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