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/proc_fs.h> 15 16 #include "ext4.h" 17 #include "ext4_jbd2.h" 18 19 typedef enum { 20 attr_noop, 21 attr_delayed_allocation_blocks, 22 attr_session_write_kbytes, 23 attr_lifetime_write_kbytes, 24 attr_reserved_clusters, 25 attr_inode_readahead, 26 attr_trigger_test_error, 27 attr_feature, 28 attr_pointer_ui, 29 attr_pointer_atomic, 30 } attr_id_t; 31 32 typedef enum { 33 ptr_explicit, 34 ptr_ext4_sb_info_offset, 35 ptr_ext4_super_block_offset, 36 } attr_ptr_t; 37 38 static const char proc_dirname[] = "fs/ext4"; 39 static struct proc_dir_entry *ext4_proc_root; 40 41 struct ext4_attr { 42 struct attribute attr; 43 short attr_id; 44 short attr_ptr; 45 union { 46 int offset; 47 void *explicit_ptr; 48 } u; 49 }; 50 51 static ssize_t session_write_kbytes_show(struct ext4_attr *a, 52 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_attr *a, 64 struct ext4_sb_info *sbi, char *buf) 65 { 66 struct super_block *sb = sbi->s_buddy_cache->i_sb; 67 68 if (!sb->s_bdev->bd_part) 69 return snprintf(buf, PAGE_SIZE, "0\n"); 70 return snprintf(buf, PAGE_SIZE, "%llu\n", 71 (unsigned long long)(sbi->s_kbytes_written + 72 ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) - 73 EXT4_SB(sb)->s_sectors_written_start) >> 1))); 74 } 75 76 static ssize_t inode_readahead_blks_store(struct ext4_attr *a, 77 struct ext4_sb_info *sbi, 78 const char *buf, size_t count) 79 { 80 unsigned long t; 81 int ret; 82 83 ret = kstrtoul(skip_spaces(buf), 0, &t); 84 if (ret) 85 return ret; 86 87 if (t && (!is_power_of_2(t) || t > 0x40000000)) 88 return -EINVAL; 89 90 sbi->s_inode_readahead_blks = t; 91 return count; 92 } 93 94 static ssize_t reserved_clusters_store(struct ext4_attr *a, 95 struct ext4_sb_info *sbi, 96 const char *buf, size_t count) 97 { 98 unsigned long long val; 99 ext4_fsblk_t clusters = (ext4_blocks_count(sbi->s_es) >> 100 sbi->s_cluster_bits); 101 int ret; 102 103 ret = kstrtoull(skip_spaces(buf), 0, &val); 104 if (ret || val >= clusters) 105 return -EINVAL; 106 107 atomic64_set(&sbi->s_resv_clusters, val); 108 return count; 109 } 110 111 static ssize_t trigger_test_error(struct ext4_attr *a, 112 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_RO_ATTR_ES_UI(first_error_time, s_first_error_time); 190 EXT4_RO_ATTR_ES_UI(last_error_time, s_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 ext4_attr_show(struct kobject *kobj, 257 struct attribute *attr, char *buf) 258 { 259 struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info, 260 s_kobj); 261 struct ext4_attr *a = container_of(attr, struct ext4_attr, attr); 262 void *ptr = calc_ptr(a, sbi); 263 264 switch (a->attr_id) { 265 case attr_delayed_allocation_blocks: 266 return snprintf(buf, PAGE_SIZE, "%llu\n", 267 (s64) EXT4_C2B(sbi, 268 percpu_counter_sum(&sbi->s_dirtyclusters_counter))); 269 case attr_session_write_kbytes: 270 return session_write_kbytes_show(a, sbi, buf); 271 case attr_lifetime_write_kbytes: 272 return lifetime_write_kbytes_show(a, sbi, buf); 273 case attr_reserved_clusters: 274 return snprintf(buf, PAGE_SIZE, "%llu\n", 275 (unsigned long long) 276 atomic64_read(&sbi->s_resv_clusters)); 277 case attr_inode_readahead: 278 case attr_pointer_ui: 279 if (!ptr) 280 return 0; 281 return snprintf(buf, PAGE_SIZE, "%u\n", 282 *((unsigned int *) ptr)); 283 case attr_pointer_atomic: 284 if (!ptr) 285 return 0; 286 return snprintf(buf, PAGE_SIZE, "%d\n", 287 atomic_read((atomic_t *) ptr)); 288 case attr_feature: 289 return snprintf(buf, PAGE_SIZE, "supported\n"); 290 } 291 292 return 0; 293 } 294 295 static ssize_t ext4_attr_store(struct kobject *kobj, 296 struct attribute *attr, 297 const char *buf, size_t len) 298 { 299 struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info, 300 s_kobj); 301 struct ext4_attr *a = container_of(attr, struct ext4_attr, attr); 302 void *ptr = calc_ptr(a, sbi); 303 unsigned long t; 304 int ret; 305 306 switch (a->attr_id) { 307 case attr_reserved_clusters: 308 return reserved_clusters_store(a, sbi, buf, len); 309 case attr_pointer_ui: 310 if (!ptr) 311 return 0; 312 ret = kstrtoul(skip_spaces(buf), 0, &t); 313 if (ret) 314 return ret; 315 *((unsigned int *) ptr) = t; 316 return len; 317 case attr_inode_readahead: 318 return inode_readahead_blks_store(a, sbi, buf, len); 319 case attr_trigger_test_error: 320 return trigger_test_error(a, sbi, buf, len); 321 } 322 return 0; 323 } 324 325 static void ext4_sb_release(struct kobject *kobj) 326 { 327 struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info, 328 s_kobj); 329 complete(&sbi->s_kobj_unregister); 330 } 331 332 static const struct sysfs_ops ext4_attr_ops = { 333 .show = ext4_attr_show, 334 .store = ext4_attr_store, 335 }; 336 337 static struct kobj_type ext4_sb_ktype = { 338 .default_attrs = ext4_attrs, 339 .sysfs_ops = &ext4_attr_ops, 340 .release = ext4_sb_release, 341 }; 342 343 static struct kobj_type ext4_ktype = { 344 .sysfs_ops = &ext4_attr_ops, 345 }; 346 347 static struct kset ext4_kset = { 348 .kobj = {.ktype = &ext4_ktype}, 349 }; 350 351 static struct kobj_type ext4_feat_ktype = { 352 .default_attrs = ext4_feat_attrs, 353 .sysfs_ops = &ext4_attr_ops, 354 }; 355 356 static struct kobject ext4_feat = { 357 .kset = &ext4_kset, 358 }; 359 360 #define PROC_FILE_SHOW_DEFN(name) \ 361 static int name##_open(struct inode *inode, struct file *file) \ 362 { \ 363 return single_open(file, ext4_seq_##name##_show, PDE_DATA(inode)); \ 364 } \ 365 \ 366 static const struct file_operations ext4_seq_##name##_fops = { \ 367 .open = name##_open, \ 368 .read = seq_read, \ 369 .llseek = seq_lseek, \ 370 .release = single_release, \ 371 } 372 373 #define PROC_FILE_LIST(name) \ 374 { __stringify(name), &ext4_seq_##name##_fops } 375 376 PROC_FILE_SHOW_DEFN(es_shrinker_info); 377 PROC_FILE_SHOW_DEFN(options); 378 379 static const struct ext4_proc_files { 380 const char *name; 381 const struct file_operations *fops; 382 } proc_files[] = { 383 PROC_FILE_LIST(options), 384 PROC_FILE_LIST(es_shrinker_info), 385 PROC_FILE_LIST(mb_groups), 386 { NULL, NULL }, 387 }; 388 389 int ext4_register_sysfs(struct super_block *sb) 390 { 391 struct ext4_sb_info *sbi = EXT4_SB(sb); 392 const struct ext4_proc_files *p; 393 int err; 394 395 sbi->s_kobj.kset = &ext4_kset; 396 init_completion(&sbi->s_kobj_unregister); 397 err = kobject_init_and_add(&sbi->s_kobj, &ext4_sb_ktype, NULL, 398 "%s", sb->s_id); 399 if (err) 400 return err; 401 402 if (ext4_proc_root) 403 sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root); 404 405 if (sbi->s_proc) { 406 for (p = proc_files; p->name; p++) 407 proc_create_data(p->name, S_IRUGO, sbi->s_proc, 408 p->fops, sb); 409 } 410 return 0; 411 } 412 413 void ext4_unregister_sysfs(struct super_block *sb) 414 { 415 struct ext4_sb_info *sbi = EXT4_SB(sb); 416 const struct ext4_proc_files *p; 417 418 if (sbi->s_proc) { 419 for (p = proc_files; p->name; p++) 420 remove_proc_entry(p->name, sbi->s_proc); 421 remove_proc_entry(sb->s_id, ext4_proc_root); 422 } 423 kobject_del(&sbi->s_kobj); 424 } 425 426 int __init ext4_init_sysfs(void) 427 { 428 int ret; 429 430 kobject_set_name(&ext4_kset.kobj, "ext4"); 431 ext4_kset.kobj.parent = fs_kobj; 432 ret = kset_register(&ext4_kset); 433 if (ret) 434 return ret; 435 436 ret = kobject_init_and_add(&ext4_feat, &ext4_feat_ktype, 437 NULL, "features"); 438 if (ret) 439 kset_unregister(&ext4_kset); 440 else 441 ext4_proc_root = proc_mkdir(proc_dirname, NULL); 442 return ret; 443 } 444 445 void ext4_exit_sysfs(void) 446 { 447 kobject_put(&ext4_feat); 448 kset_unregister(&ext4_kset); 449 remove_proc_entry(proc_dirname, NULL); 450 ext4_proc_root = NULL; 451 } 452 453