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/buffer_head.h> 11 #include <linux/kobject.h> 12 #include <linux/bug.h> 13 #include <linux/genhd.h> 14 #include <linux/debugfs.h> 15 16 #include "ctree.h" 17 #include "disk-io.h" 18 #include "transaction.h" 19 #include "sysfs.h" 20 #include "volumes.h" 21 22 static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj); 23 static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj); 24 25 static u64 get_features(struct btrfs_fs_info *fs_info, 26 enum btrfs_feature_set set) 27 { 28 struct btrfs_super_block *disk_super = fs_info->super_copy; 29 if (set == FEAT_COMPAT) 30 return btrfs_super_compat_flags(disk_super); 31 else if (set == FEAT_COMPAT_RO) 32 return btrfs_super_compat_ro_flags(disk_super); 33 else 34 return btrfs_super_incompat_flags(disk_super); 35 } 36 37 static void set_features(struct btrfs_fs_info *fs_info, 38 enum btrfs_feature_set set, u64 features) 39 { 40 struct btrfs_super_block *disk_super = fs_info->super_copy; 41 if (set == FEAT_COMPAT) 42 btrfs_set_super_compat_flags(disk_super, features); 43 else if (set == FEAT_COMPAT_RO) 44 btrfs_set_super_compat_ro_flags(disk_super, features); 45 else 46 btrfs_set_super_incompat_flags(disk_super, features); 47 } 48 49 static int can_modify_feature(struct btrfs_feature_attr *fa) 50 { 51 int val = 0; 52 u64 set, clear; 53 switch (fa->feature_set) { 54 case FEAT_COMPAT: 55 set = BTRFS_FEATURE_COMPAT_SAFE_SET; 56 clear = BTRFS_FEATURE_COMPAT_SAFE_CLEAR; 57 break; 58 case FEAT_COMPAT_RO: 59 set = BTRFS_FEATURE_COMPAT_RO_SAFE_SET; 60 clear = BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR; 61 break; 62 case FEAT_INCOMPAT: 63 set = BTRFS_FEATURE_INCOMPAT_SAFE_SET; 64 clear = BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR; 65 break; 66 default: 67 pr_warn("btrfs: sysfs: unknown feature set %d\n", 68 fa->feature_set); 69 return 0; 70 } 71 72 if (set & fa->feature_bit) 73 val |= 1; 74 if (clear & fa->feature_bit) 75 val |= 2; 76 77 return val; 78 } 79 80 static ssize_t btrfs_feature_attr_show(struct kobject *kobj, 81 struct kobj_attribute *a, char *buf) 82 { 83 int val = 0; 84 struct btrfs_fs_info *fs_info = to_fs_info(kobj); 85 struct btrfs_feature_attr *fa = to_btrfs_feature_attr(a); 86 if (fs_info) { 87 u64 features = get_features(fs_info, fa->feature_set); 88 if (features & fa->feature_bit) 89 val = 1; 90 } else 91 val = can_modify_feature(fa); 92 93 return snprintf(buf, PAGE_SIZE, "%d\n", val); 94 } 95 96 static ssize_t btrfs_feature_attr_store(struct kobject *kobj, 97 struct kobj_attribute *a, 98 const char *buf, size_t count) 99 { 100 struct btrfs_fs_info *fs_info; 101 struct btrfs_feature_attr *fa = to_btrfs_feature_attr(a); 102 u64 features, set, clear; 103 unsigned long val; 104 int ret; 105 106 fs_info = to_fs_info(kobj); 107 if (!fs_info) 108 return -EPERM; 109 110 if (sb_rdonly(fs_info->sb)) 111 return -EROFS; 112 113 ret = kstrtoul(skip_spaces(buf), 0, &val); 114 if (ret) 115 return ret; 116 117 if (fa->feature_set == FEAT_COMPAT) { 118 set = BTRFS_FEATURE_COMPAT_SAFE_SET; 119 clear = BTRFS_FEATURE_COMPAT_SAFE_CLEAR; 120 } else if (fa->feature_set == FEAT_COMPAT_RO) { 121 set = BTRFS_FEATURE_COMPAT_RO_SAFE_SET; 122 clear = BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR; 123 } else { 124 set = BTRFS_FEATURE_INCOMPAT_SAFE_SET; 125 clear = BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR; 126 } 127 128 features = get_features(fs_info, fa->feature_set); 129 130 /* Nothing to do */ 131 if ((val && (features & fa->feature_bit)) || 132 (!val && !(features & fa->feature_bit))) 133 return count; 134 135 if ((val && !(set & fa->feature_bit)) || 136 (!val && !(clear & fa->feature_bit))) { 137 btrfs_info(fs_info, 138 "%sabling feature %s on mounted fs is not supported.", 139 val ? "En" : "Dis", fa->kobj_attr.attr.name); 140 return -EPERM; 141 } 142 143 btrfs_info(fs_info, "%s %s feature flag", 144 val ? "Setting" : "Clearing", fa->kobj_attr.attr.name); 145 146 spin_lock(&fs_info->super_lock); 147 features = get_features(fs_info, fa->feature_set); 148 if (val) 149 features |= fa->feature_bit; 150 else 151 features &= ~fa->feature_bit; 152 set_features(fs_info, fa->feature_set, features); 153 spin_unlock(&fs_info->super_lock); 154 155 /* 156 * We don't want to do full transaction commit from inside sysfs 157 */ 158 btrfs_set_pending(fs_info, COMMIT); 159 wake_up_process(fs_info->transaction_kthread); 160 161 return count; 162 } 163 164 static umode_t btrfs_feature_visible(struct kobject *kobj, 165 struct attribute *attr, int unused) 166 { 167 struct btrfs_fs_info *fs_info = to_fs_info(kobj); 168 umode_t mode = attr->mode; 169 170 if (fs_info) { 171 struct btrfs_feature_attr *fa; 172 u64 features; 173 174 fa = attr_to_btrfs_feature_attr(attr); 175 features = get_features(fs_info, fa->feature_set); 176 177 if (can_modify_feature(fa)) 178 mode |= S_IWUSR; 179 else if (!(features & fa->feature_bit)) 180 mode = 0; 181 } 182 183 return mode; 184 } 185 186 BTRFS_FEAT_ATTR_INCOMPAT(mixed_backref, MIXED_BACKREF); 187 BTRFS_FEAT_ATTR_INCOMPAT(default_subvol, DEFAULT_SUBVOL); 188 BTRFS_FEAT_ATTR_INCOMPAT(mixed_groups, MIXED_GROUPS); 189 BTRFS_FEAT_ATTR_INCOMPAT(compress_lzo, COMPRESS_LZO); 190 BTRFS_FEAT_ATTR_INCOMPAT(compress_zstd, COMPRESS_ZSTD); 191 BTRFS_FEAT_ATTR_INCOMPAT(big_metadata, BIG_METADATA); 192 BTRFS_FEAT_ATTR_INCOMPAT(extended_iref, EXTENDED_IREF); 193 BTRFS_FEAT_ATTR_INCOMPAT(raid56, RAID56); 194 BTRFS_FEAT_ATTR_INCOMPAT(skinny_metadata, SKINNY_METADATA); 195 BTRFS_FEAT_ATTR_INCOMPAT(no_holes, NO_HOLES); 196 BTRFS_FEAT_ATTR_COMPAT_RO(free_space_tree, FREE_SPACE_TREE); 197 198 static struct attribute *btrfs_supported_feature_attrs[] = { 199 BTRFS_FEAT_ATTR_PTR(mixed_backref), 200 BTRFS_FEAT_ATTR_PTR(default_subvol), 201 BTRFS_FEAT_ATTR_PTR(mixed_groups), 202 BTRFS_FEAT_ATTR_PTR(compress_lzo), 203 BTRFS_FEAT_ATTR_PTR(compress_zstd), 204 BTRFS_FEAT_ATTR_PTR(big_metadata), 205 BTRFS_FEAT_ATTR_PTR(extended_iref), 206 BTRFS_FEAT_ATTR_PTR(raid56), 207 BTRFS_FEAT_ATTR_PTR(skinny_metadata), 208 BTRFS_FEAT_ATTR_PTR(no_holes), 209 BTRFS_FEAT_ATTR_PTR(free_space_tree), 210 NULL 211 }; 212 213 static const struct attribute_group btrfs_feature_attr_group = { 214 .name = "features", 215 .is_visible = btrfs_feature_visible, 216 .attrs = btrfs_supported_feature_attrs, 217 }; 218 219 static ssize_t btrfs_show_u64(u64 *value_ptr, spinlock_t *lock, char *buf) 220 { 221 u64 val; 222 if (lock) 223 spin_lock(lock); 224 val = *value_ptr; 225 if (lock) 226 spin_unlock(lock); 227 return snprintf(buf, PAGE_SIZE, "%llu\n", val); 228 } 229 230 static ssize_t global_rsv_size_show(struct kobject *kobj, 231 struct kobj_attribute *ka, char *buf) 232 { 233 struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent); 234 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv; 235 return btrfs_show_u64(&block_rsv->size, &block_rsv->lock, buf); 236 } 237 BTRFS_ATTR(allocation, global_rsv_size, global_rsv_size_show); 238 239 static ssize_t global_rsv_reserved_show(struct kobject *kobj, 240 struct kobj_attribute *a, char *buf) 241 { 242 struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent); 243 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv; 244 return btrfs_show_u64(&block_rsv->reserved, &block_rsv->lock, buf); 245 } 246 BTRFS_ATTR(allocation, global_rsv_reserved, global_rsv_reserved_show); 247 248 #define to_space_info(_kobj) container_of(_kobj, struct btrfs_space_info, kobj) 249 #define to_raid_kobj(_kobj) container_of(_kobj, struct raid_kobject, kobj) 250 251 static ssize_t raid_bytes_show(struct kobject *kobj, 252 struct kobj_attribute *attr, char *buf); 253 BTRFS_ATTR(raid, total_bytes, raid_bytes_show); 254 BTRFS_ATTR(raid, used_bytes, raid_bytes_show); 255 256 static ssize_t raid_bytes_show(struct kobject *kobj, 257 struct kobj_attribute *attr, char *buf) 258 259 { 260 struct btrfs_space_info *sinfo = to_space_info(kobj->parent); 261 struct btrfs_block_group_cache *block_group; 262 int index = btrfs_bg_flags_to_raid_index(to_raid_kobj(kobj)->flags); 263 u64 val = 0; 264 265 down_read(&sinfo->groups_sem); 266 list_for_each_entry(block_group, &sinfo->block_groups[index], list) { 267 if (&attr->attr == BTRFS_ATTR_PTR(raid, total_bytes)) 268 val += block_group->key.offset; 269 else 270 val += btrfs_block_group_used(&block_group->item); 271 } 272 up_read(&sinfo->groups_sem); 273 return snprintf(buf, PAGE_SIZE, "%llu\n", val); 274 } 275 276 static struct attribute *raid_attributes[] = { 277 BTRFS_ATTR_PTR(raid, total_bytes), 278 BTRFS_ATTR_PTR(raid, used_bytes), 279 NULL 280 }; 281 282 static void release_raid_kobj(struct kobject *kobj) 283 { 284 kfree(to_raid_kobj(kobj)); 285 } 286 287 struct kobj_type btrfs_raid_ktype = { 288 .sysfs_ops = &kobj_sysfs_ops, 289 .release = release_raid_kobj, 290 .default_attrs = raid_attributes, 291 }; 292 293 #define SPACE_INFO_ATTR(field) \ 294 static ssize_t btrfs_space_info_show_##field(struct kobject *kobj, \ 295 struct kobj_attribute *a, \ 296 char *buf) \ 297 { \ 298 struct btrfs_space_info *sinfo = to_space_info(kobj); \ 299 return btrfs_show_u64(&sinfo->field, &sinfo->lock, buf); \ 300 } \ 301 BTRFS_ATTR(space_info, field, btrfs_space_info_show_##field) 302 303 static ssize_t btrfs_space_info_show_total_bytes_pinned(struct kobject *kobj, 304 struct kobj_attribute *a, 305 char *buf) 306 { 307 struct btrfs_space_info *sinfo = to_space_info(kobj); 308 s64 val = percpu_counter_sum(&sinfo->total_bytes_pinned); 309 return snprintf(buf, PAGE_SIZE, "%lld\n", val); 310 } 311 312 SPACE_INFO_ATTR(flags); 313 SPACE_INFO_ATTR(total_bytes); 314 SPACE_INFO_ATTR(bytes_used); 315 SPACE_INFO_ATTR(bytes_pinned); 316 SPACE_INFO_ATTR(bytes_reserved); 317 SPACE_INFO_ATTR(bytes_may_use); 318 SPACE_INFO_ATTR(bytes_readonly); 319 SPACE_INFO_ATTR(disk_used); 320 SPACE_INFO_ATTR(disk_total); 321 BTRFS_ATTR(space_info, total_bytes_pinned, 322 btrfs_space_info_show_total_bytes_pinned); 323 324 static struct attribute *space_info_attrs[] = { 325 BTRFS_ATTR_PTR(space_info, flags), 326 BTRFS_ATTR_PTR(space_info, total_bytes), 327 BTRFS_ATTR_PTR(space_info, bytes_used), 328 BTRFS_ATTR_PTR(space_info, bytes_pinned), 329 BTRFS_ATTR_PTR(space_info, bytes_reserved), 330 BTRFS_ATTR_PTR(space_info, bytes_may_use), 331 BTRFS_ATTR_PTR(space_info, bytes_readonly), 332 BTRFS_ATTR_PTR(space_info, disk_used), 333 BTRFS_ATTR_PTR(space_info, disk_total), 334 BTRFS_ATTR_PTR(space_info, total_bytes_pinned), 335 NULL, 336 }; 337 338 static void space_info_release(struct kobject *kobj) 339 { 340 struct btrfs_space_info *sinfo = to_space_info(kobj); 341 percpu_counter_destroy(&sinfo->total_bytes_pinned); 342 kfree(sinfo); 343 } 344 345 struct kobj_type space_info_ktype = { 346 .sysfs_ops = &kobj_sysfs_ops, 347 .release = space_info_release, 348 .default_attrs = space_info_attrs, 349 }; 350 351 static const struct attribute *allocation_attrs[] = { 352 BTRFS_ATTR_PTR(allocation, global_rsv_reserved), 353 BTRFS_ATTR_PTR(allocation, global_rsv_size), 354 NULL, 355 }; 356 357 static ssize_t btrfs_label_show(struct kobject *kobj, 358 struct kobj_attribute *a, char *buf) 359 { 360 struct btrfs_fs_info *fs_info = to_fs_info(kobj); 361 char *label = fs_info->super_copy->label; 362 ssize_t ret; 363 364 spin_lock(&fs_info->super_lock); 365 ret = snprintf(buf, PAGE_SIZE, label[0] ? "%s\n" : "%s", label); 366 spin_unlock(&fs_info->super_lock); 367 368 return ret; 369 } 370 371 static ssize_t btrfs_label_store(struct kobject *kobj, 372 struct kobj_attribute *a, 373 const char *buf, size_t len) 374 { 375 struct btrfs_fs_info *fs_info = to_fs_info(kobj); 376 size_t p_len; 377 378 if (!fs_info) 379 return -EPERM; 380 381 if (sb_rdonly(fs_info->sb)) 382 return -EROFS; 383 384 /* 385 * p_len is the len until the first occurrence of either 386 * '\n' or '\0' 387 */ 388 p_len = strcspn(buf, "\n"); 389 390 if (p_len >= BTRFS_LABEL_SIZE) 391 return -EINVAL; 392 393 spin_lock(&fs_info->super_lock); 394 memset(fs_info->super_copy->label, 0, BTRFS_LABEL_SIZE); 395 memcpy(fs_info->super_copy->label, buf, p_len); 396 spin_unlock(&fs_info->super_lock); 397 398 /* 399 * We don't want to do full transaction commit from inside sysfs 400 */ 401 btrfs_set_pending(fs_info, COMMIT); 402 wake_up_process(fs_info->transaction_kthread); 403 404 return len; 405 } 406 BTRFS_ATTR_RW(, label, btrfs_label_show, btrfs_label_store); 407 408 static ssize_t btrfs_nodesize_show(struct kobject *kobj, 409 struct kobj_attribute *a, char *buf) 410 { 411 struct btrfs_fs_info *fs_info = to_fs_info(kobj); 412 413 return snprintf(buf, PAGE_SIZE, "%u\n", fs_info->super_copy->nodesize); 414 } 415 416 BTRFS_ATTR(, nodesize, btrfs_nodesize_show); 417 418 static ssize_t btrfs_sectorsize_show(struct kobject *kobj, 419 struct kobj_attribute *a, char *buf) 420 { 421 struct btrfs_fs_info *fs_info = to_fs_info(kobj); 422 423 return snprintf(buf, PAGE_SIZE, "%u\n", 424 fs_info->super_copy->sectorsize); 425 } 426 427 BTRFS_ATTR(, sectorsize, btrfs_sectorsize_show); 428 429 static ssize_t btrfs_clone_alignment_show(struct kobject *kobj, 430 struct kobj_attribute *a, char *buf) 431 { 432 struct btrfs_fs_info *fs_info = to_fs_info(kobj); 433 434 return snprintf(buf, PAGE_SIZE, "%u\n", 435 fs_info->super_copy->sectorsize); 436 } 437 438 BTRFS_ATTR(, clone_alignment, btrfs_clone_alignment_show); 439 440 static ssize_t quota_override_show(struct kobject *kobj, 441 struct kobj_attribute *a, char *buf) 442 { 443 struct btrfs_fs_info *fs_info = to_fs_info(kobj); 444 int quota_override; 445 446 quota_override = test_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags); 447 return snprintf(buf, PAGE_SIZE, "%d\n", quota_override); 448 } 449 450 static ssize_t quota_override_store(struct kobject *kobj, 451 struct kobj_attribute *a, 452 const char *buf, size_t len) 453 { 454 struct btrfs_fs_info *fs_info = to_fs_info(kobj); 455 unsigned long knob; 456 int err; 457 458 if (!fs_info) 459 return -EPERM; 460 461 if (!capable(CAP_SYS_RESOURCE)) 462 return -EPERM; 463 464 err = kstrtoul(buf, 10, &knob); 465 if (err) 466 return err; 467 if (knob > 1) 468 return -EINVAL; 469 470 if (knob) 471 set_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags); 472 else 473 clear_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags); 474 475 return len; 476 } 477 478 BTRFS_ATTR_RW(, quota_override, quota_override_show, quota_override_store); 479 480 static const struct attribute *btrfs_attrs[] = { 481 BTRFS_ATTR_PTR(, label), 482 BTRFS_ATTR_PTR(, nodesize), 483 BTRFS_ATTR_PTR(, sectorsize), 484 BTRFS_ATTR_PTR(, clone_alignment), 485 BTRFS_ATTR_PTR(, quota_override), 486 NULL, 487 }; 488 489 static void btrfs_release_fsid_kobj(struct kobject *kobj) 490 { 491 struct btrfs_fs_devices *fs_devs = to_fs_devs(kobj); 492 493 memset(&fs_devs->fsid_kobj, 0, sizeof(struct kobject)); 494 complete(&fs_devs->kobj_unregister); 495 } 496 497 static struct kobj_type btrfs_ktype = { 498 .sysfs_ops = &kobj_sysfs_ops, 499 .release = btrfs_release_fsid_kobj, 500 }; 501 502 static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj) 503 { 504 if (kobj->ktype != &btrfs_ktype) 505 return NULL; 506 return container_of(kobj, struct btrfs_fs_devices, fsid_kobj); 507 } 508 509 static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj) 510 { 511 if (kobj->ktype != &btrfs_ktype) 512 return NULL; 513 return to_fs_devs(kobj)->fs_info; 514 } 515 516 #define NUM_FEATURE_BITS 64 517 static char btrfs_unknown_feature_names[3][NUM_FEATURE_BITS][13]; 518 static struct btrfs_feature_attr btrfs_feature_attrs[3][NUM_FEATURE_BITS]; 519 520 static const u64 supported_feature_masks[3] = { 521 [FEAT_COMPAT] = BTRFS_FEATURE_COMPAT_SUPP, 522 [FEAT_COMPAT_RO] = BTRFS_FEATURE_COMPAT_RO_SUPP, 523 [FEAT_INCOMPAT] = BTRFS_FEATURE_INCOMPAT_SUPP, 524 }; 525 526 static int addrm_unknown_feature_attrs(struct btrfs_fs_info *fs_info, bool add) 527 { 528 int set; 529 530 for (set = 0; set < FEAT_MAX; set++) { 531 int i; 532 struct attribute *attrs[2]; 533 struct attribute_group agroup = { 534 .name = "features", 535 .attrs = attrs, 536 }; 537 u64 features = get_features(fs_info, set); 538 features &= ~supported_feature_masks[set]; 539 540 if (!features) 541 continue; 542 543 attrs[1] = NULL; 544 for (i = 0; i < NUM_FEATURE_BITS; i++) { 545 struct btrfs_feature_attr *fa; 546 547 if (!(features & (1ULL << i))) 548 continue; 549 550 fa = &btrfs_feature_attrs[set][i]; 551 attrs[0] = &fa->kobj_attr.attr; 552 if (add) { 553 int ret; 554 ret = sysfs_merge_group(&fs_info->fs_devices->fsid_kobj, 555 &agroup); 556 if (ret) 557 return ret; 558 } else 559 sysfs_unmerge_group(&fs_info->fs_devices->fsid_kobj, 560 &agroup); 561 } 562 563 } 564 return 0; 565 } 566 567 static void __btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs) 568 { 569 if (fs_devs->device_dir_kobj) { 570 kobject_del(fs_devs->device_dir_kobj); 571 kobject_put(fs_devs->device_dir_kobj); 572 fs_devs->device_dir_kobj = NULL; 573 } 574 575 if (fs_devs->fsid_kobj.state_initialized) { 576 kobject_del(&fs_devs->fsid_kobj); 577 kobject_put(&fs_devs->fsid_kobj); 578 wait_for_completion(&fs_devs->kobj_unregister); 579 } 580 } 581 582 /* when fs_devs is NULL it will remove all fsid kobject */ 583 void btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs) 584 { 585 struct list_head *fs_uuids = btrfs_get_fs_uuids(); 586 587 if (fs_devs) { 588 __btrfs_sysfs_remove_fsid(fs_devs); 589 return; 590 } 591 592 list_for_each_entry(fs_devs, fs_uuids, list) { 593 __btrfs_sysfs_remove_fsid(fs_devs); 594 } 595 } 596 597 void btrfs_sysfs_remove_mounted(struct btrfs_fs_info *fs_info) 598 { 599 btrfs_reset_fs_info_ptr(fs_info); 600 601 if (fs_info->space_info_kobj) { 602 sysfs_remove_files(fs_info->space_info_kobj, allocation_attrs); 603 kobject_del(fs_info->space_info_kobj); 604 kobject_put(fs_info->space_info_kobj); 605 } 606 addrm_unknown_feature_attrs(fs_info, false); 607 sysfs_remove_group(&fs_info->fs_devices->fsid_kobj, &btrfs_feature_attr_group); 608 sysfs_remove_files(&fs_info->fs_devices->fsid_kobj, btrfs_attrs); 609 btrfs_sysfs_rm_device_link(fs_info->fs_devices, NULL); 610 } 611 612 const char * const btrfs_feature_set_names[3] = { 613 [FEAT_COMPAT] = "compat", 614 [FEAT_COMPAT_RO] = "compat_ro", 615 [FEAT_INCOMPAT] = "incompat", 616 }; 617 618 char *btrfs_printable_features(enum btrfs_feature_set set, u64 flags) 619 { 620 size_t bufsize = 4096; /* safe max, 64 names * 64 bytes */ 621 int len = 0; 622 int i; 623 char *str; 624 625 str = kmalloc(bufsize, GFP_KERNEL); 626 if (!str) 627 return str; 628 629 for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) { 630 const char *name; 631 632 if (!(flags & (1ULL << i))) 633 continue; 634 635 name = btrfs_feature_attrs[set][i].kobj_attr.attr.name; 636 len += snprintf(str + len, bufsize - len, "%s%s", 637 len ? "," : "", name); 638 } 639 640 return str; 641 } 642 643 static void init_feature_attrs(void) 644 { 645 struct btrfs_feature_attr *fa; 646 int set, i; 647 648 BUILD_BUG_ON(ARRAY_SIZE(btrfs_unknown_feature_names) != 649 ARRAY_SIZE(btrfs_feature_attrs)); 650 BUILD_BUG_ON(ARRAY_SIZE(btrfs_unknown_feature_names[0]) != 651 ARRAY_SIZE(btrfs_feature_attrs[0])); 652 653 memset(btrfs_feature_attrs, 0, sizeof(btrfs_feature_attrs)); 654 memset(btrfs_unknown_feature_names, 0, 655 sizeof(btrfs_unknown_feature_names)); 656 657 for (i = 0; btrfs_supported_feature_attrs[i]; i++) { 658 struct btrfs_feature_attr *sfa; 659 struct attribute *a = btrfs_supported_feature_attrs[i]; 660 int bit; 661 sfa = attr_to_btrfs_feature_attr(a); 662 bit = ilog2(sfa->feature_bit); 663 fa = &btrfs_feature_attrs[sfa->feature_set][bit]; 664 665 fa->kobj_attr.attr.name = sfa->kobj_attr.attr.name; 666 } 667 668 for (set = 0; set < FEAT_MAX; set++) { 669 for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) { 670 char *name = btrfs_unknown_feature_names[set][i]; 671 fa = &btrfs_feature_attrs[set][i]; 672 673 if (fa->kobj_attr.attr.name) 674 continue; 675 676 snprintf(name, 13, "%s:%u", 677 btrfs_feature_set_names[set], i); 678 679 fa->kobj_attr.attr.name = name; 680 fa->kobj_attr.attr.mode = S_IRUGO; 681 fa->feature_set = set; 682 fa->feature_bit = 1ULL << i; 683 } 684 } 685 } 686 687 /* when one_device is NULL, it removes all device links */ 688 689 int btrfs_sysfs_rm_device_link(struct btrfs_fs_devices *fs_devices, 690 struct btrfs_device *one_device) 691 { 692 struct hd_struct *disk; 693 struct kobject *disk_kobj; 694 695 if (!fs_devices->device_dir_kobj) 696 return -EINVAL; 697 698 if (one_device && one_device->bdev) { 699 disk = one_device->bdev->bd_part; 700 disk_kobj = &part_to_dev(disk)->kobj; 701 702 sysfs_remove_link(fs_devices->device_dir_kobj, 703 disk_kobj->name); 704 } 705 706 if (one_device) 707 return 0; 708 709 list_for_each_entry(one_device, 710 &fs_devices->devices, dev_list) { 711 if (!one_device->bdev) 712 continue; 713 disk = one_device->bdev->bd_part; 714 disk_kobj = &part_to_dev(disk)->kobj; 715 716 sysfs_remove_link(fs_devices->device_dir_kobj, 717 disk_kobj->name); 718 } 719 720 return 0; 721 } 722 723 int btrfs_sysfs_add_device(struct btrfs_fs_devices *fs_devs) 724 { 725 if (!fs_devs->device_dir_kobj) 726 fs_devs->device_dir_kobj = kobject_create_and_add("devices", 727 &fs_devs->fsid_kobj); 728 729 if (!fs_devs->device_dir_kobj) 730 return -ENOMEM; 731 732 return 0; 733 } 734 735 int btrfs_sysfs_add_device_link(struct btrfs_fs_devices *fs_devices, 736 struct btrfs_device *one_device) 737 { 738 int error = 0; 739 struct btrfs_device *dev; 740 741 list_for_each_entry(dev, &fs_devices->devices, dev_list) { 742 struct hd_struct *disk; 743 struct kobject *disk_kobj; 744 745 if (!dev->bdev) 746 continue; 747 748 if (one_device && one_device != dev) 749 continue; 750 751 disk = dev->bdev->bd_part; 752 disk_kobj = &part_to_dev(disk)->kobj; 753 754 error = sysfs_create_link(fs_devices->device_dir_kobj, 755 disk_kobj, disk_kobj->name); 756 if (error) 757 break; 758 } 759 760 return error; 761 } 762 763 /* /sys/fs/btrfs/ entry */ 764 static struct kset *btrfs_kset; 765 766 /* /sys/kernel/debug/btrfs */ 767 static struct dentry *btrfs_debugfs_root_dentry; 768 769 /* Debugging tunables and exported data */ 770 u64 btrfs_debugfs_test; 771 772 /* 773 * Can be called by the device discovery thread. 774 * And parent can be specified for seed device 775 */ 776 int btrfs_sysfs_add_fsid(struct btrfs_fs_devices *fs_devs, 777 struct kobject *parent) 778 { 779 int error; 780 781 init_completion(&fs_devs->kobj_unregister); 782 fs_devs->fsid_kobj.kset = btrfs_kset; 783 error = kobject_init_and_add(&fs_devs->fsid_kobj, 784 &btrfs_ktype, parent, "%pU", fs_devs->fsid); 785 return error; 786 } 787 788 int btrfs_sysfs_add_mounted(struct btrfs_fs_info *fs_info) 789 { 790 int error; 791 struct btrfs_fs_devices *fs_devs = fs_info->fs_devices; 792 struct kobject *fsid_kobj = &fs_devs->fsid_kobj; 793 794 btrfs_set_fs_info_ptr(fs_info); 795 796 error = btrfs_sysfs_add_device_link(fs_devs, NULL); 797 if (error) 798 return error; 799 800 error = sysfs_create_files(fsid_kobj, btrfs_attrs); 801 if (error) { 802 btrfs_sysfs_rm_device_link(fs_devs, NULL); 803 return error; 804 } 805 806 error = sysfs_create_group(fsid_kobj, 807 &btrfs_feature_attr_group); 808 if (error) 809 goto failure; 810 811 error = addrm_unknown_feature_attrs(fs_info, true); 812 if (error) 813 goto failure; 814 815 fs_info->space_info_kobj = kobject_create_and_add("allocation", 816 fsid_kobj); 817 if (!fs_info->space_info_kobj) { 818 error = -ENOMEM; 819 goto failure; 820 } 821 822 error = sysfs_create_files(fs_info->space_info_kobj, allocation_attrs); 823 if (error) 824 goto failure; 825 826 return 0; 827 failure: 828 btrfs_sysfs_remove_mounted(fs_info); 829 return error; 830 } 831 832 833 /* 834 * Change per-fs features in /sys/fs/btrfs/UUID/features to match current 835 * values in superblock. Call after any changes to incompat/compat_ro flags 836 */ 837 void btrfs_sysfs_feature_update(struct btrfs_fs_info *fs_info, 838 u64 bit, enum btrfs_feature_set set) 839 { 840 struct btrfs_fs_devices *fs_devs; 841 struct kobject *fsid_kobj; 842 u64 features; 843 int ret; 844 845 if (!fs_info) 846 return; 847 848 features = get_features(fs_info, set); 849 ASSERT(bit & supported_feature_masks[set]); 850 851 fs_devs = fs_info->fs_devices; 852 fsid_kobj = &fs_devs->fsid_kobj; 853 854 if (!fsid_kobj->state_initialized) 855 return; 856 857 /* 858 * FIXME: this is too heavy to update just one value, ideally we'd like 859 * to use sysfs_update_group but some refactoring is needed first. 860 */ 861 sysfs_remove_group(fsid_kobj, &btrfs_feature_attr_group); 862 ret = sysfs_create_group(fsid_kobj, &btrfs_feature_attr_group); 863 } 864 865 static int btrfs_init_debugfs(void) 866 { 867 #ifdef CONFIG_DEBUG_FS 868 btrfs_debugfs_root_dentry = debugfs_create_dir("btrfs", NULL); 869 if (!btrfs_debugfs_root_dentry) 870 return -ENOMEM; 871 872 /* 873 * Example code, how to export data through debugfs. 874 * 875 * file: /sys/kernel/debug/btrfs/test 876 * contents of: btrfs_debugfs_test 877 */ 878 #ifdef CONFIG_BTRFS_DEBUG 879 debugfs_create_u64("test", S_IRUGO | S_IWUSR, btrfs_debugfs_root_dentry, 880 &btrfs_debugfs_test); 881 #endif 882 883 #endif 884 return 0; 885 } 886 887 int __init btrfs_init_sysfs(void) 888 { 889 int ret; 890 891 btrfs_kset = kset_create_and_add("btrfs", NULL, fs_kobj); 892 if (!btrfs_kset) 893 return -ENOMEM; 894 895 ret = btrfs_init_debugfs(); 896 if (ret) 897 goto out1; 898 899 init_feature_attrs(); 900 ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_feature_attr_group); 901 if (ret) 902 goto out2; 903 904 return 0; 905 out2: 906 debugfs_remove_recursive(btrfs_debugfs_root_dentry); 907 out1: 908 kset_unregister(btrfs_kset); 909 910 return ret; 911 } 912 913 void __cold btrfs_exit_sysfs(void) 914 { 915 sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group); 916 kset_unregister(btrfs_kset); 917 debugfs_remove_recursive(btrfs_debugfs_root_dentry); 918 } 919 920