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_sb_info *sbi, char *buf) 53 { 54 struct super_block *sb = sbi->s_buddy_cache->i_sb; 55 56 if (!sb->s_bdev->bd_part) 57 return snprintf(buf, PAGE_SIZE, "0\n"); 58 return snprintf(buf, PAGE_SIZE, "%lu\n", 59 (part_stat_read(sb->s_bdev->bd_part, sectors[1]) - 60 sbi->s_sectors_written_start) >> 1); 61 } 62 63 static ssize_t lifetime_write_kbytes_show(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_sb_info *sbi, 76 const char *buf, size_t count) 77 { 78 unsigned long t; 79 int ret; 80 81 ret = kstrtoul(skip_spaces(buf), 0, &t); 82 if (ret) 83 return ret; 84 85 if (t && (!is_power_of_2(t) || t > 0x40000000)) 86 return -EINVAL; 87 88 sbi->s_inode_readahead_blks = t; 89 return count; 90 } 91 92 static ssize_t reserved_clusters_store(struct ext4_sb_info *sbi, 93 const char *buf, size_t count) 94 { 95 unsigned long long val; 96 ext4_fsblk_t clusters = (ext4_blocks_count(sbi->s_es) >> 97 sbi->s_cluster_bits); 98 int ret; 99 100 ret = kstrtoull(skip_spaces(buf), 0, &val); 101 if (ret || val >= clusters) 102 return -EINVAL; 103 104 atomic64_set(&sbi->s_resv_clusters, val); 105 return count; 106 } 107 108 static ssize_t trigger_test_error(struct ext4_sb_info *sbi, 109 const char *buf, size_t count) 110 { 111 int len = count; 112 113 if (!capable(CAP_SYS_ADMIN)) 114 return -EPERM; 115 116 if (len && buf[len-1] == '\n') 117 len--; 118 119 if (len) 120 ext4_error(sbi->s_sb, "%.*s", len, buf); 121 return count; 122 } 123 124 #define EXT4_ATTR(_name,_mode,_id) \ 125 static struct ext4_attr ext4_attr_##_name = { \ 126 .attr = {.name = __stringify(_name), .mode = _mode }, \ 127 .attr_id = attr_##_id, \ 128 } 129 130 #define EXT4_ATTR_FUNC(_name,_mode) EXT4_ATTR(_name,_mode,_name) 131 132 #define EXT4_ATTR_FEATURE(_name) EXT4_ATTR(_name, 0444, feature) 133 134 #define EXT4_ATTR_OFFSET(_name,_mode,_id,_struct,_elname) \ 135 static struct ext4_attr ext4_attr_##_name = { \ 136 .attr = {.name = __stringify(_name), .mode = _mode }, \ 137 .attr_id = attr_##_id, \ 138 .attr_ptr = ptr_##_struct##_offset, \ 139 .u = { \ 140 .offset = offsetof(struct _struct, _elname),\ 141 }, \ 142 } 143 144 #define EXT4_RO_ATTR_ES_UI(_name,_elname) \ 145 EXT4_ATTR_OFFSET(_name, 0444, pointer_ui, ext4_super_block, _elname) 146 147 #define EXT4_RW_ATTR_SBI_UI(_name,_elname) \ 148 EXT4_ATTR_OFFSET(_name, 0644, pointer_ui, ext4_sb_info, _elname) 149 150 #define EXT4_ATTR_PTR(_name,_mode,_id,_ptr) \ 151 static struct ext4_attr ext4_attr_##_name = { \ 152 .attr = {.name = __stringify(_name), .mode = _mode }, \ 153 .attr_id = attr_##_id, \ 154 .attr_ptr = ptr_explicit, \ 155 .u = { \ 156 .explicit_ptr = _ptr, \ 157 }, \ 158 } 159 160 #define ATTR_LIST(name) &ext4_attr_##name.attr 161 162 EXT4_ATTR_FUNC(delayed_allocation_blocks, 0444); 163 EXT4_ATTR_FUNC(session_write_kbytes, 0444); 164 EXT4_ATTR_FUNC(lifetime_write_kbytes, 0444); 165 EXT4_ATTR_FUNC(reserved_clusters, 0644); 166 167 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, inode_readahead, 168 ext4_sb_info, s_inode_readahead_blks); 169 EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal); 170 EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats); 171 EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan); 172 EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan); 173 EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs); 174 EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request); 175 EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc); 176 EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb); 177 EXT4_ATTR(trigger_fs_error, 0200, trigger_test_error); 178 EXT4_RW_ATTR_SBI_UI(err_ratelimit_interval_ms, s_err_ratelimit_state.interval); 179 EXT4_RW_ATTR_SBI_UI(err_ratelimit_burst, s_err_ratelimit_state.burst); 180 EXT4_RW_ATTR_SBI_UI(warning_ratelimit_interval_ms, s_warning_ratelimit_state.interval); 181 EXT4_RW_ATTR_SBI_UI(warning_ratelimit_burst, s_warning_ratelimit_state.burst); 182 EXT4_RW_ATTR_SBI_UI(msg_ratelimit_interval_ms, s_msg_ratelimit_state.interval); 183 EXT4_RW_ATTR_SBI_UI(msg_ratelimit_burst, s_msg_ratelimit_state.burst); 184 EXT4_RO_ATTR_ES_UI(errors_count, s_error_count); 185 EXT4_RO_ATTR_ES_UI(first_error_time, s_first_error_time); 186 EXT4_RO_ATTR_ES_UI(last_error_time, s_last_error_time); 187 188 static unsigned int old_bump_val = 128; 189 EXT4_ATTR_PTR(max_writeback_mb_bump, 0444, pointer_ui, &old_bump_val); 190 191 static struct attribute *ext4_attrs[] = { 192 ATTR_LIST(delayed_allocation_blocks), 193 ATTR_LIST(session_write_kbytes), 194 ATTR_LIST(lifetime_write_kbytes), 195 ATTR_LIST(reserved_clusters), 196 ATTR_LIST(inode_readahead_blks), 197 ATTR_LIST(inode_goal), 198 ATTR_LIST(mb_stats), 199 ATTR_LIST(mb_max_to_scan), 200 ATTR_LIST(mb_min_to_scan), 201 ATTR_LIST(mb_order2_req), 202 ATTR_LIST(mb_stream_req), 203 ATTR_LIST(mb_group_prealloc), 204 ATTR_LIST(max_writeback_mb_bump), 205 ATTR_LIST(extent_max_zeroout_kb), 206 ATTR_LIST(trigger_fs_error), 207 ATTR_LIST(err_ratelimit_interval_ms), 208 ATTR_LIST(err_ratelimit_burst), 209 ATTR_LIST(warning_ratelimit_interval_ms), 210 ATTR_LIST(warning_ratelimit_burst), 211 ATTR_LIST(msg_ratelimit_interval_ms), 212 ATTR_LIST(msg_ratelimit_burst), 213 ATTR_LIST(errors_count), 214 ATTR_LIST(first_error_time), 215 ATTR_LIST(last_error_time), 216 NULL, 217 }; 218 219 /* Features this copy of ext4 supports */ 220 EXT4_ATTR_FEATURE(lazy_itable_init); 221 EXT4_ATTR_FEATURE(batched_discard); 222 EXT4_ATTR_FEATURE(meta_bg_resize); 223 #ifdef CONFIG_EXT4_FS_ENCRYPTION 224 EXT4_ATTR_FEATURE(encryption); 225 #endif 226 EXT4_ATTR_FEATURE(metadata_csum_seed); 227 228 static struct attribute *ext4_feat_attrs[] = { 229 ATTR_LIST(lazy_itable_init), 230 ATTR_LIST(batched_discard), 231 ATTR_LIST(meta_bg_resize), 232 #ifdef CONFIG_EXT4_FS_ENCRYPTION 233 ATTR_LIST(encryption), 234 #endif 235 ATTR_LIST(metadata_csum_seed), 236 NULL, 237 }; 238 239 static void *calc_ptr(struct ext4_attr *a, struct ext4_sb_info *sbi) 240 { 241 switch (a->attr_ptr) { 242 case ptr_explicit: 243 return a->u.explicit_ptr; 244 case ptr_ext4_sb_info_offset: 245 return (void *) (((char *) sbi) + a->u.offset); 246 case ptr_ext4_super_block_offset: 247 return (void *) (((char *) sbi->s_es) + a->u.offset); 248 } 249 return NULL; 250 } 251 252 static ssize_t ext4_attr_show(struct kobject *kobj, 253 struct attribute *attr, char *buf) 254 { 255 struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info, 256 s_kobj); 257 struct ext4_attr *a = container_of(attr, struct ext4_attr, attr); 258 void *ptr = calc_ptr(a, sbi); 259 260 switch (a->attr_id) { 261 case attr_delayed_allocation_blocks: 262 return snprintf(buf, PAGE_SIZE, "%llu\n", 263 (s64) EXT4_C2B(sbi, 264 percpu_counter_sum(&sbi->s_dirtyclusters_counter))); 265 case attr_session_write_kbytes: 266 return session_write_kbytes_show(sbi, buf); 267 case attr_lifetime_write_kbytes: 268 return lifetime_write_kbytes_show(sbi, buf); 269 case attr_reserved_clusters: 270 return snprintf(buf, PAGE_SIZE, "%llu\n", 271 (unsigned long long) 272 atomic64_read(&sbi->s_resv_clusters)); 273 case attr_inode_readahead: 274 case attr_pointer_ui: 275 if (!ptr) 276 return 0; 277 return snprintf(buf, PAGE_SIZE, "%u\n", 278 *((unsigned int *) ptr)); 279 case attr_pointer_atomic: 280 if (!ptr) 281 return 0; 282 return snprintf(buf, PAGE_SIZE, "%d\n", 283 atomic_read((atomic_t *) ptr)); 284 case attr_feature: 285 return snprintf(buf, PAGE_SIZE, "supported\n"); 286 } 287 288 return 0; 289 } 290 291 static ssize_t ext4_attr_store(struct kobject *kobj, 292 struct attribute *attr, 293 const char *buf, size_t len) 294 { 295 struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info, 296 s_kobj); 297 struct ext4_attr *a = container_of(attr, struct ext4_attr, attr); 298 void *ptr = calc_ptr(a, sbi); 299 unsigned long t; 300 int ret; 301 302 switch (a->attr_id) { 303 case attr_reserved_clusters: 304 return reserved_clusters_store(sbi, buf, len); 305 case attr_pointer_ui: 306 if (!ptr) 307 return 0; 308 ret = kstrtoul(skip_spaces(buf), 0, &t); 309 if (ret) 310 return ret; 311 *((unsigned int *) ptr) = t; 312 return len; 313 case attr_inode_readahead: 314 return inode_readahead_blks_store(sbi, buf, len); 315 case attr_trigger_test_error: 316 return trigger_test_error(sbi, buf, len); 317 } 318 return 0; 319 } 320 321 static void ext4_sb_release(struct kobject *kobj) 322 { 323 struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info, 324 s_kobj); 325 complete(&sbi->s_kobj_unregister); 326 } 327 328 static const struct sysfs_ops ext4_attr_ops = { 329 .show = ext4_attr_show, 330 .store = ext4_attr_store, 331 }; 332 333 static struct kobj_type ext4_sb_ktype = { 334 .default_attrs = ext4_attrs, 335 .sysfs_ops = &ext4_attr_ops, 336 .release = ext4_sb_release, 337 }; 338 339 static struct kobj_type ext4_feat_ktype = { 340 .default_attrs = ext4_feat_attrs, 341 .sysfs_ops = &ext4_attr_ops, 342 .release = (void (*)(struct kobject *))kfree, 343 }; 344 345 static struct kobject *ext4_root; 346 347 static struct kobject *ext4_feat; 348 349 #define PROC_FILE_SHOW_DEFN(name) \ 350 static int name##_open(struct inode *inode, struct file *file) \ 351 { \ 352 return single_open(file, ext4_seq_##name##_show, PDE_DATA(inode)); \ 353 } \ 354 \ 355 static const struct file_operations ext4_seq_##name##_fops = { \ 356 .open = name##_open, \ 357 .read = seq_read, \ 358 .llseek = seq_lseek, \ 359 .release = single_release, \ 360 } 361 362 #define PROC_FILE_LIST(name) \ 363 { __stringify(name), &ext4_seq_##name##_fops } 364 365 PROC_FILE_SHOW_DEFN(es_shrinker_info); 366 PROC_FILE_SHOW_DEFN(options); 367 368 static const struct ext4_proc_files { 369 const char *name; 370 const struct file_operations *fops; 371 } proc_files[] = { 372 PROC_FILE_LIST(options), 373 PROC_FILE_LIST(es_shrinker_info), 374 PROC_FILE_LIST(mb_groups), 375 { NULL, NULL }, 376 }; 377 378 int ext4_register_sysfs(struct super_block *sb) 379 { 380 struct ext4_sb_info *sbi = EXT4_SB(sb); 381 const struct ext4_proc_files *p; 382 int err; 383 384 init_completion(&sbi->s_kobj_unregister); 385 err = kobject_init_and_add(&sbi->s_kobj, &ext4_sb_ktype, ext4_root, 386 "%s", sb->s_id); 387 if (err) { 388 kobject_put(&sbi->s_kobj); 389 wait_for_completion(&sbi->s_kobj_unregister); 390 return err; 391 } 392 393 if (ext4_proc_root) 394 sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root); 395 396 if (sbi->s_proc) { 397 for (p = proc_files; p->name; p++) 398 proc_create_data(p->name, S_IRUGO, sbi->s_proc, 399 p->fops, sb); 400 } 401 return 0; 402 } 403 404 void ext4_unregister_sysfs(struct super_block *sb) 405 { 406 struct ext4_sb_info *sbi = EXT4_SB(sb); 407 const struct ext4_proc_files *p; 408 409 if (sbi->s_proc) { 410 for (p = proc_files; p->name; p++) 411 remove_proc_entry(p->name, sbi->s_proc); 412 remove_proc_entry(sb->s_id, ext4_proc_root); 413 } 414 kobject_del(&sbi->s_kobj); 415 } 416 417 int __init ext4_init_sysfs(void) 418 { 419 int ret; 420 421 ext4_root = kobject_create_and_add("ext4", fs_kobj); 422 if (!ext4_root) 423 return -ENOMEM; 424 425 ext4_feat = kzalloc(sizeof(*ext4_feat), GFP_KERNEL); 426 if (!ext4_feat) { 427 ret = -ENOMEM; 428 goto root_err; 429 } 430 431 ret = kobject_init_and_add(ext4_feat, &ext4_feat_ktype, 432 ext4_root, "features"); 433 if (ret) 434 goto feat_err; 435 436 ext4_proc_root = proc_mkdir(proc_dirname, NULL); 437 return ret; 438 439 feat_err: 440 kobject_put(ext4_feat); 441 ext4_feat = NULL; 442 root_err: 443 kobject_put(ext4_root); 444 ext4_root = NULL; 445 return ret; 446 } 447 448 void ext4_exit_sysfs(void) 449 { 450 kobject_put(ext4_feat); 451 ext4_feat = NULL; 452 kobject_put(ext4_root); 453 ext4_root = NULL; 454 remove_proc_entry(proc_dirname, NULL); 455 ext4_proc_root = NULL; 456 } 457 458