linux/fs/ext4/sysfs.c
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   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
  18typedef 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
  31typedef enum {
  32        ptr_explicit,
  33        ptr_ext4_sb_info_offset,
  34        ptr_ext4_super_block_offset,
  35} attr_ptr_t;
  36
  37static const char *proc_dirname = "fs/ext4";
  38static struct proc_dir_entry *ext4_proc_root;
  39
  40struct 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
  50static 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
  62static 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
  75static 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
  93static 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
 110static 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)                                      \
 128static 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)       \
 138static 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) \
 154static 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
 165EXT4_ATTR_FUNC(delayed_allocation_blocks, 0444);
 166EXT4_ATTR_FUNC(session_write_kbytes, 0444);
 167EXT4_ATTR_FUNC(lifetime_write_kbytes, 0444);
 168EXT4_ATTR_FUNC(reserved_clusters, 0644);
 169
 170EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, inode_readahead,
 171                 ext4_sb_info, s_inode_readahead_blks);
 172EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
 173EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
 174EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
 175EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
 176EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
 177EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
 178EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
 179EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb);
 180EXT4_ATTR(trigger_fs_error, 0200, trigger_test_error);
 181EXT4_RW_ATTR_SBI_UI(err_ratelimit_interval_ms, s_err_ratelimit_state.interval);
 182EXT4_RW_ATTR_SBI_UI(err_ratelimit_burst, s_err_ratelimit_state.burst);
 183EXT4_RW_ATTR_SBI_UI(warning_ratelimit_interval_ms, s_warning_ratelimit_state.interval);
 184EXT4_RW_ATTR_SBI_UI(warning_ratelimit_burst, s_warning_ratelimit_state.burst);
 185EXT4_RW_ATTR_SBI_UI(msg_ratelimit_interval_ms, s_msg_ratelimit_state.interval);
 186EXT4_RW_ATTR_SBI_UI(msg_ratelimit_burst, s_msg_ratelimit_state.burst);
 187EXT4_RO_ATTR_ES_UI(errors_count, s_error_count);
 188EXT4_RO_ATTR_ES_UI(first_error_time, s_first_error_time);
 189EXT4_RO_ATTR_ES_UI(last_error_time, s_last_error_time);
 190
 191static unsigned int old_bump_val = 128;
 192EXT4_ATTR_PTR(max_writeback_mb_bump, 0444, pointer_ui, &old_bump_val);
 193
 194static 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 */
 223EXT4_ATTR_FEATURE(lazy_itable_init);
 224EXT4_ATTR_FEATURE(batched_discard);
 225EXT4_ATTR_FEATURE(meta_bg_resize);
 226#ifdef CONFIG_EXT4_FS_ENCRYPTION
 227EXT4_ATTR_FEATURE(encryption);
 228#endif
 229EXT4_ATTR_FEATURE(metadata_csum_seed);
 230
 231static 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
 242static 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
 255static 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                return snprintf(buf, PAGE_SIZE, "%u\n",
 281                                *((unsigned int *) ptr));
 282        case attr_pointer_atomic:
 283                if (!ptr)
 284                        return 0;
 285                return snprintf(buf, PAGE_SIZE, "%d\n",
 286                                atomic_read((atomic_t *) ptr));
 287        case attr_feature:
 288                return snprintf(buf, PAGE_SIZE, "supported\n");
 289        }
 290
 291        return 0;
 292}
 293
 294static ssize_t ext4_attr_store(struct kobject *kobj,
 295                               struct attribute *attr,
 296                               const char *buf, size_t len)
 297{
 298        struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
 299                                                s_kobj);
 300        struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
 301        void *ptr = calc_ptr(a, sbi);
 302        unsigned long t;
 303        int ret;
 304
 305        switch (a->attr_id) {
 306        case attr_reserved_clusters:
 307                return reserved_clusters_store(a, sbi, buf, len);
 308        case attr_pointer_ui:
 309                if (!ptr)
 310                        return 0;
 311                ret = kstrtoul(skip_spaces(buf), 0, &t);
 312                if (ret)
 313                        return ret;
 314                *((unsigned int *) ptr) = t;
 315                return len;
 316        case attr_inode_readahead:
 317                return inode_readahead_blks_store(a, sbi, buf, len);
 318        case attr_trigger_test_error:
 319                return trigger_test_error(a, sbi, buf, len);
 320        }
 321        return 0;
 322}
 323
 324static void ext4_sb_release(struct kobject *kobj)
 325{
 326        struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
 327                                                s_kobj);
 328        complete(&sbi->s_kobj_unregister);
 329}
 330
 331static const struct sysfs_ops ext4_attr_ops = {
 332        .show   = ext4_attr_show,
 333        .store  = ext4_attr_store,
 334};
 335
 336static struct kobj_type ext4_sb_ktype = {
 337        .default_attrs  = ext4_attrs,
 338        .sysfs_ops      = &ext4_attr_ops,
 339        .release        = ext4_sb_release,
 340};
 341
 342static struct kobj_type ext4_ktype = {
 343        .sysfs_ops      = &ext4_attr_ops,
 344};
 345
 346static struct kset ext4_kset = {
 347        .kobj   = {.ktype = &ext4_ktype},
 348};
 349
 350static struct kobj_type ext4_feat_ktype = {
 351        .default_attrs  = ext4_feat_attrs,
 352        .sysfs_ops      = &ext4_attr_ops,
 353};
 354
 355static struct kobject ext4_feat = {
 356        .kset   = &ext4_kset,
 357};
 358
 359#define PROC_FILE_SHOW_DEFN(name) \
 360static int name##_open(struct inode *inode, struct file *file) \
 361{ \
 362        return single_open(file, ext4_seq_##name##_show, PDE_DATA(inode)); \
 363} \
 364\
 365static const struct file_operations ext4_seq_##name##_fops = { \
 366        .open           = name##_open, \
 367        .read           = seq_read, \
 368        .llseek         = seq_lseek, \
 369        .release        = single_release, \
 370}
 371
 372#define PROC_FILE_LIST(name) \
 373        { __stringify(name), &ext4_seq_##name##_fops }
 374
 375PROC_FILE_SHOW_DEFN(es_shrinker_info);
 376PROC_FILE_SHOW_DEFN(options);
 377
 378static struct ext4_proc_files {
 379        const char *name;
 380        const struct file_operations *fops;
 381} proc_files[] = {
 382        PROC_FILE_LIST(options),
 383        PROC_FILE_LIST(es_shrinker_info),
 384        PROC_FILE_LIST(mb_groups),
 385        { NULL, NULL },
 386};
 387
 388int ext4_register_sysfs(struct super_block *sb)
 389{
 390        struct ext4_sb_info *sbi = EXT4_SB(sb);
 391        struct ext4_proc_files *p;
 392        int err;
 393
 394        sbi->s_kobj.kset = &ext4_kset;
 395        init_completion(&sbi->s_kobj_unregister);
 396        err = kobject_init_and_add(&sbi->s_kobj, &ext4_sb_ktype, NULL,
 397                                   "%s", sb->s_id);
 398        if (err)
 399                return err;
 400
 401        if (ext4_proc_root)
 402                sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
 403
 404        if (sbi->s_proc) {
 405                for (p = proc_files; p->name; p++)
 406                        proc_create_data(p->name, S_IRUGO, sbi->s_proc,
 407                                         p->fops, sb);
 408        }
 409        return 0;
 410}
 411
 412void ext4_unregister_sysfs(struct super_block *sb)
 413{
 414        struct ext4_sb_info *sbi = EXT4_SB(sb);
 415        struct ext4_proc_files *p;
 416
 417        if (sbi->s_proc) {
 418                for (p = proc_files; p->name; p++)
 419                        remove_proc_entry(p->name, sbi->s_proc);
 420                remove_proc_entry(sb->s_id, ext4_proc_root);
 421        }
 422        kobject_del(&sbi->s_kobj);
 423}
 424
 425int __init ext4_init_sysfs(void)
 426{
 427        int ret;
 428
 429        kobject_set_name(&ext4_kset.kobj, "ext4");
 430        ext4_kset.kobj.parent = fs_kobj;
 431        ret = kset_register(&ext4_kset);
 432        if (ret)
 433                return ret;
 434
 435        ret = kobject_init_and_add(&ext4_feat, &ext4_feat_ktype,
 436                                   NULL, "features");
 437        if (ret)
 438                kset_unregister(&ext4_kset);
 439        else
 440                ext4_proc_root = proc_mkdir(proc_dirname, NULL);
 441        return ret;
 442}
 443
 444void ext4_exit_sysfs(void)
 445{
 446        kobject_put(&ext4_feat);
 447        kset_unregister(&ext4_kset);
 448        remove_proc_entry(proc_dirname, NULL);
 449        ext4_proc_root = NULL;
 450}
 451
 452