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 17 #include "ext4.h" 18 #include "ext4_jbd2.h" 19 20 typedef enum { 21 attr_noop, 22 attr_delayed_allocation_blocks, 23 attr_session_write_kbytes, 24 attr_lifetime_write_kbytes, 25 attr_reserved_clusters, 26 attr_inode_readahead, 27 attr_trigger_test_error, 28 attr_first_error_time, 29 attr_last_error_time, 30 attr_feature, 31 attr_pointer_ui, 32 attr_pointer_atomic, 33 } attr_id_t; 34 35 typedef enum { 36 ptr_explicit, 37 ptr_ext4_sb_info_offset, 38 ptr_ext4_super_block_offset, 39 } attr_ptr_t; 40 41 static const char proc_dirname[] = "fs/ext4"; 42 static struct proc_dir_entry *ext4_proc_root; 43 44 struct ext4_attr { 45 struct attribute attr; 46 short attr_id; 47 short attr_ptr; 48 union { 49 int offset; 50 void *explicit_ptr; 51 } u; 52 }; 53 54 static ssize_t session_write_kbytes_show(struct ext4_sb_info *sbi, char *buf) 55 { 56 struct super_block *sb = sbi->s_buddy_cache->i_sb; 57 58 if (!sb->s_bdev->bd_part) 59 return snprintf(buf, PAGE_SIZE, "0\n"); 60 return snprintf(buf, PAGE_SIZE, "%lu\n", 61 (part_stat_read(sb->s_bdev->bd_part, 62 sectors[STAT_WRITE]) - 63 sbi->s_sectors_written_start) >> 1); 64 } 65 66 static ssize_t lifetime_write_kbytes_show(struct ext4_sb_info *sbi, char *buf) 67 { 68 struct super_block *sb = sbi->s_buddy_cache->i_sb; 69 70 if (!sb->s_bdev->bd_part) 71 return snprintf(buf, PAGE_SIZE, "0\n"); 72 return snprintf(buf, PAGE_SIZE, "%llu\n", 73 (unsigned long long)(sbi->s_kbytes_written + 74 ((part_stat_read(sb->s_bdev->bd_part, 75 sectors[STAT_WRITE]) - 76 EXT4_SB(sb)->s_sectors_written_start) >> 1))); 77 } 78 79 static ssize_t inode_readahead_blks_store(struct ext4_sb_info *sbi, 80 const char *buf, size_t count) 81 { 82 unsigned long t; 83 int ret; 84 85 ret = kstrtoul(skip_spaces(buf), 0, &t); 86 if (ret) 87 return ret; 88 89 if (t && (!is_power_of_2(t) || t > 0x40000000)) 90 return -EINVAL; 91 92 sbi->s_inode_readahead_blks = t; 93 return count; 94 } 95 96 static ssize_t reserved_clusters_store(struct ext4_sb_info *sbi, 97 const char *buf, size_t count) 98 { 99 unsigned long long val; 100 ext4_fsblk_t clusters = (ext4_blocks_count(sbi->s_es) >> 101 sbi->s_cluster_bits); 102 int ret; 103 104 ret = kstrtoull(skip_spaces(buf), 0, &val); 105 if (ret || val >= clusters) 106 return -EINVAL; 107 108 atomic64_set(&sbi->s_resv_clusters, val); 109 return count; 110 } 111 112 static ssize_t trigger_test_error(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_ATTR(first_error_time, 0444, first_error_time); 190 EXT4_ATTR(last_error_time, 0444, 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 __print_tstamp(char *buf, __le32 lo, __u8 hi) 257 { 258 return snprintf(buf, PAGE_SIZE, "%lld", 259 ((time64_t)hi << 32) + le32_to_cpu(lo)); 260 } 261 262 #define print_tstamp(buf, es, tstamp) \ 263 __print_tstamp(buf, (es)->tstamp, (es)->tstamp ## _hi) 264 265 static ssize_t ext4_attr_show(struct kobject *kobj, 266 struct attribute *attr, char *buf) 267 { 268 struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info, 269 s_kobj); 270 struct ext4_attr *a = container_of(attr, struct ext4_attr, attr); 271 void *ptr = calc_ptr(a, sbi); 272 273 switch (a->attr_id) { 274 case attr_delayed_allocation_blocks: 275 return snprintf(buf, PAGE_SIZE, "%llu\n", 276 (s64) EXT4_C2B(sbi, 277 percpu_counter_sum(&sbi->s_dirtyclusters_counter))); 278 case attr_session_write_kbytes: 279 return session_write_kbytes_show(sbi, buf); 280 case attr_lifetime_write_kbytes: 281 return lifetime_write_kbytes_show(sbi, buf); 282 case attr_reserved_clusters: 283 return snprintf(buf, PAGE_SIZE, "%llu\n", 284 (unsigned long long) 285 atomic64_read(&sbi->s_resv_clusters)); 286 case attr_inode_readahead: 287 case attr_pointer_ui: 288 if (!ptr) 289 return 0; 290 if (a->attr_ptr == ptr_ext4_super_block_offset) 291 return snprintf(buf, PAGE_SIZE, "%u\n", 292 le32_to_cpup(ptr)); 293 else 294 return snprintf(buf, PAGE_SIZE, "%u\n", 295 *((unsigned int *) ptr)); 296 case attr_pointer_atomic: 297 if (!ptr) 298 return 0; 299 return snprintf(buf, PAGE_SIZE, "%d\n", 300 atomic_read((atomic_t *) ptr)); 301 case attr_feature: 302 return snprintf(buf, PAGE_SIZE, "supported\n"); 303 case attr_first_error_time: 304 return print_tstamp(buf, sbi->s_es, s_first_error_time); 305 case attr_last_error_time: 306 return print_tstamp(buf, sbi->s_es, s_last_error_time); 307 } 308 309 return 0; 310 } 311 312 static ssize_t ext4_attr_store(struct kobject *kobj, 313 struct attribute *attr, 314 const char *buf, size_t len) 315 { 316 struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info, 317 s_kobj); 318 struct ext4_attr *a = container_of(attr, struct ext4_attr, attr); 319 void *ptr = calc_ptr(a, sbi); 320 unsigned long t; 321 int ret; 322 323 switch (a->attr_id) { 324 case attr_reserved_clusters: 325 return reserved_clusters_store(sbi, buf, len); 326 case attr_pointer_ui: 327 if (!ptr) 328 return 0; 329 ret = kstrtoul(skip_spaces(buf), 0, &t); 330 if (ret) 331 return ret; 332 if (a->attr_ptr == ptr_ext4_super_block_offset) 333 *((__le32 *) ptr) = cpu_to_le32(t); 334 else 335 *((unsigned int *) ptr) = t; 336 return len; 337 case attr_inode_readahead: 338 return inode_readahead_blks_store(sbi, buf, len); 339 case attr_trigger_test_error: 340 return trigger_test_error(sbi, buf, len); 341 } 342 return 0; 343 } 344 345 static void ext4_sb_release(struct kobject *kobj) 346 { 347 struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info, 348 s_kobj); 349 complete(&sbi->s_kobj_unregister); 350 } 351 352 static const struct sysfs_ops ext4_attr_ops = { 353 .show = ext4_attr_show, 354 .store = ext4_attr_store, 355 }; 356 357 static struct kobj_type ext4_sb_ktype = { 358 .default_attrs = ext4_attrs, 359 .sysfs_ops = &ext4_attr_ops, 360 .release = ext4_sb_release, 361 }; 362 363 static struct kobj_type ext4_feat_ktype = { 364 .default_attrs = ext4_feat_attrs, 365 .sysfs_ops = &ext4_attr_ops, 366 .release = (void (*)(struct kobject *))kfree, 367 }; 368 369 static struct kobject *ext4_root; 370 371 static struct kobject *ext4_feat; 372 373 int ext4_register_sysfs(struct super_block *sb) 374 { 375 struct ext4_sb_info *sbi = EXT4_SB(sb); 376 int err; 377 378 init_completion(&sbi->s_kobj_unregister); 379 err = kobject_init_and_add(&sbi->s_kobj, &ext4_sb_ktype, ext4_root, 380 "%s", sb->s_id); 381 if (err) { 382 kobject_put(&sbi->s_kobj); 383 wait_for_completion(&sbi->s_kobj_unregister); 384 return err; 385 } 386 387 if (ext4_proc_root) 388 sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root); 389 if (sbi->s_proc) { 390 proc_create_single_data("options", S_IRUGO, sbi->s_proc, 391 ext4_seq_options_show, sb); 392 proc_create_single_data("es_shrinker_info", S_IRUGO, 393 sbi->s_proc, ext4_seq_es_shrinker_info_show, 394 sb); 395 proc_create_seq_data("mb_groups", S_IRUGO, sbi->s_proc, 396 &ext4_mb_seq_groups_ops, sb); 397 } 398 return 0; 399 } 400 401 void ext4_unregister_sysfs(struct super_block *sb) 402 { 403 struct ext4_sb_info *sbi = EXT4_SB(sb); 404 405 if (sbi->s_proc) 406 remove_proc_subtree(sb->s_id, ext4_proc_root); 407 kobject_del(&sbi->s_kobj); 408 } 409 410 int __init ext4_init_sysfs(void) 411 { 412 int ret; 413 414 ext4_root = kobject_create_and_add("ext4", fs_kobj); 415 if (!ext4_root) 416 return -ENOMEM; 417 418 ext4_feat = kzalloc(sizeof(*ext4_feat), GFP_KERNEL); 419 if (!ext4_feat) { 420 ret = -ENOMEM; 421 goto root_err; 422 } 423 424 ret = kobject_init_and_add(ext4_feat, &ext4_feat_ktype, 425 ext4_root, "features"); 426 if (ret) 427 goto feat_err; 428 429 ext4_proc_root = proc_mkdir(proc_dirname, NULL); 430 return ret; 431 432 feat_err: 433 kobject_put(ext4_feat); 434 ext4_feat = NULL; 435 root_err: 436 kobject_put(ext4_root); 437 ext4_root = NULL; 438 return ret; 439 } 440 441 void ext4_exit_sysfs(void) 442 { 443 kobject_put(ext4_feat); 444 ext4_feat = NULL; 445 kobject_put(ext4_root); 446 ext4_root = NULL; 447 remove_proc_entry(proc_dirname, NULL); 448 ext4_proc_root = NULL; 449 } 450 451