                 kset_unregister(&ext4_kset);
 436         else
 437                 ext4_proc_root = proc_mkdir(proc_dirname, NULL);
 438         return ret;
 439 }
 440
 441 void ext4_exit_sysfs(void)
 442 {
 443         kobject_put(&ext4_feat);
 444         kset_unregister(&ext4_kset);
 445         remove_proc_entry(proc_dirname, NULL);
 446         ext4_proc_root = NULL;
 447 }
 448