1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (C) 2007 Oracle. All rights reserved. 4 */ 5 6 #include <linux/sched.h> 7 #include <linux/sched/mm.h> 8 #include <linux/slab.h> 9 #include <linux/spinlock.h> 10 #include <linux/completion.h> 11 #include <linux/bug.h> 12 13 #include "ctree.h" 14 #include "disk-io.h" 15 #include "transaction.h" 16 #include "sysfs.h" 17 #include "volumes.h" 18 #include "space-info.h" 19 #include "block-group.h" 20 21 struct btrfs_feature_attr { 22 struct kobj_attribute kobj_attr; 23 enum btrfs_feature_set feature_set; 24 u64 feature_bit; 25 }; 26 27 /* For raid type sysfs entries */ 28 struct raid_kobject { 29 u64 flags; 30 struct kobject kobj; 31 }; 32 33 #define __INIT_KOBJ_ATTR(_name, _mode, _show, _store) \ 34 { \ 35 .attr = { .name = __stringify(_name), .mode = _mode }, \ 36 .show = _show, \ 37 .store = _store, \ 38 } 39 40 #define BTRFS_ATTR_RW(_prefix, _name, _show, _store) \ 41 static struct kobj_attribute btrfs_attr_##_prefix##_##_name = \ 42 __INIT_KOBJ_ATTR(_name, 0644, _show, _store) 43 44 #define BTRFS_ATTR(_prefix, _name, _show) \ 45 static struct kobj_attribute btrfs_attr_##_prefix##_##_name = \ 46 __INIT_KOBJ_ATTR(_name, 0444, _show, NULL) 47 48 #define BTRFS_ATTR_PTR(_prefix, _name) \ 49 (&btrfs_attr_##_prefix##_##_name.attr) 50 51 #define BTRFS_FEAT_ATTR(_name, _feature_set, _feature_prefix, _feature_bit) \ 52 static struct btrfs_feature_attr btrfs_attr_features_##_name = { \ 53 .kobj_attr = __INIT_KOBJ_ATTR(_name, S_IRUGO, \ 54 btrfs_feature_attr_show, \ 55 btrfs_feature_attr_store), \ 56 .feature_set = _feature_set, \ 57 .feature_bit = _feature_prefix ##_## _feature_bit, \ 58 } 59 #define BTRFS_FEAT_ATTR_PTR(_name) \ 60 (&btrfs_attr_features_##_name.kobj_attr.attr) 61 62 #define BTRFS_FEAT_ATTR_COMPAT(name, feature) \ 63 BTRFS_FEAT_ATTR(name, FEAT_COMPAT, BTRFS_FEATURE_COMPAT, feature) 64 #define BTRFS_FEAT_ATTR_COMPAT_RO(name, feature) \ 65 BTRFS_FEAT_ATTR(name, FEAT_COMPAT_RO, BTRFS_FEATURE_COMPAT_RO, feature) 66 #define BTRFS_FEAT_ATTR_INCOMPAT(name, feature) \ 67 BTRFS_FEAT_ATTR(name, FEAT_INCOMPAT, BTRFS_FEATURE_INCOMPAT, feature) 68 69 static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj); 70 static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj); 71 72 static struct btrfs_feature_attr *to_btrfs_feature_attr(struct kobj_attribute *a) 73 { 74 return container_of(a, struct btrfs_feature_attr, kobj_attr); 75 } 76 77 static struct kobj_attribute *attr_to_btrfs_attr(struct attribute *attr) 78 { 79 return container_of(attr, struct kobj_attribute, attr); 80 } 81 82 static struct btrfs_feature_attr *attr_to_btrfs_feature_attr( 83 struct attribute *attr) 84 { 85 return to_btrfs_feature_attr(attr_to_btrfs_attr(attr)); 86 } 87 88 static u64 get_features(struct btrfs_fs_info *fs_info, 89 enum btrfs_feature_set set) 90 { 91 struct btrfs_super_block *disk_super = fs_info->super_copy; 92 if (set == FEAT_COMPAT) 93 return btrfs_super_compat_flags(disk_super); 94 else if (set == FEAT_COMPAT_RO) 95 return btrfs_super_compat_ro_flags(disk_super); 96 else 97 return btrfs_super_incompat_flags(disk_super); 98 } 99 100 static void set_features(struct btrfs_fs_info *fs_info, 101 enum btrfs_feature_set set, u64 features) 102 { 103 struct btrfs_super_block *disk_super = fs_info->super_copy; 104 if (set == FEAT_COMPAT) 105 btrfs_set_super_compat_flags(disk_super, features); 106 else if (set == FEAT_COMPAT_RO) 107 btrfs_set_super_compat_ro_flags(disk_super, features); 108 else 109 btrfs_set_super_incompat_flags(disk_super, features); 110 } 111 112 static int can_modify_feature(struct btrfs_feature_attr *fa) 113 { 114 int val = 0; 115 u64 set, clear; 116 switch (fa->feature_set) { 117 case FEAT_COMPAT: 118 set = BTRFS_FEATURE_COMPAT_SAFE_SET; 119 clear = BTRFS_FEATURE_COMPAT_SAFE_CLEAR; 120 break; 121 case FEAT_COMPAT_RO: 122 set = BTRFS_FEATURE_COMPAT_RO_SAFE_SET; 123 clear = BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR; 124 break; 125 case FEAT_INCOMPAT: 126 set = BTRFS_FEATURE_INCOMPAT_SAFE_SET; 127 clear = BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR; 128 break; 129 default: 130 pr_warn("btrfs: sysfs: unknown feature set %d\n", 131 fa->feature_set); 132 return 0; 133 } 134 135 if (set & fa->feature_bit) 136 val |= 1; 137 if (clear & fa->feature_bit) 138 val |= 2; 139 140 return val; 141 } 142 143 static ssize_t btrfs_feature_attr_show(struct kobject *kobj, 144 struct kobj_attribute *a, char *buf) 145 { 146 int val = 0; 147 struct btrfs_fs_info *fs_info = to_fs_info(kobj); 148 struct btrfs_feature_attr *fa = to_btrfs_feature_attr(a); 149 if (fs_info) { 150 u64 features = get_features(fs_info, fa->feature_set); 151 if (features & fa->feature_bit) 152 val = 1; 153 } else 154 val = can_modify_feature(fa); 155 156 return snprintf(buf, PAGE_SIZE, "%d\n", val); 157 } 158 159 static ssize_t btrfs_feature_attr_store(struct kobject *kobj, 160 struct kobj_attribute *a, 161 const char *buf, size_t count) 162 { 163 struct btrfs_fs_info *fs_info; 164 struct btrfs_feature_attr *fa = to_btrfs_feature_attr(a); 165 u64 features, set, clear; 166 unsigned long val; 167 int ret; 168 169 fs_info = to_fs_info(kobj); 170 if (!fs_info) 171 return -EPERM; 172 173 if (sb_rdonly(fs_info->sb)) 174 return -EROFS; 175 176 ret = kstrtoul(skip_spaces(buf), 0, &val); 177 if (ret) 178 return ret; 179 180 if (fa->feature_set == FEAT_COMPAT) { 181 set = BTRFS_FEATURE_COMPAT_SAFE_SET; 182 clear = BTRFS_FEATURE_COMPAT_SAFE_CLEAR; 183 } else if (fa->feature_set == FEAT_COMPAT_RO) { 184 set = BTRFS_FEATURE_COMPAT_RO_SAFE_SET; 185 clear = BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR; 186 } else { 187 set = BTRFS_FEATURE_INCOMPAT_SAFE_SET; 188 clear = BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR; 189 } 190 191 features = get_features(fs_info, fa->feature_set); 192 193 /* Nothing to do */ 194 if ((val && (features & fa->feature_bit)) || 195 (!val && !(features & fa->feature_bit))) 196 return count; 197 198 if ((val && !(set & fa->feature_bit)) || 199 (!val && !(clear & fa->feature_bit))) { 200 btrfs_info(fs_info, 201 "%sabling feature %s on mounted fs is not supported.", 202 val ? "En" : "Dis", fa->kobj_attr.attr.name); 203 return -EPERM; 204 } 205 206 btrfs_info(fs_info, "%s %s feature flag", 207 val ? "Setting" : "Clearing", fa->kobj_attr.attr.name); 208 209 spin_lock(&fs_info->super_lock); 210 features = get_features(fs_info, fa->feature_set); 211 if (val) 212 features |= fa->feature_bit; 213 else 214 features &= ~fa->feature_bit; 215 set_features(fs_info, fa->feature_set, features); 216 spin_unlock(&fs_info->super_lock); 217 218 /* 219 * We don't want to do full transaction commit from inside sysfs 220 */ 221 btrfs_set_pending(fs_info, COMMIT); 222 wake_up_process(fs_info->transaction_kthread); 223 224 return count; 225 } 226 227 static umode_t btrfs_feature_visible(struct kobject *kobj, 228 struct attribute *attr, int unused) 229 { 230 struct btrfs_fs_info *fs_info = to_fs_info(kobj); 231 umode_t mode = attr->mode; 232 233 if (fs_info) { 234 struct btrfs_feature_attr *fa; 235 u64 features; 236 237 fa = attr_to_btrfs_feature_attr(attr); 238 features = get_features(fs_info, fa->feature_set); 239 240 if (can_modify_feature(fa)) 241 mode |= S_IWUSR; 242 else if (!(features & fa->feature_bit)) 243 mode = 0; 244 } 245 246 return mode; 247 } 248 249 BTRFS_FEAT_ATTR_INCOMPAT(mixed_backref, MIXED_BACKREF); 250 BTRFS_FEAT_ATTR_INCOMPAT(default_subvol, DEFAULT_SUBVOL); 251 BTRFS_FEAT_ATTR_INCOMPAT(mixed_groups, MIXED_GROUPS); 252 BTRFS_FEAT_ATTR_INCOMPAT(compress_lzo, COMPRESS_LZO); 253 BTRFS_FEAT_ATTR_INCOMPAT(compress_zstd, COMPRESS_ZSTD); 254 BTRFS_FEAT_ATTR_INCOMPAT(big_metadata, BIG_METADATA); 255 BTRFS_FEAT_ATTR_INCOMPAT(extended_iref, EXTENDED_IREF); 256 BTRFS_FEAT_ATTR_INCOMPAT(raid56, RAID56); 257 BTRFS_FEAT_ATTR_INCOMPAT(skinny_metadata, SKINNY_METADATA); 258 BTRFS_FEAT_ATTR_INCOMPAT(no_holes, NO_HOLES); 259 BTRFS_FEAT_ATTR_INCOMPAT(metadata_uuid, METADATA_UUID); 260 BTRFS_FEAT_ATTR_COMPAT_RO(free_space_tree, FREE_SPACE_TREE); 261 262 static struct attribute *btrfs_supported_feature_attrs[] = { 263 BTRFS_FEAT_ATTR_PTR(mixed_backref), 264 BTRFS_FEAT_ATTR_PTR(default_subvol), 265 BTRFS_FEAT_ATTR_PTR(mixed_groups), 266 BTRFS_FEAT_ATTR_PTR(compress_lzo), 267 BTRFS_FEAT_ATTR_PTR(compress_zstd), 268 BTRFS_FEAT_ATTR_PTR(big_metadata), 269 BTRFS_FEAT_ATTR_PTR(extended_iref), 270 BTRFS_FEAT_ATTR_PTR(raid56), 271 BTRFS_FEAT_ATTR_PTR(skinny_metadata), 272 BTRFS_FEAT_ATTR_PTR(no_holes), 273 BTRFS_FEAT_ATTR_PTR(metadata_uuid), 274 BTRFS_FEAT_ATTR_PTR(free_space_tree), 275 NULL 276 }; 277 278 /* 279 * Features which depend on feature bits and may differ between each fs. 280 * 281 * /sys/fs/btrfs/features lists all available features of this kernel while 282 * /sys/fs/btrfs/UUID/features shows features of the fs which are enabled or 283 * can be changed online. 284 */ 285 static const struct attribute_group btrfs_feature_attr_group = { 286 .name = "features", 287 .is_visible = btrfs_feature_visible, 288 .attrs = btrfs_supported_feature_attrs, 289 }; 290 291 static ssize_t rmdir_subvol_show(struct kobject *kobj, 292 struct kobj_attribute *ka, char *buf) 293 { 294 return snprintf(buf, PAGE_SIZE, "0\n"); 295 } 296 BTRFS_ATTR(static_feature, rmdir_subvol, rmdir_subvol_show); 297 298 static struct attribute *btrfs_supported_static_feature_attrs[] = { 299 BTRFS_ATTR_PTR(static_feature, rmdir_subvol), 300 NULL 301 }; 302 303 /* 304 * Features which only depend on kernel version. 305 * 306 * These are listed in /sys/fs/btrfs/features along with 307 * btrfs_feature_attr_group 308 */ 309 static const struct attribute_group btrfs_static_feature_attr_group = { 310 .name = "features", 311 .attrs = btrfs_supported_static_feature_attrs, 312 }; 313 314 #ifdef CONFIG_BTRFS_DEBUG 315 316 /* 317 * Runtime debugging exported via sysfs 318 * 319 * /sys/fs/btrfs/debug - applies to module or all filesystems 320 * /sys/fs/btrfs/UUID - applies only to the given filesystem 321 */ 322 static struct attribute *btrfs_debug_feature_attrs[] = { 323 NULL 324 }; 325 326 static const struct attribute_group btrfs_debug_feature_attr_group = { 327 .name = "debug", 328 .attrs = btrfs_debug_feature_attrs, 329 }; 330 331 #endif 332 333 static ssize_t btrfs_show_u64(u64 *value_ptr, spinlock_t *lock, char *buf) 334 { 335 u64 val; 336 if (lock) 337 spin_lock(lock); 338 val = *value_ptr; 339 if (lock) 340 spin_unlock(lock); 341 return snprintf(buf, PAGE_SIZE, "%llu\n", val); 342 } 343 344 static ssize_t global_rsv_size_show(struct kobject *kobj, 345 struct kobj_attribute *ka, char *buf) 346 { 347 struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent); 348 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv; 349 return btrfs_show_u64(&block_rsv->size, &block_rsv->lock, buf); 350 } 351 BTRFS_ATTR(allocation, global_rsv_size, global_rsv_size_show); 352 353 static ssize_t global_rsv_reserved_show(struct kobject *kobj, 354 struct kobj_attribute *a, char *buf) 355 { 356 struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent); 357 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv; 358 return btrfs_show_u64(&block_rsv->reserved, &block_rsv->lock, buf); 359 } 360 BTRFS_ATTR(allocation, global_rsv_reserved, global_rsv_reserved_show); 361 362 #define to_space_info(_kobj) container_of(_kobj, struct btrfs_space_info, kobj) 363 #define to_raid_kobj(_kobj) container_of(_kobj, struct raid_kobject, kobj) 364 365 static ssize_t raid_bytes_show(struct kobject *kobj, 366 struct kobj_attribute *attr, char *buf); 367 BTRFS_ATTR(raid, total_bytes, raid_bytes_show); 368 BTRFS_ATTR(raid, used_bytes, raid_bytes_show); 369 370 static ssize_t raid_bytes_show(struct kobject *kobj, 371 struct kobj_attribute *attr, char *buf) 372 373 { 374 struct btrfs_space_info *sinfo = to_space_info(kobj->parent); 375 struct btrfs_block_group_cache *block_group; 376 int index = btrfs_bg_flags_to_raid_index(to_raid_kobj(kobj)->flags); 377 u64 val = 0; 378 379 down_read(&sinfo->groups_sem); 380 list_for_each_entry(block_group, &sinfo->block_groups[index], list) { 381 if (&attr->attr == BTRFS_ATTR_PTR(raid, total_bytes)) 382 val += block_group->key.offset; 383 else 384 val += btrfs_block_group_used(&block_group->item); 385 } 386 up_read(&sinfo->groups_sem); 387 return snprintf(buf, PAGE_SIZE, "%llu\n", val); 388 } 389 390 static struct attribute *raid_attrs[] = { 391 BTRFS_ATTR_PTR(raid, total_bytes), 392 BTRFS_ATTR_PTR(raid, used_bytes), 393 NULL 394 }; 395 ATTRIBUTE_GROUPS(raid); 396 397 static void release_raid_kobj(struct kobject *kobj) 398 { 399 kfree(to_raid_kobj(kobj)); 400 } 401 402 static struct kobj_type btrfs_raid_ktype = { 403 .sysfs_ops = &kobj_sysfs_ops, 404 .release = release_raid_kobj, 405 .default_groups = raid_groups, 406 }; 407 408 #define SPACE_INFO_ATTR(field) \ 409 static ssize_t btrfs_space_info_show_##field(struct kobject *kobj, \ 410 struct kobj_attribute *a, \ 411 char *buf) \ 412 { \ 413 struct btrfs_space_info *sinfo = to_space_info(kobj); \ 414 return btrfs_show_u64(&sinfo->field, &sinfo->lock, buf); \ 415 } \ 416 BTRFS_ATTR(space_info, field, btrfs_space_info_show_##field) 417 418 static ssize_t btrfs_space_info_show_total_bytes_pinned(struct kobject *kobj, 419 struct kobj_attribute *a, 420 char *buf) 421 { 422 struct btrfs_space_info *sinfo = to_space_info(kobj); 423 s64 val = percpu_counter_sum(&sinfo->total_bytes_pinned); 424 return snprintf(buf, PAGE_SIZE, "%lld\n", val); 425 } 426 427 SPACE_INFO_ATTR(flags); 428 SPACE_INFO_ATTR(total_bytes); 429 SPACE_INFO_ATTR(bytes_used); 430 SPACE_INFO_ATTR(bytes_pinned); 431 SPACE_INFO_ATTR(bytes_reserved); 432 SPACE_INFO_ATTR(bytes_may_use); 433 SPACE_INFO_ATTR(bytes_readonly); 434 SPACE_INFO_ATTR(disk_used); 435 SPACE_INFO_ATTR(disk_total); 436 BTRFS_ATTR(space_info, total_bytes_pinned, 437 btrfs_space_info_show_total_bytes_pinned); 438 439 static struct attribute *space_info_attrs[] = { 440 BTRFS_ATTR_PTR(space_info, flags), 441 BTRFS_ATTR_PTR(space_info, total_bytes), 442 BTRFS_ATTR_PTR(space_info, bytes_used), 443 BTRFS_ATTR_PTR(space_info, bytes_pinned), 444 BTRFS_ATTR_PTR(space_info, bytes_reserved), 445 BTRFS_ATTR_PTR(space_info, bytes_may_use), 446 BTRFS_ATTR_PTR(space_info, bytes_readonly), 447 BTRFS_ATTR_PTR(space_info, disk_used), 448 BTRFS_ATTR_PTR(space_info, disk_total), 449 BTRFS_ATTR_PTR(space_info, total_bytes_pinned), 450 NULL, 451 }; 452 ATTRIBUTE_GROUPS(space_info); 453 454 static void space_info_release(struct kobject *kobj) 455 { 456 struct btrfs_space_info *sinfo = to_space_info(kobj); 457 percpu_counter_destroy(&sinfo->total_bytes_pinned); 458 kfree(sinfo); 459 } 460 461 static struct kobj_type space_info_ktype = { 462 .sysfs_ops = &kobj_sysfs_ops, 463 .release = space_info_release, 464 .default_groups = space_info_groups, 465 }; 466 467 static const struct attribute *allocation_attrs[] = { 468 BTRFS_ATTR_PTR(allocation, global_rsv_reserved), 469 BTRFS_ATTR_PTR(allocation, global_rsv_size), 470 NULL, 471 }; 472 473 static ssize_t btrfs_label_show(struct kobject *kobj, 474 struct kobj_attribute *a, char *buf) 475 { 476 struct btrfs_fs_info *fs_info = to_fs_info(kobj); 477 char *label = fs_info->super_copy->label; 478 ssize_t ret; 479 480 spin_lock(&fs_info->super_lock); 481 ret = snprintf(buf, PAGE_SIZE, label[0] ? "%s\n" : "%s", label); 482 spin_unlock(&fs_info->super_lock); 483 484 return ret; 485 } 486 487 static ssize_t btrfs_label_store(struct kobject *kobj, 488 struct kobj_attribute *a, 489 const char *buf, size_t len) 490 { 491 struct btrfs_fs_info *fs_info = to_fs_info(kobj); 492 size_t p_len; 493 494 if (!fs_info) 495 return -EPERM; 496 497 if (sb_rdonly(fs_info->sb)) 498 return -EROFS; 499 500 /* 501 * p_len is the len until the first occurrence of either 502 * '\n' or '\0' 503 */ 504 p_len = strcspn(buf, "\n"); 505 506 if (p_len >= BTRFS_LABEL_SIZE) 507 return -EINVAL; 508 509 spin_lock(&fs_info->super_lock); 510 memset(fs_info->super_copy->label, 0, BTRFS_LABEL_SIZE); 511 memcpy(fs_info->super_copy->label, buf, p_len); 512 spin_unlock(&fs_info->super_lock); 513 514 /* 515 * We don't want to do full transaction commit from inside sysfs 516 */ 517 btrfs_set_pending(fs_info, COMMIT); 518 wake_up_process(fs_info->transaction_kthread); 519 520 return len; 521 } 522 BTRFS_ATTR_RW(, label, btrfs_label_show, btrfs_label_store); 523 524 static ssize_t btrfs_nodesize_show(struct kobject *kobj, 525 struct kobj_attribute *a, char *buf) 526 { 527 struct btrfs_fs_info *fs_info = to_fs_info(kobj); 528 529 return snprintf(buf, PAGE_SIZE, "%u\n", fs_info->super_copy->nodesize); 530 } 531 532 BTRFS_ATTR(, nodesize, btrfs_nodesize_show); 533 534 static ssize_t btrfs_sectorsize_show(struct kobject *kobj, 535 struct kobj_attribute *a, char *buf) 536 { 537 struct btrfs_fs_info *fs_info = to_fs_info(kobj); 538 539 return snprintf(buf, PAGE_SIZE, "%u\n", 540 fs_info->super_copy->sectorsize); 541 } 542 543 BTRFS_ATTR(, sectorsize, btrfs_sectorsize_show); 544 545 static ssize_t btrfs_clone_alignment_show(struct kobject *kobj, 546 struct kobj_attribute *a, char *buf) 547 { 548 struct btrfs_fs_info *fs_info = to_fs_info(kobj); 549 550 return snprintf(buf, PAGE_SIZE, "%u\n", 551 fs_info->super_copy->sectorsize); 552 } 553 554 BTRFS_ATTR(, clone_alignment, btrfs_clone_alignment_show); 555 556 static ssize_t quota_override_show(struct kobject *kobj, 557 struct kobj_attribute *a, char *buf) 558 { 559 struct btrfs_fs_info *fs_info = to_fs_info(kobj); 560 int quota_override; 561 562 quota_override = test_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags); 563 return snprintf(buf, PAGE_SIZE, "%d\n", quota_override); 564 } 565 566 static ssize_t quota_override_store(struct kobject *kobj, 567 struct kobj_attribute *a, 568 const char *buf, size_t len) 569 { 570 struct btrfs_fs_info *fs_info = to_fs_info(kobj); 571 unsigned long knob; 572 int err; 573 574 if (!fs_info) 575 return -EPERM; 576 577 if (!capable(CAP_SYS_RESOURCE)) 578 return -EPERM; 579 580 err = kstrtoul(buf, 10, &knob); 581 if (err) 582 return err; 583 if (knob > 1) 584 return -EINVAL; 585 586 if (knob) 587 set_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags); 588 else 589 clear_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags); 590 591 return len; 592 } 593 594 BTRFS_ATTR_RW(, quota_override, quota_override_show, quota_override_store); 595 596 static ssize_t btrfs_metadata_uuid_show(struct kobject *kobj, 597 struct kobj_attribute *a, char *buf) 598 { 599 struct btrfs_fs_info *fs_info = to_fs_info(kobj); 600 601 return snprintf(buf, PAGE_SIZE, "%pU\n", 602 fs_info->fs_devices->metadata_uuid); 603 } 604 605 BTRFS_ATTR(, metadata_uuid, btrfs_metadata_uuid_show); 606 607 static const struct attribute *btrfs_attrs[] = { 608 BTRFS_ATTR_PTR(, label), 609 BTRFS_ATTR_PTR(, nodesize), 610 BTRFS_ATTR_PTR(, sectorsize), 611 BTRFS_ATTR_PTR(, clone_alignment), 612 BTRFS_ATTR_PTR(, quota_override), 613 BTRFS_ATTR_PTR(, metadata_uuid), 614 NULL, 615 }; 616 617 static void btrfs_release_fsid_kobj(struct kobject *kobj) 618 { 619 struct btrfs_fs_devices *fs_devs = to_fs_devs(kobj); 620 621 memset(&fs_devs->fsid_kobj, 0, sizeof(struct kobject)); 622 complete(&fs_devs->kobj_unregister); 623 } 624 625 static struct kobj_type btrfs_ktype = { 626 .sysfs_ops = &kobj_sysfs_ops, 627 .release = btrfs_release_fsid_kobj, 628 }; 629 630 static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj) 631 { 632 if (kobj->ktype != &btrfs_ktype) 633 return NULL; 634 return container_of(kobj, struct btrfs_fs_devices, fsid_kobj); 635 } 636 637 static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj) 638 { 639 if (kobj->ktype != &btrfs_ktype) 640 return NULL; 641 return to_fs_devs(kobj)->fs_info; 642 } 643 644 #define NUM_FEATURE_BITS 64 645 #define BTRFS_FEATURE_NAME_MAX 13 646 static char btrfs_unknown_feature_names[FEAT_MAX][NUM_FEATURE_BITS][BTRFS_FEATURE_NAME_MAX]; 647 static struct btrfs_feature_attr btrfs_feature_attrs[FEAT_MAX][NUM_FEATURE_BITS]; 648 649 static const u64 supported_feature_masks[FEAT_MAX] = { 650 [FEAT_COMPAT] = BTRFS_FEATURE_COMPAT_SUPP, 651 [FEAT_COMPAT_RO] = BTRFS_FEATURE_COMPAT_RO_SUPP, 652 [FEAT_INCOMPAT] = BTRFS_FEATURE_INCOMPAT_SUPP, 653 }; 654 655 static int addrm_unknown_feature_attrs(struct btrfs_fs_info *fs_info, bool add) 656 { 657 int set; 658 659 for (set = 0; set < FEAT_MAX; set++) { 660 int i; 661 struct attribute *attrs[2]; 662 struct attribute_group agroup = { 663 .name = "features", 664 .attrs = attrs, 665 }; 666 u64 features = get_features(fs_info, set); 667 features &= ~supported_feature_masks[set]; 668 669 if (!features) 670 continue; 671 672 attrs[1] = NULL; 673 for (i = 0; i < NUM_FEATURE_BITS; i++) { 674 struct btrfs_feature_attr *fa; 675 676 if (!(features & (1ULL << i))) 677 continue; 678 679 fa = &btrfs_feature_attrs[set][i]; 680 attrs[0] = &fa->kobj_attr.attr; 681 if (add) { 682 int ret; 683 ret = sysfs_merge_group(&fs_info->fs_devices->fsid_kobj, 684 &agroup); 685 if (ret) 686 return ret; 687 } else 688 sysfs_unmerge_group(&fs_info->fs_devices->fsid_kobj, 689 &agroup); 690 } 691 692 } 693 return 0; 694 } 695 696 static void __btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs) 697 { 698 if (fs_devs->device_dir_kobj) { 699 kobject_del(fs_devs->device_dir_kobj); 700 kobject_put(fs_devs->device_dir_kobj); 701 fs_devs->device_dir_kobj = NULL; 702 } 703 704 if (fs_devs->fsid_kobj.state_initialized) { 705 kobject_del(&fs_devs->fsid_kobj); 706 kobject_put(&fs_devs->fsid_kobj); 707 wait_for_completion(&fs_devs->kobj_unregister); 708 } 709 } 710 711 /* when fs_devs is NULL it will remove all fsid kobject */ 712 void btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs) 713 { 714 struct list_head *fs_uuids = btrfs_get_fs_uuids(); 715 716 if (fs_devs) { 717 __btrfs_sysfs_remove_fsid(fs_devs); 718 return; 719 } 720 721 list_for_each_entry(fs_devs, fs_uuids, fs_list) { 722 __btrfs_sysfs_remove_fsid(fs_devs); 723 } 724 } 725 726 void btrfs_sysfs_remove_mounted(struct btrfs_fs_info *fs_info) 727 { 728 btrfs_reset_fs_info_ptr(fs_info); 729 730 if (fs_info->space_info_kobj) { 731 sysfs_remove_files(fs_info->space_info_kobj, allocation_attrs); 732 kobject_del(fs_info->space_info_kobj); 733 kobject_put(fs_info->space_info_kobj); 734 } 735 addrm_unknown_feature_attrs(fs_info, false); 736 sysfs_remove_group(&fs_info->fs_devices->fsid_kobj, &btrfs_feature_attr_group); 737 sysfs_remove_files(&fs_info->fs_devices->fsid_kobj, btrfs_attrs); 738 btrfs_sysfs_rm_device_link(fs_info->fs_devices, NULL); 739 } 740 741 static const char * const btrfs_feature_set_names[FEAT_MAX] = { 742 [FEAT_COMPAT] = "compat", 743 [FEAT_COMPAT_RO] = "compat_ro", 744 [FEAT_INCOMPAT] = "incompat", 745 }; 746 747 const char * const btrfs_feature_set_name(enum btrfs_feature_set set) 748 { 749 return btrfs_feature_set_names[set]; 750 } 751 752 char *btrfs_printable_features(enum btrfs_feature_set set, u64 flags) 753 { 754 size_t bufsize = 4096; /* safe max, 64 names * 64 bytes */ 755 int len = 0; 756 int i; 757 char *str; 758 759 str = kmalloc(bufsize, GFP_KERNEL); 760 if (!str) 761 return str; 762 763 for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) { 764 const char *name; 765 766 if (!(flags & (1ULL << i))) 767 continue; 768 769 name = btrfs_feature_attrs[set][i].kobj_attr.attr.name; 770 len += snprintf(str + len, bufsize - len, "%s%s", 771 len ? "," : "", name); 772 } 773 774 return str; 775 } 776 777 static void init_feature_attrs(void) 778 { 779 struct btrfs_feature_attr *fa; 780 int set, i; 781 782 BUILD_BUG_ON(ARRAY_SIZE(btrfs_unknown_feature_names) != 783 ARRAY_SIZE(btrfs_feature_attrs)); 784 BUILD_BUG_ON(ARRAY_SIZE(btrfs_unknown_feature_names[0]) != 785 ARRAY_SIZE(btrfs_feature_attrs[0])); 786 787 memset(btrfs_feature_attrs, 0, sizeof(btrfs_feature_attrs)); 788 memset(btrfs_unknown_feature_names, 0, 789 sizeof(btrfs_unknown_feature_names)); 790 791 for (i = 0; btrfs_supported_feature_attrs[i]; i++) { 792 struct btrfs_feature_attr *sfa; 793 struct attribute *a = btrfs_supported_feature_attrs[i]; 794 int bit; 795 sfa = attr_to_btrfs_feature_attr(a); 796 bit = ilog2(sfa->feature_bit); 797 fa = &btrfs_feature_attrs[sfa->feature_set][bit]; 798 799 fa->kobj_attr.attr.name = sfa->kobj_attr.attr.name; 800 } 801 802 for (set = 0; set < FEAT_MAX; set++) { 803 for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) { 804 char *name = btrfs_unknown_feature_names[set][i]; 805 fa = &btrfs_feature_attrs[set][i]; 806 807 if (fa->kobj_attr.attr.name) 808 continue; 809 810 snprintf(name, BTRFS_FEATURE_NAME_MAX, "%s:%u", 811 btrfs_feature_set_names[set], i); 812 813 fa->kobj_attr.attr.name = name; 814 fa->kobj_attr.attr.mode = S_IRUGO; 815 fa->feature_set = set; 816 fa->feature_bit = 1ULL << i; 817 } 818 } 819 } 820 821 /* 822 * Create a sysfs entry for a given block group type at path 823 * /sys/fs/btrfs/UUID/allocation/data/TYPE 824 */ 825 void btrfs_sysfs_add_block_group_type(struct btrfs_block_group_cache *cache) 826 { 827 struct btrfs_fs_info *fs_info = cache->fs_info; 828 struct btrfs_space_info *space_info = cache->space_info; 829 struct raid_kobject *rkobj; 830 const int index = btrfs_bg_flags_to_raid_index(cache->flags); 831 unsigned int nofs_flag; 832 int ret; 833 834 /* 835 * Setup a NOFS context because kobject_add(), deep in its call chain, 836 * does GFP_KERNEL allocations, and we are often called in a context 837 * where if reclaim is triggered we can deadlock (we are either holding 838 * a transaction handle or some lock required for a transaction 839 * commit). 840 */ 841 nofs_flag = memalloc_nofs_save(); 842 843 rkobj = kzalloc(sizeof(*rkobj), GFP_NOFS); 844 if (!rkobj) { 845 memalloc_nofs_restore(nofs_flag); 846 btrfs_warn(cache->fs_info, 847 "couldn't alloc memory for raid level kobject"); 848 return; 849 } 850 851 rkobj->flags = cache->flags; 852 kobject_init(&rkobj->kobj, &btrfs_raid_ktype); 853 ret = kobject_add(&rkobj->kobj, &space_info->kobj, "%s", 854 btrfs_bg_type_to_raid_name(rkobj->flags)); 855 memalloc_nofs_restore(nofs_flag); 856 if (ret) { 857 kobject_put(&rkobj->kobj); 858 btrfs_warn(fs_info, 859 "failed to add kobject for block cache, ignoring"); 860 return; 861 } 862 863 space_info->block_group_kobjs[index] = &rkobj->kobj; 864 } 865 866 /* 867 * Remove sysfs directories for all block group types of a given space info and 868 * the space info as well 869 */ 870 void btrfs_sysfs_remove_space_info(struct btrfs_space_info *space_info) 871 { 872 int i; 873 874 for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) { 875 struct kobject *kobj; 876 877 kobj = space_info->block_group_kobjs[i]; 878 space_info->block_group_kobjs[i] = NULL; 879 if (kobj) { 880 kobject_del(kobj); 881 kobject_put(kobj); 882 } 883 } 884 kobject_del(&space_info->kobj); 885 kobject_put(&space_info->kobj); 886 } 887 888 static const char *alloc_name(u64 flags) 889 { 890 switch (flags) { 891 case BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA: 892 return "mixed"; 893 case BTRFS_BLOCK_GROUP_METADATA: 894 return "metadata"; 895 case BTRFS_BLOCK_GROUP_DATA: 896 return "data"; 897 case BTRFS_BLOCK_GROUP_SYSTEM: 898 return "system"; 899 default: 900 WARN_ON(1); 901 return "invalid-combination"; 902 }; 903 } 904 905 /* 906 * Create a sysfs entry for a space info type at path 907 * /sys/fs/btrfs/UUID/allocation/TYPE 908 */ 909 int btrfs_sysfs_add_space_info_type(struct btrfs_fs_info *fs_info, 910 struct btrfs_space_info *space_info) 911 { 912 int ret; 913 914 ret = kobject_init_and_add(&space_info->kobj, &space_info_ktype, 915 fs_info->space_info_kobj, "%s", 916 alloc_name(space_info->flags)); 917 if (ret) { 918 kobject_put(&space_info->kobj); 919 return ret; 920 } 921 922 return 0; 923 } 924 925 /* when one_device is NULL, it removes all device links */ 926 927 int btrfs_sysfs_rm_device_link(struct btrfs_fs_devices *fs_devices, 928 struct btrfs_device *one_device) 929 { 930 struct hd_struct *disk; 931 struct kobject *disk_kobj; 932 933 if (!fs_devices->device_dir_kobj) 934 return -EINVAL; 935 936 if (one_device && one_device->bdev) { 937 disk = one_device->bdev->bd_part; 938 disk_kobj = &part_to_dev(disk)->kobj; 939 940 sysfs_remove_link(fs_devices->device_dir_kobj, 941 disk_kobj->name); 942 } 943 944 if (one_device) 945 return 0; 946 947 list_for_each_entry(one_device, 948 &fs_devices->devices, dev_list) { 949 if (!one_device->bdev) 950 continue; 951 disk = one_device->bdev->bd_part; 952 disk_kobj = &part_to_dev(disk)->kobj; 953 954 sysfs_remove_link(fs_devices->device_dir_kobj, 955 disk_kobj->name); 956 } 957 958 return 0; 959 } 960 961 int btrfs_sysfs_add_device(struct btrfs_fs_devices *fs_devs) 962 { 963 if (!fs_devs->device_dir_kobj) 964 fs_devs->device_dir_kobj = kobject_create_and_add("devices", 965 &fs_devs->fsid_kobj); 966 967 if (!fs_devs->device_dir_kobj) 968 return -ENOMEM; 969 970 return 0; 971 } 972 973 int btrfs_sysfs_add_device_link(struct btrfs_fs_devices *fs_devices, 974 struct btrfs_device *one_device) 975 { 976 int error = 0; 977 struct btrfs_device *dev; 978 979 list_for_each_entry(dev, &fs_devices->devices, dev_list) { 980 struct hd_struct *disk; 981 struct kobject *disk_kobj; 982 983 if (!dev->bdev) 984 continue; 985 986 if (one_device && one_device != dev) 987 continue; 988 989 disk = dev->bdev->bd_part; 990 disk_kobj = &part_to_dev(disk)->kobj; 991 992 error = sysfs_create_link(fs_devices->device_dir_kobj, 993 disk_kobj, disk_kobj->name); 994 if (error) 995 break; 996 } 997 998 return error; 999 } 1000 1001 void btrfs_kobject_uevent(struct block_device *bdev, enum kobject_action action) 1002 { 1003 int ret; 1004 1005 ret = kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, action); 1006 if (ret) 1007 pr_warn("BTRFS: Sending event '%d' to kobject: '%s' (%p): failed\n", 1008 action, kobject_name(&disk_to_dev(bdev->bd_disk)->kobj), 1009 &disk_to_dev(bdev->bd_disk)->kobj); 1010 } 1011 1012 void btrfs_sysfs_update_sprout_fsid(struct btrfs_fs_devices *fs_devices, 1013 const u8 *fsid) 1014 { 1015 char fsid_buf[BTRFS_UUID_UNPARSED_SIZE]; 1016 1017 /* 1018 * Sprouting changes fsid of the mounted filesystem, rename the fsid 1019 * directory 1020 */ 1021 snprintf(fsid_buf, BTRFS_UUID_UNPARSED_SIZE, "%pU", fsid); 1022 if (kobject_rename(&fs_devices->fsid_kobj, fsid_buf)) 1023 btrfs_warn(fs_devices->fs_info, 1024 "sysfs: failed to create fsid for sprout"); 1025 } 1026 1027 /* /sys/fs/btrfs/ entry */ 1028 static struct kset *btrfs_kset; 1029 1030 /* 1031 * Can be called by the device discovery thread. 1032 * And parent can be specified for seed device 1033 */ 1034 int btrfs_sysfs_add_fsid(struct btrfs_fs_devices *fs_devs, 1035 struct kobject *parent) 1036 { 1037 int error; 1038 1039 init_completion(&fs_devs->kobj_unregister); 1040 fs_devs->fsid_kobj.kset = btrfs_kset; 1041 error = kobject_init_and_add(&fs_devs->fsid_kobj, 1042 &btrfs_ktype, parent, "%pU", fs_devs->fsid); 1043 if (error) { 1044 kobject_put(&fs_devs->fsid_kobj); 1045 return error; 1046 } 1047 1048 return 0; 1049 } 1050 1051 int btrfs_sysfs_add_mounted(struct btrfs_fs_info *fs_info) 1052 { 1053 int error; 1054 struct btrfs_fs_devices *fs_devs = fs_info->fs_devices; 1055 struct kobject *fsid_kobj = &fs_devs->fsid_kobj; 1056 1057 btrfs_set_fs_info_ptr(fs_info); 1058 1059 error = btrfs_sysfs_add_device_link(fs_devs, NULL); 1060 if (error) 1061 return error; 1062 1063 error = sysfs_create_files(fsid_kobj, btrfs_attrs); 1064 if (error) { 1065 btrfs_sysfs_rm_device_link(fs_devs, NULL); 1066 return error; 1067 } 1068 1069 error = sysfs_create_group(fsid_kobj, 1070 &btrfs_feature_attr_group); 1071 if (error) 1072 goto failure; 1073 1074 #ifdef CONFIG_BTRFS_DEBUG 1075 error = sysfs_create_group(fsid_kobj, 1076 &btrfs_debug_feature_attr_group); 1077 if (error) 1078 goto failure; 1079 #endif 1080 1081 error = addrm_unknown_feature_attrs(fs_info, true); 1082 if (error) 1083 goto failure; 1084 1085 fs_info->space_info_kobj = kobject_create_and_add("allocation", 1086 fsid_kobj); 1087 if (!fs_info->space_info_kobj) { 1088 error = -ENOMEM; 1089 goto failure; 1090 } 1091 1092 error = sysfs_create_files(fs_info->space_info_kobj, allocation_attrs); 1093 if (error) 1094 goto failure; 1095 1096 return 0; 1097 failure: 1098 btrfs_sysfs_remove_mounted(fs_info); 1099 return error; 1100 } 1101 1102 1103 /* 1104 * Change per-fs features in /sys/fs/btrfs/UUID/features to match current 1105 * values in superblock. Call after any changes to incompat/compat_ro flags 1106 */ 1107 void btrfs_sysfs_feature_update(struct btrfs_fs_info *fs_info, 1108 u64 bit, enum btrfs_feature_set set) 1109 { 1110 struct btrfs_fs_devices *fs_devs; 1111 struct kobject *fsid_kobj; 1112 u64 features; 1113 int ret; 1114 1115 if (!fs_info) 1116 return; 1117 1118 features = get_features(fs_info, set); 1119 ASSERT(bit & supported_feature_masks[set]); 1120 1121 fs_devs = fs_info->fs_devices; 1122 fsid_kobj = &fs_devs->fsid_kobj; 1123 1124 if (!fsid_kobj->state_initialized) 1125 return; 1126 1127 /* 1128 * FIXME: this is too heavy to update just one value, ideally we'd like 1129 * to use sysfs_update_group but some refactoring is needed first. 1130 */ 1131 sysfs_remove_group(fsid_kobj, &btrfs_feature_attr_group); 1132 ret = sysfs_create_group(fsid_kobj, &btrfs_feature_attr_group); 1133 } 1134 1135 int __init btrfs_init_sysfs(void) 1136 { 1137 int ret; 1138 1139 btrfs_kset = kset_create_and_add("btrfs", NULL, fs_kobj); 1140 if (!btrfs_kset) 1141 return -ENOMEM; 1142 1143 init_feature_attrs(); 1144 ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_feature_attr_group); 1145 if (ret) 1146 goto out2; 1147 ret = sysfs_merge_group(&btrfs_kset->kobj, 1148 &btrfs_static_feature_attr_group); 1149 if (ret) 1150 goto out_remove_group; 1151 1152 #ifdef CONFIG_BTRFS_DEBUG 1153 ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_debug_feature_attr_group); 1154 if (ret) 1155 goto out2; 1156 #endif 1157 1158 return 0; 1159 1160 out_remove_group: 1161 sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group); 1162 out2: 1163 kset_unregister(btrfs_kset); 1164 1165 return ret; 1166 } 1167 1168 void __cold btrfs_exit_sysfs(void) 1169 { 1170 sysfs_unmerge_group(&btrfs_kset->kobj, 1171 &btrfs_static_feature_attr_group); 1172 sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group); 1173 kset_unregister(btrfs_kset); 1174 } 1175 1176