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(allocation, 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(allocation, 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_ATTR(raid, total_bytes, raid_bytes_show); 267 BTRFS_ATTR(raid, 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_ATTR_PTR(raid, 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_ATTR_PTR(raid, total_bytes), 291 BTRFS_ATTR_PTR(raid, 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(space_info, 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(space_info, total_bytes_pinned, 335 btrfs_space_info_show_total_bytes_pinned); 336 337 static struct attribute *space_info_attrs[] = { 338 BTRFS_ATTR_PTR(space_info, flags), 339 BTRFS_ATTR_PTR(space_info, total_bytes), 340 BTRFS_ATTR_PTR(space_info, bytes_used), 341 BTRFS_ATTR_PTR(space_info, bytes_pinned), 342 BTRFS_ATTR_PTR(space_info, bytes_reserved), 343 BTRFS_ATTR_PTR(space_info, bytes_may_use), 344 BTRFS_ATTR_PTR(space_info, bytes_readonly), 345 BTRFS_ATTR_PTR(space_info, disk_used), 346 BTRFS_ATTR_PTR(space_info, disk_total), 347 BTRFS_ATTR_PTR(space_info, total_bytes_pinned), 348 NULL, 349 }; 350 351 static void space_info_release(struct kobject *kobj) 352 { 353 struct btrfs_space_info *sinfo = to_space_info(kobj); 354 percpu_counter_destroy(&sinfo->total_bytes_pinned); 355 kfree(sinfo); 356 } 357 358 struct kobj_type space_info_ktype = { 359 .sysfs_ops = &kobj_sysfs_ops, 360 .release = space_info_release, 361 .default_attrs = space_info_attrs, 362 }; 363 364 static const struct attribute *allocation_attrs[] = { 365 BTRFS_ATTR_PTR(allocation, global_rsv_reserved), 366 BTRFS_ATTR_PTR(allocation, global_rsv_size), 367 NULL, 368 }; 369 370 static ssize_t btrfs_label_show(struct kobject *kobj, 371 struct kobj_attribute *a, char *buf) 372 { 373 struct btrfs_fs_info *fs_info = to_fs_info(kobj); 374 char *label = fs_info->super_copy->label; 375 ssize_t ret; 376 377 spin_lock(&fs_info->super_lock); 378 ret = snprintf(buf, PAGE_SIZE, label[0] ? "%s\n" : "%s", label); 379 spin_unlock(&fs_info->super_lock); 380 381 return ret; 382 } 383 384 static ssize_t btrfs_label_store(struct kobject *kobj, 385 struct kobj_attribute *a, 386 const char *buf, size_t len) 387 { 388 struct btrfs_fs_info *fs_info = to_fs_info(kobj); 389 size_t p_len; 390 391 if (!fs_info) 392 return -EPERM; 393 394 if (sb_rdonly(fs_info->sb)) 395 return -EROFS; 396 397 /* 398 * p_len is the len until the first occurrence of either 399 * '\n' or '\0' 400 */ 401 p_len = strcspn(buf, "\n"); 402 403 if (p_len >= BTRFS_LABEL_SIZE) 404 return -EINVAL; 405 406 spin_lock(&fs_info->super_lock); 407 memset(fs_info->super_copy->label, 0, BTRFS_LABEL_SIZE); 408 memcpy(fs_info->super_copy->label, buf, p_len); 409 spin_unlock(&fs_info->super_lock); 410 411 /* 412 * We don't want to do full transaction commit from inside sysfs 413 */ 414 btrfs_set_pending(fs_info, COMMIT); 415 wake_up_process(fs_info->transaction_kthread); 416 417 return len; 418 } 419 BTRFS_ATTR_RW(, label, btrfs_label_show, btrfs_label_store); 420 421 static ssize_t btrfs_nodesize_show(struct kobject *kobj, 422 struct kobj_attribute *a, char *buf) 423 { 424 struct btrfs_fs_info *fs_info = to_fs_info(kobj); 425 426 return snprintf(buf, PAGE_SIZE, "%u\n", fs_info->super_copy->nodesize); 427 } 428 429 BTRFS_ATTR(, nodesize, btrfs_nodesize_show); 430 431 static ssize_t btrfs_sectorsize_show(struct kobject *kobj, 432 struct kobj_attribute *a, char *buf) 433 { 434 struct btrfs_fs_info *fs_info = to_fs_info(kobj); 435 436 return snprintf(buf, PAGE_SIZE, "%u\n", 437 fs_info->super_copy->sectorsize); 438 } 439 440 BTRFS_ATTR(, sectorsize, btrfs_sectorsize_show); 441 442 static ssize_t btrfs_clone_alignment_show(struct kobject *kobj, 443 struct kobj_attribute *a, char *buf) 444 { 445 struct btrfs_fs_info *fs_info = to_fs_info(kobj); 446 447 return snprintf(buf, PAGE_SIZE, "%u\n", 448 fs_info->super_copy->sectorsize); 449 } 450 451 BTRFS_ATTR(, clone_alignment, btrfs_clone_alignment_show); 452 453 static ssize_t quota_override_show(struct kobject *kobj, 454 struct kobj_attribute *a, char *buf) 455 { 456 struct btrfs_fs_info *fs_info = to_fs_info(kobj); 457 int quota_override; 458 459 quota_override = test_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags); 460 return snprintf(buf, PAGE_SIZE, "%d\n", quota_override); 461 } 462 463 static ssize_t quota_override_store(struct kobject *kobj, 464 struct kobj_attribute *a, 465 const char *buf, size_t len) 466 { 467 struct btrfs_fs_info *fs_info = to_fs_info(kobj); 468 unsigned long knob; 469 int err; 470 471 if (!fs_info) 472 return -EPERM; 473 474 if (!capable(CAP_SYS_RESOURCE)) 475 return -EPERM; 476 477 err = kstrtoul(buf, 10, &knob); 478 if (err) 479 return err; 480 if (knob > 1) 481 return -EINVAL; 482 483 if (knob) 484 set_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags); 485 else 486 clear_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags); 487 488 return len; 489 } 490 491 BTRFS_ATTR_RW(, quota_override, quota_override_show, quota_override_store); 492 493 static const struct attribute *btrfs_attrs[] = { 494 BTRFS_ATTR_PTR(, label), 495 BTRFS_ATTR_PTR(, nodesize), 496 BTRFS_ATTR_PTR(, sectorsize), 497 BTRFS_ATTR_PTR(, clone_alignment), 498 BTRFS_ATTR_PTR(, quota_override), 499 NULL, 500 }; 501 502 static void btrfs_release_fsid_kobj(struct kobject *kobj) 503 { 504 struct btrfs_fs_devices *fs_devs = to_fs_devs(kobj); 505 506 memset(&fs_devs->fsid_kobj, 0, sizeof(struct kobject)); 507 complete(&fs_devs->kobj_unregister); 508 } 509 510 static struct kobj_type btrfs_ktype = { 511 .sysfs_ops = &kobj_sysfs_ops, 512 .release = btrfs_release_fsid_kobj, 513 }; 514 515 static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj) 516 { 517 if (kobj->ktype != &btrfs_ktype) 518 return NULL; 519 return container_of(kobj, struct btrfs_fs_devices, fsid_kobj); 520 } 521 522 static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj) 523 { 524 if (kobj->ktype != &btrfs_ktype) 525 return NULL; 526 return to_fs_devs(kobj)->fs_info; 527 } 528 529 #define NUM_FEATURE_BITS 64 530 static char btrfs_unknown_feature_names[3][NUM_FEATURE_BITS][13]; 531 static struct btrfs_feature_attr btrfs_feature_attrs[3][NUM_FEATURE_BITS]; 532 533 static const u64 supported_feature_masks[3] = { 534 [FEAT_COMPAT] = BTRFS_FEATURE_COMPAT_SUPP, 535 [FEAT_COMPAT_RO] = BTRFS_FEATURE_COMPAT_RO_SUPP, 536 [FEAT_INCOMPAT] = BTRFS_FEATURE_INCOMPAT_SUPP, 537 }; 538 539 static int addrm_unknown_feature_attrs(struct btrfs_fs_info *fs_info, bool add) 540 { 541 int set; 542 543 for (set = 0; set < FEAT_MAX; set++) { 544 int i; 545 struct attribute *attrs[2]; 546 struct attribute_group agroup = { 547 .name = "features", 548 .attrs = attrs, 549 }; 550 u64 features = get_features(fs_info, set); 551 features &= ~supported_feature_masks[set]; 552 553 if (!features) 554 continue; 555 556 attrs[1] = NULL; 557 for (i = 0; i < NUM_FEATURE_BITS; i++) { 558 struct btrfs_feature_attr *fa; 559 560 if (!(features & (1ULL << i))) 561 continue; 562 563 fa = &btrfs_feature_attrs[set][i]; 564 attrs[0] = &fa->kobj_attr.attr; 565 if (add) { 566 int ret; 567 ret = sysfs_merge_group(&fs_info->fs_devices->fsid_kobj, 568 &agroup); 569 if (ret) 570 return ret; 571 } else 572 sysfs_unmerge_group(&fs_info->fs_devices->fsid_kobj, 573 &agroup); 574 } 575 576 } 577 return 0; 578 } 579 580 static void __btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs) 581 { 582 if (fs_devs->device_dir_kobj) { 583 kobject_del(fs_devs->device_dir_kobj); 584 kobject_put(fs_devs->device_dir_kobj); 585 fs_devs->device_dir_kobj = NULL; 586 } 587 588 if (fs_devs->fsid_kobj.state_initialized) { 589 kobject_del(&fs_devs->fsid_kobj); 590 kobject_put(&fs_devs->fsid_kobj); 591 wait_for_completion(&fs_devs->kobj_unregister); 592 } 593 } 594 595 /* when fs_devs is NULL it will remove all fsid kobject */ 596 void btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs) 597 { 598 struct list_head *fs_uuids = btrfs_get_fs_uuids(); 599 600 if (fs_devs) { 601 __btrfs_sysfs_remove_fsid(fs_devs); 602 return; 603 } 604 605 list_for_each_entry(fs_devs, fs_uuids, list) { 606 __btrfs_sysfs_remove_fsid(fs_devs); 607 } 608 } 609 610 void btrfs_sysfs_remove_mounted(struct btrfs_fs_info *fs_info) 611 { 612 btrfs_reset_fs_info_ptr(fs_info); 613 614 if (fs_info->space_info_kobj) { 615 sysfs_remove_files(fs_info->space_info_kobj, allocation_attrs); 616 kobject_del(fs_info->space_info_kobj); 617 kobject_put(fs_info->space_info_kobj); 618 } 619 addrm_unknown_feature_attrs(fs_info, false); 620 sysfs_remove_group(&fs_info->fs_devices->fsid_kobj, &btrfs_feature_attr_group); 621 sysfs_remove_files(&fs_info->fs_devices->fsid_kobj, btrfs_attrs); 622 btrfs_sysfs_rm_device_link(fs_info->fs_devices, NULL); 623 } 624 625 const char * const btrfs_feature_set_names[3] = { 626 [FEAT_COMPAT] = "compat", 627 [FEAT_COMPAT_RO] = "compat_ro", 628 [FEAT_INCOMPAT] = "incompat", 629 }; 630 631 char *btrfs_printable_features(enum btrfs_feature_set set, u64 flags) 632 { 633 size_t bufsize = 4096; /* safe max, 64 names * 64 bytes */ 634 int len = 0; 635 int i; 636 char *str; 637 638 str = kmalloc(bufsize, GFP_KERNEL); 639 if (!str) 640 return str; 641 642 for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) { 643 const char *name; 644 645 if (!(flags & (1ULL << i))) 646 continue; 647 648 name = btrfs_feature_attrs[set][i].kobj_attr.attr.name; 649 len += snprintf(str + len, bufsize - len, "%s%s", 650 len ? "," : "", name); 651 } 652 653 return str; 654 } 655 656 static void init_feature_attrs(void) 657 { 658 struct btrfs_feature_attr *fa; 659 int set, i; 660 661 BUILD_BUG_ON(ARRAY_SIZE(btrfs_unknown_feature_names) != 662 ARRAY_SIZE(btrfs_feature_attrs)); 663 BUILD_BUG_ON(ARRAY_SIZE(btrfs_unknown_feature_names[0]) != 664 ARRAY_SIZE(btrfs_feature_attrs[0])); 665 666 memset(btrfs_feature_attrs, 0, sizeof(btrfs_feature_attrs)); 667 memset(btrfs_unknown_feature_names, 0, 668 sizeof(btrfs_unknown_feature_names)); 669 670 for (i = 0; btrfs_supported_feature_attrs[i]; i++) { 671 struct btrfs_feature_attr *sfa; 672 struct attribute *a = btrfs_supported_feature_attrs[i]; 673 int bit; 674 sfa = attr_to_btrfs_feature_attr(a); 675 bit = ilog2(sfa->feature_bit); 676 fa = &btrfs_feature_attrs[sfa->feature_set][bit]; 677 678 fa->kobj_attr.attr.name = sfa->kobj_attr.attr.name; 679 } 680 681 for (set = 0; set < FEAT_MAX; set++) { 682 for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) { 683 char *name = btrfs_unknown_feature_names[set][i]; 684 fa = &btrfs_feature_attrs[set][i]; 685 686 if (fa->kobj_attr.attr.name) 687 continue; 688 689 snprintf(name, 13, "%s:%u", 690 btrfs_feature_set_names[set], i); 691 692 fa->kobj_attr.attr.name = name; 693 fa->kobj_attr.attr.mode = S_IRUGO; 694 fa->feature_set = set; 695 fa->feature_bit = 1ULL << i; 696 } 697 } 698 } 699 700 /* when one_device is NULL, it removes all device links */ 701 702 int btrfs_sysfs_rm_device_link(struct btrfs_fs_devices *fs_devices, 703 struct btrfs_device *one_device) 704 { 705 struct hd_struct *disk; 706 struct kobject *disk_kobj; 707 708 if (!fs_devices->device_dir_kobj) 709 return -EINVAL; 710 711 if (one_device && one_device->bdev) { 712 disk = one_device->bdev->bd_part; 713 disk_kobj = &part_to_dev(disk)->kobj; 714 715 sysfs_remove_link(fs_devices->device_dir_kobj, 716 disk_kobj->name); 717 } 718 719 if (one_device) 720 return 0; 721 722 list_for_each_entry(one_device, 723 &fs_devices->devices, dev_list) { 724 if (!one_device->bdev) 725 continue; 726 disk = one_device->bdev->bd_part; 727 disk_kobj = &part_to_dev(disk)->kobj; 728 729 sysfs_remove_link(fs_devices->device_dir_kobj, 730 disk_kobj->name); 731 } 732 733 return 0; 734 } 735 736 int btrfs_sysfs_add_device(struct btrfs_fs_devices *fs_devs) 737 { 738 if (!fs_devs->device_dir_kobj) 739 fs_devs->device_dir_kobj = kobject_create_and_add("devices", 740 &fs_devs->fsid_kobj); 741 742 if (!fs_devs->device_dir_kobj) 743 return -ENOMEM; 744 745 return 0; 746 } 747 748 int btrfs_sysfs_add_device_link(struct btrfs_fs_devices *fs_devices, 749 struct btrfs_device *one_device) 750 { 751 int error = 0; 752 struct btrfs_device *dev; 753 754 list_for_each_entry(dev, &fs_devices->devices, dev_list) { 755 struct hd_struct *disk; 756 struct kobject *disk_kobj; 757 758 if (!dev->bdev) 759 continue; 760 761 if (one_device && one_device != dev) 762 continue; 763 764 disk = dev->bdev->bd_part; 765 disk_kobj = &part_to_dev(disk)->kobj; 766 767 error = sysfs_create_link(fs_devices->device_dir_kobj, 768 disk_kobj, disk_kobj->name); 769 if (error) 770 break; 771 } 772 773 return error; 774 } 775 776 /* /sys/fs/btrfs/ entry */ 777 static struct kset *btrfs_kset; 778 779 /* /sys/kernel/debug/btrfs */ 780 static struct dentry *btrfs_debugfs_root_dentry; 781 782 /* Debugging tunables and exported data */ 783 u64 btrfs_debugfs_test; 784 785 /* 786 * Can be called by the device discovery thread. 787 * And parent can be specified for seed device 788 */ 789 int btrfs_sysfs_add_fsid(struct btrfs_fs_devices *fs_devs, 790 struct kobject *parent) 791 { 792 int error; 793 794 init_completion(&fs_devs->kobj_unregister); 795 fs_devs->fsid_kobj.kset = btrfs_kset; 796 error = kobject_init_and_add(&fs_devs->fsid_kobj, 797 &btrfs_ktype, parent, "%pU", fs_devs->fsid); 798 return error; 799 } 800 801 int btrfs_sysfs_add_mounted(struct btrfs_fs_info *fs_info) 802 { 803 int error; 804 struct btrfs_fs_devices *fs_devs = fs_info->fs_devices; 805 struct kobject *fsid_kobj = &fs_devs->fsid_kobj; 806 807 btrfs_set_fs_info_ptr(fs_info); 808 809 error = btrfs_sysfs_add_device_link(fs_devs, NULL); 810 if (error) 811 return error; 812 813 error = sysfs_create_files(fsid_kobj, btrfs_attrs); 814 if (error) { 815 btrfs_sysfs_rm_device_link(fs_devs, NULL); 816 return error; 817 } 818 819 error = sysfs_create_group(fsid_kobj, 820 &btrfs_feature_attr_group); 821 if (error) 822 goto failure; 823 824 error = addrm_unknown_feature_attrs(fs_info, true); 825 if (error) 826 goto failure; 827 828 fs_info->space_info_kobj = kobject_create_and_add("allocation", 829 fsid_kobj); 830 if (!fs_info->space_info_kobj) { 831 error = -ENOMEM; 832 goto failure; 833 } 834 835 error = sysfs_create_files(fs_info->space_info_kobj, allocation_attrs); 836 if (error) 837 goto failure; 838 839 return 0; 840 failure: 841 btrfs_sysfs_remove_mounted(fs_info); 842 return error; 843 } 844 845 846 /* 847 * Change per-fs features in /sys/fs/btrfs/UUID/features to match current 848 * values in superblock. Call after any changes to incompat/compat_ro flags 849 */ 850 void btrfs_sysfs_feature_update(struct btrfs_fs_info *fs_info, 851 u64 bit, enum btrfs_feature_set set) 852 { 853 struct btrfs_fs_devices *fs_devs; 854 struct kobject *fsid_kobj; 855 u64 features; 856 int ret; 857 858 if (!fs_info) 859 return; 860 861 features = get_features(fs_info, set); 862 ASSERT(bit & supported_feature_masks[set]); 863 864 fs_devs = fs_info->fs_devices; 865 fsid_kobj = &fs_devs->fsid_kobj; 866 867 if (!fsid_kobj->state_initialized) 868 return; 869 870 /* 871 * FIXME: this is too heavy to update just one value, ideally we'd like 872 * to use sysfs_update_group but some refactoring is needed first. 873 */ 874 sysfs_remove_group(fsid_kobj, &btrfs_feature_attr_group); 875 ret = sysfs_create_group(fsid_kobj, &btrfs_feature_attr_group); 876 } 877 878 static int btrfs_init_debugfs(void) 879 { 880 #ifdef CONFIG_DEBUG_FS 881 btrfs_debugfs_root_dentry = debugfs_create_dir("btrfs", NULL); 882 if (!btrfs_debugfs_root_dentry) 883 return -ENOMEM; 884 885 /* 886 * Example code, how to export data through debugfs. 887 * 888 * file: /sys/kernel/debug/btrfs/test 889 * contents of: btrfs_debugfs_test 890 */ 891 #ifdef CONFIG_BTRFS_DEBUG 892 debugfs_create_u64("test", S_IRUGO | S_IWUSR, btrfs_debugfs_root_dentry, 893 &btrfs_debugfs_test); 894 #endif 895 896 #endif 897 return 0; 898 } 899 900 int btrfs_init_sysfs(void) 901 { 902 int ret; 903 904 btrfs_kset = kset_create_and_add("btrfs", NULL, fs_kobj); 905 if (!btrfs_kset) 906 return -ENOMEM; 907 908 ret = btrfs_init_debugfs(); 909 if (ret) 910 goto out1; 911 912 init_feature_attrs(); 913 ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_feature_attr_group); 914 if (ret) 915 goto out2; 916 917 return 0; 918 out2: 919 debugfs_remove_recursive(btrfs_debugfs_root_dentry); 920 out1: 921 kset_unregister(btrfs_kset); 922 923 return ret; 924 } 925 926 void btrfs_exit_sysfs(void) 927 { 928 sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group); 929 kset_unregister(btrfs_kset); 930 debugfs_remove_recursive(btrfs_debugfs_root_dentry); 931 } 932 933