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_feature, 29 attr_pointer_ui, 30 attr_pointer_atomic, 31 } attr_id_t; 32 33 typedef enum { 34 ptr_explicit, 35 ptr_ext4_sb_info_offset, 36 ptr_ext4_super_block_offset, 37 } attr_ptr_t; 38 39 static const char proc_dirname[] = "fs/ext4"; 40 static struct proc_dir_entry *ext4_proc_root; 41 42 struct ext4_attr { 43 struct attribute attr; 44 short attr_id; 45 short attr_ptr; 46 union { 47 int offset; 48 void *explicit_ptr; 49 } u; 50 }; 51 52 static ssize_t session_write_kbytes_show(struct ext4_attr *a, 53 struct ext4_sb_info *sbi, char *buf) 54 { 55 struct super_block *sb = sbi->s_buddy_cache->i_sb; 56 57 if (!sb->s_bdev->bd_part) 58 return snprintf(buf, PAGE_SIZE, "0\n"); 59 return snprintf(buf, PAGE_SIZE, "%lu\n", 60 (part_stat_read(sb->s_bdev->bd_part, sectors[1]) - 61 sbi->s_sectors_written_start) >> 1); 62 } 63 64 static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a, 65 struct ext4_sb_info *sbi, char *buf) 66 { 67 struct super_block *sb = sbi->s_buddy_cache->i_sb; 68 69 if (!sb->s_bdev->bd_part) 70 return snprintf(buf, PAGE_SIZE, "0\n"); 71 return snprintf(buf, PAGE_SIZE, "%llu\n", 72 (unsigned long long)(sbi->s_kbytes_written + 73 ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) - 74 EXT4_SB(sb)->s_sectors_written_start) >> 1))); 75 } 76 77 static ssize_t inode_readahead_blks_store(struct ext4_attr *a, 78 struct ext4_sb_info *sbi, 79 const char *buf, size_t count) 80 { 81 unsigned long t; 82 int ret; 83 84 ret = kstrtoul(skip_spaces(buf), 0, &t); 85 if (ret) 86 return ret; 87 88 if (t && (!is_power_of_2(t) || t > 0x40000000)) 89 return -EINVAL; 90 91 sbi->s_inode_readahead_blks = t; 92 return count; 93 } 94 95 static ssize_t reserved_clusters_store(struct ext4_attr *a, 96 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_attr *a, 113 struct ext4_sb_info *sbi, 114 const char *buf, size_t count) 115 { 116 int len = count; 117 118 if (!capable(CAP_SYS_ADMIN)) 119 return -EPERM; 120 121 if (len && buf[len-1] == '\n') 122 len--; 123 124 if (len) 125 ext4_error(sbi->s_sb, "%.*s", len, buf); 126 return count; 127 } 128 129 #define EXT4_ATTR(_name,_mode,_id) \ 130 static struct ext4_attr ext4_attr_##_name = { \ 131 .attr = {.name = __stringify(_name), .mode = _mode }, \ 132 .attr_id = attr_##_id, \ 133 } 134 135 #define EXT4_ATTR_FUNC(_name,_mode) EXT4_ATTR(_name,_mode,_name) 136 137 #define EXT4_ATTR_FEATURE(_name) EXT4_ATTR(_name, 0444, feature) 138 139 #define EXT4_ATTR_OFFSET(_name,_mode,_id,_struct,_elname) \ 140 static struct ext4_attr ext4_attr_##_name = { \ 141 .attr = {.name = __stringify(_name), .mode = _mode }, \ 142 .attr_id = attr_##_id, \ 143 .attr_ptr = ptr_##_struct##_offset, \ 144 .u = { \ 145 .offset = offsetof(struct _struct, _elname),\ 146 }, \ 147 } 148 149 #define EXT4_RO_ATTR_ES_UI(_name,_elname) \ 150 EXT4_ATTR_OFFSET(_name, 0444, pointer_ui, ext4_super_block, _elname) 151 152 #define EXT4_RW_ATTR_SBI_UI(_name,_elname) \ 153 EXT4_ATTR_OFFSET(_name, 0644, pointer_ui, ext4_sb_info, _elname) 154 155 #define EXT4_ATTR_PTR(_name,_mode,_id,_ptr) \ 156 static struct ext4_attr ext4_attr_##_name = { \ 157 .attr = {.name = __stringify(_name), .mode = _mode }, \ 158 .attr_id = attr_##_id, \ 159 .attr_ptr = ptr_explicit, \ 160 .u = { \ 161 .explicit_ptr = _ptr, \ 162 }, \ 163 } 164 165 #define ATTR_LIST(name) &ext4_attr_##name.attr 166 167 EXT4_ATTR_FUNC(delayed_allocation_blocks, 0444); 168 EXT4_ATTR_FUNC(session_write_kbytes, 0444); 169 EXT4_ATTR_FUNC(lifetime_write_kbytes, 0444); 170 EXT4_ATTR_FUNC(reserved_clusters, 0644); 171 172 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, inode_readahead, 173 ext4_sb_info, s_inode_readahead_blks); 174 EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal); 175 EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats); 176 EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan); 177 EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan); 178 EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs); 179 EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request); 180 EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc); 181 EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb); 182 EXT4_ATTR(trigger_fs_error, 0200, trigger_test_error); 183 EXT4_RW_ATTR_SBI_UI(err_ratelimit_interval_ms, s_err_ratelimit_state.interval); 184 EXT4_RW_ATTR_SBI_UI(err_ratelimit_burst, s_err_ratelimit_state.burst); 185 EXT4_RW_ATTR_SBI_UI(warning_ratelimit_interval_ms, s_warning_ratelimit_state.interval); 186 EXT4_RW_ATTR_SBI_UI(warning_ratelimit_burst, s_warning_ratelimit_state.burst); 187 EXT4_RW_ATTR_SBI_UI(msg_ratelimit_interval_ms, s_msg_ratelimit_state.interval); 188 EXT4_RW_ATTR_SBI_UI(msg_ratelimit_burst, s_msg_ratelimit_state.burst); 189 EXT4_RO_ATTR_ES_UI(errors_count, s_error_count); 190 EXT4_RO_ATTR_ES_UI(first_error_time, s_first_error_time); 191 EXT4_RO_ATTR_ES_UI(last_error_time, s_last_error_time); 192 193 static unsigned int old_bump_val = 128; 194 EXT4_ATTR_PTR(max_writeback_mb_bump, 0444, pointer_ui, &old_bump_val); 195 196 static struct attribute *ext4_attrs[] = { 197 ATTR_LIST(delayed_allocation_blocks), 198 ATTR_LIST(session_write_kbytes), 199 ATTR_LIST(lifetime_write_kbytes), 200 ATTR_LIST(reserved_clusters), 201 ATTR_LIST(inode_readahead_blks), 202 ATTR_LIST(inode_goal), 203 ATTR_LIST(mb_stats), 204 ATTR_LIST(mb_max_to_scan), 205 ATTR_LIST(mb_min_to_scan), 206 ATTR_LIST(mb_order2_req), 207 ATTR_LIST(mb_stream_req), 208 ATTR_LIST(mb_group_prealloc), 209 ATTR_LIST(max_writeback_mb_bump), 210 ATTR_LIST(extent_max_zeroout_kb), 211 ATTR_LIST(trigger_fs_error), 212 ATTR_LIST(err_ratelimit_interval_ms), 213 ATTR_LIST(err_ratelimit_burst), 214 ATTR_LIST(warning_ratelimit_interval_ms), 215 ATTR_LIST(warning_ratelimit_burst), 216 ATTR_LIST(msg_ratelimit_interval_ms), 217 ATTR_LIST(msg_ratelimit_burst), 218 ATTR_LIST(errors_count), 219 ATTR_LIST(first_error_time), 220 ATTR_LIST(last_error_time), 221 NULL, 222 }; 223 224 /* Features this copy of ext4 supports */ 225 EXT4_ATTR_FEATURE(lazy_itable_init); 226 EXT4_ATTR_FEATURE(batched_discard); 227 EXT4_ATTR_FEATURE(meta_bg_resize); 228 #ifdef CONFIG_EXT4_FS_ENCRYPTION 229 EXT4_ATTR_FEATURE(encryption); 230 #endif 231 EXT4_ATTR_FEATURE(metadata_csum_seed); 232 233 static struct attribute *ext4_feat_attrs[] = { 234 ATTR_LIST(lazy_itable_init), 235 ATTR_LIST(batched_discard), 236 ATTR_LIST(meta_bg_resize), 237 #ifdef CONFIG_EXT4_FS_ENCRYPTION 238 ATTR_LIST(encryption), 239 #endif 240 ATTR_LIST(metadata_csum_seed), 241 NULL, 242 }; 243 244 static void *calc_ptr(struct ext4_attr *a, struct ext4_sb_info *sbi) 245 { 246 switch (a->attr_ptr) { 247 case ptr_explicit: 248 return a->u.explicit_ptr; 249 case ptr_ext4_sb_info_offset: 250 return (void *) (((char *) sbi) + a->u.offset); 251 case ptr_ext4_super_block_offset: 252 return (void *) (((char *) sbi->s_es) + a->u.offset); 253 } 254 return NULL; 255 } 256 257 static ssize_t ext4_attr_show(struct kobject *kobj, 258 struct attribute *attr, char *buf) 259 { 260 struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info, 261 s_kobj); 262 struct ext4_attr *a = container_of(attr, struct ext4_attr, attr); 263 void *ptr = calc_ptr(a, sbi); 264 265 switch (a->attr_id) { 266 case attr_delayed_allocation_blocks: 267 return snprintf(buf, PAGE_SIZE, "%llu\n", 268 (s64) EXT4_C2B(sbi, 269 percpu_counter_sum(&sbi->s_dirtyclusters_counter))); 270 case attr_session_write_kbytes: 271 return session_write_kbytes_show(a, sbi, buf); 272 case attr_lifetime_write_kbytes: 273 return lifetime_write_kbytes_show(a, sbi, buf); 274 case attr_reserved_clusters: 275 return snprintf(buf, PAGE_SIZE, "%llu\n", 276 (unsigned long long) 277 atomic64_read(&sbi->s_resv_clusters)); 278 case attr_inode_readahead: 279 case attr_pointer_ui: 280 if (!ptr) 281 return 0; 282 return snprintf(buf, PAGE_SIZE, "%u\n", 283 *((unsigned int *) ptr)); 284 case attr_pointer_atomic: 285 if (!ptr) 286 return 0; 287 return snprintf(buf, PAGE_SIZE, "%d\n", 288 atomic_read((atomic_t *) ptr)); 289 case attr_feature: 290 return snprintf(buf, PAGE_SIZE, "supported\n"); 291 } 292 293 return 0; 294 } 295 296 static ssize_t ext4_attr_store(struct kobject *kobj, 297 struct attribute *attr, 298 const char *buf, size_t len) 299 { 300 struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info, 301 s_kobj); 302 struct ext4_attr *a = container_of(attr, struct ext4_attr, attr); 303 void *ptr = calc_ptr(a, sbi); 304 unsigned long t; 305 int ret; 306 307 switch (a->attr_id) { 308 case attr_reserved_clusters: 309 return reserved_clusters_store(a, sbi, buf, len); 310 case attr_pointer_ui: 311 if (!ptr) 312 return 0; 313 ret = kstrtoul(skip_spaces(buf), 0, &t); 314 if (ret) 315 return ret; 316 *((unsigned int *) ptr) = t; 317 return len; 318 case attr_inode_readahead: 319 return inode_readahead_blks_store(a, sbi, buf, len); 320 case attr_trigger_test_error: 321 return trigger_test_error(a, sbi, buf, len); 322 } 323 return 0; 324 } 325 326 static void ext4_sb_release(struct kobject *kobj) 327 { 328 struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info, 329 s_kobj); 330 complete(&sbi->s_kobj_unregister); 331 } 332 333 static void ext4_kset_release(struct kobject *kobj) 334 { 335 struct kset *kset = container_of(kobj, struct kset, kobj); 336 337 kfree(kset); 338 } 339 340 static const struct sysfs_ops ext4_attr_ops = { 341 .show = ext4_attr_show, 342 .store = ext4_attr_store, 343 }; 344 345 static struct kobj_type ext4_sb_ktype = { 346 .default_attrs = ext4_attrs, 347 .sysfs_ops = &ext4_attr_ops, 348 .release = ext4_sb_release, 349 }; 350 351 static struct kobj_type ext4_ktype = { 352 .sysfs_ops = &ext4_attr_ops, 353 .release = ext4_kset_release, 354 }; 355 356 static struct kset *ext4_kset; 357 358 static struct kobj_type ext4_feat_ktype = { 359 .default_attrs = ext4_feat_attrs, 360 .sysfs_ops = &ext4_attr_ops, 361 .release = (void (*)(struct kobject *))kfree, 362 }; 363 364 static struct kobject *ext4_feat; 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 const 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 const 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 kobject_put(&sbi->s_kobj); 407 wait_for_completion(&sbi->s_kobj_unregister); 408 return err; 409 } 410 411 if (ext4_proc_root) 412 sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root); 413 414 if (sbi->s_proc) { 415 for (p = proc_files; p->name; p++) 416 proc_create_data(p->name, S_IRUGO, sbi->s_proc, 417 p->fops, sb); 418 } 419 return 0; 420 } 421 422 void ext4_unregister_sysfs(struct super_block *sb) 423 { 424 struct ext4_sb_info *sbi = EXT4_SB(sb); 425 const struct ext4_proc_files *p; 426 427 if (sbi->s_proc) { 428 for (p = proc_files; p->name; p++) 429 remove_proc_entry(p->name, sbi->s_proc); 430 remove_proc_entry(sb->s_id, ext4_proc_root); 431 } 432 kobject_del(&sbi->s_kobj); 433 } 434 435 int __init ext4_init_sysfs(void) 436 { 437 int ret; 438 439 ext4_kset = kzalloc(sizeof(*ext4_kset), GFP_KERNEL); 440 if (!ext4_kset) 441 return -ENOMEM; 442 443 kobject_set_name(&ext4_kset->kobj, "ext4"); 444 ext4_kset->kobj.parent = fs_kobj; 445 ext4_kset->kobj.ktype = &ext4_ktype; 446 ret = kset_register(ext4_kset); 447 if (ret) 448 goto kset_err; 449 450 ext4_feat = kzalloc(sizeof(*ext4_feat), GFP_KERNEL); 451 if (!ext4_feat) { 452 ret = -ENOMEM; 453 goto kset_err; 454 } 455 456 ext4_feat->kset = ext4_kset; 457 ret = kobject_init_and_add(ext4_feat, &ext4_feat_ktype, 458 NULL, "features"); 459 if (ret) 460 goto feat_err; 461 462 ext4_proc_root = proc_mkdir(proc_dirname, NULL); 463 return ret; 464 465 feat_err: 466 kobject_put(ext4_feat); 467 kset_err: 468 kset_unregister(ext4_kset); 469 ext4_kset = NULL; 470 return ret; 471 } 472 473 void ext4_exit_sysfs(void) 474 { 475 kobject_put(ext4_feat); 476 kset_unregister(ext4_kset); 477 ext4_kset = NULL; 478 remove_proc_entry(proc_dirname, NULL); 479 ext4_proc_root = NULL; 480 } 481 482