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/slab.h> 8 #include <linux/spinlock.h> 9 #include <linux/completion.h> 10 #include <linux/kobject.h> 11 #include <linux/bug.h> 12 #include <linux/debugfs.h> 13 14 #include "ctree.h" 15 #include "disk-io.h" 16 #include "transaction.h" 17 #include "sysfs.h" 18 #include "volumes.h" 19 20 static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj); 21 static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj); 22 23 static u64 get_features(struct btrfs_fs_info *fs_info, 24 enum btrfs_feature_set set) 25 { 26 struct btrfs_super_block *disk_super = fs_info->super_copy; 27 if (set == FEAT_COMPAT) 28 return btrfs_super_compat_flags(disk_super); 29 else if (set == FEAT_COMPAT_RO) 30 return btrfs_super_compat_ro_flags(disk_super); 31 else 32 return btrfs_super_incompat_flags(disk_super); 33 } 34 35 static void set_features(struct btrfs_fs_info *fs_info, 36 enum btrfs_feature_set set, u64 features) 37 { 38 struct btrfs_super_block *disk_super = fs_info->super_copy; 39 if (set == FEAT_COMPAT) 40 btrfs_set_super_compat_flags(disk_super, features); 41 else if (set == FEAT_COMPAT_RO) 42 btrfs_set_super_compat_ro_flags(disk_super, features); 43 else 44 btrfs_set_super_incompat_flags(disk_super, features); 45 } 46 47 static int can_modify_feature(struct btrfs_feature_attr *fa) 48 { 49 int val = 0; 50 u64 set, clear; 51 switch (fa->feature_set) { 52 case FEAT_COMPAT: 53 set = BTRFS_FEATURE_COMPAT_SAFE_SET; 54 clear = BTRFS_FEATURE_COMPAT_SAFE_CLEAR; 55 break; 56 case FEAT_COMPAT_RO: 57 set = BTRFS_FEATURE_COMPAT_RO_SAFE_SET; 58 clear = BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR; 59 break; 60 case FEAT_INCOMPAT: 61 set = BTRFS_FEATURE_INCOMPAT_SAFE_SET; 62 clear = BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR; 63 break; 64 default: 65 pr_warn("btrfs: sysfs: unknown feature set %d\n", 66 fa->feature_set); 67 return 0; 68 } 69 70 if (set & fa->feature_bit) 71 val |= 1; 72 if (clear & fa->feature_bit) 73 val |= 2; 74 75 return val; 76 } 77 78 static ssize_t btrfs_feature_attr_show(struct kobject *kobj, 79 struct kobj_attribute *a, char *buf) 80 { 81 int val = 0; 82 struct btrfs_fs_info *fs_info = to_fs_info(kobj); 83 struct btrfs_feature_attr *fa = to_btrfs_feature_attr(a); 84 if (fs_info) { 85 u64 features = get_features(fs_info, fa->feature_set); 86 if (features & fa->feature_bit) 87 val = 1; 88 } else 89 val = can_modify_feature(fa); 90 91 return snprintf(buf, PAGE_SIZE, "%d\n", val); 92 } 93 94 static ssize_t btrfs_feature_attr_store(struct kobject *kobj, 95 struct kobj_attribute *a, 96 const char *buf, size_t count) 97 { 98 struct btrfs_fs_info *fs_info; 99 struct btrfs_feature_attr *fa = to_btrfs_feature_attr(a); 100 u64 features, set, clear; 101 unsigned long val; 102 int ret; 103 104 fs_info = to_fs_info(kobj); 105 if (!fs_info) 106 return -EPERM; 107 108 if (sb_rdonly(fs_info->sb)) 109 return -EROFS; 110 111 ret = kstrtoul(skip_spaces(buf), 0, &val); 112 if (ret) 113 return ret; 114 115 if (fa->feature_set == FEAT_COMPAT) { 116 set = BTRFS_FEATURE_COMPAT_SAFE_SET; 117 clear = BTRFS_FEATURE_COMPAT_SAFE_CLEAR; 118 } else if (fa->feature_set == FEAT_COMPAT_RO) { 119 set = BTRFS_FEATURE_COMPAT_RO_SAFE_SET; 120 clear = BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR; 121 } else { 122 set = BTRFS_FEATURE_INCOMPAT_SAFE_SET; 123 clear = BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR; 124 } 125 126 features = get_features(fs_info, fa->feature_set); 127 128 /* Nothing to do */ 129 if ((val && (features & fa->feature_bit)) || 130 (!val && !(features & fa->feature_bit))) 131 return count; 132 133 if ((val && !(set & fa->feature_bit)) || 134 (!val && !(clear & fa->feature_bit))) { 135 btrfs_info(fs_info, 136 "%sabling feature %s on mounted fs is not supported.", 137 val ? "En" : "Dis", fa->kobj_attr.attr.name); 138 return -EPERM; 139 } 140 141 btrfs_info(fs_info, "%s %s feature flag", 142 val ? "Setting" : "Clearing", fa->kobj_attr.attr.name); 143 144 spin_lock(&fs_info->super_lock); 145 features = get_features(fs_info, fa->feature_set); 146 if (val) 147 features |= fa->feature_bit; 148 else 149 features &= ~fa->feature_bit; 150 set_features(fs_info, fa->feature_set, features); 151 spin_unlock(&fs_info->super_lock); 152 153 /* 154 * We don't want to do full transaction commit from inside sysfs 155 */ 156 btrfs_set_pending(fs_info, COMMIT); 157 wake_up_process(fs_info->transaction_kthread); 158 159 return count; 160 } 161 162 static umode_t btrfs_feature_visible(struct kobject *kobj, 163 struct attribute *attr, int unused) 164 { 165 struct btrfs_fs_info *fs_info = to_fs_info(kobj); 166 umode_t mode = attr->mode; 167 168 if (fs_info) { 169 struct btrfs_feature_attr *fa; 170 u64 features; 171 172 fa = attr_to_btrfs_feature_attr(attr); 173 features = get_features(fs_info, fa->feature_set); 174 175 if (can_modify_feature(fa)) 176 mode |= S_IWUSR; 177 else if (!(features & fa->feature_bit)) 178 mode = 0; 179 } 180 181 return mode; 182 } 183 184 BTRFS_FEAT_ATTR_INCOMPAT(mixed_backref, MIXED_BACKREF); 185 BTRFS_FEAT_ATTR_INCOMPAT(default_subvol, DEFAULT_SUBVOL); 186 BTRFS_FEAT_ATTR_INCOMPAT(mixed_groups, MIXED_GROUPS); 187 BTRFS_FEAT_ATTR_INCOMPAT(compress_lzo, COMPRESS_LZO); 188 BTRFS_FEAT_ATTR_INCOMPAT(compress_zstd, COMPRESS_ZSTD); 189 BTRFS_FEAT_ATTR_INCOMPAT(big_metadata, BIG_METADATA); 190 BTRFS_FEAT_ATTR_INCOMPAT(extended_iref, EXTENDED_IREF); 191 BTRFS_FEAT_ATTR_INCOMPAT(raid56, RAID56); 192 BTRFS_FEAT_ATTR_INCOMPAT(skinny_metadata, SKINNY_METADATA); 193 BTRFS_FEAT_ATTR_INCOMPAT(no_holes, NO_HOLES); 194 BTRFS_FEAT_ATTR_INCOMPAT(metadata_uuid, METADATA_UUID); 195 BTRFS_FEAT_ATTR_COMPAT_RO(free_space_tree, FREE_SPACE_TREE); 196 197 static struct attribute *btrfs_supported_feature_attrs[] = { 198 BTRFS_FEAT_ATTR_PTR(mixed_backref), 199 BTRFS_FEAT_ATTR_PTR(default_subvol), 200 BTRFS_FEAT_ATTR_PTR(mixed_groups), 201 BTRFS_FEAT_ATTR_PTR(compress_lzo), 202 BTRFS_FEAT_ATTR_PTR(compress_zstd), 203 BTRFS_FEAT_ATTR_PTR(big_metadata), 204 BTRFS_FEAT_ATTR_PTR(extended_iref), 205 BTRFS_FEAT_ATTR_PTR(raid56), 206 BTRFS_FEAT_ATTR_PTR(skinny_metadata), 207 BTRFS_FEAT_ATTR_PTR(no_holes), 208 BTRFS_FEAT_ATTR_PTR(metadata_uuid), 209 BTRFS_FEAT_ATTR_PTR(free_space_tree), 210 NULL 211 }; 212 213 /* 214 * Features which depend on feature bits and may differ between each fs. 215 * 216 * /sys/fs/btrfs/features lists all available features of this kernel while 217 * /sys/fs/btrfs/UUID/features shows features of the fs which are enabled or 218 * can be changed online. 219 */ 220 static const struct attribute_group btrfs_feature_attr_group = { 221 .name = "features", 222 .is_visible = btrfs_feature_visible, 223 .attrs = btrfs_supported_feature_attrs, 224 }; 225 226 static ssize_t rmdir_subvol_show(struct kobject *kobj, 227 struct kobj_attribute *ka, char *buf) 228 { 229 return snprintf(buf, PAGE_SIZE, "0\n"); 230 } 231 BTRFS_ATTR(static_feature, rmdir_subvol, rmdir_subvol_show); 232 233 static struct attribute *btrfs_supported_static_feature_attrs[] = { 234 BTRFS_ATTR_PTR(static_feature, rmdir_subvol), 235 NULL 236 }; 237 238 /* 239 * Features which only depend on kernel version. 240 * 241 * These are listed in /sys/fs/btrfs/features along with 242 * btrfs_feature_attr_group 243 */ 244 static const struct attribute_group btrfs_static_feature_attr_group = { 245 .name = "features", 246 .attrs = btrfs_supported_static_feature_attrs, 247 }; 248 249 static ssize_t btrfs_show_u64(u64 *value_ptr, spinlock_t *lock, char *buf) 250 { 251 u64 val; 252 if (lock) 253 spin_lock(lock); 254 val = *value_ptr; 255 if (lock) 256 spin_unlock(lock); 257 return snprintf(buf, PAGE_SIZE, "%llu\n", val); 258 } 259 260 static ssize_t global_rsv_size_show(struct kobject *kobj, 261 struct kobj_attribute *ka, char *buf) 262 { 263 struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent); 264 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv; 265 return btrfs_show_u64(&block_rsv->size, &block_rsv->lock, buf); 266 } 267 BTRFS_ATTR(allocation, global_rsv_size, global_rsv_size_show); 268 269 static ssize_t global_rsv_reserved_show(struct kobject *kobj, 270 struct kobj_attribute *a, char *buf) 271 { 272 struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent); 273 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv; 274 return btrfs_show_u64(&block_rsv->reserved, &block_rsv->lock, buf); 275 } 276 BTRFS_ATTR(allocation, global_rsv_reserved, global_rsv_reserved_show); 277 278 #define to_space_info(_kobj) container_of(_kobj, struct btrfs_space_info, kobj) 279 #define to_raid_kobj(_kobj) container_of(_kobj, struct raid_kobject, kobj) 280 281 static ssize_t raid_bytes_show(struct kobject *kobj, 282 struct kobj_attribute *attr, char *buf); 283 BTRFS_ATTR(raid, total_bytes, raid_bytes_show); 284 BTRFS_ATTR(raid, used_bytes, raid_bytes_show); 285 286 static ssize_t raid_bytes_show(struct kobject *kobj, 287 struct kobj_attribute *attr, char *buf) 288 289 { 290 struct btrfs_space_info *sinfo = to_space_info(kobj->parent); 291 struct btrfs_block_group_cache *block_group; 292 int index = btrfs_bg_flags_to_raid_index(to_raid_kobj(kobj)->flags); 293 u64 val = 0; 294 295 down_read(&sinfo->groups_sem); 296 list_for_each_entry(block_group, &sinfo->block_groups[index], list) { 297 if (&attr->attr == BTRFS_ATTR_PTR(raid, total_bytes)) 298 val += block_group->key.offset; 299 else 300 val += btrfs_block_group_used(&block_group->item); 301 } 302 up_read(&sinfo->groups_sem); 303 return snprintf(buf, PAGE_SIZE, "%llu\n", val); 304 } 305 306 static struct attribute *raid_attributes[] = { 307 BTRFS_ATTR_PTR(raid, total_bytes), 308 BTRFS_ATTR_PTR(raid, used_bytes), 309 NULL 310 }; 311 312 static void release_raid_kobj(struct kobject *kobj) 313 { 314 kfree(to_raid_kobj(kobj)); 315 } 316 317 struct kobj_type btrfs_raid_ktype = { 318 .sysfs_ops = &kobj_sysfs_ops, 319 .release = release_raid_kobj, 320 .default_attrs = raid_attributes, 321 }; 322 323 #define SPACE_INFO_ATTR(field) \ 324 static ssize_t btrfs_space_info_show_##field(struct kobject *kobj, \ 325 struct kobj_attribute *a, \ 326 char *buf) \ 327 { \ 328 struct btrfs_space_info *sinfo = to_space_info(kobj); \ 329 return btrfs_show_u64(&sinfo->field, &sinfo->lock, buf); \ 330 } \ 331 BTRFS_ATTR(space_info, field, btrfs_space_info_show_##field) 332 333 static ssize_t btrfs_space_info_show_total_bytes_pinned(struct kobject *kobj, 334 struct kobj_attribute *a, 335 char *buf) 336 { 337 struct btrfs_space_info *sinfo = to_space_info(kobj); 338 s64 val = percpu_counter_sum(&sinfo->total_bytes_pinned); 339 return snprintf(buf, PAGE_SIZE, "%lld\n", val); 340 } 341 342 SPACE_INFO_ATTR(flags); 343 SPACE_INFO_ATTR(total_bytes); 344 SPACE_INFO_ATTR(bytes_used); 345 SPACE_INFO_ATTR(bytes_pinned); 346 SPACE_INFO_ATTR(bytes_reserved); 347 SPACE_INFO_ATTR(bytes_may_use); 348 SPACE_INFO_ATTR(bytes_readonly); 349 SPACE_INFO_ATTR(disk_used); 350 SPACE_INFO_ATTR(disk_total); 351 BTRFS_ATTR(space_info, total_bytes_pinned, 352 btrfs_space_info_show_total_bytes_pinned); 353 354 static struct attribute *space_info_attrs[] = { 355 BTRFS_ATTR_PTR(space_info, flags), 356 BTRFS_ATTR_PTR(space_info, total_bytes), 357 BTRFS_ATTR_PTR(space_info, bytes_used), 358 BTRFS_ATTR_PTR(space_info, bytes_pinned), 359 BTRFS_ATTR_PTR(space_info, bytes_reserved), 360 BTRFS_ATTR_PTR(space_info, bytes_may_use), 361 BTRFS_ATTR_PTR(space_info, bytes_readonly), 362 BTRFS_ATTR_PTR(space_info, disk_used), 363 BTRFS_ATTR_PTR(space_info, disk_total), 364 BTRFS_ATTR_PTR(space_info, total_bytes_pinned), 365 NULL, 366 }; 367 368 static void space_info_release(struct kobject *kobj) 369 { 370 struct btrfs_space_info *sinfo = to_space_info(kobj); 371 percpu_counter_destroy(&sinfo->total_bytes_pinned); 372 kfree(sinfo); 373 } 374 375 struct kobj_type space_info_ktype = { 376 .sysfs_ops = &kobj_sysfs_ops, 377 .release = space_info_release, 378 .default_attrs = space_info_attrs, 379 }; 380 381 static const struct attribute *allocation_attrs[] = { 382 BTRFS_ATTR_PTR(allocation, global_rsv_reserved), 383 BTRFS_ATTR_PTR(allocation, global_rsv_size), 384 NULL, 385 }; 386 387 static ssize_t btrfs_label_show(struct kobject *kobj, 388 struct kobj_attribute *a, char *buf) 389 { 390 struct btrfs_fs_info *fs_info = to_fs_info(kobj); 391 char *label = fs_info->super_copy->label; 392 ssize_t ret; 393 394 spin_lock(&fs_info->super_lock); 395 ret = snprintf(buf, PAGE_SIZE, label[0] ? "%s\n" : "%s", label); 396 spin_unlock(&fs_info->super_lock); 397 398 return ret; 399 } 400 401 static ssize_t btrfs_label_store(struct kobject *kobj, 402 struct kobj_attribute *a, 403 const char *buf, size_t len) 404 { 405 struct btrfs_fs_info *fs_info = to_fs_info(kobj); 406 size_t p_len; 407 408 if (!fs_info) 409 return -EPERM; 410 411 if (sb_rdonly(fs_info->sb)) 412 return -EROFS; 413 414 /* 415 * p_len is the len until the first occurrence of either 416 * '\n' or '\0' 417 */ 418 p_len = strcspn(buf, "\n"); 419 420 if (p_len >= BTRFS_LABEL_SIZE) 421 return -EINVAL; 422 423 spin_lock(&fs_info->super_lock); 424 memset(fs_info->super_copy->label, 0, BTRFS_LABEL_SIZE); 425 memcpy(fs_info->super_copy->label, buf, p_len); 426 spin_unlock(&fs_info->super_lock); 427 428 /* 429 * We don't want to do full transaction commit from inside sysfs 430 */ 431 btrfs_set_pending(fs_info, COMMIT); 432 wake_up_process(fs_info->transaction_kthread); 433 434 return len; 435 } 436 BTRFS_ATTR_RW(, label, btrfs_label_show, btrfs_label_store); 437 438 static ssize_t btrfs_nodesize_show(struct kobject *kobj, 439 struct kobj_attribute *a, char *buf) 440 { 441 struct btrfs_fs_info *fs_info = to_fs_info(kobj); 442 443 return snprintf(buf, PAGE_SIZE, "%u\n", fs_info->super_copy->nodesize); 444 } 445 446 BTRFS_ATTR(, nodesize, btrfs_nodesize_show); 447 448 static ssize_t btrfs_sectorsize_show(struct kobject *kobj, 449 struct kobj_attribute *a, char *buf) 450 { 451 struct btrfs_fs_info *fs_info = to_fs_info(kobj); 452 453 return snprintf(buf, PAGE_SIZE, "%u\n", 454 fs_info->super_copy->sectorsize); 455 } 456 457 BTRFS_ATTR(, sectorsize, btrfs_sectorsize_show); 458 459 static ssize_t btrfs_clone_alignment_show(struct kobject *kobj, 460 struct kobj_attribute *a, char *buf) 461 { 462 struct btrfs_fs_info *fs_info = to_fs_info(kobj); 463 464 return snprintf(buf, PAGE_SIZE, "%u\n", 465 fs_info->super_copy->sectorsize); 466 } 467 468 BTRFS_ATTR(, clone_alignment, btrfs_clone_alignment_show); 469 470 static ssize_t quota_override_show(struct kobject *kobj, 471 struct kobj_attribute *a, char *buf) 472 { 473 struct btrfs_fs_info *fs_info = to_fs_info(kobj); 474 int quota_override; 475 476 quota_override = test_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags); 477 return snprintf(buf, PAGE_SIZE, "%d\n", quota_override); 478 } 479 480 static ssize_t quota_override_store(struct kobject *kobj, 481 struct kobj_attribute *a, 482 const char *buf, size_t len) 483 { 484 struct btrfs_fs_info *fs_info = to_fs_info(kobj); 485 unsigned long knob; 486 int err; 487 488 if (!fs_info) 489 return -EPERM; 490 491 if (!capable(CAP_SYS_RESOURCE)) 492 return -EPERM; 493 494 err = kstrtoul(buf, 10, &knob); 495 if (err) 496 return err; 497 if (knob > 1) 498 return -EINVAL; 499 500 if (knob) 501 set_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags); 502 else 503 clear_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags); 504 505 return len; 506 } 507 508 BTRFS_ATTR_RW(, quota_override, quota_override_show, quota_override_store); 509 510 static ssize_t btrfs_metadata_uuid_show(struct kobject *kobj, 511 struct kobj_attribute *a, char *buf) 512 { 513 struct btrfs_fs_info *fs_info = to_fs_info(kobj); 514 515 return snprintf(buf, PAGE_SIZE, "%pU\n", 516 fs_info->fs_devices->metadata_uuid); 517 } 518 519 BTRFS_ATTR(, metadata_uuid, btrfs_metadata_uuid_show); 520 521 static const struct attribute *btrfs_attrs[] = { 522 BTRFS_ATTR_PTR(, label), 523 BTRFS_ATTR_PTR(, nodesize), 524 BTRFS_ATTR_PTR(, sectorsize), 525 BTRFS_ATTR_PTR(, clone_alignment), 526 BTRFS_ATTR_PTR(, quota_override), 527 BTRFS_ATTR_PTR(, metadata_uuid), 528 NULL, 529 }; 530 531 static void btrfs_release_fsid_kobj(struct kobject *kobj) 532 { 533 struct btrfs_fs_devices *fs_devs = to_fs_devs(kobj); 534 535 memset(&fs_devs->fsid_kobj, 0, sizeof(struct kobject)); 536 complete(&fs_devs->kobj_unregister); 537 } 538 539 static struct kobj_type btrfs_ktype = { 540 .sysfs_ops = &kobj_sysfs_ops, 541 .release = btrfs_release_fsid_kobj, 542 }; 543 544 static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj) 545 { 546 if (kobj->ktype != &btrfs_ktype) 547 return NULL; 548 return container_of(kobj, struct btrfs_fs_devices, fsid_kobj); 549 } 550 551 static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj) 552 { 553 if (kobj->ktype != &btrfs_ktype) 554 return NULL; 555 return to_fs_devs(kobj)->fs_info; 556 } 557 558 #define NUM_FEATURE_BITS 64 559 #define BTRFS_FEATURE_NAME_MAX 13 560 static char btrfs_unknown_feature_names[FEAT_MAX][NUM_FEATURE_BITS][BTRFS_FEATURE_NAME_MAX]; 561 static struct btrfs_feature_attr btrfs_feature_attrs[FEAT_MAX][NUM_FEATURE_BITS]; 562 563 static const u64 supported_feature_masks[FEAT_MAX] = { 564 [FEAT_COMPAT] = BTRFS_FEATURE_COMPAT_SUPP, 565 [FEAT_COMPAT_RO] = BTRFS_FEATURE_COMPAT_RO_SUPP, 566 [FEAT_INCOMPAT] = BTRFS_FEATURE_INCOMPAT_SUPP, 567 }; 568 569 static int addrm_unknown_feature_attrs(struct btrfs_fs_info *fs_info, bool add) 570 { 571 int set; 572 573 for (set = 0; set < FEAT_MAX; set++) { 574 int i; 575 struct attribute *attrs[2]; 576 struct attribute_group agroup = { 577 .name = "features", 578 .attrs = attrs, 579 }; 580 u64 features = get_features(fs_info, set); 581 features &= ~supported_feature_masks[set]; 582 583 if (!features) 584 continue; 585 586 attrs[1] = NULL; 587 for (i = 0; i < NUM_FEATURE_BITS; i++) { 588 struct btrfs_feature_attr *fa; 589 590 if (!(features & (1ULL << i))) 591 continue; 592 593 fa = &btrfs_feature_attrs[set][i]; 594 attrs[0] = &fa->kobj_attr.attr; 595 if (add) { 596 int ret; 597 ret = sysfs_merge_group(&fs_info->fs_devices->fsid_kobj, 598 &agroup); 599 if (ret) 600 return ret; 601 } else 602 sysfs_unmerge_group(&fs_info->fs_devices->fsid_kobj, 603 &agroup); 604 } 605 606 } 607 return 0; 608 } 609 610 static void __btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs) 611 { 612 if (fs_devs->device_dir_kobj) { 613 kobject_del(fs_devs->device_dir_kobj); 614 kobject_put(fs_devs->device_dir_kobj); 615 fs_devs->device_dir_kobj = NULL; 616 } 617 618 if (fs_devs->fsid_kobj.state_initialized) { 619 kobject_del(&fs_devs->fsid_kobj); 620 kobject_put(&fs_devs->fsid_kobj); 621 wait_for_completion(&fs_devs->kobj_unregister); 622 } 623 } 624 625 /* when fs_devs is NULL it will remove all fsid kobject */ 626 void btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs) 627 { 628 struct list_head *fs_uuids = btrfs_get_fs_uuids(); 629 630 if (fs_devs) { 631 __btrfs_sysfs_remove_fsid(fs_devs); 632 return; 633 } 634 635 list_for_each_entry(fs_devs, fs_uuids, fs_list) { 636 __btrfs_sysfs_remove_fsid(fs_devs); 637 } 638 } 639 640 void btrfs_sysfs_remove_mounted(struct btrfs_fs_info *fs_info) 641 { 642 btrfs_reset_fs_info_ptr(fs_info); 643 644 if (fs_info->space_info_kobj) { 645 sysfs_remove_files(fs_info->space_info_kobj, allocation_attrs); 646 kobject_del(fs_info->space_info_kobj); 647 kobject_put(fs_info->space_info_kobj); 648 } 649 addrm_unknown_feature_attrs(fs_info, false); 650 sysfs_remove_group(&fs_info->fs_devices->fsid_kobj, &btrfs_feature_attr_group); 651 sysfs_remove_files(&fs_info->fs_devices->fsid_kobj, btrfs_attrs); 652 btrfs_sysfs_rm_device_link(fs_info->fs_devices, NULL); 653 } 654 655 const char * const btrfs_feature_set_names[FEAT_MAX] = { 656 [FEAT_COMPAT] = "compat", 657 [FEAT_COMPAT_RO] = "compat_ro", 658 [FEAT_INCOMPAT] = "incompat", 659 }; 660 661 char *btrfs_printable_features(enum btrfs_feature_set set, u64 flags) 662 { 663 size_t bufsize = 4096; /* safe max, 64 names * 64 bytes */ 664 int len = 0; 665 int i; 666 char *str; 667 668 str = kmalloc(bufsize, GFP_KERNEL); 669 if (!str) 670 return str; 671 672 for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) { 673 const char *name; 674 675 if (!(flags & (1ULL << i))) 676 continue; 677 678 name = btrfs_feature_attrs[set][i].kobj_attr.attr.name; 679 len += snprintf(str + len, bufsize - len, "%s%s", 680 len ? "," : "", name); 681 } 682 683 return str; 684 } 685 686 static void init_feature_attrs(void) 687 { 688 struct btrfs_feature_attr *fa; 689 int set, i; 690 691 BUILD_BUG_ON(ARRAY_SIZE(btrfs_unknown_feature_names) != 692 ARRAY_SIZE(btrfs_feature_attrs)); 693 BUILD_BUG_ON(ARRAY_SIZE(btrfs_unknown_feature_names[0]) != 694 ARRAY_SIZE(btrfs_feature_attrs[0])); 695 696 memset(btrfs_feature_attrs, 0, sizeof(btrfs_feature_attrs)); 697 memset(btrfs_unknown_feature_names, 0, 698 sizeof(btrfs_unknown_feature_names)); 699 700 for (i = 0; btrfs_supported_feature_attrs[i]; i++) { 701 struct btrfs_feature_attr *sfa; 702 struct attribute *a = btrfs_supported_feature_attrs[i]; 703 int bit; 704 sfa = attr_to_btrfs_feature_attr(a); 705 bit = ilog2(sfa->feature_bit); 706 fa = &btrfs_feature_attrs[sfa->feature_set][bit]; 707 708 fa->kobj_attr.attr.name = sfa->kobj_attr.attr.name; 709 } 710 711 for (set = 0; set < FEAT_MAX; set++) { 712 for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) { 713 char *name = btrfs_unknown_feature_names[set][i]; 714 fa = &btrfs_feature_attrs[set][i]; 715 716 if (fa->kobj_attr.attr.name) 717 continue; 718 719 snprintf(name, BTRFS_FEATURE_NAME_MAX, "%s:%u", 720 btrfs_feature_set_names[set], i); 721 722 fa->kobj_attr.attr.name = name; 723 fa->kobj_attr.attr.mode = S_IRUGO; 724 fa->feature_set = set; 725 fa->feature_bit = 1ULL << i; 726 } 727 } 728 } 729 730 /* when one_device is NULL, it removes all device links */ 731 732 int btrfs_sysfs_rm_device_link(struct btrfs_fs_devices *fs_devices, 733 struct btrfs_device *one_device) 734 { 735 struct hd_struct *disk; 736 struct kobject *disk_kobj; 737 738 if (!fs_devices->device_dir_kobj) 739 return -EINVAL; 740 741 if (one_device && one_device->bdev) { 742 disk = one_device->bdev->bd_part; 743 disk_kobj = &part_to_dev(disk)->kobj; 744 745 sysfs_remove_link(fs_devices->device_dir_kobj, 746 disk_kobj->name); 747 } 748 749 if (one_device) 750 return 0; 751 752 list_for_each_entry(one_device, 753 &fs_devices->devices, dev_list) { 754 if (!one_device->bdev) 755 continue; 756 disk = one_device->bdev->bd_part; 757 disk_kobj = &part_to_dev(disk)->kobj; 758 759 sysfs_remove_link(fs_devices->device_dir_kobj, 760 disk_kobj->name); 761 } 762 763 return 0; 764 } 765 766 int btrfs_sysfs_add_device(struct btrfs_fs_devices *fs_devs) 767 { 768 if (!fs_devs->device_dir_kobj) 769 fs_devs->device_dir_kobj = kobject_create_and_add("devices", 770 &fs_devs->fsid_kobj); 771 772 if (!fs_devs->device_dir_kobj) 773 return -ENOMEM; 774 775 return 0; 776 } 777 778 int btrfs_sysfs_add_device_link(struct btrfs_fs_devices *fs_devices, 779 struct btrfs_device *one_device) 780 { 781 int error = 0; 782 struct btrfs_device *dev; 783 784 list_for_each_entry(dev, &fs_devices->devices, dev_list) { 785 struct hd_struct *disk; 786 struct kobject *disk_kobj; 787 788 if (!dev->bdev) 789 continue; 790 791 if (one_device && one_device != dev) 792 continue; 793 794 disk = dev->bdev->bd_part; 795 disk_kobj = &part_to_dev(disk)->kobj; 796 797 error = sysfs_create_link(fs_devices->device_dir_kobj, 798 disk_kobj, disk_kobj->name); 799 if (error) 800 break; 801 } 802 803 return error; 804 } 805 806 /* /sys/fs/btrfs/ entry */ 807 static struct kset *btrfs_kset; 808 809 /* /sys/kernel/debug/btrfs */ 810 static struct dentry *btrfs_debugfs_root_dentry; 811 812 /* Debugging tunables and exported data */ 813 u64 btrfs_debugfs_test; 814 815 /* 816 * Can be called by the device discovery thread. 817 * And parent can be specified for seed device 818 */ 819 int btrfs_sysfs_add_fsid(struct btrfs_fs_devices *fs_devs, 820 struct kobject *parent) 821 { 822 int error; 823 824 init_completion(&fs_devs->kobj_unregister); 825 fs_devs->fsid_kobj.kset = btrfs_kset; 826 error = kobject_init_and_add(&fs_devs->fsid_kobj, 827 &btrfs_ktype, parent, "%pU", fs_devs->fsid); 828 return error; 829 } 830 831 int btrfs_sysfs_add_mounted(struct btrfs_fs_info *fs_info) 832 { 833 int error; 834 struct btrfs_fs_devices *fs_devs = fs_info->fs_devices; 835 struct kobject *fsid_kobj = &fs_devs->fsid_kobj; 836 837 btrfs_set_fs_info_ptr(fs_info); 838 839 error = btrfs_sysfs_add_device_link(fs_devs, NULL); 840 if (error) 841 return error; 842 843 error = sysfs_create_files(fsid_kobj, btrfs_attrs); 844 if (error) { 845 btrfs_sysfs_rm_device_link(fs_devs, NULL); 846 return error; 847 } 848 849 error = sysfs_create_group(fsid_kobj, 850 &btrfs_feature_attr_group); 851 if (error) 852 goto failure; 853 854 error = addrm_unknown_feature_attrs(fs_info, true); 855 if (error) 856 goto failure; 857 858 fs_info->space_info_kobj = kobject_create_and_add("allocation", 859 fsid_kobj); 860 if (!fs_info->space_info_kobj) { 861 error = -ENOMEM; 862 goto failure; 863 } 864 865 error = sysfs_create_files(fs_info->space_info_kobj, allocation_attrs); 866 if (error) 867 goto failure; 868 869 return 0; 870 failure: 871 btrfs_sysfs_remove_mounted(fs_info); 872 return error; 873 } 874 875 876 /* 877 * Change per-fs features in /sys/fs/btrfs/UUID/features to match current 878 * values in superblock. Call after any changes to incompat/compat_ro flags 879 */ 880 void btrfs_sysfs_feature_update(struct btrfs_fs_info *fs_info, 881 u64 bit, enum btrfs_feature_set set) 882 { 883 struct btrfs_fs_devices *fs_devs; 884 struct kobject *fsid_kobj; 885 u64 features; 886 int ret; 887 888 if (!fs_info) 889 return; 890 891 features = get_features(fs_info, set); 892 ASSERT(bit & supported_feature_masks[set]); 893 894 fs_devs = fs_info->fs_devices; 895 fsid_kobj = &fs_devs->fsid_kobj; 896 897 if (!fsid_kobj->state_initialized) 898 return; 899 900 /* 901 * FIXME: this is too heavy to update just one value, ideally we'd like 902 * to use sysfs_update_group but some refactoring is needed first. 903 */ 904 sysfs_remove_group(fsid_kobj, &btrfs_feature_attr_group); 905 ret = sysfs_create_group(fsid_kobj, &btrfs_feature_attr_group); 906 } 907 908 static int btrfs_init_debugfs(void) 909 { 910 #ifdef CONFIG_DEBUG_FS 911 btrfs_debugfs_root_dentry = debugfs_create_dir("btrfs", NULL); 912 if (!btrfs_debugfs_root_dentry) 913 return -ENOMEM; 914 915 /* 916 * Example code, how to export data through debugfs. 917 * 918 * file: /sys/kernel/debug/btrfs/test 919 * contents of: btrfs_debugfs_test 920 */ 921 #ifdef CONFIG_BTRFS_DEBUG 922 debugfs_create_u64("test", S_IRUGO | S_IWUSR, btrfs_debugfs_root_dentry, 923 &btrfs_debugfs_test); 924 #endif 925 926 #endif 927 return 0; 928 } 929 930 int __init btrfs_init_sysfs(void) 931 { 932 int ret; 933 934 btrfs_kset = kset_create_and_add("btrfs", NULL, fs_kobj); 935 if (!btrfs_kset) 936 return -ENOMEM; 937 938 ret = btrfs_init_debugfs(); 939 if (ret) 940 goto out1; 941 942 init_feature_attrs(); 943 ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_feature_attr_group); 944 if (ret) 945 goto out2; 946 ret = sysfs_merge_group(&btrfs_kset->kobj, 947 &btrfs_static_feature_attr_group); 948 if (ret) 949 goto out_remove_group; 950 951 return 0; 952 953 out_remove_group: 954 sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group); 955 out2: 956 debugfs_remove_recursive(btrfs_debugfs_root_dentry); 957 out1: 958 kset_unregister(btrfs_kset); 959 960 return ret; 961 } 962 963 void __cold btrfs_exit_sysfs(void) 964 { 965 sysfs_unmerge_group(&btrfs_kset->kobj, 966 &btrfs_static_feature_attr_group); 967 sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group); 968 kset_unregister(btrfs_kset); 969 debugfs_remove_recursive(btrfs_debugfs_root_dentry); 970 } 971 972