1 /* 2 * Copyright (C) 2007 Oracle. All rights reserved. 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public 6 * License v2 as published by the Free Software Foundation. 7 * 8 * This program is distributed in the hope that it will be useful, 9 * but WITHOUT ANY WARRANTY; without even the implied warranty of 10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 11 * General Public License for more details. 12 * 13 * You should have received a copy of the GNU General Public 14 * License along with this program; if not, write to the 15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330, 16 * Boston, MA 021110-1307, USA. 17 */ 18 19 #include <linux/sched.h> 20 #include <linux/slab.h> 21 #include <linux/spinlock.h> 22 #include <linux/completion.h> 23 #include <linux/buffer_head.h> 24 #include <linux/kobject.h> 25 #include <linux/bug.h> 26 #include <linux/genhd.h> 27 #include <linux/debugfs.h> 28 29 #include "ctree.h" 30 #include "disk-io.h" 31 #include "transaction.h" 32 #include "sysfs.h" 33 #include "volumes.h" 34 35 static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj); 36 static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj); 37 38 static u64 get_features(struct btrfs_fs_info *fs_info, 39 enum btrfs_feature_set set) 40 { 41 struct btrfs_super_block *disk_super = fs_info->super_copy; 42 if (set == FEAT_COMPAT) 43 return btrfs_super_compat_flags(disk_super); 44 else if (set == FEAT_COMPAT_RO) 45 return btrfs_super_compat_ro_flags(disk_super); 46 else 47 return btrfs_super_incompat_flags(disk_super); 48 } 49 50 static void set_features(struct btrfs_fs_info *fs_info, 51 enum btrfs_feature_set set, u64 features) 52 { 53 struct btrfs_super_block *disk_super = fs_info->super_copy; 54 if (set == FEAT_COMPAT) 55 btrfs_set_super_compat_flags(disk_super, features); 56 else if (set == FEAT_COMPAT_RO) 57 btrfs_set_super_compat_ro_flags(disk_super, features); 58 else 59 btrfs_set_super_incompat_flags(disk_super, features); 60 } 61 62 static int can_modify_feature(struct btrfs_feature_attr *fa) 63 { 64 int val = 0; 65 u64 set, clear; 66 switch (fa->feature_set) { 67 case FEAT_COMPAT: 68 set = BTRFS_FEATURE_COMPAT_SAFE_SET; 69 clear = BTRFS_FEATURE_COMPAT_SAFE_CLEAR; 70 break; 71 case FEAT_COMPAT_RO: 72 set = BTRFS_FEATURE_COMPAT_RO_SAFE_SET; 73 clear = BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR; 74 break; 75 case FEAT_INCOMPAT: 76 set = BTRFS_FEATURE_INCOMPAT_SAFE_SET; 77 clear = BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR; 78 break; 79 default: 80 pr_warn("btrfs: sysfs: unknown feature set %d\n", 81 fa->feature_set); 82 return 0; 83 } 84 85 if (set & fa->feature_bit) 86 val |= 1; 87 if (clear & fa->feature_bit) 88 val |= 2; 89 90 return val; 91 } 92 93 static ssize_t btrfs_feature_attr_show(struct kobject *kobj, 94 struct kobj_attribute *a, char *buf) 95 { 96 int val = 0; 97 struct btrfs_fs_info *fs_info = to_fs_info(kobj); 98 struct btrfs_feature_attr *fa = to_btrfs_feature_attr(a); 99 if (fs_info) { 100 u64 features = get_features(fs_info, fa->feature_set); 101 if (features & fa->feature_bit) 102 val = 1; 103 } else 104 val = can_modify_feature(fa); 105 106 return snprintf(buf, PAGE_SIZE, "%d\n", val); 107 } 108 109 static ssize_t btrfs_feature_attr_store(struct kobject *kobj, 110 struct kobj_attribute *a, 111 const char *buf, size_t count) 112 { 113 struct btrfs_fs_info *fs_info; 114 struct btrfs_feature_attr *fa = to_btrfs_feature_attr(a); 115 u64 features, set, clear; 116 unsigned long val; 117 int ret; 118 119 fs_info = to_fs_info(kobj); 120 if (!fs_info) 121 return -EPERM; 122 123 if (sb_rdonly(fs_info->sb)) 124 return -EROFS; 125 126 ret = kstrtoul(skip_spaces(buf), 0, &val); 127 if (ret) 128 return ret; 129 130 if (fa->feature_set == FEAT_COMPAT) { 131 set = BTRFS_FEATURE_COMPAT_SAFE_SET; 132 clear = BTRFS_FEATURE_COMPAT_SAFE_CLEAR; 133 } else if (fa->feature_set == FEAT_COMPAT_RO) { 134 set = BTRFS_FEATURE_COMPAT_RO_SAFE_SET; 135 clear = BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR; 136 } else { 137 set = BTRFS_FEATURE_INCOMPAT_SAFE_SET; 138 clear = BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR; 139 } 140 141 features = get_features(fs_info, fa->feature_set); 142 143 /* Nothing to do */ 144 if ((val && (features & fa->feature_bit)) || 145 (!val && !(features & fa->feature_bit))) 146 return count; 147 148 if ((val && !(set & fa->feature_bit)) || 149 (!val && !(clear & fa->feature_bit))) { 150 btrfs_info(fs_info, 151 "%sabling feature %s on mounted fs is not supported.", 152 val ? "En" : "Dis", fa->kobj_attr.attr.name); 153 return -EPERM; 154 } 155 156 btrfs_info(fs_info, "%s %s feature flag", 157 val ? "Setting" : "Clearing", fa->kobj_attr.attr.name); 158 159 spin_lock(&fs_info->super_lock); 160 features = get_features(fs_info, fa->feature_set); 161 if (val) 162 features |= fa->feature_bit; 163 else 164 features &= ~fa->feature_bit; 165 set_features(fs_info, fa->feature_set, features); 166 spin_unlock(&fs_info->super_lock); 167 168 /* 169 * We don't want to do full transaction commit from inside sysfs 170 */ 171 btrfs_set_pending(fs_info, COMMIT); 172 wake_up_process(fs_info->transaction_kthread); 173 174 return count; 175 } 176 177 static umode_t btrfs_feature_visible(struct kobject *kobj, 178 struct attribute *attr, int unused) 179 { 180 struct btrfs_fs_info *fs_info = to_fs_info(kobj); 181 umode_t mode = attr->mode; 182 183 if (fs_info) { 184 struct btrfs_feature_attr *fa; 185 u64 features; 186 187 fa = attr_to_btrfs_feature_attr(attr); 188 features = get_features(fs_info, fa->feature_set); 189 190 if (can_modify_feature(fa)) 191 mode |= S_IWUSR; 192 else if (!(features & fa->feature_bit)) 193 mode = 0; 194 } 195 196 return mode; 197 } 198 199 BTRFS_FEAT_ATTR_INCOMPAT(mixed_backref, MIXED_BACKREF); 200 BTRFS_FEAT_ATTR_INCOMPAT(default_subvol, DEFAULT_SUBVOL); 201 BTRFS_FEAT_ATTR_INCOMPAT(mixed_groups, MIXED_GROUPS); 202 BTRFS_FEAT_ATTR_INCOMPAT(compress_lzo, COMPRESS_LZO); 203 BTRFS_FEAT_ATTR_INCOMPAT(compress_zstd, COMPRESS_ZSTD); 204 BTRFS_FEAT_ATTR_INCOMPAT(big_metadata, BIG_METADATA); 205 BTRFS_FEAT_ATTR_INCOMPAT(extended_iref, EXTENDED_IREF); 206 BTRFS_FEAT_ATTR_INCOMPAT(raid56, RAID56); 207 BTRFS_FEAT_ATTR_INCOMPAT(skinny_metadata, SKINNY_METADATA); 208 BTRFS_FEAT_ATTR_INCOMPAT(no_holes, NO_HOLES); 209 BTRFS_FEAT_ATTR_COMPAT_RO(free_space_tree, FREE_SPACE_TREE); 210 211 static struct attribute *btrfs_supported_feature_attrs[] = { 212 BTRFS_FEAT_ATTR_PTR(mixed_backref), 213 BTRFS_FEAT_ATTR_PTR(default_subvol), 214 BTRFS_FEAT_ATTR_PTR(mixed_groups), 215 BTRFS_FEAT_ATTR_PTR(compress_lzo), 216 BTRFS_FEAT_ATTR_PTR(compress_zstd), 217 BTRFS_FEAT_ATTR_PTR(big_metadata), 218 BTRFS_FEAT_ATTR_PTR(extended_iref), 219 BTRFS_FEAT_ATTR_PTR(raid56), 220 BTRFS_FEAT_ATTR_PTR(skinny_metadata), 221 BTRFS_FEAT_ATTR_PTR(no_holes), 222 BTRFS_FEAT_ATTR_PTR(free_space_tree), 223 NULL 224 }; 225 226 static const struct attribute_group btrfs_feature_attr_group = { 227 .name = "features", 228 .is_visible = btrfs_feature_visible, 229 .attrs = btrfs_supported_feature_attrs, 230 }; 231 232 static ssize_t btrfs_show_u64(u64 *value_ptr, spinlock_t *lock, char *buf) 233 { 234 u64 val; 235 if (lock) 236 spin_lock(lock); 237 val = *value_ptr; 238 if (lock) 239 spin_unlock(lock); 240 return snprintf(buf, PAGE_SIZE, "%llu\n", val); 241 } 242 243 static ssize_t global_rsv_size_show(struct kobject *kobj, 244 struct kobj_attribute *ka, char *buf) 245 { 246 struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent); 247 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv; 248 return btrfs_show_u64(&block_rsv->size, &block_rsv->lock, buf); 249 } 250 BTRFS_ATTR(global_rsv_size, global_rsv_size_show); 251 252 static ssize_t global_rsv_reserved_show(struct kobject *kobj, 253 struct kobj_attribute *a, char *buf) 254 { 255 struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent); 256 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv; 257 return btrfs_show_u64(&block_rsv->reserved, &block_rsv->lock, buf); 258 } 259 BTRFS_ATTR(global_rsv_reserved, global_rsv_reserved_show); 260 261 #define to_space_info(_kobj) container_of(_kobj, struct btrfs_space_info, kobj) 262 #define to_raid_kobj(_kobj) container_of(_kobj, struct raid_kobject, kobj) 263 264 static ssize_t raid_bytes_show(struct kobject *kobj, 265 struct kobj_attribute *attr, char *buf); 266 BTRFS_RAID_ATTR(total_bytes, raid_bytes_show); 267 BTRFS_RAID_ATTR(used_bytes, raid_bytes_show); 268 269 static ssize_t raid_bytes_show(struct kobject *kobj, 270 struct kobj_attribute *attr, char *buf) 271 272 { 273 struct btrfs_space_info *sinfo = to_space_info(kobj->parent); 274 struct btrfs_block_group_cache *block_group; 275 int index = to_raid_kobj(kobj)->raid_type; 276 u64 val = 0; 277 278 down_read(&sinfo->groups_sem); 279 list_for_each_entry(block_group, &sinfo->block_groups[index], list) { 280 if (&attr->attr == BTRFS_RAID_ATTR_PTR(total_bytes)) 281 val += block_group->key.offset; 282 else 283 val += btrfs_block_group_used(&block_group->item); 284 } 285 up_read(&sinfo->groups_sem); 286 return snprintf(buf, PAGE_SIZE, "%llu\n", val); 287 } 288 289 static struct attribute *raid_attributes[] = { 290 BTRFS_RAID_ATTR_PTR(total_bytes), 291 BTRFS_RAID_ATTR_PTR(used_bytes), 292 NULL 293 }; 294 295 static void release_raid_kobj(struct kobject *kobj) 296 { 297 kfree(to_raid_kobj(kobj)); 298 } 299 300 struct kobj_type btrfs_raid_ktype = { 301 .sysfs_ops = &kobj_sysfs_ops, 302 .release = release_raid_kobj, 303 .default_attrs = raid_attributes, 304 }; 305 306 #define SPACE_INFO_ATTR(field) \ 307 static ssize_t btrfs_space_info_show_##field(struct kobject *kobj, \ 308 struct kobj_attribute *a, \ 309 char *buf) \ 310 { \ 311 struct btrfs_space_info *sinfo = to_space_info(kobj); \ 312 return btrfs_show_u64(&sinfo->field, &sinfo->lock, buf); \ 313 } \ 314 BTRFS_ATTR(field, btrfs_space_info_show_##field) 315 316 static ssize_t btrfs_space_info_show_total_bytes_pinned(struct kobject *kobj, 317 struct kobj_attribute *a, 318 char *buf) 319 { 320 struct btrfs_space_info *sinfo = to_space_info(kobj); 321 s64 val = percpu_counter_sum(&sinfo->total_bytes_pinned); 322 return snprintf(buf, PAGE_SIZE, "%lld\n", val); 323 } 324 325 SPACE_INFO_ATTR(flags); 326 SPACE_INFO_ATTR(total_bytes); 327 SPACE_INFO_ATTR(bytes_used); 328 SPACE_INFO_ATTR(bytes_pinned); 329 SPACE_INFO_ATTR(bytes_reserved); 330 SPACE_INFO_ATTR(bytes_may_use); 331 SPACE_INFO_ATTR(bytes_readonly); 332 SPACE_INFO_ATTR(disk_used); 333 SPACE_INFO_ATTR(disk_total); 334 BTRFS_ATTR(total_bytes_pinned, btrfs_space_info_show_total_bytes_pinned); 335 336 static struct attribute *space_info_attrs[] = { 337 BTRFS_ATTR_PTR(flags), 338 BTRFS_ATTR_PTR(total_bytes), 339 BTRFS_ATTR_PTR(bytes_used), 340 BTRFS_ATTR_PTR(bytes_pinned), 341 BTRFS_ATTR_PTR(bytes_reserved), 342 BTRFS_ATTR_PTR(bytes_may_use), 343 BTRFS_ATTR_PTR(bytes_readonly), 344 BTRFS_ATTR_PTR(disk_used), 345 BTRFS_ATTR_PTR(disk_total), 346 BTRFS_ATTR_PTR(total_bytes_pinned), 347 NULL, 348 }; 349 350 static void space_info_release(struct kobject *kobj) 351 { 352 struct btrfs_space_info *sinfo = to_space_info(kobj); 353 percpu_counter_destroy(&sinfo->total_bytes_pinned); 354 kfree(sinfo); 355 } 356 357 struct kobj_type space_info_ktype = { 358 .sysfs_ops = &kobj_sysfs_ops, 359 .release = space_info_release, 360 .default_attrs = space_info_attrs, 361 }; 362 363 static const struct attribute *allocation_attrs[] = { 364 BTRFS_ATTR_PTR(global_rsv_reserved), 365 BTRFS_ATTR_PTR(global_rsv_size), 366 NULL, 367 }; 368 369 static ssize_t btrfs_label_show(struct kobject *kobj, 370 struct kobj_attribute *a, char *buf) 371 { 372 struct btrfs_fs_info *fs_info = to_fs_info(kobj); 373 char *label = fs_info->super_copy->label; 374 ssize_t ret; 375 376 spin_lock(&fs_info->super_lock); 377 ret = snprintf(buf, PAGE_SIZE, label[0] ? "%s\n" : "%s", label); 378 spin_unlock(&fs_info->super_lock); 379 380 return ret; 381 } 382 383 static ssize_t btrfs_label_store(struct kobject *kobj, 384 struct kobj_attribute *a, 385 const char *buf, size_t len) 386 { 387 struct btrfs_fs_info *fs_info = to_fs_info(kobj); 388 size_t p_len; 389 390 if (!fs_info) 391 return -EPERM; 392 393 if (sb_rdonly(fs_info->sb)) 394 return -EROFS; 395 396 /* 397 * p_len is the len until the first occurrence of either 398 * '\n' or '\0' 399 */ 400 p_len = strcspn(buf, "\n"); 401 402 if (p_len >= BTRFS_LABEL_SIZE) 403 return -EINVAL; 404 405 spin_lock(&fs_info->super_lock); 406 memset(fs_info->super_copy->label, 0, BTRFS_LABEL_SIZE); 407 memcpy(fs_info->super_copy->label, buf, p_len); 408 spin_unlock(&fs_info->super_lock); 409 410 /* 411 * We don't want to do full transaction commit from inside sysfs 412 */ 413 btrfs_set_pending(fs_info, COMMIT); 414 wake_up_process(fs_info->transaction_kthread); 415 416 return len; 417 } 418 BTRFS_ATTR_RW(label, btrfs_label_show, btrfs_label_store); 419 420 static ssize_t btrfs_nodesize_show(struct kobject *kobj, 421 struct kobj_attribute *a, char *buf) 422 { 423 struct btrfs_fs_info *fs_info = to_fs_info(kobj); 424 425 return snprintf(buf, PAGE_SIZE, "%u\n", fs_info->super_copy->nodesize); 426 } 427 428 BTRFS_ATTR(nodesize, btrfs_nodesize_show); 429 430 static ssize_t btrfs_sectorsize_show(struct kobject *kobj, 431 struct kobj_attribute *a, char *buf) 432 { 433 struct btrfs_fs_info *fs_info = to_fs_info(kobj); 434 435 return snprintf(buf, PAGE_SIZE, "%u\n", 436 fs_info->super_copy->sectorsize); 437 } 438 439 BTRFS_ATTR(sectorsize, btrfs_sectorsize_show); 440 441 static ssize_t btrfs_clone_alignment_show(struct kobject *kobj, 442 struct kobj_attribute *a, char *buf) 443 { 444 struct btrfs_fs_info *fs_info = to_fs_info(kobj); 445 446 return snprintf(buf, PAGE_SIZE, "%u\n", 447 fs_info->super_copy->sectorsize); 448 } 449 450 BTRFS_ATTR(clone_alignment, btrfs_clone_alignment_show); 451 452 static ssize_t quota_override_show(struct kobject *kobj, 453 struct kobj_attribute *a, char *buf) 454 { 455 struct btrfs_fs_info *fs_info = to_fs_info(kobj); 456 int quota_override; 457 458 quota_override = test_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags); 459 return snprintf(buf, PAGE_SIZE, "%d\n", quota_override); 460 } 461 462 static ssize_t quota_override_store(struct kobject *kobj, 463 struct kobj_attribute *a, 464 const char *buf, size_t len) 465 { 466 struct btrfs_fs_info *fs_info = to_fs_info(kobj); 467 unsigned long knob; 468 int err; 469 470 if (!fs_info) 471 return -EPERM; 472 473 if (!capable(CAP_SYS_RESOURCE)) 474 return -EPERM; 475 476 err = kstrtoul(buf, 10, &knob); 477 if (err) 478 return err; 479 if (knob > 1) 480 return -EINVAL; 481 482 if (knob) 483 set_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags); 484 else 485 clear_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags); 486 487 return len; 488 } 489 490 BTRFS_ATTR_RW(quota_override, quota_override_show, quota_override_store); 491 492 static const struct attribute *btrfs_attrs[] = { 493 BTRFS_ATTR_PTR(label), 494 BTRFS_ATTR_PTR(nodesize), 495 BTRFS_ATTR_PTR(sectorsize), 496 BTRFS_ATTR_PTR(clone_alignment), 497 BTRFS_ATTR_PTR(quota_override), 498 NULL, 499 }; 500 501 static void btrfs_release_fsid_kobj(struct kobject *kobj) 502 { 503 struct btrfs_fs_devices *fs_devs = to_fs_devs(kobj); 504 505 memset(&fs_devs->fsid_kobj, 0, sizeof(struct kobject)); 506 complete(&fs_devs->kobj_unregister); 507 } 508 509 static struct kobj_type btrfs_ktype = { 510 .sysfs_ops = &kobj_sysfs_ops, 511 .release = btrfs_release_fsid_kobj, 512 }; 513 514 static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj) 515 { 516 if (kobj->ktype != &btrfs_ktype) 517 return NULL; 518 return container_of(kobj, struct btrfs_fs_devices, fsid_kobj); 519 } 520 521 static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj) 522 { 523 if (kobj->ktype != &btrfs_ktype) 524 return NULL; 525 return to_fs_devs(kobj)->fs_info; 526 } 527 528 #define NUM_FEATURE_BITS 64 529 static char btrfs_unknown_feature_names[3][NUM_FEATURE_BITS][13]; 530 static struct btrfs_feature_attr btrfs_feature_attrs[3][NUM_FEATURE_BITS]; 531 532 static const u64 supported_feature_masks[3] = { 533 [FEAT_COMPAT] = BTRFS_FEATURE_COMPAT_SUPP, 534 [FEAT_COMPAT_RO] = BTRFS_FEATURE_COMPAT_RO_SUPP, 535 [FEAT_INCOMPAT] = BTRFS_FEATURE_INCOMPAT_SUPP, 536 }; 537 538 static int addrm_unknown_feature_attrs(struct btrfs_fs_info *fs_info, bool add) 539 { 540 int set; 541 542 for (set = 0; set < FEAT_MAX; set++) { 543 int i; 544 struct attribute *attrs[2]; 545 struct attribute_group agroup = { 546 .name = "features", 547 .attrs = attrs, 548 }; 549 u64 features = get_features(fs_info, set); 550 features &= ~supported_feature_masks[set]; 551 552 if (!features) 553 continue; 554 555 attrs[1] = NULL; 556 for (i = 0; i < NUM_FEATURE_BITS; i++) { 557 struct btrfs_feature_attr *fa; 558 559 if (!(features & (1ULL << i))) 560 continue; 561 562 fa = &btrfs_feature_attrs[set][i]; 563 attrs[0] = &fa->kobj_attr.attr; 564 if (add) { 565 int ret; 566 ret = sysfs_merge_group(&fs_info->fs_devices->fsid_kobj, 567 &agroup); 568 if (ret) 569 return ret; 570 } else 571 sysfs_unmerge_group(&fs_info->fs_devices->fsid_kobj, 572 &agroup); 573 } 574 575 } 576 return 0; 577 } 578 579 static void __btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs) 580 { 581 if (fs_devs->device_dir_kobj) { 582 kobject_del(fs_devs->device_dir_kobj); 583 kobject_put(fs_devs->device_dir_kobj); 584 fs_devs->device_dir_kobj = NULL; 585 } 586 587 if (fs_devs->fsid_kobj.state_initialized) { 588 kobject_del(&fs_devs->fsid_kobj); 589 kobject_put(&fs_devs->fsid_kobj); 590 wait_for_completion(&fs_devs->kobj_unregister); 591 } 592 } 593 594 /* when fs_devs is NULL it will remove all fsid kobject */ 595 void btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs) 596 { 597 struct list_head *fs_uuids = btrfs_get_fs_uuids(); 598 599 if (fs_devs) { 600 __btrfs_sysfs_remove_fsid(fs_devs); 601 return; 602 } 603 604 list_for_each_entry(fs_devs, fs_uuids, list) { 605 __btrfs_sysfs_remove_fsid(fs_devs); 606 } 607 } 608 609 void btrfs_sysfs_remove_mounted(struct btrfs_fs_info *fs_info) 610 { 611 btrfs_reset_fs_info_ptr(fs_info); 612 613 if (fs_info->space_info_kobj) { 614 sysfs_remove_files(fs_info->space_info_kobj, allocation_attrs); 615 kobject_del(fs_info->space_info_kobj); 616 kobject_put(fs_info->space_info_kobj); 617 } 618 addrm_unknown_feature_attrs(fs_info, false); 619 sysfs_remove_group(&fs_info->fs_devices->fsid_kobj, &btrfs_feature_attr_group); 620 sysfs_remove_files(&fs_info->fs_devices->fsid_kobj, btrfs_attrs); 621 btrfs_sysfs_rm_device_link(fs_info->fs_devices, NULL); 622 } 623 624 const char * const btrfs_feature_set_names[3] = { 625 [FEAT_COMPAT] = "compat", 626 [FEAT_COMPAT_RO] = "compat_ro", 627 [FEAT_INCOMPAT] = "incompat", 628 }; 629 630 char *btrfs_printable_features(enum btrfs_feature_set set, u64 flags) 631 { 632 size_t bufsize = 4096; /* safe max, 64 names * 64 bytes */ 633 int len = 0; 634 int i; 635 char *str; 636 637 str = kmalloc(bufsize, GFP_KERNEL); 638 if (!str) 639 return str; 640 641 for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) { 642 const char *name; 643 644 if (!(flags & (1ULL << i))) 645 continue; 646 647 name = btrfs_feature_attrs[set][i].kobj_attr.attr.name; 648 len += snprintf(str + len, bufsize - len, "%s%s", 649 len ? "," : "", name); 650 } 651 652 return str; 653 } 654 655 static void init_feature_attrs(void) 656 { 657 struct btrfs_feature_attr *fa; 658 int set, i; 659 660 BUILD_BUG_ON(ARRAY_SIZE(btrfs_unknown_feature_names) != 661 ARRAY_SIZE(btrfs_feature_attrs)); 662 BUILD_BUG_ON(ARRAY_SIZE(btrfs_unknown_feature_names[0]) != 663 ARRAY_SIZE(btrfs_feature_attrs[0])); 664 665 memset(btrfs_feature_attrs, 0, sizeof(btrfs_feature_attrs)); 666 memset(btrfs_unknown_feature_names, 0, 667 sizeof(btrfs_unknown_feature_names)); 668 669 for (i = 0; btrfs_supported_feature_attrs[i]; i++) { 670 struct btrfs_feature_attr *sfa; 671 struct attribute *a = btrfs_supported_feature_attrs[i]; 672 int bit; 673 sfa = attr_to_btrfs_feature_attr(a); 674 bit = ilog2(sfa->feature_bit); 675 fa = &btrfs_feature_attrs[sfa->feature_set][bit]; 676 677 fa->kobj_attr.attr.name = sfa->kobj_attr.attr.name; 678 } 679 680 for (set = 0; set < FEAT_MAX; set++) { 681 for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) { 682 char *name = btrfs_unknown_feature_names[set][i]; 683 fa = &btrfs_feature_attrs[set][i]; 684 685 if (fa->kobj_attr.attr.name) 686 continue; 687 688 snprintf(name, 13, "%s:%u", 689 btrfs_feature_set_names[set], i); 690 691 fa->kobj_attr.attr.name = name; 692 fa->kobj_attr.attr.mode = S_IRUGO; 693 fa->feature_set = set; 694 fa->feature_bit = 1ULL << i; 695 } 696 } 697 } 698 699 /* when one_device is NULL, it removes all device links */ 700 701 int btrfs_sysfs_rm_device_link(struct btrfs_fs_devices *fs_devices, 702 struct btrfs_device *one_device) 703 { 704 struct hd_struct *disk; 705 struct kobject *disk_kobj; 706 707 if (!fs_devices->device_dir_kobj) 708 return -EINVAL; 709 710 if (one_device && one_device->bdev) { 711 disk = one_device->bdev->bd_part; 712 disk_kobj = &part_to_dev(disk)->kobj; 713 714 sysfs_remove_link(fs_devices->device_dir_kobj, 715 disk_kobj->name); 716 } 717 718 if (one_device) 719 return 0; 720 721 list_for_each_entry(one_device, 722 &fs_devices->devices, dev_list) { 723 if (!one_device->bdev) 724 continue; 725 disk = one_device->bdev->bd_part; 726 disk_kobj = &part_to_dev(disk)->kobj; 727 728 sysfs_remove_link(fs_devices->device_dir_kobj, 729 disk_kobj->name); 730 } 731 732 return 0; 733 } 734 735 int btrfs_sysfs_add_device(struct btrfs_fs_devices *fs_devs) 736 { 737 if (!fs_devs->device_dir_kobj) 738 fs_devs->device_dir_kobj = kobject_create_and_add("devices", 739 &fs_devs->fsid_kobj); 740 741 if (!fs_devs->device_dir_kobj) 742 return -ENOMEM; 743 744 return 0; 745 } 746 747 int btrfs_sysfs_add_device_link(struct btrfs_fs_devices *fs_devices, 748 struct btrfs_device *one_device) 749 { 750 int error = 0; 751 struct btrfs_device *dev; 752 753 list_for_each_entry(dev, &fs_devices->devices, dev_list) { 754 struct hd_struct *disk; 755 struct kobject *disk_kobj; 756 757 if (!dev->bdev) 758 continue; 759 760 if (one_device && one_device != dev) 761 continue; 762 763 disk = dev->bdev->bd_part; 764 disk_kobj = &part_to_dev(disk)->kobj; 765 766 error = sysfs_create_link(fs_devices->device_dir_kobj, 767 disk_kobj, disk_kobj->name); 768 if (error) 769 break; 770 } 771 772 return error; 773 } 774 775 /* /sys/fs/btrfs/ entry */ 776 static struct kset *btrfs_kset; 777 778 /* /sys/kernel/debug/btrfs */ 779 static struct dentry *btrfs_debugfs_root_dentry; 780 781 /* Debugging tunables and exported data */ 782 u64 btrfs_debugfs_test; 783 784 /* 785 * Can be called by the device discovery thread. 786 * And parent can be specified for seed device 787 */ 788 int btrfs_sysfs_add_fsid(struct btrfs_fs_devices *fs_devs, 789 struct kobject *parent) 790 { 791 int error; 792 793 init_completion(&fs_devs->kobj_unregister); 794 fs_devs->fsid_kobj.kset = btrfs_kset; 795 error = kobject_init_and_add(&fs_devs->fsid_kobj, 796 &btrfs_ktype, parent, "%pU", fs_devs->fsid); 797 return error; 798 } 799 800 int btrfs_sysfs_add_mounted(struct btrfs_fs_info *fs_info) 801 { 802 int error; 803 struct btrfs_fs_devices *fs_devs = fs_info->fs_devices; 804 struct kobject *fsid_kobj = &fs_devs->fsid_kobj; 805 806 btrfs_set_fs_info_ptr(fs_info); 807 808 error = btrfs_sysfs_add_device_link(fs_devs, NULL); 809 if (error) 810 return error; 811 812 error = sysfs_create_files(fsid_kobj, btrfs_attrs); 813 if (error) { 814 btrfs_sysfs_rm_device_link(fs_devs, NULL); 815 return error; 816 } 817 818 error = sysfs_create_group(fsid_kobj, 819 &btrfs_feature_attr_group); 820 if (error) 821 goto failure; 822 823 error = addrm_unknown_feature_attrs(fs_info, true); 824 if (error) 825 goto failure; 826 827 fs_info->space_info_kobj = kobject_create_and_add("allocation", 828 fsid_kobj); 829 if (!fs_info->space_info_kobj) { 830 error = -ENOMEM; 831 goto failure; 832 } 833 834 error = sysfs_create_files(fs_info->space_info_kobj, allocation_attrs); 835 if (error) 836 goto failure; 837 838 return 0; 839 failure: 840 btrfs_sysfs_remove_mounted(fs_info); 841 return error; 842 } 843 844 845 /* 846 * Change per-fs features in /sys/fs/btrfs/UUID/features to match current 847 * values in superblock. Call after any changes to incompat/compat_ro flags 848 */ 849 void btrfs_sysfs_feature_update(struct btrfs_fs_info *fs_info, 850 u64 bit, enum btrfs_feature_set set) 851 { 852 struct btrfs_fs_devices *fs_devs; 853 struct kobject *fsid_kobj; 854 u64 features; 855 int ret; 856 857 if (!fs_info) 858 return; 859 860 features = get_features(fs_info, set); 861 ASSERT(bit & supported_feature_masks[set]); 862 863 fs_devs = fs_info->fs_devices; 864 fsid_kobj = &fs_devs->fsid_kobj; 865 866 if (!fsid_kobj->state_initialized) 867 return; 868 869 /* 870 * FIXME: this is too heavy to update just one value, ideally we'd like 871 * to use sysfs_update_group but some refactoring is needed first. 872 */ 873 sysfs_remove_group(fsid_kobj, &btrfs_feature_attr_group); 874 ret = sysfs_create_group(fsid_kobj, &btrfs_feature_attr_group); 875 } 876 877 static int btrfs_init_debugfs(void) 878 { 879 #ifdef CONFIG_DEBUG_FS 880 btrfs_debugfs_root_dentry = debugfs_create_dir("btrfs", NULL); 881 if (!btrfs_debugfs_root_dentry) 882 return -ENOMEM; 883 884 /* 885 * Example code, how to export data through debugfs. 886 * 887 * file: /sys/kernel/debug/btrfs/test 888 * contents of: btrfs_debugfs_test 889 */ 890 #ifdef CONFIG_BTRFS_DEBUG 891 debugfs_create_u64("test", S_IRUGO | S_IWUSR, btrfs_debugfs_root_dentry, 892 &btrfs_debugfs_test); 893 #endif 894 895 #endif 896 return 0; 897 } 898 899 int btrfs_init_sysfs(void) 900 { 901 int ret; 902 903 btrfs_kset = kset_create_and_add("btrfs", NULL, fs_kobj); 904 if (!btrfs_kset) 905 return -ENOMEM; 906 907 ret = btrfs_init_debugfs(); 908 if (ret) 909 goto out1; 910 911 init_feature_attrs(); 912 ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_feature_attr_group); 913 if (ret) 914 goto out2; 915 916 return 0; 917 out2: 918 debugfs_remove_recursive(btrfs_debugfs_root_dentry); 919 out1: 920 kset_unregister(btrfs_kset); 921 922 return ret; 923 } 924 925 void btrfs_exit_sysfs(void) 926 { 927 sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group); 928 kset_unregister(btrfs_kset); 929 debugfs_remove_recursive(btrfs_debugfs_root_dentry); 930 } 931 932