fs/btrfs/sysfs.c

   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/sched/mm.h>
   8 #include <linux/slab.h>
   9 #include <linux/spinlock.h>
  10 #include <linux/completion.h>
  11 #include <linux/bug.h>
  12 #include <crypto/hash.h>
  13
  14 #include "ctree.h"
  15 #include "discard.h"
  16 #include "disk-io.h"
  17 #include "send.h"
  18 #include "transaction.h"
  19 #include "sysfs.h"
  20 #include "volumes.h"
  21 #include "space-info.h"
  22 #include "block-group.h"
  23 #include "qgroup.h"
  24
  25 struct btrfs_feature_attr {
  26         struct kobj_attribute kobj_attr;
  27         enum btrfs_feature_set feature_set;
  28         u64 feature_bit;
  29 };
  30
  31 /* For raid type sysfs entries */
  32 struct raid_kobject {
  33         u64 flags;
  34         struct kobject kobj;
  35 };
  36
  37 #define __INIT_KOBJ_ATTR(_name, _mode, _show, _store)                   \
  38 {                                                                       \
  39         .attr   = { .name = __stringify(_name), .mode = _mode },        \
  40         .show   = _show,                                                \
  41         .store  = _store,                                               \
  42 }
  43
  44 #define BTRFS_ATTR_RW(_prefix, _name, _show, _store)                    \
  45         static struct kobj_attribute btrfs_attr_##_prefix##_##_name =   \
  46                         __INIT_KOBJ_ATTR(_name, 0644, _show, _store)
  47
  48 #define BTRFS_ATTR(_prefix, _name, _show)                               \
  49         static struct kobj_attribute btrfs_attr_##_prefix##_##_name =   \
  50                         __INIT_KOBJ_ATTR(_name, 0444, _show, NULL)
  51
  52 #define BTRFS_ATTR_PTR(_prefix, _name)                                  \
  53         (&btrfs_attr_##_prefix##_##_name.attr)
  54
  55 #define BTRFS_FEAT_ATTR(_name, _feature_set, _feature_prefix, _feature_bit)  \
  56 static struct btrfs_feature_attr btrfs_attr_features_##_name = {             \
  57         .kobj_attr = __INIT_KOBJ_ATTR(_name, S_IRUGO,                        \
  58                                       btrfs_feature_attr_show,               \
  59                                       btrfs_feature_attr_store),             \
  60         .feature_set    = _feature_set,                                      \
  61         .feature_bit    = _feature_prefix ##_## _feature_bit,                \
  62 }
  63 #define BTRFS_FEAT_ATTR_PTR(_name)                                           \
  64         (&btrfs_attr_features_##_name.kobj_attr.attr)
  65
  66 #define BTRFS_FEAT_ATTR_COMPAT(name, feature) \
  67         BTRFS_FEAT_ATTR(name, FEAT_COMPAT, BTRFS_FEATURE_COMPAT, feature)
  68 #define BTRFS_FEAT_ATTR_COMPAT_RO(name, feature) \
  69         BTRFS_FEAT_ATTR(name, FEAT_COMPAT_RO, BTRFS_FEATURE_COMPAT_RO, feature)
  70 #define BTRFS_FEAT_ATTR_INCOMPAT(name, feature) \
  71         BTRFS_FEAT_ATTR(name, FEAT_INCOMPAT, BTRFS_FEATURE_INCOMPAT, feature)
  72
  73 static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj);
  74 static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj);
  75
  76 static struct btrfs_feature_attr *to_btrfs_feature_attr(struct kobj_attribute *a)
  77 {
  78         return container_of(a, struct btrfs_feature_attr, kobj_attr);
  79 }
  80
  81 static struct kobj_attribute *attr_to_btrfs_attr(struct attribute *attr)
  82 {
  83         return container_of(attr, struct kobj_attribute, attr);
  84 }
  85
  86 static struct btrfs_feature_attr *attr_to_btrfs_feature_attr(
  87                 struct attribute *attr)
  88 {
  89         return to_btrfs_feature_attr(attr_to_btrfs_attr(attr));
  90 }
  91
  92 static u64 get_features(struct btrfs_fs_info *fs_info,
  93                         enum btrfs_feature_set set)
  94 {
  95         struct btrfs_super_block *disk_super = fs_info->super_copy;
  96         if (set == FEAT_COMPAT)
  97                 return btrfs_super_compat_flags(disk_super);
  98         else if (set == FEAT_COMPAT_RO)
  99                 return btrfs_super_compat_ro_flags(disk_super);
 100         else
 101                 return btrfs_super_incompat_flags(disk_super);
 102 }
 103
 104 static void set_features(struct btrfs_fs_info *fs_info,
 105                          enum btrfs_feature_set set, u64 features)
 106 {
 107         struct btrfs_super_block *disk_super = fs_info->super_copy;
 108         if (set == FEAT_COMPAT)
 109                 btrfs_set_super_compat_flags(disk_super, features);
 110         else if (set == FEAT_COMPAT_RO)
 111                 btrfs_set_super_compat_ro_flags(disk_super, features);
 112         else
 113                 btrfs_set_super_incompat_flags(disk_super, features);
 114 }
 115
 116 static int can_modify_feature(struct btrfs_feature_attr *fa)
 117 {
 118         int val = 0;
 119         u64 set, clear;
 120         switch (fa->feature_set) {
 121         case FEAT_COMPAT:
 122                 set = BTRFS_FEATURE_COMPAT_SAFE_SET;
 123                 clear = BTRFS_FEATURE_COMPAT_SAFE_CLEAR;
 124                 break;
 125         case FEAT_COMPAT_RO:
 126                 set = BTRFS_FEATURE_COMPAT_RO_SAFE_SET;
 127                 clear = BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR;
 128                 break;
 129         case FEAT_INCOMPAT:
 130                 set = BTRFS_FEATURE_INCOMPAT_SAFE_SET;
 131                 clear = BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR;
 132                 break;
 133         default:
 134                 pr_warn("btrfs: sysfs: unknown feature set %d\n",
 135                                 fa->feature_set);
 136                 return 0;
 137         }
 138
 139         if (set & fa->feature_bit)
 140                 val |= 1;
 141         if (clear & fa->feature_bit)
 142                 val |= 2;
 143
 144         return val;
 145 }
 146
 147 static ssize_t btrfs_feature_attr_show(struct kobject *kobj,
 148                                        struct kobj_attribute *a, char *buf)
 149 {
 150         int val = 0;
 151         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 152         struct btrfs_feature_attr *fa = to_btrfs_feature_attr(a);
 153         if (fs_info) {
 154                 u64 features = get_features(fs_info, fa->feature_set);
 155                 if (features & fa->feature_bit)
 156                         val = 1;
 157         } else
 158                 val = can_modify_feature(fa);
 159
 160         return scnprintf(buf, PAGE_SIZE, "%d\n", val);
 161 }
 162
 163 static ssize_t btrfs_feature_attr_store(struct kobject *kobj,
 164                                         struct kobj_attribute *a,
 165                                         const char *buf, size_t count)
 166 {
 167         struct btrfs_fs_info *fs_info;
 168         struct btrfs_feature_attr *fa = to_btrfs_feature_attr(a);
 169         u64 features, set, clear;
 170         unsigned long val;
 171         int ret;
 172
 173         fs_info = to_fs_info(kobj);
 174         if (!fs_info)
 175                 return -EPERM;
 176
 177         if (sb_rdonly(fs_info->sb))
 178                 return -EROFS;
 179
 180         ret = kstrtoul(skip_spaces(buf), 0, &val);
 181         if (ret)
 182                 return ret;
 183
 184         if (fa->feature_set == FEAT_COMPAT) {
 185                 set = BTRFS_FEATURE_COMPAT_SAFE_SET;
 186                 clear = BTRFS_FEATURE_COMPAT_SAFE_CLEAR;
 187         } else if (fa->feature_set == FEAT_COMPAT_RO) {
 188                 set = BTRFS_FEATURE_COMPAT_RO_SAFE_SET;
 189                 clear = BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR;
 190         } else {
 191                 set = BTRFS_FEATURE_INCOMPAT_SAFE_SET;
 192                 clear = BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR;
 193         }
 194
 195         features = get_features(fs_info, fa->feature_set);
 196
 197         /* Nothing to do */
 198         if ((val && (features & fa->feature_bit)) ||
 199             (!val && !(features & fa->feature_bit)))
 200                 return count;
 201
 202         if ((val && !(set & fa->feature_bit)) ||
 203             (!val && !(clear & fa->feature_bit))) {
 204                 btrfs_info(fs_info,
 205                         "%sabling feature %s on mounted fs is not supported.",
 206                         val ? "En" : "Dis", fa->kobj_attr.attr.name);
 207                 return -EPERM;
 208         }
 209
 210         btrfs_info(fs_info, "%s %s feature flag",
 211                    val ? "Setting" : "Clearing", fa->kobj_attr.attr.name);
 212
 213         spin_lock(&fs_info->super_lock);
 214         features = get_features(fs_info, fa->feature_set);
 215         if (val)
 216                 features |= fa->feature_bit;
 217         else
 218                 features &= ~fa->feature_bit;
 219         set_features(fs_info, fa->feature_set, features);
 220         spin_unlock(&fs_info->super_lock);
 221
 222         /*
 223          * We don't want to do full transaction commit from inside sysfs
 224          */
 225         btrfs_set_pending(fs_info, COMMIT);
 226         wake_up_process(fs_info->transaction_kthread);
 227
 228         return count;
 229 }
 230
 231 static umode_t btrfs_feature_visible(struct kobject *kobj,
 232                                      struct attribute *attr, int unused)
 233 {
 234         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 235         umode_t mode = attr->mode;
 236
 237         if (fs_info) {
 238                 struct btrfs_feature_attr *fa;
 239                 u64 features;
 240
 241                 fa = attr_to_btrfs_feature_attr(attr);
 242                 features = get_features(fs_info, fa->feature_set);
 243
 244                 if (can_modify_feature(fa))
 245                         mode |= S_IWUSR;
 246                 else if (!(features & fa->feature_bit))
 247                         mode = 0;
 248         }
 249
 250         return mode;
 251 }
 252
 253 BTRFS_FEAT_ATTR_INCOMPAT(mixed_backref, MIXED_BACKREF);
 254 BTRFS_FEAT_ATTR_INCOMPAT(default_subvol, DEFAULT_SUBVOL);
 255 BTRFS_FEAT_ATTR_INCOMPAT(mixed_groups, MIXED_GROUPS);
 256 BTRFS_FEAT_ATTR_INCOMPAT(compress_lzo, COMPRESS_LZO);
 257 BTRFS_FEAT_ATTR_INCOMPAT(compress_zstd, COMPRESS_ZSTD);
 258 BTRFS_FEAT_ATTR_INCOMPAT(big_metadata, BIG_METADATA);
 259 BTRFS_FEAT_ATTR_INCOMPAT(extended_iref, EXTENDED_IREF);
 260 BTRFS_FEAT_ATTR_INCOMPAT(raid56, RAID56);
 261 BTRFS_FEAT_ATTR_INCOMPAT(skinny_metadata, SKINNY_METADATA);
 262 BTRFS_FEAT_ATTR_INCOMPAT(no_holes, NO_HOLES);
 263 BTRFS_FEAT_ATTR_INCOMPAT(metadata_uuid, METADATA_UUID);
 264 BTRFS_FEAT_ATTR_COMPAT_RO(free_space_tree, FREE_SPACE_TREE);
 265 BTRFS_FEAT_ATTR_INCOMPAT(raid1c34, RAID1C34);
 266 /* Remove once support for zoned allocation is feature complete */
 267 #ifdef CONFIG_BTRFS_DEBUG
 268 BTRFS_FEAT_ATTR_INCOMPAT(zoned, ZONED);
 269 #endif
 270
 271 static struct attribute *btrfs_supported_feature_attrs[] = {
 272         BTRFS_FEAT_ATTR_PTR(mixed_backref),
 273         BTRFS_FEAT_ATTR_PTR(default_subvol),
 274         BTRFS_FEAT_ATTR_PTR(mixed_groups),
 275         BTRFS_FEAT_ATTR_PTR(compress_lzo),
 276         BTRFS_FEAT_ATTR_PTR(compress_zstd),
 277         BTRFS_FEAT_ATTR_PTR(big_metadata),
 278         BTRFS_FEAT_ATTR_PTR(extended_iref),
 279         BTRFS_FEAT_ATTR_PTR(raid56),
 280         BTRFS_FEAT_ATTR_PTR(skinny_metadata),
 281         BTRFS_FEAT_ATTR_PTR(no_holes),
 282         BTRFS_FEAT_ATTR_PTR(metadata_uuid),
 283         BTRFS_FEAT_ATTR_PTR(free_space_tree),
 284         BTRFS_FEAT_ATTR_PTR(raid1c34),
 285 #ifdef CONFIG_BTRFS_DEBUG
 286         BTRFS_FEAT_ATTR_PTR(zoned),
 287 #endif
 288         NULL
 289 };
 290
 291 /*
 292  * Features which depend on feature bits and may differ between each fs.
 293  *
 294  * /sys/fs/btrfs/features lists all available features of this kernel while
 295  * /sys/fs/btrfs/UUID/features shows features of the fs which are enabled or
 296  * can be changed online.
 297  */
 298 static const struct attribute_group btrfs_feature_attr_group = {
 299         .name = "features",
 300         .is_visible = btrfs_feature_visible,
 301         .attrs = btrfs_supported_feature_attrs,
 302 };
 303
 304 static ssize_t rmdir_subvol_show(struct kobject *kobj,
 305                                  struct kobj_attribute *ka, char *buf)
 306 {
 307         return scnprintf(buf, PAGE_SIZE, "0\n");
 308 }
 309 BTRFS_ATTR(static_feature, rmdir_subvol, rmdir_subvol_show);
 310
 311 static ssize_t supported_checksums_show(struct kobject *kobj,
 312                                         struct kobj_attribute *a, char *buf)
 313 {
 314         ssize_t ret = 0;
 315         int i;
 316
 317         for (i = 0; i < btrfs_get_num_csums(); i++) {
 318                 /*
 319                  * This "trick" only works as long as 'enum btrfs_csum_type' has
 320                  * no holes in it
 321                  */
 322                 ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%s",
 323                                 (i == 0 ? "" : " "), btrfs_super_csum_name(i));
 324
 325         }
 326
 327         ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
 328         return ret;
 329 }
 330 BTRFS_ATTR(static_feature, supported_checksums, supported_checksums_show);
 331
 332 static ssize_t send_stream_version_show(struct kobject *kobj,
 333                                         struct kobj_attribute *ka, char *buf)
 334 {
 335         return snprintf(buf, PAGE_SIZE, "%d\n", BTRFS_SEND_STREAM_VERSION);
 336 }
 337 BTRFS_ATTR(static_feature, send_stream_version, send_stream_version_show);
 338
 339 static const char *rescue_opts[] = {
 340         "usebackuproot",
 341         "nologreplay",
 342         "ignorebadroots",
 343         "ignoredatacsums",
 344         "all",
 345 };
 346
 347 static ssize_t supported_rescue_options_show(struct kobject *kobj,
 348                                              struct kobj_attribute *a,
 349                                              char *buf)
 350 {
 351         ssize_t ret = 0;
 352         int i;
 353
 354         for (i = 0; i < ARRAY_SIZE(rescue_opts); i++)
 355                 ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%s",
 356                                  (i ? " " : ""), rescue_opts[i]);
 357         ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
 358         return ret;
 359 }
 360 BTRFS_ATTR(static_feature, supported_rescue_options,
 361            supported_rescue_options_show);
 362
 363 static ssize_t supported_sectorsizes_show(struct kobject *kobj,
 364                                           struct kobj_attribute *a,
 365                                           char *buf)
 366 {
 367         ssize_t ret = 0;
 368
 369         /* Only sectorsize == PAGE_SIZE is now supported */
 370         ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%lu\n", PAGE_SIZE);
 371
 372         return ret;
 373 }
 374 BTRFS_ATTR(static_feature, supported_sectorsizes,
 375            supported_sectorsizes_show);
 376
 377 static struct attribute *btrfs_supported_static_feature_attrs[] = {
 378         BTRFS_ATTR_PTR(static_feature, rmdir_subvol),
 379         BTRFS_ATTR_PTR(static_feature, supported_checksums),
 380         BTRFS_ATTR_PTR(static_feature, send_stream_version),
 381         BTRFS_ATTR_PTR(static_feature, supported_rescue_options),
 382         BTRFS_ATTR_PTR(static_feature, supported_sectorsizes),
 383         NULL
 384 };
 385
 386 /*
 387  * Features which only depend on kernel version.
 388  *
 389  * These are listed in /sys/fs/btrfs/features along with
 390  * btrfs_feature_attr_group
 391  */
 392 static const struct attribute_group btrfs_static_feature_attr_group = {
 393         .name = "features",
 394         .attrs = btrfs_supported_static_feature_attrs,
 395 };
 396
 397 #ifdef CONFIG_BTRFS_DEBUG
 398
 399 /*
 400  * Discard statistics and tunables
 401  */
 402 #define discard_to_fs_info(_kobj)       to_fs_info((_kobj)->parent->parent)
 403
 404 static ssize_t btrfs_discardable_bytes_show(struct kobject *kobj,
 405                                             struct kobj_attribute *a,
 406                                             char *buf)
 407 {
 408         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 409
 410         return scnprintf(buf, PAGE_SIZE, "%lld\n",
 411                         atomic64_read(&fs_info->discard_ctl.discardable_bytes));
 412 }
 413 BTRFS_ATTR(discard, discardable_bytes, btrfs_discardable_bytes_show);
 414
 415 static ssize_t btrfs_discardable_extents_show(struct kobject *kobj,
 416                                               struct kobj_attribute *a,
 417                                               char *buf)
 418 {
 419         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 420
 421         return scnprintf(buf, PAGE_SIZE, "%d\n",
 422                         atomic_read(&fs_info->discard_ctl.discardable_extents));
 423 }
 424 BTRFS_ATTR(discard, discardable_extents, btrfs_discardable_extents_show);
 425
 426 static ssize_t btrfs_discard_bitmap_bytes_show(struct kobject *kobj,
 427                                                struct kobj_attribute *a,
 428                                                char *buf)
 429 {
 430         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 431
 432         return scnprintf(buf, PAGE_SIZE, "%llu\n",
 433                         fs_info->discard_ctl.discard_bitmap_bytes);
 434 }
 435 BTRFS_ATTR(discard, discard_bitmap_bytes, btrfs_discard_bitmap_bytes_show);
 436
 437 static ssize_t btrfs_discard_bytes_saved_show(struct kobject *kobj,
 438                                               struct kobj_attribute *a,
 439                                               char *buf)
 440 {
 441         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 442
 443         return scnprintf(buf, PAGE_SIZE, "%lld\n",
 444                 atomic64_read(&fs_info->discard_ctl.discard_bytes_saved));
 445 }
 446 BTRFS_ATTR(discard, discard_bytes_saved, btrfs_discard_bytes_saved_show);
 447
 448 static ssize_t btrfs_discard_extent_bytes_show(struct kobject *kobj,
 449                                                struct kobj_attribute *a,
 450                                                char *buf)
 451 {
 452         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 453
 454         return scnprintf(buf, PAGE_SIZE, "%llu\n",
 455                         fs_info->discard_ctl.discard_extent_bytes);
 456 }
 457 BTRFS_ATTR(discard, discard_extent_bytes, btrfs_discard_extent_bytes_show);
 458
 459 static ssize_t btrfs_discard_iops_limit_show(struct kobject *kobj,
 460                                              struct kobj_attribute *a,
 461                                              char *buf)
 462 {
 463         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 464
 465         return scnprintf(buf, PAGE_SIZE, "%u\n",
 466                         READ_ONCE(fs_info->discard_ctl.iops_limit));
 467 }
 468
 469 static ssize_t btrfs_discard_iops_limit_store(struct kobject *kobj,
 470                                               struct kobj_attribute *a,
 471                                               const char *buf, size_t len)
 472 {
 473         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 474         struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
 475         u32 iops_limit;
 476         int ret;
 477
 478         ret = kstrtou32(buf, 10, &iops_limit);
 479         if (ret)
 480                 return -EINVAL;
 481
 482         WRITE_ONCE(discard_ctl->iops_limit, iops_limit);
 483         btrfs_discard_calc_delay(discard_ctl);
 484         btrfs_discard_schedule_work(discard_ctl, true);
 485         return len;
 486 }
 487 BTRFS_ATTR_RW(discard, iops_limit, btrfs_discard_iops_limit_show,
 488               btrfs_discard_iops_limit_store);
 489
 490 static ssize_t btrfs_discard_kbps_limit_show(struct kobject *kobj,
 491                                              struct kobj_attribute *a,
 492                                              char *buf)
 493 {
 494         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 495
 496         return scnprintf(buf, PAGE_SIZE, "%u\n",
 497                         READ_ONCE(fs_info->discard_ctl.kbps_limit));
 498 }
 499
 500 static ssize_t btrfs_discard_kbps_limit_store(struct kobject *kobj,
 501                                               struct kobj_attribute *a,
 502                                               const char *buf, size_t len)
 503 {
 504         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 505         struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
 506         u32 kbps_limit;
 507         int ret;
 508
 509         ret = kstrtou32(buf, 10, &kbps_limit);
 510         if (ret)
 511                 return -EINVAL;
 512
 513         WRITE_ONCE(discard_ctl->kbps_limit, kbps_limit);
 514         btrfs_discard_schedule_work(discard_ctl, true);
 515         return len;
 516 }
 517 BTRFS_ATTR_RW(discard, kbps_limit, btrfs_discard_kbps_limit_show,
 518               btrfs_discard_kbps_limit_store);
 519
 520 static ssize_t btrfs_discard_max_discard_size_show(struct kobject *kobj,
 521                                                    struct kobj_attribute *a,
 522                                                    char *buf)
 523 {
 524         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 525
 526         return scnprintf(buf, PAGE_SIZE, "%llu\n",
 527                         READ_ONCE(fs_info->discard_ctl.max_discard_size));
 528 }
 529
 530 static ssize_t btrfs_discard_max_discard_size_store(struct kobject *kobj,
 531                                                     struct kobj_attribute *a,
 532                                                     const char *buf, size_t len)
 533 {
 534         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 535         struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
 536         u64 max_discard_size;
 537         int ret;
 538
 539         ret = kstrtou64(buf, 10, &max_discard_size);
 540         if (ret)
 541                 return -EINVAL;
 542
 543         WRITE_ONCE(discard_ctl->max_discard_size, max_discard_size);
 544
 545         return len;
 546 }
 547 BTRFS_ATTR_RW(discard, max_discard_size, btrfs_discard_max_discard_size_show,
 548               btrfs_discard_max_discard_size_store);
 549
 550 static const struct attribute *discard_debug_attrs[] = {
 551         BTRFS_ATTR_PTR(discard, discardable_bytes),
 552         BTRFS_ATTR_PTR(discard, discardable_extents),
 553         BTRFS_ATTR_PTR(discard, discard_bitmap_bytes),
 554         BTRFS_ATTR_PTR(discard, discard_bytes_saved),
 555         BTRFS_ATTR_PTR(discard, discard_extent_bytes),
 556         BTRFS_ATTR_PTR(discard, iops_limit),
 557         BTRFS_ATTR_PTR(discard, kbps_limit),
 558         BTRFS_ATTR_PTR(discard, max_discard_size),
 559         NULL,
 560 };
 561
 562 /*
 563  * Runtime debugging exported via sysfs
 564  *
 565  * /sys/fs/btrfs/debug - applies to module or all filesystems
 566  * /sys/fs/btrfs/UUID  - applies only to the given filesystem
 567  */
 568 static const struct attribute *btrfs_debug_mount_attrs[] = {
 569         NULL,
 570 };
 571
 572 static struct attribute *btrfs_debug_feature_attrs[] = {
 573         NULL
 574 };
 575
 576 static const struct attribute_group btrfs_debug_feature_attr_group = {
 577         .name = "debug",
 578         .attrs = btrfs_debug_feature_attrs,
 579 };
 580
 581 #endif
 582
 583 static ssize_t btrfs_show_u64(u64 *value_ptr, spinlock_t *lock, char *buf)
 584 {
 585         u64 val;
 586         if (lock)
 587                 spin_lock(lock);
 588         val = *value_ptr;
 589         if (lock)
 590                 spin_unlock(lock);
 591         return scnprintf(buf, PAGE_SIZE, "%llu\n", val);
 592 }
 593
 594 static ssize_t global_rsv_size_show(struct kobject *kobj,
 595                                     struct kobj_attribute *ka, char *buf)
 596 {
 597         struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent);
 598         struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
 599         return btrfs_show_u64(&block_rsv->size, &block_rsv->lock, buf);
 600 }
 601 BTRFS_ATTR(allocation, global_rsv_size, global_rsv_size_show);
 602
 603 static ssize_t global_rsv_reserved_show(struct kobject *kobj,
 604                                         struct kobj_attribute *a, char *buf)
 605 {
 606         struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent);
 607         struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
 608         return btrfs_show_u64(&block_rsv->reserved, &block_rsv->lock, buf);
 609 }
 610 BTRFS_ATTR(allocation, global_rsv_reserved, global_rsv_reserved_show);
 611
 612 #define to_space_info(_kobj) container_of(_kobj, struct btrfs_space_info, kobj)
 613 #define to_raid_kobj(_kobj) container_of(_kobj, struct raid_kobject, kobj)
 614
 615 static ssize_t raid_bytes_show(struct kobject *kobj,
 616                                struct kobj_attribute *attr, char *buf);
 617 BTRFS_ATTR(raid, total_bytes, raid_bytes_show);
 618 BTRFS_ATTR(raid, used_bytes, raid_bytes_show);
 619
 620 static ssize_t raid_bytes_show(struct kobject *kobj,
 621                                struct kobj_attribute *attr, char *buf)
 622
 623 {
 624         struct btrfs_space_info *sinfo = to_space_info(kobj->parent);
 625         struct btrfs_block_group *block_group;
 626         int index = btrfs_bg_flags_to_raid_index(to_raid_kobj(kobj)->flags);
 627         u64 val = 0;
 628
 629         down_read(&sinfo->groups_sem);
 630         list_for_each_entry(block_group, &sinfo->block_groups[index], list) {
 631                 if (&attr->attr == BTRFS_ATTR_PTR(raid, total_bytes))
 632                         val += block_group->length;
 633                 else
 634                         val += block_group->used;
 635         }
 636         up_read(&sinfo->groups_sem);
 637         return scnprintf(buf, PAGE_SIZE, "%llu\n", val);
 638 }
 639
 640 static struct attribute *raid_attrs[] = {
 641         BTRFS_ATTR_PTR(raid, total_bytes),
 642         BTRFS_ATTR_PTR(raid, used_bytes),
 643         NULL
 644 };
 645 ATTRIBUTE_GROUPS(raid);
 646
 647 static void release_raid_kobj(struct kobject *kobj)
 648 {
 649         kfree(to_raid_kobj(kobj));
 650 }
 651
 652 static struct kobj_type btrfs_raid_ktype = {
 653         .sysfs_ops = &kobj_sysfs_ops,
 654         .release = release_raid_kobj,
 655         .default_groups = raid_groups,
 656 };
 657
 658 #define SPACE_INFO_ATTR(field)                                          \
 659 static ssize_t btrfs_space_info_show_##field(struct kobject *kobj,      \
 660                                              struct kobj_attribute *a,  \
 661                                              char *buf)                 \
 662 {                                                                       \
 663         struct btrfs_space_info *sinfo = to_space_info(kobj);           \
 664         return btrfs_show_u64(&sinfo->field, &sinfo->lock, buf);        \
 665 }                                                                       \
 666 BTRFS_ATTR(space_info, field, btrfs_space_info_show_##field)
 667
 668 SPACE_INFO_ATTR(flags);
 669 SPACE_INFO_ATTR(total_bytes);
 670 SPACE_INFO_ATTR(bytes_used);
 671 SPACE_INFO_ATTR(bytes_pinned);
 672 SPACE_INFO_ATTR(bytes_reserved);
 673 SPACE_INFO_ATTR(bytes_may_use);
 674 SPACE_INFO_ATTR(bytes_readonly);
 675 SPACE_INFO_ATTR(bytes_zone_unusable);
 676 SPACE_INFO_ATTR(disk_used);
 677 SPACE_INFO_ATTR(disk_total);
 678
 679 static struct attribute *space_info_attrs[] = {
 680         BTRFS_ATTR_PTR(space_info, flags),
 681         BTRFS_ATTR_PTR(space_info, total_bytes),
 682         BTRFS_ATTR_PTR(space_info, bytes_used),
 683         BTRFS_ATTR_PTR(space_info, bytes_pinned),
 684         BTRFS_ATTR_PTR(space_info, bytes_reserved),
 685         BTRFS_ATTR_PTR(space_info, bytes_may_use),
 686         BTRFS_ATTR_PTR(space_info, bytes_readonly),
 687         BTRFS_ATTR_PTR(space_info, bytes_zone_unusable),
 688         BTRFS_ATTR_PTR(space_info, disk_used),
 689         BTRFS_ATTR_PTR(space_info, disk_total),
 690         NULL,
 691 };
 692 ATTRIBUTE_GROUPS(space_info);
 693
 694 static void space_info_release(struct kobject *kobj)
 695 {
 696         struct btrfs_space_info *sinfo = to_space_info(kobj);
 697         kfree(sinfo);
 698 }
 699
 700 static struct kobj_type space_info_ktype = {
 701         .sysfs_ops = &kobj_sysfs_ops,
 702         .release = space_info_release,
 703         .default_groups = space_info_groups,
 704 };
 705
 706 static const struct attribute *allocation_attrs[] = {
 707         BTRFS_ATTR_PTR(allocation, global_rsv_reserved),
 708         BTRFS_ATTR_PTR(allocation, global_rsv_size),
 709         NULL,
 710 };
 711
 712 static ssize_t btrfs_label_show(struct kobject *kobj,
 713                                 struct kobj_attribute *a, char *buf)
 714 {
 715         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 716         char *label = fs_info->super_copy->label;
 717         ssize_t ret;
 718
 719         spin_lock(&fs_info->super_lock);
 720         ret = scnprintf(buf, PAGE_SIZE, label[0] ? "%s\n" : "%s", label);
 721         spin_unlock(&fs_info->super_lock);
 722
 723         return ret;
 724 }
 725
 726 static ssize_t btrfs_label_store(struct kobject *kobj,
 727                                  struct kobj_attribute *a,
 728                                  const char *buf, size_t len)
 729 {
 730         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 731         size_t p_len;
 732
 733         if (!fs_info)
 734                 return -EPERM;
 735
 736         if (sb_rdonly(fs_info->sb))
 737                 return -EROFS;
 738
 739         /*
 740          * p_len is the len until the first occurrence of either
 741          * '\n' or '\0'
 742          */
 743         p_len = strcspn(buf, "\n");
 744
 745         if (p_len >= BTRFS_LABEL_SIZE)
 746                 return -EINVAL;
 747
 748         spin_lock(&fs_info->super_lock);
 749         memset(fs_info->super_copy->label, 0, BTRFS_LABEL_SIZE);
 750         memcpy(fs_info->super_copy->label, buf, p_len);
 751         spin_unlock(&fs_info->super_lock);
 752
 753         /*
 754          * We don't want to do full transaction commit from inside sysfs
 755          */
 756         btrfs_set_pending(fs_info, COMMIT);
 757         wake_up_process(fs_info->transaction_kthread);
 758
 759         return len;
 760 }
 761 BTRFS_ATTR_RW(, label, btrfs_label_show, btrfs_label_store);
 762
 763 static ssize_t btrfs_nodesize_show(struct kobject *kobj,
 764                                 struct kobj_attribute *a, char *buf)
 765 {
 766         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 767
 768         return scnprintf(buf, PAGE_SIZE, "%u\n", fs_info->super_copy->nodesize);
 769 }
 770
 771 BTRFS_ATTR(, nodesize, btrfs_nodesize_show);
 772
 773 static ssize_t btrfs_sectorsize_show(struct kobject *kobj,
 774                                 struct kobj_attribute *a, char *buf)
 775 {
 776         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 777
 778         return scnprintf(buf, PAGE_SIZE, "%u\n",
 779                          fs_info->super_copy->sectorsize);
 780 }
 781
 782 BTRFS_ATTR(, sectorsize, btrfs_sectorsize_show);
 783
 784 static ssize_t btrfs_clone_alignment_show(struct kobject *kobj,
 785                                 struct kobj_attribute *a, char *buf)
 786 {
 787         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 788
 789         return scnprintf(buf, PAGE_SIZE, "%u\n", fs_info->super_copy->sectorsize);
 790 }
 791
 792 BTRFS_ATTR(, clone_alignment, btrfs_clone_alignment_show);
 793
 794 static ssize_t quota_override_show(struct kobject *kobj,
 795                                    struct kobj_attribute *a, char *buf)
 796 {
 797         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 798         int quota_override;
 799
 800         quota_override = test_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
 801         return scnprintf(buf, PAGE_SIZE, "%d\n", quota_override);
 802 }
 803
 804 static ssize_t quota_override_store(struct kobject *kobj,
 805                                     struct kobj_attribute *a,
 806                                     const char *buf, size_t len)
 807 {
 808         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 809         unsigned long knob;
 810         int err;
 811
 812         if (!fs_info)
 813                 return -EPERM;
 814
 815         if (!capable(CAP_SYS_RESOURCE))
 816                 return -EPERM;
 817
 818         err = kstrtoul(buf, 10, &knob);
 819         if (err)
 820                 return err;
 821         if (knob > 1)
 822                 return -EINVAL;
 823
 824         if (knob)
 825                 set_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
 826         else
 827                 clear_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
 828
 829         return len;
 830 }
 831
 832 BTRFS_ATTR_RW(, quota_override, quota_override_show, quota_override_store);
 833
 834 static ssize_t btrfs_metadata_uuid_show(struct kobject *kobj,
 835                                 struct kobj_attribute *a, char *buf)
 836 {
 837         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 838
 839         return scnprintf(buf, PAGE_SIZE, "%pU\n",
 840                         fs_info->fs_devices->metadata_uuid);
 841 }
 842
 843 BTRFS_ATTR(, metadata_uuid, btrfs_metadata_uuid_show);
 844
 845 static ssize_t btrfs_checksum_show(struct kobject *kobj,
 846                                    struct kobj_attribute *a, char *buf)
 847 {
 848         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 849         u16 csum_type = btrfs_super_csum_type(fs_info->super_copy);
 850
 851         return scnprintf(buf, PAGE_SIZE, "%s (%s)\n",
 852                         btrfs_super_csum_name(csum_type),
 853                         crypto_shash_driver_name(fs_info->csum_shash));
 854 }
 855
 856 BTRFS_ATTR(, checksum, btrfs_checksum_show);
 857
 858 static ssize_t btrfs_exclusive_operation_show(struct kobject *kobj,
 859                 struct kobj_attribute *a, char *buf)
 860 {
 861         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 862         const char *str;
 863
 864         switch (READ_ONCE(fs_info->exclusive_operation)) {
 865                 case  BTRFS_EXCLOP_NONE:
 866                         str = "none\n";
 867                         break;
 868                 case BTRFS_EXCLOP_BALANCE:
 869                         str = "balance\n";
 870                         break;
 871                 case BTRFS_EXCLOP_DEV_ADD:
 872                         str = "device add\n";
 873                         break;
 874                 case BTRFS_EXCLOP_DEV_REMOVE:
 875                         str = "device remove\n";
 876                         break;
 877                 case BTRFS_EXCLOP_DEV_REPLACE:
 878                         str = "device replace\n";
 879                         break;
 880                 case BTRFS_EXCLOP_RESIZE:
 881                         str = "resize\n";
 882                         break;
 883                 case BTRFS_EXCLOP_SWAP_ACTIVATE:
 884                         str = "swap activate\n";
 885                         break;
 886                 default:
 887                         str = "UNKNOWN\n";
 888                         break;
 889         }
 890         return scnprintf(buf, PAGE_SIZE, "%s", str);
 891 }
 892 BTRFS_ATTR(, exclusive_operation, btrfs_exclusive_operation_show);
 893
 894 static ssize_t btrfs_generation_show(struct kobject *kobj,
 895                                      struct kobj_attribute *a, char *buf)
 896 {
 897         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 898
 899         return scnprintf(buf, PAGE_SIZE, "%llu\n", fs_info->generation);
 900 }
 901 BTRFS_ATTR(, generation, btrfs_generation_show);
 902
 903 /*
 904  * Look for an exact string @string in @buffer with possible leading or
 905  * trailing whitespace
 906  */
 907 static bool strmatch(const char *buffer, const char *string)
 908 {
 909         const size_t len = strlen(string);
 910
 911         /* Skip leading whitespace */
 912         buffer = skip_spaces(buffer);
 913
 914         /* Match entire string, check if the rest is whitespace or empty */
 915         if (strncmp(string, buffer, len) == 0 &&
 916             strlen(skip_spaces(buffer + len)) == 0)
 917                 return true;
 918
 919         return false;
 920 }
 921
 922 static const char * const btrfs_read_policy_name[] = { "pid" };
 923
 924 static ssize_t btrfs_read_policy_show(struct kobject *kobj,
 925                                       struct kobj_attribute *a, char *buf)
 926 {
 927         struct btrfs_fs_devices *fs_devices = to_fs_devs(kobj);
 928         ssize_t ret = 0;
 929         int i;
 930
 931         for (i = 0; i < BTRFS_NR_READ_POLICY; i++) {
 932                 if (fs_devices->read_policy == i)
 933                         ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s[%s]",
 934                                          (ret == 0 ? "" : " "),
 935                                          btrfs_read_policy_name[i]);
 936                 else
 937                         ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%s",
 938                                          (ret == 0 ? "" : " "),
 939                                          btrfs_read_policy_name[i]);
 940         }
 941
 942         ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
 943
 944         return ret;
 945 }
 946
 947 static ssize_t btrfs_read_policy_store(struct kobject *kobj,
 948                                        struct kobj_attribute *a,
 949                                        const char *buf, size_t len)
 950 {
 951         struct btrfs_fs_devices *fs_devices = to_fs_devs(kobj);
 952         int i;
 953
 954         for (i = 0; i < BTRFS_NR_READ_POLICY; i++) {
 955                 if (strmatch(buf, btrfs_read_policy_name[i])) {
 956                         if (i != fs_devices->read_policy) {
 957                                 fs_devices->read_policy = i;
 958                                 btrfs_info(fs_devices->fs_info,
 959                                            "read policy set to '%s'",
 960                                            btrfs_read_policy_name[i]);
 961                         }
 962                         return len;
 963                 }
 964         }
 965
 966         return -EINVAL;
 967 }
 968 BTRFS_ATTR_RW(, read_policy, btrfs_read_policy_show, btrfs_read_policy_store);
 969
 970 static ssize_t btrfs_bg_reclaim_threshold_show(struct kobject *kobj,
 971                                                struct kobj_attribute *a,
 972                                                char *buf)
 973 {
 974         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 975         ssize_t ret;
 976
 977         ret = scnprintf(buf, PAGE_SIZE, "%d\n", fs_info->bg_reclaim_threshold);
 978
 979         return ret;
 980 }
 981
 982 static ssize_t btrfs_bg_reclaim_threshold_store(struct kobject *kobj,
 983                                                 struct kobj_attribute *a,
 984                                                 const char *buf, size_t len)
 985 {
 986         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 987         int thresh;
 988         int ret;
 989
 990         ret = kstrtoint(buf, 10, &thresh);
 991         if (ret)
 992                 return ret;
 993
 994         if (thresh <= 50 || thresh > 100)
 995                 return -EINVAL;
 996
 997         fs_info->bg_reclaim_threshold = thresh;
 998
 999         return len;
1000 }
1001 BTRFS_ATTR_RW(, bg_reclaim_threshold, btrfs_bg_reclaim_threshold_show,
1002               btrfs_bg_reclaim_threshold_store);
1003
1004 static const struct attribute *btrfs_attrs[] = {
1005         BTRFS_ATTR_PTR(, label),
1006         BTRFS_ATTR_PTR(, nodesize),
1007         BTRFS_ATTR_PTR(, sectorsize),
1008         BTRFS_ATTR_PTR(, clone_alignment),
1009         BTRFS_ATTR_PTR(, quota_override),
1010         BTRFS_ATTR_PTR(, metadata_uuid),
1011         BTRFS_ATTR_PTR(, checksum),
1012         BTRFS_ATTR_PTR(, exclusive_operation),
1013         BTRFS_ATTR_PTR(, generation),
1014         BTRFS_ATTR_PTR(, read_policy),
1015         BTRFS_ATTR_PTR(, bg_reclaim_threshold),
1016         NULL,
1017 };
1018
1019 static void btrfs_release_fsid_kobj(struct kobject *kobj)
1020 {
1021         struct btrfs_fs_devices *fs_devs = to_fs_devs(kobj);
1022
1023         memset(&fs_devs->fsid_kobj, 0, sizeof(struct kobject));
1024         complete(&fs_devs->kobj_unregister);
1025 }
1026
1027 static struct kobj_type btrfs_ktype = {
1028         .sysfs_ops      = &kobj_sysfs_ops,
1029         .release        = btrfs_release_fsid_kobj,
1030 };
1031
1032 static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj)
1033 {
1034         if (kobj->ktype != &btrfs_ktype)
1035                 return NULL;
1036         return container_of(kobj, struct btrfs_fs_devices, fsid_kobj);
1037 }
1038
1039 static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj)
1040 {
1041         if (kobj->ktype != &btrfs_ktype)
1042                 return NULL;
1043         return to_fs_devs(kobj)->fs_info;
1044 }
1045
1046 #define NUM_FEATURE_BITS 64
1047 #define BTRFS_FEATURE_NAME_MAX 13
1048 static char btrfs_unknown_feature_names[FEAT_MAX][NUM_FEATURE_BITS][BTRFS_FEATURE_NAME_MAX];
1049 static struct btrfs_feature_attr btrfs_feature_attrs[FEAT_MAX][NUM_FEATURE_BITS];
1050
1051 static const u64 supported_feature_masks[FEAT_MAX] = {
1052         [FEAT_COMPAT]    = BTRFS_FEATURE_COMPAT_SUPP,
1053         [FEAT_COMPAT_RO] = BTRFS_FEATURE_COMPAT_RO_SUPP,
1054         [FEAT_INCOMPAT]  = BTRFS_FEATURE_INCOMPAT_SUPP,
1055 };
1056
1057 static int addrm_unknown_feature_attrs(struct btrfs_fs_info *fs_info, bool add)
1058 {
1059         int set;
1060
1061         for (set = 0; set < FEAT_MAX; set++) {
1062                 int i;
1063                 struct attribute *attrs[2];
1064                 struct attribute_group agroup = {
1065                         .name = "features",
1066                         .attrs = attrs,
1067                 };
1068                 u64 features = get_features(fs_info, set);
1069                 features &= ~supported_feature_masks[set];
1070
1071                 if (!features)
1072                         continue;
1073
1074                 attrs[1] = NULL;
1075                 for (i = 0; i < NUM_FEATURE_BITS; i++) {
1076                         struct btrfs_feature_attr *fa;
1077
1078                         if (!(features & (1ULL << i)))
1079                                 continue;
1080
1081                         fa = &btrfs_feature_attrs[set][i];
1082                         attrs[0] = &fa->kobj_attr.attr;
1083                         if (add) {
1084                                 int ret;
1085                                 ret = sysfs_merge_group(&fs_info->fs_devices->fsid_kobj,
1086                                                         &agroup);
1087                                 if (ret)
1088                                         return ret;
1089                         } else
1090                                 sysfs_unmerge_group(&fs_info->fs_devices->fsid_kobj,
1091                                                     &agroup);
1092                 }
1093
1094         }
1095         return 0;
1096 }
1097
1098 static void __btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs)
1099 {
1100         if (fs_devs->devinfo_kobj) {
1101                 kobject_del(fs_devs->devinfo_kobj);
1102                 kobject_put(fs_devs->devinfo_kobj);
1103                 fs_devs->devinfo_kobj = NULL;
1104         }
1105
1106         if (fs_devs->devices_kobj) {
1107                 kobject_del(fs_devs->devices_kobj);
1108                 kobject_put(fs_devs->devices_kobj);
1109                 fs_devs->devices_kobj = NULL;
1110         }
1111
1112         if (fs_devs->fsid_kobj.state_initialized) {
1113                 kobject_del(&fs_devs->fsid_kobj);
1114                 kobject_put(&fs_devs->fsid_kobj);
1115                 wait_for_completion(&fs_devs->kobj_unregister);
1116         }
1117 }
1118
1119 /* when fs_devs is NULL it will remove all fsid kobject */
1120 void btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs)
1121 {
1122         struct list_head *fs_uuids = btrfs_get_fs_uuids();
1123
1124         if (fs_devs) {
1125                 __btrfs_sysfs_remove_fsid(fs_devs);
1126                 return;
1127         }
1128
1129         list_for_each_entry(fs_devs, fs_uuids, fs_list) {
1130                 __btrfs_sysfs_remove_fsid(fs_devs);
1131         }
1132 }
1133
1134 static void btrfs_sysfs_remove_fs_devices(struct btrfs_fs_devices *fs_devices)
1135 {
1136         struct btrfs_device *device;
1137         struct btrfs_fs_devices *seed;
1138
1139         list_for_each_entry(device, &fs_devices->devices, dev_list)
1140                 btrfs_sysfs_remove_device(device);
1141
1142         list_for_each_entry(seed, &fs_devices->seed_list, seed_list) {
1143                 list_for_each_entry(device, &seed->devices, dev_list)
1144                         btrfs_sysfs_remove_device(device);
1145         }
1146 }
1147
1148 void btrfs_sysfs_remove_mounted(struct btrfs_fs_info *fs_info)
1149 {
1150         struct kobject *fsid_kobj = &fs_info->fs_devices->fsid_kobj;
1151
1152         sysfs_remove_link(fsid_kobj, "bdi");
1153
1154         if (fs_info->space_info_kobj) {
1155                 sysfs_remove_files(fs_info->space_info_kobj, allocation_attrs);
1156                 kobject_del(fs_info->space_info_kobj);
1157                 kobject_put(fs_info->space_info_kobj);
1158         }
1159 #ifdef CONFIG_BTRFS_DEBUG
1160         if (fs_info->discard_debug_kobj) {
1161                 sysfs_remove_files(fs_info->discard_debug_kobj,
1162                                    discard_debug_attrs);
1163                 kobject_del(fs_info->discard_debug_kobj);
1164                 kobject_put(fs_info->discard_debug_kobj);
1165         }
1166         if (fs_info->debug_kobj) {
1167                 sysfs_remove_files(fs_info->debug_kobj, btrfs_debug_mount_attrs);
1168                 kobject_del(fs_info->debug_kobj);
1169                 kobject_put(fs_info->debug_kobj);
1170         }
1171 #endif
1172         addrm_unknown_feature_attrs(fs_info, false);
1173         sysfs_remove_group(fsid_kobj, &btrfs_feature_attr_group);
1174         sysfs_remove_files(fsid_kobj, btrfs_attrs);
1175         btrfs_sysfs_remove_fs_devices(fs_info->fs_devices);
1176 }
1177
1178 static const char * const btrfs_feature_set_names[FEAT_MAX] = {
1179         [FEAT_COMPAT]    = "compat",
1180         [FEAT_COMPAT_RO] = "compat_ro",
1181         [FEAT_INCOMPAT]  = "incompat",
1182 };
1183
1184 const char *btrfs_feature_set_name(enum btrfs_feature_set set)
1185 {
1186         return btrfs_feature_set_names[set];
1187 }
1188
1189 char *btrfs_printable_features(enum btrfs_feature_set set, u64 flags)
1190 {
1191         size_t bufsize = 4096; /* safe max, 64 names * 64 bytes */
1192         int len = 0;
1193         int i;
1194         char *str;
1195
1196         str = kmalloc(bufsize, GFP_KERNEL);
1197         if (!str)
1198                 return str;
1199
1200         for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
1201                 const char *name;
1202
1203                 if (!(flags & (1ULL << i)))
1204                         continue;
1205
1206                 name = btrfs_feature_attrs[set][i].kobj_attr.attr.name;
1207                 len += scnprintf(str + len, bufsize - len, "%s%s",
1208                                 len ? "," : "", name);
1209         }
1210
1211         return str;
1212 }
1213
1214 static void init_feature_attrs(void)
1215 {
1216         struct btrfs_feature_attr *fa;
1217         int set, i;
1218
1219         BUILD_BUG_ON(ARRAY_SIZE(btrfs_unknown_feature_names) !=
1220                      ARRAY_SIZE(btrfs_feature_attrs));
1221         BUILD_BUG_ON(ARRAY_SIZE(btrfs_unknown_feature_names[0]) !=
1222                      ARRAY_SIZE(btrfs_feature_attrs[0]));
1223
1224         memset(btrfs_feature_attrs, 0, sizeof(btrfs_feature_attrs));
1225         memset(btrfs_unknown_feature_names, 0,
1226                sizeof(btrfs_unknown_feature_names));
1227
1228         for (i = 0; btrfs_supported_feature_attrs[i]; i++) {
1229                 struct btrfs_feature_attr *sfa;
1230                 struct attribute *a = btrfs_supported_feature_attrs[i];
1231                 int bit;
1232                 sfa = attr_to_btrfs_feature_attr(a);
1233                 bit = ilog2(sfa->feature_bit);
1234                 fa = &btrfs_feature_attrs[sfa->feature_set][bit];
1235
1236                 fa->kobj_attr.attr.name = sfa->kobj_attr.attr.name;
1237         }
1238
1239         for (set = 0; set < FEAT_MAX; set++) {
1240                 for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
1241                         char *name = btrfs_unknown_feature_names[set][i];
1242                         fa = &btrfs_feature_attrs[set][i];
1243
1244                         if (fa->kobj_attr.attr.name)
1245                                 continue;
1246
1247                         snprintf(name, BTRFS_FEATURE_NAME_MAX, "%s:%u",
1248                                  btrfs_feature_set_names[set], i);
1249
1250                         fa->kobj_attr.attr.name = name;
1251                         fa->kobj_attr.attr.mode = S_IRUGO;
1252                         fa->feature_set = set;
1253                         fa->feature_bit = 1ULL << i;
1254                 }
1255         }
1256 }
1257
1258 /*
1259  * Create a sysfs entry for a given block group type at path
1260  * /sys/fs/btrfs/UUID/allocation/data/TYPE
1261  */
1262 void btrfs_sysfs_add_block_group_type(struct btrfs_block_group *cache)
1263 {
1264         struct btrfs_fs_info *fs_info = cache->fs_info;
1265         struct btrfs_space_info *space_info = cache->space_info;
1266         struct raid_kobject *rkobj;
1267         const int index = btrfs_bg_flags_to_raid_index(cache->flags);
1268         unsigned int nofs_flag;
1269         int ret;
1270
1271         /*
1272          * Setup a NOFS context because kobject_add(), deep in its call chain,
1273          * does GFP_KERNEL allocations, and we are often called in a context
1274          * where if reclaim is triggered we can deadlock (we are either holding
1275          * a transaction handle or some lock required for a transaction
1276          * commit).
1277          */
1278         nofs_flag = memalloc_nofs_save();
1279
1280         rkobj = kzalloc(sizeof(*rkobj), GFP_NOFS);
1281         if (!rkobj) {
1282                 memalloc_nofs_restore(nofs_flag);
1283                 btrfs_warn(cache->fs_info,
1284                                 "couldn't alloc memory for raid level kobject");
1285                 return;
1286         }
1287
1288         rkobj->flags = cache->flags;
1289         kobject_init(&rkobj->kobj, &btrfs_raid_ktype);
1290
1291         /*
1292          * We call this either on mount, or if we've created a block group for a
1293          * new index type while running (i.e. when restriping).  The running
1294          * case is tricky because we could race with other threads, so we need
1295          * to have this check to make sure we didn't already init the kobject.
1296          *
1297          * We don't have to protect on the free side because it only happens on
1298          * unmount.
1299          */
1300         spin_lock(&space_info->lock);
1301         if (space_info->block_group_kobjs[index]) {
1302                 spin_unlock(&space_info->lock);
1303                 kobject_put(&rkobj->kobj);
1304                 return;
1305         } else {
1306                 space_info->block_group_kobjs[index] = &rkobj->kobj;
1307         }
1308         spin_unlock(&space_info->lock);
1309
1310         ret = kobject_add(&rkobj->kobj, &space_info->kobj, "%s",
1311                           btrfs_bg_type_to_raid_name(rkobj->flags));
1312         memalloc_nofs_restore(nofs_flag);
1313         if (ret) {
1314                 spin_lock(&space_info->lock);
1315                 space_info->block_group_kobjs[index] = NULL;
1316                 spin_unlock(&space_info->lock);
1317                 kobject_put(&rkobj->kobj);
1318                 btrfs_warn(fs_info,
1319                         "failed to add kobject for block cache, ignoring");
1320                 return;
1321         }
1322 }
1323
1324 /*
1325  * Remove sysfs directories for all block group types of a given space info and
1326  * the space info as well
1327  */
1328 void btrfs_sysfs_remove_space_info(struct btrfs_space_info *space_info)
1329 {
1330         int i;
1331
1332         for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) {
1333                 struct kobject *kobj;
1334
1335                 kobj = space_info->block_group_kobjs[i];
1336                 space_info->block_group_kobjs[i] = NULL;
1337                 if (kobj) {
1338                         kobject_del(kobj);
1339                         kobject_put(kobj);
1340                 }
1341         }
1342         kobject_del(&space_info->kobj);
1343         kobject_put(&space_info->kobj);
1344 }
1345
1346 static const char *alloc_name(u64 flags)
1347 {
1348         switch (flags) {
1349         case BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA:
1350                 return "mixed";
1351         case BTRFS_BLOCK_GROUP_METADATA:
1352                 return "metadata";
1353         case BTRFS_BLOCK_GROUP_DATA:
1354                 return "data";
1355         case BTRFS_BLOCK_GROUP_SYSTEM:
1356                 return "system";
1357         default:
1358                 WARN_ON(1);
1359                 return "invalid-combination";
1360         }
1361 }
1362
1363 /*
1364  * Create a sysfs entry for a space info type at path
1365  * /sys/fs/btrfs/UUID/allocation/TYPE
1366  */
1367 int btrfs_sysfs_add_space_info_type(struct btrfs_fs_info *fs_info,
1368                                     struct btrfs_space_info *space_info)
1369 {
1370         int ret;
1371
1372         ret = kobject_init_and_add(&space_info->kobj, &space_info_ktype,
1373                                    fs_info->space_info_kobj, "%s",
1374                                    alloc_name(space_info->flags));
1375         if (ret) {
1376                 kobject_put(&space_info->kobj);
1377                 return ret;
1378         }
1379
1380         return 0;
1381 }
1382
1383 void btrfs_sysfs_remove_device(struct btrfs_device *device)
1384 {
1385         struct kobject *devices_kobj;
1386
1387         /*
1388          * Seed fs_devices devices_kobj aren't used, fetch kobject from the
1389          * fs_info::fs_devices.
1390          */
1391         devices_kobj = device->fs_info->fs_devices->devices_kobj;
1392         ASSERT(devices_kobj);
1393
1394         if (device->bdev)
1395                 sysfs_remove_link(devices_kobj, bdev_kobj(device->bdev)->name);
1396
1397         if (device->devid_kobj.state_initialized) {
1398                 kobject_del(&device->devid_kobj);
1399                 kobject_put(&device->devid_kobj);
1400                 wait_for_completion(&device->kobj_unregister);
1401         }
1402 }
1403
1404 static ssize_t btrfs_devinfo_in_fs_metadata_show(struct kobject *kobj,
1405                                                  struct kobj_attribute *a,
1406                                                  char *buf)
1407 {
1408         int val;
1409         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1410                                                    devid_kobj);
1411
1412         val = !!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state);
1413
1414         return scnprintf(buf, PAGE_SIZE, "%d\n", val);
1415 }
1416 BTRFS_ATTR(devid, in_fs_metadata, btrfs_devinfo_in_fs_metadata_show);
1417
1418 static ssize_t btrfs_devinfo_missing_show(struct kobject *kobj,
1419                                         struct kobj_attribute *a, char *buf)
1420 {
1421         int val;
1422         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1423                                                    devid_kobj);
1424
1425         val = !!test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state);
1426
1427         return scnprintf(buf, PAGE_SIZE, "%d\n", val);
1428 }
1429 BTRFS_ATTR(devid, missing, btrfs_devinfo_missing_show);
1430
1431 static ssize_t btrfs_devinfo_replace_target_show(struct kobject *kobj,
1432                                                  struct kobj_attribute *a,
1433                                                  char *buf)
1434 {
1435         int val;
1436         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1437                                                    devid_kobj);
1438
1439         val = !!test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state);
1440
1441         return scnprintf(buf, PAGE_SIZE, "%d\n", val);
1442 }
1443 BTRFS_ATTR(devid, replace_target, btrfs_devinfo_replace_target_show);
1444
1445 static ssize_t btrfs_devinfo_scrub_speed_max_show(struct kobject *kobj,
1446                                              struct kobj_attribute *a,
1447                                              char *buf)
1448 {
1449         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1450                                                    devid_kobj);
1451
1452         return scnprintf(buf, PAGE_SIZE, "%llu\n",
1453                          READ_ONCE(device->scrub_speed_max));
1454 }
1455
1456 static ssize_t btrfs_devinfo_scrub_speed_max_store(struct kobject *kobj,
1457                                               struct kobj_attribute *a,
1458                                               const char *buf, size_t len)
1459 {
1460         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1461                                                    devid_kobj);
1462         char *endptr;
1463         unsigned long long limit;
1464
1465         limit = memparse(buf, &endptr);
1466         WRITE_ONCE(device->scrub_speed_max, limit);
1467         return len;
1468 }
1469 BTRFS_ATTR_RW(devid, scrub_speed_max, btrfs_devinfo_scrub_speed_max_show,
1470               btrfs_devinfo_scrub_speed_max_store);
1471
1472 static ssize_t btrfs_devinfo_writeable_show(struct kobject *kobj,
1473                                             struct kobj_attribute *a, char *buf)
1474 {
1475         int val;
1476         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1477                                                    devid_kobj);
1478
1479         val = !!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state);
1480
1481         return scnprintf(buf, PAGE_SIZE, "%d\n", val);
1482 }
1483 BTRFS_ATTR(devid, writeable, btrfs_devinfo_writeable_show);
1484
1485 static ssize_t btrfs_devinfo_error_stats_show(struct kobject *kobj,
1486                 struct kobj_attribute *a, char *buf)
1487 {
1488         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1489                                                    devid_kobj);
1490
1491         if (!device->dev_stats_valid)
1492                 return scnprintf(buf, PAGE_SIZE, "invalid\n");
1493
1494         /*
1495          * Print all at once so we get a snapshot of all values from the same
1496          * time. Keep them in sync and in order of definition of
1497          * btrfs_dev_stat_values.
1498          */
1499         return scnprintf(buf, PAGE_SIZE,
1500                 "write_errs %d\n"
1501                 "read_errs %d\n"
1502                 "flush_errs %d\n"
1503                 "corruption_errs %d\n"
1504                 "generation_errs %d\n",
1505                 btrfs_dev_stat_read(device, BTRFS_DEV_STAT_WRITE_ERRS),
1506                 btrfs_dev_stat_read(device, BTRFS_DEV_STAT_READ_ERRS),
1507                 btrfs_dev_stat_read(device, BTRFS_DEV_STAT_FLUSH_ERRS),
1508                 btrfs_dev_stat_read(device, BTRFS_DEV_STAT_CORRUPTION_ERRS),
1509                 btrfs_dev_stat_read(device, BTRFS_DEV_STAT_GENERATION_ERRS));
1510 }
1511 BTRFS_ATTR(devid, error_stats, btrfs_devinfo_error_stats_show);
1512
1513 static struct attribute *devid_attrs[] = {
1514         BTRFS_ATTR_PTR(devid, error_stats),
1515         BTRFS_ATTR_PTR(devid, in_fs_metadata),
1516         BTRFS_ATTR_PTR(devid, missing),
1517         BTRFS_ATTR_PTR(devid, replace_target),
1518         BTRFS_ATTR_PTR(devid, scrub_speed_max),
1519         BTRFS_ATTR_PTR(devid, writeable),
1520         NULL
1521 };
1522 ATTRIBUTE_GROUPS(devid);
1523
1524 static void btrfs_release_devid_kobj(struct kobject *kobj)
1525 {
1526         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1527                                                    devid_kobj);
1528
1529         memset(&device->devid_kobj, 0, sizeof(struct kobject));
1530         complete(&device->kobj_unregister);
1531 }
1532
1533 static struct kobj_type devid_ktype = {
1534         .sysfs_ops      = &kobj_sysfs_ops,
1535         .default_groups = devid_groups,
1536         .release        = btrfs_release_devid_kobj,
1537 };
1538
1539 int btrfs_sysfs_add_device(struct btrfs_device *device)
1540 {
1541         int ret;
1542         unsigned int nofs_flag;
1543         struct kobject *devices_kobj;
1544         struct kobject *devinfo_kobj;
1545
1546         /*
1547          * Make sure we use the fs_info::fs_devices to fetch the kobjects even
1548          * for the seed fs_devices
1549          */
1550         devices_kobj = device->fs_info->fs_devices->devices_kobj;
1551         devinfo_kobj = device->fs_info->fs_devices->devinfo_kobj;
1552         ASSERT(devices_kobj);
1553         ASSERT(devinfo_kobj);
1554
1555         nofs_flag = memalloc_nofs_save();
1556
1557         if (device->bdev) {
1558                 struct kobject *disk_kobj = bdev_kobj(device->bdev);
1559
1560                 ret = sysfs_create_link(devices_kobj, disk_kobj, disk_kobj->name);
1561                 if (ret) {
1562                         btrfs_warn(device->fs_info,
1563                                 "creating sysfs device link for devid %llu failed: %d",
1564                                 device->devid, ret);
1565                         goto out;
1566                 }
1567         }
1568
1569         init_completion(&device->kobj_unregister);
1570         ret = kobject_init_and_add(&device->devid_kobj, &devid_ktype,
1571                                    devinfo_kobj, "%llu", device->devid);
1572         if (ret) {
1573                 kobject_put(&device->devid_kobj);
1574                 btrfs_warn(device->fs_info,
1575                            "devinfo init for devid %llu failed: %d",
1576                            device->devid, ret);
1577         }
1578
1579 out:
1580         memalloc_nofs_restore(nofs_flag);
1581         return ret;
1582 }
1583
1584 static int btrfs_sysfs_add_fs_devices(struct btrfs_fs_devices *fs_devices)
1585 {
1586         int ret;
1587         struct btrfs_device *device;
1588         struct btrfs_fs_devices *seed;
1589
1590         list_for_each_entry(device, &fs_devices->devices, dev_list) {
1591                 ret = btrfs_sysfs_add_device(device);
1592                 if (ret)
1593                         goto fail;
1594         }
1595
1596         list_for_each_entry(seed, &fs_devices->seed_list, seed_list) {
1597                 list_for_each_entry(device, &seed->devices, dev_list) {
1598                         ret = btrfs_sysfs_add_device(device);
1599                         if (ret)
1600                                 goto fail;
1601                 }
1602         }
1603
1604         return 0;
1605
1606 fail:
1607         btrfs_sysfs_remove_fs_devices(fs_devices);
1608         return ret;
1609 }
1610
1611 void btrfs_kobject_uevent(struct block_device *bdev, enum kobject_action action)
1612 {
1613         int ret;
1614
1615         ret = kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, action);
1616         if (ret)
1617                 pr_warn("BTRFS: Sending event '%d' to kobject: '%s' (%p): failed\n",
1618                         action, kobject_name(&disk_to_dev(bdev->bd_disk)->kobj),
1619                         &disk_to_dev(bdev->bd_disk)->kobj);
1620 }
1621
1622 void btrfs_sysfs_update_sprout_fsid(struct btrfs_fs_devices *fs_devices)
1623
1624 {
1625         char fsid_buf[BTRFS_UUID_UNPARSED_SIZE];
1626
1627         /*
1628          * Sprouting changes fsid of the mounted filesystem, rename the fsid
1629          * directory
1630          */
1631         snprintf(fsid_buf, BTRFS_UUID_UNPARSED_SIZE, "%pU", fs_devices->fsid);
1632         if (kobject_rename(&fs_devices->fsid_kobj, fsid_buf))
1633                 btrfs_warn(fs_devices->fs_info,
1634                                 "sysfs: failed to create fsid for sprout");
1635 }
1636
1637 void btrfs_sysfs_update_devid(struct btrfs_device *device)
1638 {
1639         char tmp[24];
1640
1641         snprintf(tmp, sizeof(tmp), "%llu", device->devid);
1642
1643         if (kobject_rename(&device->devid_kobj, tmp))
1644                 btrfs_warn(device->fs_devices->fs_info,
1645                            "sysfs: failed to update devid for %llu",
1646                            device->devid);
1647 }
1648
1649 /* /sys/fs/btrfs/ entry */
1650 static struct kset *btrfs_kset;
1651
1652 /*
1653  * Creates:
1654  *              /sys/fs/btrfs/UUID
1655  *
1656  * Can be called by the device discovery thread.
1657  */
1658 int btrfs_sysfs_add_fsid(struct btrfs_fs_devices *fs_devs)
1659 {
1660         int error;
1661
1662         init_completion(&fs_devs->kobj_unregister);
1663         fs_devs->fsid_kobj.kset = btrfs_kset;
1664         error = kobject_init_and_add(&fs_devs->fsid_kobj, &btrfs_ktype, NULL,
1665                                      "%pU", fs_devs->fsid);
1666         if (error) {
1667                 kobject_put(&fs_devs->fsid_kobj);
1668                 return error;
1669         }
1670
1671         fs_devs->devices_kobj = kobject_create_and_add("devices",
1672                                                        &fs_devs->fsid_kobj);
1673         if (!fs_devs->devices_kobj) {
1674                 btrfs_err(fs_devs->fs_info,
1675                           "failed to init sysfs device interface");
1676                 btrfs_sysfs_remove_fsid(fs_devs);
1677                 return -ENOMEM;
1678         }
1679
1680         fs_devs->devinfo_kobj = kobject_create_and_add("devinfo",
1681                                                        &fs_devs->fsid_kobj);
1682         if (!fs_devs->devinfo_kobj) {
1683                 btrfs_err(fs_devs->fs_info,
1684                           "failed to init sysfs devinfo kobject");
1685                 btrfs_sysfs_remove_fsid(fs_devs);
1686                 return -ENOMEM;
1687         }
1688
1689         return 0;
1690 }
1691
1692 int btrfs_sysfs_add_mounted(struct btrfs_fs_info *fs_info)
1693 {
1694         int error;
1695         struct btrfs_fs_devices *fs_devs = fs_info->fs_devices;
1696         struct kobject *fsid_kobj = &fs_devs->fsid_kobj;
1697
1698         error = btrfs_sysfs_add_fs_devices(fs_devs);
1699         if (error)
1700                 return error;
1701
1702         error = sysfs_create_files(fsid_kobj, btrfs_attrs);
1703         if (error) {
1704                 btrfs_sysfs_remove_fs_devices(fs_devs);
1705                 return error;
1706         }
1707
1708         error = sysfs_create_group(fsid_kobj,
1709                                    &btrfs_feature_attr_group);
1710         if (error)
1711                 goto failure;
1712
1713 #ifdef CONFIG_BTRFS_DEBUG
1714         fs_info->debug_kobj = kobject_create_and_add("debug", fsid_kobj);
1715         if (!fs_info->debug_kobj) {
1716                 error = -ENOMEM;
1717                 goto failure;
1718         }
1719
1720         error = sysfs_create_files(fs_info->debug_kobj, btrfs_debug_mount_attrs);
1721         if (error)
1722                 goto failure;
1723
1724         /* Discard directory */
1725         fs_info->discard_debug_kobj = kobject_create_and_add("discard",
1726                                                      fs_info->debug_kobj);
1727         if (!fs_info->discard_debug_kobj) {
1728                 error = -ENOMEM;
1729                 goto failure;
1730         }
1731
1732         error = sysfs_create_files(fs_info->discard_debug_kobj,
1733                                    discard_debug_attrs);
1734         if (error)
1735                 goto failure;
1736 #endif
1737
1738         error = addrm_unknown_feature_attrs(fs_info, true);
1739         if (error)
1740                 goto failure;
1741
1742         error = sysfs_create_link(fsid_kobj, &fs_info->sb->s_bdi->dev->kobj, "bdi");
1743         if (error)
1744                 goto failure;
1745
1746         fs_info->space_info_kobj = kobject_create_and_add("allocation",
1747                                                   fsid_kobj);
1748         if (!fs_info->space_info_kobj) {
1749                 error = -ENOMEM;
1750                 goto failure;
1751         }
1752
1753         error = sysfs_create_files(fs_info->space_info_kobj, allocation_attrs);
1754         if (error)
1755                 goto failure;
1756
1757         return 0;
1758 failure:
1759         btrfs_sysfs_remove_mounted(fs_info);
1760         return error;
1761 }
1762
1763 static inline struct btrfs_fs_info *qgroup_kobj_to_fs_info(struct kobject *kobj)
1764 {
1765         return to_fs_info(kobj->parent->parent);
1766 }
1767
1768 #define QGROUP_ATTR(_member, _show_name)                                        \
1769 static ssize_t btrfs_qgroup_show_##_member(struct kobject *qgroup_kobj,         \
1770                                            struct kobj_attribute *a,            \
1771                                            char *buf)                           \
1772 {                                                                               \
1773         struct btrfs_fs_info *fs_info = qgroup_kobj_to_fs_info(qgroup_kobj);    \
1774         struct btrfs_qgroup *qgroup = container_of(qgroup_kobj,                 \
1775                         struct btrfs_qgroup, kobj);                             \
1776         return btrfs_show_u64(&qgroup->_member, &fs_info->qgroup_lock, buf);    \
1777 }                                                                               \
1778 BTRFS_ATTR(qgroup, _show_name, btrfs_qgroup_show_##_member)
1779
1780 #define QGROUP_RSV_ATTR(_name, _type)                                           \
1781 static ssize_t btrfs_qgroup_rsv_show_##_name(struct kobject *qgroup_kobj,       \
1782                                              struct kobj_attribute *a,          \
1783                                              char *buf)                         \
1784 {                                                                               \
1785         struct btrfs_fs_info *fs_info = qgroup_kobj_to_fs_info(qgroup_kobj);    \
1786         struct btrfs_qgroup *qgroup = container_of(qgroup_kobj,                 \
1787                         struct btrfs_qgroup, kobj);                             \
1788         return btrfs_show_u64(&qgroup->rsv.values[_type],                       \
1789                         &fs_info->qgroup_lock, buf);                            \
1790 }                                                                               \
1791 BTRFS_ATTR(qgroup, rsv_##_name, btrfs_qgroup_rsv_show_##_name)
1792
1793 QGROUP_ATTR(rfer, referenced);
1794 QGROUP_ATTR(excl, exclusive);
1795 QGROUP_ATTR(max_rfer, max_referenced);
1796 QGROUP_ATTR(max_excl, max_exclusive);
1797 QGROUP_ATTR(lim_flags, limit_flags);
1798 QGROUP_RSV_ATTR(data, BTRFS_QGROUP_RSV_DATA);
1799 QGROUP_RSV_ATTR(meta_pertrans, BTRFS_QGROUP_RSV_META_PERTRANS);
1800 QGROUP_RSV_ATTR(meta_prealloc, BTRFS_QGROUP_RSV_META_PREALLOC);
1801
1802 static struct attribute *qgroup_attrs[] = {
1803         BTRFS_ATTR_PTR(qgroup, referenced),
1804         BTRFS_ATTR_PTR(qgroup, exclusive),
1805         BTRFS_ATTR_PTR(qgroup, max_referenced),
1806         BTRFS_ATTR_PTR(qgroup, max_exclusive),
1807         BTRFS_ATTR_PTR(qgroup, limit_flags),
1808         BTRFS_ATTR_PTR(qgroup, rsv_data),
1809         BTRFS_ATTR_PTR(qgroup, rsv_meta_pertrans),
1810         BTRFS_ATTR_PTR(qgroup, rsv_meta_prealloc),
1811         NULL
1812 };
1813 ATTRIBUTE_GROUPS(qgroup);
1814
1815 static void qgroup_release(struct kobject *kobj)
1816 {
1817         struct btrfs_qgroup *qgroup = container_of(kobj, struct btrfs_qgroup, kobj);
1818
1819         memset(&qgroup->kobj, 0, sizeof(*kobj));
1820 }
1821
1822 static struct kobj_type qgroup_ktype = {
1823         .sysfs_ops = &kobj_sysfs_ops,
1824         .release = qgroup_release,
1825         .default_groups = qgroup_groups,
1826 };
1827
1828 int btrfs_sysfs_add_one_qgroup(struct btrfs_fs_info *fs_info,
1829                                 struct btrfs_qgroup *qgroup)
1830 {
1831         struct kobject *qgroups_kobj = fs_info->qgroups_kobj;
1832         int ret;
1833
1834         if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
1835                 return 0;
1836         if (qgroup->kobj.state_initialized)
1837                 return 0;
1838         if (!qgroups_kobj)
1839                 return -EINVAL;
1840
1841         ret = kobject_init_and_add(&qgroup->kobj, &qgroup_ktype, qgroups_kobj,
1842                         "%hu_%llu", btrfs_qgroup_level(qgroup->qgroupid),
1843                         btrfs_qgroup_subvolid(qgroup->qgroupid));
1844         if (ret < 0)
1845                 kobject_put(&qgroup->kobj);
1846
1847         return ret;
1848 }
1849
1850 void btrfs_sysfs_del_qgroups(struct btrfs_fs_info *fs_info)
1851 {
1852         struct btrfs_qgroup *qgroup;
1853         struct btrfs_qgroup *next;
1854
1855         if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
1856                 return;
1857
1858         rbtree_postorder_for_each_entry_safe(qgroup, next,
1859                                              &fs_info->qgroup_tree, node)
1860                 btrfs_sysfs_del_one_qgroup(fs_info, qgroup);
1861         if (fs_info->qgroups_kobj) {
1862                 kobject_del(fs_info->qgroups_kobj);
1863                 kobject_put(fs_info->qgroups_kobj);
1864                 fs_info->qgroups_kobj = NULL;
1865         }
1866 }
1867
1868 /* Called when qgroups get initialized, thus there is no need for locking */
1869 int btrfs_sysfs_add_qgroups(struct btrfs_fs_info *fs_info)
1870 {
1871         struct kobject *fsid_kobj = &fs_info->fs_devices->fsid_kobj;
1872         struct btrfs_qgroup *qgroup;
1873         struct btrfs_qgroup *next;
1874         int ret = 0;
1875
1876         if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
1877                 return 0;
1878
1879         ASSERT(fsid_kobj);
1880         if (fs_info->qgroups_kobj)
1881                 return 0;
1882
1883         fs_info->qgroups_kobj = kobject_create_and_add("qgroups", fsid_kobj);
1884         if (!fs_info->qgroups_kobj) {
1885                 ret = -ENOMEM;
1886                 goto out;
1887         }
1888         rbtree_postorder_for_each_entry_safe(qgroup, next,
1889                                              &fs_info->qgroup_tree, node) {
1890                 ret = btrfs_sysfs_add_one_qgroup(fs_info, qgroup);
1891                 if (ret < 0)
1892                         goto out;
1893         }
1894
1895 out:
1896         if (ret < 0)
1897                 btrfs_sysfs_del_qgroups(fs_info);
1898         return ret;
1899 }
1900
1901 void btrfs_sysfs_del_one_qgroup(struct btrfs_fs_info *fs_info,
1902                                 struct btrfs_qgroup *qgroup)
1903 {
1904         if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
1905                 return;
1906
1907         if (qgroup->kobj.state_initialized) {
1908                 kobject_del(&qgroup->kobj);
1909                 kobject_put(&qgroup->kobj);
1910         }
1911 }
1912
1913 /*
1914  * Change per-fs features in /sys/fs/btrfs/UUID/features to match current
1915  * values in superblock. Call after any changes to incompat/compat_ro flags
1916  */
1917 void btrfs_sysfs_feature_update(struct btrfs_fs_info *fs_info,
1918                 u64 bit, enum btrfs_feature_set set)
1919 {
1920         struct btrfs_fs_devices *fs_devs;
1921         struct kobject *fsid_kobj;
1922         u64 __maybe_unused features;
1923         int __maybe_unused ret;
1924
1925         if (!fs_info)
1926                 return;
1927
1928         /*
1929          * See 14e46e04958df74 and e410e34fad913dd, feature bit updates are not
1930          * safe when called from some contexts (eg. balance)
1931          */
1932         features = get_features(fs_info, set);
1933         ASSERT(bit & supported_feature_masks[set]);
1934
1935         fs_devs = fs_info->fs_devices;
1936         fsid_kobj = &fs_devs->fsid_kobj;
1937
1938         if (!fsid_kobj->state_initialized)
1939                 return;
1940
1941         /*
1942          * FIXME: this is too heavy to update just one value, ideally we'd like
1943          * to use sysfs_update_group but some refactoring is needed first.
1944          */
1945         sysfs_remove_group(fsid_kobj, &btrfs_feature_attr_group);
1946         ret = sysfs_create_group(fsid_kobj, &btrfs_feature_attr_group);
1947 }
1948
1949 int __init btrfs_init_sysfs(void)
1950 {
1951         int ret;
1952
1953         btrfs_kset = kset_create_and_add("btrfs", NULL, fs_kobj);
1954         if (!btrfs_kset)
1955                 return -ENOMEM;
1956
1957         init_feature_attrs();
1958         ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
1959         if (ret)
1960                 goto out2;
1961         ret = sysfs_merge_group(&btrfs_kset->kobj,
1962                                 &btrfs_static_feature_attr_group);
1963         if (ret)
1964                 goto out_remove_group;
1965
1966 #ifdef CONFIG_BTRFS_DEBUG
1967         ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_debug_feature_attr_group);
1968         if (ret)
1969                 goto out2;
1970 #endif
1971
1972         return 0;
1973
1974 out_remove_group:
1975         sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
1976 out2:
1977         kset_unregister(btrfs_kset);
1978
1979         return ret;
1980 }
1981
1982 void __cold btrfs_exit_sysfs(void)
1983 {
1984         sysfs_unmerge_group(&btrfs_kset->kobj,
1985                             &btrfs_static_feature_attr_group);
1986         sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
1987 #ifdef CONFIG_BTRFS_DEBUG
1988         sysfs_remove_group(&btrfs_kset->kobj, &btrfs_debug_feature_attr_group);
1989 #endif
1990         kset_unregister(btrfs_kset);
1991 }
1992