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
 267 static struct attribute *btrfs_supported_feature_attrs[] = {
 268         BTRFS_FEAT_ATTR_PTR(mixed_backref),
 269         BTRFS_FEAT_ATTR_PTR(default_subvol),
 270         BTRFS_FEAT_ATTR_PTR(mixed_groups),
 271         BTRFS_FEAT_ATTR_PTR(compress_lzo),
 272         BTRFS_FEAT_ATTR_PTR(compress_zstd),
 273         BTRFS_FEAT_ATTR_PTR(big_metadata),
 274         BTRFS_FEAT_ATTR_PTR(extended_iref),
 275         BTRFS_FEAT_ATTR_PTR(raid56),
 276         BTRFS_FEAT_ATTR_PTR(skinny_metadata),
 277         BTRFS_FEAT_ATTR_PTR(no_holes),
 278         BTRFS_FEAT_ATTR_PTR(metadata_uuid),
 279         BTRFS_FEAT_ATTR_PTR(free_space_tree),
 280         BTRFS_FEAT_ATTR_PTR(raid1c34),
 281         NULL
 282 };
 283
 284 /*
 285  * Features which depend on feature bits and may differ between each fs.
 286  *
 287  * /sys/fs/btrfs/features lists all available features of this kernel while
 288  * /sys/fs/btrfs/UUID/features shows features of the fs which are enabled or
 289  * can be changed online.
 290  */
 291 static const struct attribute_group btrfs_feature_attr_group = {
 292         .name = "features",
 293         .is_visible = btrfs_feature_visible,
 294         .attrs = btrfs_supported_feature_attrs,
 295 };
 296
 297 static ssize_t rmdir_subvol_show(struct kobject *kobj,
 298                                  struct kobj_attribute *ka, char *buf)
 299 {
 300         return scnprintf(buf, PAGE_SIZE, "0\n");
 301 }
 302 BTRFS_ATTR(static_feature, rmdir_subvol, rmdir_subvol_show);
 303
 304 static ssize_t supported_checksums_show(struct kobject *kobj,
 305                                         struct kobj_attribute *a, char *buf)
 306 {
 307         ssize_t ret = 0;
 308         int i;
 309
 310         for (i = 0; i < btrfs_get_num_csums(); i++) {
 311                 /*
 312                  * This "trick" only works as long as 'enum btrfs_csum_type' has
 313                  * no holes in it
 314                  */
 315                 ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%s",
 316                                 (i == 0 ? "" : " "), btrfs_super_csum_name(i));
 317
 318         }
 319
 320         ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
 321         return ret;
 322 }
 323 BTRFS_ATTR(static_feature, supported_checksums, supported_checksums_show);
 324
 325 static ssize_t send_stream_version_show(struct kobject *kobj,
 326                                         struct kobj_attribute *ka, char *buf)
 327 {
 328         return snprintf(buf, PAGE_SIZE, "%d\n", BTRFS_SEND_STREAM_VERSION);
 329 }
 330 BTRFS_ATTR(static_feature, send_stream_version, send_stream_version_show);
 331
 332 static const char *rescue_opts[] = {
 333         "usebackuproot",
 334         "nologreplay",
 335         "ignorebadroots",
 336         "ignoredatacsums",
 337         "all",
 338 };
 339
 340 static ssize_t supported_rescue_options_show(struct kobject *kobj,
 341                                              struct kobj_attribute *a,
 342                                              char *buf)
 343 {
 344         ssize_t ret = 0;
 345         int i;
 346
 347         for (i = 0; i < ARRAY_SIZE(rescue_opts); i++)
 348                 ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%s",
 349                                  (i ? " " : ""), rescue_opts[i]);
 350         ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
 351         return ret;
 352 }
 353 BTRFS_ATTR(static_feature, supported_rescue_options,
 354            supported_rescue_options_show);
 355
 356 static struct attribute *btrfs_supported_static_feature_attrs[] = {
 357         BTRFS_ATTR_PTR(static_feature, rmdir_subvol),
 358         BTRFS_ATTR_PTR(static_feature, supported_checksums),
 359         BTRFS_ATTR_PTR(static_feature, send_stream_version),
 360         BTRFS_ATTR_PTR(static_feature, supported_rescue_options),
 361         NULL
 362 };
 363
 364 /*
 365  * Features which only depend on kernel version.
 366  *
 367  * These are listed in /sys/fs/btrfs/features along with
 368  * btrfs_feature_attr_group
 369  */
 370 static const struct attribute_group btrfs_static_feature_attr_group = {
 371         .name = "features",
 372         .attrs = btrfs_supported_static_feature_attrs,
 373 };
 374
 375 #ifdef CONFIG_BTRFS_DEBUG
 376
 377 /*
 378  * Discard statistics and tunables
 379  */
 380 #define discard_to_fs_info(_kobj)       to_fs_info((_kobj)->parent->parent)
 381
 382 static ssize_t btrfs_discardable_bytes_show(struct kobject *kobj,
 383                                             struct kobj_attribute *a,
 384                                             char *buf)
 385 {
 386         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 387
 388         return scnprintf(buf, PAGE_SIZE, "%lld\n",
 389                         atomic64_read(&fs_info->discard_ctl.discardable_bytes));
 390 }
 391 BTRFS_ATTR(discard, discardable_bytes, btrfs_discardable_bytes_show);
 392
 393 static ssize_t btrfs_discardable_extents_show(struct kobject *kobj,
 394                                               struct kobj_attribute *a,
 395                                               char *buf)
 396 {
 397         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 398
 399         return scnprintf(buf, PAGE_SIZE, "%d\n",
 400                         atomic_read(&fs_info->discard_ctl.discardable_extents));
 401 }
 402 BTRFS_ATTR(discard, discardable_extents, btrfs_discardable_extents_show);
 403
 404 static ssize_t btrfs_discard_bitmap_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                         fs_info->discard_ctl.discard_bitmap_bytes);
 412 }
 413 BTRFS_ATTR(discard, discard_bitmap_bytes, btrfs_discard_bitmap_bytes_show);
 414
 415 static ssize_t btrfs_discard_bytes_saved_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, "%lld\n",
 422                 atomic64_read(&fs_info->discard_ctl.discard_bytes_saved));
 423 }
 424 BTRFS_ATTR(discard, discard_bytes_saved, btrfs_discard_bytes_saved_show);
 425
 426 static ssize_t btrfs_discard_extent_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, "%lld\n",
 433                         fs_info->discard_ctl.discard_extent_bytes);
 434 }
 435 BTRFS_ATTR(discard, discard_extent_bytes, btrfs_discard_extent_bytes_show);
 436
 437 static ssize_t btrfs_discard_iops_limit_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, "%u\n",
 444                         READ_ONCE(fs_info->discard_ctl.iops_limit));
 445 }
 446
 447 static ssize_t btrfs_discard_iops_limit_store(struct kobject *kobj,
 448                                               struct kobj_attribute *a,
 449                                               const char *buf, size_t len)
 450 {
 451         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 452         struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
 453         u32 iops_limit;
 454         int ret;
 455
 456         ret = kstrtou32(buf, 10, &iops_limit);
 457         if (ret)
 458                 return -EINVAL;
 459
 460         WRITE_ONCE(discard_ctl->iops_limit, iops_limit);
 461
 462         return len;
 463 }
 464 BTRFS_ATTR_RW(discard, iops_limit, btrfs_discard_iops_limit_show,
 465               btrfs_discard_iops_limit_store);
 466
 467 static ssize_t btrfs_discard_kbps_limit_show(struct kobject *kobj,
 468                                              struct kobj_attribute *a,
 469                                              char *buf)
 470 {
 471         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 472
 473         return scnprintf(buf, PAGE_SIZE, "%u\n",
 474                         READ_ONCE(fs_info->discard_ctl.kbps_limit));
 475 }
 476
 477 static ssize_t btrfs_discard_kbps_limit_store(struct kobject *kobj,
 478                                               struct kobj_attribute *a,
 479                                               const char *buf, size_t len)
 480 {
 481         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 482         struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
 483         u32 kbps_limit;
 484         int ret;
 485
 486         ret = kstrtou32(buf, 10, &kbps_limit);
 487         if (ret)
 488                 return -EINVAL;
 489
 490         WRITE_ONCE(discard_ctl->kbps_limit, kbps_limit);
 491
 492         return len;
 493 }
 494 BTRFS_ATTR_RW(discard, kbps_limit, btrfs_discard_kbps_limit_show,
 495               btrfs_discard_kbps_limit_store);
 496
 497 static ssize_t btrfs_discard_max_discard_size_show(struct kobject *kobj,
 498                                                    struct kobj_attribute *a,
 499                                                    char *buf)
 500 {
 501         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 502
 503         return scnprintf(buf, PAGE_SIZE, "%llu\n",
 504                         READ_ONCE(fs_info->discard_ctl.max_discard_size));
 505 }
 506
 507 static ssize_t btrfs_discard_max_discard_size_store(struct kobject *kobj,
 508                                                     struct kobj_attribute *a,
 509                                                     const char *buf, size_t len)
 510 {
 511         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 512         struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
 513         u64 max_discard_size;
 514         int ret;
 515
 516         ret = kstrtou64(buf, 10, &max_discard_size);
 517         if (ret)
 518                 return -EINVAL;
 519
 520         WRITE_ONCE(discard_ctl->max_discard_size, max_discard_size);
 521
 522         return len;
 523 }
 524 BTRFS_ATTR_RW(discard, max_discard_size, btrfs_discard_max_discard_size_show,
 525               btrfs_discard_max_discard_size_store);
 526
 527 static const struct attribute *discard_debug_attrs[] = {
 528         BTRFS_ATTR_PTR(discard, discardable_bytes),
 529         BTRFS_ATTR_PTR(discard, discardable_extents),
 530         BTRFS_ATTR_PTR(discard, discard_bitmap_bytes),
 531         BTRFS_ATTR_PTR(discard, discard_bytes_saved),
 532         BTRFS_ATTR_PTR(discard, discard_extent_bytes),
 533         BTRFS_ATTR_PTR(discard, iops_limit),
 534         BTRFS_ATTR_PTR(discard, kbps_limit),
 535         BTRFS_ATTR_PTR(discard, max_discard_size),
 536         NULL,
 537 };
 538
 539 /*
 540  * Runtime debugging exported via sysfs
 541  *
 542  * /sys/fs/btrfs/debug - applies to module or all filesystems
 543  * /sys/fs/btrfs/UUID  - applies only to the given filesystem
 544  */
 545 static const struct attribute *btrfs_debug_mount_attrs[] = {
 546         NULL,
 547 };
 548
 549 static struct attribute *btrfs_debug_feature_attrs[] = {
 550         NULL
 551 };
 552
 553 static const struct attribute_group btrfs_debug_feature_attr_group = {
 554         .name = "debug",
 555         .attrs = btrfs_debug_feature_attrs,
 556 };
 557
 558 #endif
 559
 560 static ssize_t btrfs_show_u64(u64 *value_ptr, spinlock_t *lock, char *buf)
 561 {
 562         u64 val;
 563         if (lock)
 564                 spin_lock(lock);
 565         val = *value_ptr;
 566         if (lock)
 567                 spin_unlock(lock);
 568         return scnprintf(buf, PAGE_SIZE, "%llu\n", val);
 569 }
 570
 571 static ssize_t global_rsv_size_show(struct kobject *kobj,
 572                                     struct kobj_attribute *ka, char *buf)
 573 {
 574         struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent);
 575         struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
 576         return btrfs_show_u64(&block_rsv->size, &block_rsv->lock, buf);
 577 }
 578 BTRFS_ATTR(allocation, global_rsv_size, global_rsv_size_show);
 579
 580 static ssize_t global_rsv_reserved_show(struct kobject *kobj,
 581                                         struct kobj_attribute *a, char *buf)
 582 {
 583         struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent);
 584         struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
 585         return btrfs_show_u64(&block_rsv->reserved, &block_rsv->lock, buf);
 586 }
 587 BTRFS_ATTR(allocation, global_rsv_reserved, global_rsv_reserved_show);
 588
 589 #define to_space_info(_kobj) container_of(_kobj, struct btrfs_space_info, kobj)
 590 #define to_raid_kobj(_kobj) container_of(_kobj, struct raid_kobject, kobj)
 591
 592 static ssize_t raid_bytes_show(struct kobject *kobj,
 593                                struct kobj_attribute *attr, char *buf);
 594 BTRFS_ATTR(raid, total_bytes, raid_bytes_show);
 595 BTRFS_ATTR(raid, used_bytes, raid_bytes_show);
 596
 597 static ssize_t raid_bytes_show(struct kobject *kobj,
 598                                struct kobj_attribute *attr, char *buf)
 599
 600 {
 601         struct btrfs_space_info *sinfo = to_space_info(kobj->parent);
 602         struct btrfs_block_group *block_group;
 603         int index = btrfs_bg_flags_to_raid_index(to_raid_kobj(kobj)->flags);
 604         u64 val = 0;
 605
 606         down_read(&sinfo->groups_sem);
 607         list_for_each_entry(block_group, &sinfo->block_groups[index], list) {
 608                 if (&attr->attr == BTRFS_ATTR_PTR(raid, total_bytes))
 609                         val += block_group->length;
 610                 else
 611                         val += block_group->used;
 612         }
 613         up_read(&sinfo->groups_sem);
 614         return scnprintf(buf, PAGE_SIZE, "%llu\n", val);
 615 }
 616
 617 static struct attribute *raid_attrs[] = {
 618         BTRFS_ATTR_PTR(raid, total_bytes),
 619         BTRFS_ATTR_PTR(raid, used_bytes),
 620         NULL
 621 };
 622 ATTRIBUTE_GROUPS(raid);
 623
 624 static void release_raid_kobj(struct kobject *kobj)
 625 {
 626         kfree(to_raid_kobj(kobj));
 627 }
 628
 629 static struct kobj_type btrfs_raid_ktype = {
 630         .sysfs_ops = &kobj_sysfs_ops,
 631         .release = release_raid_kobj,
 632         .default_groups = raid_groups,
 633 };
 634
 635 #define SPACE_INFO_ATTR(field)                                          \
 636 static ssize_t btrfs_space_info_show_##field(struct kobject *kobj,      \
 637                                              struct kobj_attribute *a,  \
 638                                              char *buf)                 \
 639 {                                                                       \
 640         struct btrfs_space_info *sinfo = to_space_info(kobj);           \
 641         return btrfs_show_u64(&sinfo->field, &sinfo->lock, buf);        \
 642 }                                                                       \
 643 BTRFS_ATTR(space_info, field, btrfs_space_info_show_##field)
 644
 645 static ssize_t btrfs_space_info_show_total_bytes_pinned(struct kobject *kobj,
 646                                                        struct kobj_attribute *a,
 647                                                        char *buf)
 648 {
 649         struct btrfs_space_info *sinfo = to_space_info(kobj);
 650         s64 val = percpu_counter_sum(&sinfo->total_bytes_pinned);
 651         return scnprintf(buf, PAGE_SIZE, "%lld\n", val);
 652 }
 653
 654 SPACE_INFO_ATTR(flags);
 655 SPACE_INFO_ATTR(total_bytes);
 656 SPACE_INFO_ATTR(bytes_used);
 657 SPACE_INFO_ATTR(bytes_pinned);
 658 SPACE_INFO_ATTR(bytes_reserved);
 659 SPACE_INFO_ATTR(bytes_may_use);
 660 SPACE_INFO_ATTR(bytes_readonly);
 661 SPACE_INFO_ATTR(disk_used);
 662 SPACE_INFO_ATTR(disk_total);
 663 BTRFS_ATTR(space_info, total_bytes_pinned,
 664            btrfs_space_info_show_total_bytes_pinned);
 665
 666 static struct attribute *space_info_attrs[] = {
 667         BTRFS_ATTR_PTR(space_info, flags),
 668         BTRFS_ATTR_PTR(space_info, total_bytes),
 669         BTRFS_ATTR_PTR(space_info, bytes_used),
 670         BTRFS_ATTR_PTR(space_info, bytes_pinned),
 671         BTRFS_ATTR_PTR(space_info, bytes_reserved),
 672         BTRFS_ATTR_PTR(space_info, bytes_may_use),
 673         BTRFS_ATTR_PTR(space_info, bytes_readonly),
 674         BTRFS_ATTR_PTR(space_info, disk_used),
 675         BTRFS_ATTR_PTR(space_info, disk_total),
 676         BTRFS_ATTR_PTR(space_info, total_bytes_pinned),
 677         NULL,
 678 };
 679 ATTRIBUTE_GROUPS(space_info);
 680
 681 static void space_info_release(struct kobject *kobj)
 682 {
 683         struct btrfs_space_info *sinfo = to_space_info(kobj);
 684         percpu_counter_destroy(&sinfo->total_bytes_pinned);
 685         kfree(sinfo);
 686 }
 687
 688 static struct kobj_type space_info_ktype = {
 689         .sysfs_ops = &kobj_sysfs_ops,
 690         .release = space_info_release,
 691         .default_groups = space_info_groups,
 692 };
 693
 694 static const struct attribute *allocation_attrs[] = {
 695         BTRFS_ATTR_PTR(allocation, global_rsv_reserved),
 696         BTRFS_ATTR_PTR(allocation, global_rsv_size),
 697         NULL,
 698 };
 699
 700 static ssize_t btrfs_label_show(struct kobject *kobj,
 701                                 struct kobj_attribute *a, char *buf)
 702 {
 703         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 704         char *label = fs_info->super_copy->label;
 705         ssize_t ret;
 706
 707         spin_lock(&fs_info->super_lock);
 708         ret = scnprintf(buf, PAGE_SIZE, label[0] ? "%s\n" : "%s", label);
 709         spin_unlock(&fs_info->super_lock);
 710
 711         return ret;
 712 }
 713
 714 static ssize_t btrfs_label_store(struct kobject *kobj,
 715                                  struct kobj_attribute *a,
 716                                  const char *buf, size_t len)
 717 {
 718         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 719         size_t p_len;
 720
 721         if (!fs_info)
 722                 return -EPERM;
 723
 724         if (sb_rdonly(fs_info->sb))
 725                 return -EROFS;
 726
 727         /*
 728          * p_len is the len until the first occurrence of either
 729          * '\n' or '\0'
 730          */
 731         p_len = strcspn(buf, "\n");
 732
 733         if (p_len >= BTRFS_LABEL_SIZE)
 734                 return -EINVAL;
 735
 736         spin_lock(&fs_info->super_lock);
 737         memset(fs_info->super_copy->label, 0, BTRFS_LABEL_SIZE);
 738         memcpy(fs_info->super_copy->label, buf, p_len);
 739         spin_unlock(&fs_info->super_lock);
 740
 741         /*
 742          * We don't want to do full transaction commit from inside sysfs
 743          */
 744         btrfs_set_pending(fs_info, COMMIT);
 745         wake_up_process(fs_info->transaction_kthread);
 746
 747         return len;
 748 }
 749 BTRFS_ATTR_RW(, label, btrfs_label_show, btrfs_label_store);
 750
 751 static ssize_t btrfs_nodesize_show(struct kobject *kobj,
 752                                 struct kobj_attribute *a, char *buf)
 753 {
 754         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 755
 756         return scnprintf(buf, PAGE_SIZE, "%u\n", fs_info->super_copy->nodesize);
 757 }
 758
 759 BTRFS_ATTR(, nodesize, btrfs_nodesize_show);
 760
 761 static ssize_t btrfs_sectorsize_show(struct kobject *kobj,
 762                                 struct kobj_attribute *a, char *buf)
 763 {
 764         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 765
 766         return scnprintf(buf, PAGE_SIZE, "%u\n",
 767                          fs_info->super_copy->sectorsize);
 768 }
 769
 770 BTRFS_ATTR(, sectorsize, btrfs_sectorsize_show);
 771
 772 static ssize_t btrfs_clone_alignment_show(struct kobject *kobj,
 773                                 struct kobj_attribute *a, char *buf)
 774 {
 775         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 776
 777         return scnprintf(buf, PAGE_SIZE, "%u\n", fs_info->super_copy->sectorsize);
 778 }
 779
 780 BTRFS_ATTR(, clone_alignment, btrfs_clone_alignment_show);
 781
 782 static ssize_t quota_override_show(struct kobject *kobj,
 783                                    struct kobj_attribute *a, char *buf)
 784 {
 785         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 786         int quota_override;
 787
 788         quota_override = test_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
 789         return scnprintf(buf, PAGE_SIZE, "%d\n", quota_override);
 790 }
 791
 792 static ssize_t quota_override_store(struct kobject *kobj,
 793                                     struct kobj_attribute *a,
 794                                     const char *buf, size_t len)
 795 {
 796         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 797         unsigned long knob;
 798         int err;
 799
 800         if (!fs_info)
 801                 return -EPERM;
 802
 803         if (!capable(CAP_SYS_RESOURCE))
 804                 return -EPERM;
 805
 806         err = kstrtoul(buf, 10, &knob);
 807         if (err)
 808                 return err;
 809         if (knob > 1)
 810                 return -EINVAL;
 811
 812         if (knob)
 813                 set_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
 814         else
 815                 clear_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
 816
 817         return len;
 818 }
 819
 820 BTRFS_ATTR_RW(, quota_override, quota_override_show, quota_override_store);
 821
 822 static ssize_t btrfs_metadata_uuid_show(struct kobject *kobj,
 823                                 struct kobj_attribute *a, char *buf)
 824 {
 825         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 826
 827         return scnprintf(buf, PAGE_SIZE, "%pU\n",
 828                         fs_info->fs_devices->metadata_uuid);
 829 }
 830
 831 BTRFS_ATTR(, metadata_uuid, btrfs_metadata_uuid_show);
 832
 833 static ssize_t btrfs_checksum_show(struct kobject *kobj,
 834                                    struct kobj_attribute *a, char *buf)
 835 {
 836         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 837         u16 csum_type = btrfs_super_csum_type(fs_info->super_copy);
 838
 839         return scnprintf(buf, PAGE_SIZE, "%s (%s)\n",
 840                         btrfs_super_csum_name(csum_type),
 841                         crypto_shash_driver_name(fs_info->csum_shash));
 842 }
 843
 844 BTRFS_ATTR(, checksum, btrfs_checksum_show);
 845
 846 static ssize_t btrfs_exclusive_operation_show(struct kobject *kobj,
 847                 struct kobj_attribute *a, char *buf)
 848 {
 849         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 850         const char *str;
 851
 852         switch (READ_ONCE(fs_info->exclusive_operation)) {
 853                 case  BTRFS_EXCLOP_NONE:
 854                         str = "none\n";
 855                         break;
 856                 case BTRFS_EXCLOP_BALANCE:
 857                         str = "balance\n";
 858                         break;
 859                 case BTRFS_EXCLOP_DEV_ADD:
 860                         str = "device add\n";
 861                         break;
 862                 case BTRFS_EXCLOP_DEV_REMOVE:
 863                         str = "device remove\n";
 864                         break;
 865                 case BTRFS_EXCLOP_DEV_REPLACE:
 866                         str = "device replace\n";
 867                         break;
 868                 case BTRFS_EXCLOP_RESIZE:
 869                         str = "resize\n";
 870                         break;
 871                 case BTRFS_EXCLOP_SWAP_ACTIVATE:
 872                         str = "swap activate\n";
 873                         break;
 874                 default:
 875                         str = "UNKNOWN\n";
 876                         break;
 877         }
 878         return scnprintf(buf, PAGE_SIZE, "%s", str);
 879 }
 880 BTRFS_ATTR(, exclusive_operation, btrfs_exclusive_operation_show);
 881
 882 static ssize_t btrfs_generation_show(struct kobject *kobj,
 883                                      struct kobj_attribute *a, char *buf)
 884 {
 885         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 886
 887         return scnprintf(buf, PAGE_SIZE, "%llu\n", fs_info->generation);
 888 }
 889 BTRFS_ATTR(, generation, btrfs_generation_show);
 890
 891 /*
 892  * Look for an exact string @string in @buffer with possible leading or
 893  * trailing whitespace
 894  */
 895 static bool strmatch(const char *buffer, const char *string)
 896 {
 897         const size_t len = strlen(string);
 898
 899         /* Skip leading whitespace */
 900         buffer = skip_spaces(buffer);
 901
 902         /* Match entire string, check if the rest is whitespace or empty */
 903         if (strncmp(string, buffer, len) == 0 &&
 904             strlen(skip_spaces(buffer + len)) == 0)
 905                 return true;
 906
 907         return false;
 908 }
 909
 910 static const char * const btrfs_read_policy_name[] = { "pid" };
 911
 912 static ssize_t btrfs_read_policy_show(struct kobject *kobj,
 913                                       struct kobj_attribute *a, char *buf)
 914 {
 915         struct btrfs_fs_devices *fs_devices = to_fs_devs(kobj);
 916         ssize_t ret = 0;
 917         int i;
 918
 919         for (i = 0; i < BTRFS_NR_READ_POLICY; i++) {
 920                 if (fs_devices->read_policy == i)
 921                         ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s[%s]",
 922                                          (ret == 0 ? "" : " "),
 923                                          btrfs_read_policy_name[i]);
 924                 else
 925                         ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%s",
 926                                          (ret == 0 ? "" : " "),
 927                                          btrfs_read_policy_name[i]);
 928         }
 929
 930         ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
 931
 932         return ret;
 933 }
 934
 935 static ssize_t btrfs_read_policy_store(struct kobject *kobj,
 936                                        struct kobj_attribute *a,
 937                                        const char *buf, size_t len)
 938 {
 939         struct btrfs_fs_devices *fs_devices = to_fs_devs(kobj);
 940         int i;
 941
 942         for (i = 0; i < BTRFS_NR_READ_POLICY; i++) {
 943                 if (strmatch(buf, btrfs_read_policy_name[i])) {
 944                         if (i != fs_devices->read_policy) {
 945                                 fs_devices->read_policy = i;
 946                                 btrfs_info(fs_devices->fs_info,
 947                                            "read policy set to '%s'",
 948                                            btrfs_read_policy_name[i]);
 949                         }
 950                         return len;
 951                 }
 952         }
 953
 954         return -EINVAL;
 955 }
 956 BTRFS_ATTR_RW(, read_policy, btrfs_read_policy_show, btrfs_read_policy_store);
 957
 958 static const struct attribute *btrfs_attrs[] = {
 959         BTRFS_ATTR_PTR(, label),
 960         BTRFS_ATTR_PTR(, nodesize),
 961         BTRFS_ATTR_PTR(, sectorsize),
 962         BTRFS_ATTR_PTR(, clone_alignment),
 963         BTRFS_ATTR_PTR(, quota_override),
 964         BTRFS_ATTR_PTR(, metadata_uuid),
 965         BTRFS_ATTR_PTR(, checksum),
 966         BTRFS_ATTR_PTR(, exclusive_operation),
 967         BTRFS_ATTR_PTR(, generation),
 968         BTRFS_ATTR_PTR(, read_policy),
 969         NULL,
 970 };
 971
 972 static void btrfs_release_fsid_kobj(struct kobject *kobj)
 973 {
 974         struct btrfs_fs_devices *fs_devs = to_fs_devs(kobj);
 975
 976         memset(&fs_devs->fsid_kobj, 0, sizeof(struct kobject));
 977         complete(&fs_devs->kobj_unregister);
 978 }
 979
 980 static struct kobj_type btrfs_ktype = {
 981         .sysfs_ops      = &kobj_sysfs_ops,
 982         .release        = btrfs_release_fsid_kobj,
 983 };
 984
 985 static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj)
 986 {
 987         if (kobj->ktype != &btrfs_ktype)
 988                 return NULL;
 989         return container_of(kobj, struct btrfs_fs_devices, fsid_kobj);
 990 }
 991
 992 static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj)
 993 {
 994         if (kobj->ktype != &btrfs_ktype)
 995                 return NULL;
 996         return to_fs_devs(kobj)->fs_info;
 997 }
 998
 999 #define NUM_FEATURE_BITS 64
1000 #define BTRFS_FEATURE_NAME_MAX 13
1001 static char btrfs_unknown_feature_names[FEAT_MAX][NUM_FEATURE_BITS][BTRFS_FEATURE_NAME_MAX];
1002 static struct btrfs_feature_attr btrfs_feature_attrs[FEAT_MAX][NUM_FEATURE_BITS];
1003
1004 static const u64 supported_feature_masks[FEAT_MAX] = {
1005         [FEAT_COMPAT]    = BTRFS_FEATURE_COMPAT_SUPP,
1006         [FEAT_COMPAT_RO] = BTRFS_FEATURE_COMPAT_RO_SUPP,
1007         [FEAT_INCOMPAT]  = BTRFS_FEATURE_INCOMPAT_SUPP,
1008 };
1009
1010 static int addrm_unknown_feature_attrs(struct btrfs_fs_info *fs_info, bool add)
1011 {
1012         int set;
1013
1014         for (set = 0; set < FEAT_MAX; set++) {
1015                 int i;
1016                 struct attribute *attrs[2];
1017                 struct attribute_group agroup = {
1018                         .name = "features",
1019                         .attrs = attrs,
1020                 };
1021                 u64 features = get_features(fs_info, set);
1022                 features &= ~supported_feature_masks[set];
1023
1024                 if (!features)
1025                         continue;
1026
1027                 attrs[1] = NULL;
1028                 for (i = 0; i < NUM_FEATURE_BITS; i++) {
1029                         struct btrfs_feature_attr *fa;
1030
1031                         if (!(features & (1ULL << i)))
1032                                 continue;
1033
1034                         fa = &btrfs_feature_attrs[set][i];
1035                         attrs[0] = &fa->kobj_attr.attr;
1036                         if (add) {
1037                                 int ret;
1038                                 ret = sysfs_merge_group(&fs_info->fs_devices->fsid_kobj,
1039                                                         &agroup);
1040                                 if (ret)
1041                                         return ret;
1042                         } else
1043                                 sysfs_unmerge_group(&fs_info->fs_devices->fsid_kobj,
1044                                                     &agroup);
1045                 }
1046
1047         }
1048         return 0;
1049 }
1050
1051 static void __btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs)
1052 {
1053         if (fs_devs->devinfo_kobj) {
1054                 kobject_del(fs_devs->devinfo_kobj);
1055                 kobject_put(fs_devs->devinfo_kobj);
1056                 fs_devs->devinfo_kobj = NULL;
1057         }
1058
1059         if (fs_devs->devices_kobj) {
1060                 kobject_del(fs_devs->devices_kobj);
1061                 kobject_put(fs_devs->devices_kobj);
1062                 fs_devs->devices_kobj = NULL;
1063         }
1064
1065         if (fs_devs->fsid_kobj.state_initialized) {
1066                 kobject_del(&fs_devs->fsid_kobj);
1067                 kobject_put(&fs_devs->fsid_kobj);
1068                 wait_for_completion(&fs_devs->kobj_unregister);
1069         }
1070 }
1071
1072 /* when fs_devs is NULL it will remove all fsid kobject */
1073 void btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs)
1074 {
1075         struct list_head *fs_uuids = btrfs_get_fs_uuids();
1076
1077         if (fs_devs) {
1078                 __btrfs_sysfs_remove_fsid(fs_devs);
1079                 return;
1080         }
1081
1082         list_for_each_entry(fs_devs, fs_uuids, fs_list) {
1083                 __btrfs_sysfs_remove_fsid(fs_devs);
1084         }
1085 }
1086
1087 static void btrfs_sysfs_remove_fs_devices(struct btrfs_fs_devices *fs_devices)
1088 {
1089         struct btrfs_device *device;
1090         struct btrfs_fs_devices *seed;
1091
1092         list_for_each_entry(device, &fs_devices->devices, dev_list)
1093                 btrfs_sysfs_remove_device(device);
1094
1095         list_for_each_entry(seed, &fs_devices->seed_list, seed_list) {
1096                 list_for_each_entry(device, &seed->devices, dev_list)
1097                         btrfs_sysfs_remove_device(device);
1098         }
1099 }
1100
1101 void btrfs_sysfs_remove_mounted(struct btrfs_fs_info *fs_info)
1102 {
1103         struct kobject *fsid_kobj = &fs_info->fs_devices->fsid_kobj;
1104
1105         sysfs_remove_link(fsid_kobj, "bdi");
1106
1107         if (fs_info->space_info_kobj) {
1108                 sysfs_remove_files(fs_info->space_info_kobj, allocation_attrs);
1109                 kobject_del(fs_info->space_info_kobj);
1110                 kobject_put(fs_info->space_info_kobj);
1111         }
1112 #ifdef CONFIG_BTRFS_DEBUG
1113         if (fs_info->discard_debug_kobj) {
1114                 sysfs_remove_files(fs_info->discard_debug_kobj,
1115                                    discard_debug_attrs);
1116                 kobject_del(fs_info->discard_debug_kobj);
1117                 kobject_put(fs_info->discard_debug_kobj);
1118         }
1119         if (fs_info->debug_kobj) {
1120                 sysfs_remove_files(fs_info->debug_kobj, btrfs_debug_mount_attrs);
1121                 kobject_del(fs_info->debug_kobj);
1122                 kobject_put(fs_info->debug_kobj);
1123         }
1124 #endif
1125         addrm_unknown_feature_attrs(fs_info, false);
1126         sysfs_remove_group(fsid_kobj, &btrfs_feature_attr_group);
1127         sysfs_remove_files(fsid_kobj, btrfs_attrs);
1128         btrfs_sysfs_remove_fs_devices(fs_info->fs_devices);
1129 }
1130
1131 static const char * const btrfs_feature_set_names[FEAT_MAX] = {
1132         [FEAT_COMPAT]    = "compat",
1133         [FEAT_COMPAT_RO] = "compat_ro",
1134         [FEAT_INCOMPAT]  = "incompat",
1135 };
1136
1137 const char *btrfs_feature_set_name(enum btrfs_feature_set set)
1138 {
1139         return btrfs_feature_set_names[set];
1140 }
1141
1142 char *btrfs_printable_features(enum btrfs_feature_set set, u64 flags)
1143 {
1144         size_t bufsize = 4096; /* safe max, 64 names * 64 bytes */
1145         int len = 0;
1146         int i;
1147         char *str;
1148
1149         str = kmalloc(bufsize, GFP_KERNEL);
1150         if (!str)
1151                 return str;
1152
1153         for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
1154                 const char *name;
1155
1156                 if (!(flags & (1ULL << i)))
1157                         continue;
1158
1159                 name = btrfs_feature_attrs[set][i].kobj_attr.attr.name;
1160                 len += scnprintf(str + len, bufsize - len, "%s%s",
1161                                 len ? "," : "", name);
1162         }
1163
1164         return str;
1165 }
1166
1167 static void init_feature_attrs(void)
1168 {
1169         struct btrfs_feature_attr *fa;
1170         int set, i;
1171
1172         BUILD_BUG_ON(ARRAY_SIZE(btrfs_unknown_feature_names) !=
1173                      ARRAY_SIZE(btrfs_feature_attrs));
1174         BUILD_BUG_ON(ARRAY_SIZE(btrfs_unknown_feature_names[0]) !=
1175                      ARRAY_SIZE(btrfs_feature_attrs[0]));
1176
1177         memset(btrfs_feature_attrs, 0, sizeof(btrfs_feature_attrs));
1178         memset(btrfs_unknown_feature_names, 0,
1179                sizeof(btrfs_unknown_feature_names));
1180
1181         for (i = 0; btrfs_supported_feature_attrs[i]; i++) {
1182                 struct btrfs_feature_attr *sfa;
1183                 struct attribute *a = btrfs_supported_feature_attrs[i];
1184                 int bit;
1185                 sfa = attr_to_btrfs_feature_attr(a);
1186                 bit = ilog2(sfa->feature_bit);
1187                 fa = &btrfs_feature_attrs[sfa->feature_set][bit];
1188
1189                 fa->kobj_attr.attr.name = sfa->kobj_attr.attr.name;
1190         }
1191
1192         for (set = 0; set < FEAT_MAX; set++) {
1193                 for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
1194                         char *name = btrfs_unknown_feature_names[set][i];
1195                         fa = &btrfs_feature_attrs[set][i];
1196
1197                         if (fa->kobj_attr.attr.name)
1198                                 continue;
1199
1200                         snprintf(name, BTRFS_FEATURE_NAME_MAX, "%s:%u",
1201                                  btrfs_feature_set_names[set], i);
1202
1203                         fa->kobj_attr.attr.name = name;
1204                         fa->kobj_attr.attr.mode = S_IRUGO;
1205                         fa->feature_set = set;
1206                         fa->feature_bit = 1ULL << i;
1207                 }
1208         }
1209 }
1210
1211 /*
1212  * Create a sysfs entry for a given block group type at path
1213  * /sys/fs/btrfs/UUID/allocation/data/TYPE
1214  */
1215 void btrfs_sysfs_add_block_group_type(struct btrfs_block_group *cache)
1216 {
1217         struct btrfs_fs_info *fs_info = cache->fs_info;
1218         struct btrfs_space_info *space_info = cache->space_info;
1219         struct raid_kobject *rkobj;
1220         const int index = btrfs_bg_flags_to_raid_index(cache->flags);
1221         unsigned int nofs_flag;
1222         int ret;
1223
1224         /*
1225          * Setup a NOFS context because kobject_add(), deep in its call chain,
1226          * does GFP_KERNEL allocations, and we are often called in a context
1227          * where if reclaim is triggered we can deadlock (we are either holding
1228          * a transaction handle or some lock required for a transaction
1229          * commit).
1230          */
1231         nofs_flag = memalloc_nofs_save();
1232
1233         rkobj = kzalloc(sizeof(*rkobj), GFP_NOFS);
1234         if (!rkobj) {
1235                 memalloc_nofs_restore(nofs_flag);
1236                 btrfs_warn(cache->fs_info,
1237                                 "couldn't alloc memory for raid level kobject");
1238                 return;
1239         }
1240
1241         rkobj->flags = cache->flags;
1242         kobject_init(&rkobj->kobj, &btrfs_raid_ktype);
1243
1244         /*
1245          * We call this either on mount, or if we've created a block group for a
1246          * new index type while running (i.e. when restriping).  The running
1247          * case is tricky because we could race with other threads, so we need
1248          * to have this check to make sure we didn't already init the kobject.
1249          *
1250          * We don't have to protect on the free side because it only happens on
1251          * unmount.
1252          */
1253         spin_lock(&space_info->lock);
1254         if (space_info->block_group_kobjs[index]) {
1255                 spin_unlock(&space_info->lock);
1256                 kobject_put(&rkobj->kobj);
1257                 return;
1258         } else {
1259                 space_info->block_group_kobjs[index] = &rkobj->kobj;
1260         }
1261         spin_unlock(&space_info->lock);
1262
1263         ret = kobject_add(&rkobj->kobj, &space_info->kobj, "%s",
1264                           btrfs_bg_type_to_raid_name(rkobj->flags));
1265         memalloc_nofs_restore(nofs_flag);
1266         if (ret) {
1267                 spin_lock(&space_info->lock);
1268                 space_info->block_group_kobjs[index] = NULL;
1269                 spin_unlock(&space_info->lock);
1270                 kobject_put(&rkobj->kobj);
1271                 btrfs_warn(fs_info,
1272                         "failed to add kobject for block cache, ignoring");
1273                 return;
1274         }
1275 }
1276
1277 /*
1278  * Remove sysfs directories for all block group types of a given space info and
1279  * the space info as well
1280  */
1281 void btrfs_sysfs_remove_space_info(struct btrfs_space_info *space_info)
1282 {
1283         int i;
1284
1285         for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) {
1286                 struct kobject *kobj;
1287
1288                 kobj = space_info->block_group_kobjs[i];
1289                 space_info->block_group_kobjs[i] = NULL;
1290                 if (kobj) {
1291                         kobject_del(kobj);
1292                         kobject_put(kobj);
1293                 }
1294         }
1295         kobject_del(&space_info->kobj);
1296         kobject_put(&space_info->kobj);
1297 }
1298
1299 static const char *alloc_name(u64 flags)
1300 {
1301         switch (flags) {
1302         case BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA:
1303                 return "mixed";
1304         case BTRFS_BLOCK_GROUP_METADATA:
1305                 return "metadata";
1306         case BTRFS_BLOCK_GROUP_DATA:
1307                 return "data";
1308         case BTRFS_BLOCK_GROUP_SYSTEM:
1309                 return "system";
1310         default:
1311                 WARN_ON(1);
1312                 return "invalid-combination";
1313         };
1314 }
1315
1316 /*
1317  * Create a sysfs entry for a space info type at path
1318  * /sys/fs/btrfs/UUID/allocation/TYPE
1319  */
1320 int btrfs_sysfs_add_space_info_type(struct btrfs_fs_info *fs_info,
1321                                     struct btrfs_space_info *space_info)
1322 {
1323         int ret;
1324
1325         ret = kobject_init_and_add(&space_info->kobj, &space_info_ktype,
1326                                    fs_info->space_info_kobj, "%s",
1327                                    alloc_name(space_info->flags));
1328         if (ret) {
1329                 kobject_put(&space_info->kobj);
1330                 return ret;
1331         }
1332
1333         return 0;
1334 }
1335
1336 void btrfs_sysfs_remove_device(struct btrfs_device *device)
1337 {
1338         struct hd_struct *disk;
1339         struct kobject *disk_kobj;
1340         struct kobject *devices_kobj;
1341
1342         /*
1343          * Seed fs_devices devices_kobj aren't used, fetch kobject from the
1344          * fs_info::fs_devices.
1345          */
1346         devices_kobj = device->fs_info->fs_devices->devices_kobj;
1347         ASSERT(devices_kobj);
1348
1349         if (device->bdev) {
1350                 disk = device->bdev->bd_part;
1351                 disk_kobj = &part_to_dev(disk)->kobj;
1352                 sysfs_remove_link(devices_kobj, disk_kobj->name);
1353         }
1354
1355         if (device->devid_kobj.state_initialized) {
1356                 kobject_del(&device->devid_kobj);
1357                 kobject_put(&device->devid_kobj);
1358                 wait_for_completion(&device->kobj_unregister);
1359         }
1360 }
1361
1362 static ssize_t btrfs_devinfo_in_fs_metadata_show(struct kobject *kobj,
1363                                                  struct kobj_attribute *a,
1364                                                  char *buf)
1365 {
1366         int val;
1367         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1368                                                    devid_kobj);
1369
1370         val = !!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state);
1371
1372         return scnprintf(buf, PAGE_SIZE, "%d\n", val);
1373 }
1374 BTRFS_ATTR(devid, in_fs_metadata, btrfs_devinfo_in_fs_metadata_show);
1375
1376 static ssize_t btrfs_devinfo_missing_show(struct kobject *kobj,
1377                                         struct kobj_attribute *a, char *buf)
1378 {
1379         int val;
1380         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1381                                                    devid_kobj);
1382
1383         val = !!test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state);
1384
1385         return scnprintf(buf, PAGE_SIZE, "%d\n", val);
1386 }
1387 BTRFS_ATTR(devid, missing, btrfs_devinfo_missing_show);
1388
1389 static ssize_t btrfs_devinfo_replace_target_show(struct kobject *kobj,
1390                                                  struct kobj_attribute *a,
1391                                                  char *buf)
1392 {
1393         int val;
1394         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1395                                                    devid_kobj);
1396
1397         val = !!test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state);
1398
1399         return scnprintf(buf, PAGE_SIZE, "%d\n", val);
1400 }
1401 BTRFS_ATTR(devid, replace_target, btrfs_devinfo_replace_target_show);
1402
1403 static ssize_t btrfs_devinfo_writeable_show(struct kobject *kobj,
1404                                             struct kobj_attribute *a, char *buf)
1405 {
1406         int val;
1407         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1408                                                    devid_kobj);
1409
1410         val = !!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state);
1411
1412         return scnprintf(buf, PAGE_SIZE, "%d\n", val);
1413 }
1414 BTRFS_ATTR(devid, writeable, btrfs_devinfo_writeable_show);
1415
1416 static struct attribute *devid_attrs[] = {
1417         BTRFS_ATTR_PTR(devid, in_fs_metadata),
1418         BTRFS_ATTR_PTR(devid, missing),
1419         BTRFS_ATTR_PTR(devid, replace_target),
1420         BTRFS_ATTR_PTR(devid, writeable),
1421         NULL
1422 };
1423 ATTRIBUTE_GROUPS(devid);
1424
1425 static void btrfs_release_devid_kobj(struct kobject *kobj)
1426 {
1427         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1428                                                    devid_kobj);
1429
1430         memset(&device->devid_kobj, 0, sizeof(struct kobject));
1431         complete(&device->kobj_unregister);
1432 }
1433
1434 static struct kobj_type devid_ktype = {
1435         .sysfs_ops      = &kobj_sysfs_ops,
1436         .default_groups = devid_groups,
1437         .release        = btrfs_release_devid_kobj,
1438 };
1439
1440 int btrfs_sysfs_add_device(struct btrfs_device *device)
1441 {
1442         int ret;
1443         unsigned int nofs_flag;
1444         struct kobject *devices_kobj;
1445         struct kobject *devinfo_kobj;
1446
1447         /*
1448          * Make sure we use the fs_info::fs_devices to fetch the kobjects even
1449          * for the seed fs_devices
1450          */
1451         devices_kobj = device->fs_info->fs_devices->devices_kobj;
1452         devinfo_kobj = device->fs_info->fs_devices->devinfo_kobj;
1453         ASSERT(devices_kobj);
1454         ASSERT(devinfo_kobj);
1455
1456         nofs_flag = memalloc_nofs_save();
1457
1458         if (device->bdev) {
1459                 struct hd_struct *disk;
1460                 struct kobject *disk_kobj;
1461
1462                 disk = device->bdev->bd_part;
1463                 disk_kobj = &part_to_dev(disk)->kobj;
1464
1465                 ret = sysfs_create_link(devices_kobj, disk_kobj, disk_kobj->name);
1466                 if (ret) {
1467                         btrfs_warn(device->fs_info,
1468                                 "creating sysfs device link for devid %llu failed: %d",
1469                                 device->devid, ret);
1470                         goto out;
1471                 }
1472         }
1473
1474         init_completion(&device->kobj_unregister);
1475         ret = kobject_init_and_add(&device->devid_kobj, &devid_ktype,
1476                                    devinfo_kobj, "%llu", device->devid);
1477         if (ret) {
1478                 kobject_put(&device->devid_kobj);
1479                 btrfs_warn(device->fs_info,
1480                            "devinfo init for devid %llu failed: %d",
1481                            device->devid, ret);
1482         }
1483
1484 out:
1485         memalloc_nofs_restore(nofs_flag);
1486         return ret;
1487 }
1488
1489 static int btrfs_sysfs_add_fs_devices(struct btrfs_fs_devices *fs_devices)
1490 {
1491         int ret;
1492         struct btrfs_device *device;
1493         struct btrfs_fs_devices *seed;
1494
1495         list_for_each_entry(device, &fs_devices->devices, dev_list) {
1496                 ret = btrfs_sysfs_add_device(device);
1497                 if (ret)
1498                         goto fail;
1499         }
1500
1501         list_for_each_entry(seed, &fs_devices->seed_list, seed_list) {
1502                 list_for_each_entry(device, &seed->devices, dev_list) {
1503                         ret = btrfs_sysfs_add_device(device);
1504                         if (ret)
1505                                 goto fail;
1506                 }
1507         }
1508
1509         return 0;
1510
1511 fail:
1512         btrfs_sysfs_remove_fs_devices(fs_devices);
1513         return ret;
1514 }
1515
1516 void btrfs_kobject_uevent(struct block_device *bdev, enum kobject_action action)
1517 {
1518         int ret;
1519
1520         ret = kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, action);
1521         if (ret)
1522                 pr_warn("BTRFS: Sending event '%d' to kobject: '%s' (%p): failed\n",
1523                         action, kobject_name(&disk_to_dev(bdev->bd_disk)->kobj),
1524                         &disk_to_dev(bdev->bd_disk)->kobj);
1525 }
1526
1527 void btrfs_sysfs_update_sprout_fsid(struct btrfs_fs_devices *fs_devices)
1528
1529 {
1530         char fsid_buf[BTRFS_UUID_UNPARSED_SIZE];
1531
1532         /*
1533          * Sprouting changes fsid of the mounted filesystem, rename the fsid
1534          * directory
1535          */
1536         snprintf(fsid_buf, BTRFS_UUID_UNPARSED_SIZE, "%pU", fs_devices->fsid);
1537         if (kobject_rename(&fs_devices->fsid_kobj, fsid_buf))
1538                 btrfs_warn(fs_devices->fs_info,
1539                                 "sysfs: failed to create fsid for sprout");
1540 }
1541
1542 void btrfs_sysfs_update_devid(struct btrfs_device *device)
1543 {
1544         char tmp[24];
1545
1546         snprintf(tmp, sizeof(tmp), "%llu", device->devid);
1547
1548         if (kobject_rename(&device->devid_kobj, tmp))
1549                 btrfs_warn(device->fs_devices->fs_info,
1550                            "sysfs: failed to update devid for %llu",
1551                            device->devid);
1552 }
1553
1554 /* /sys/fs/btrfs/ entry */
1555 static struct kset *btrfs_kset;
1556
1557 /*
1558  * Creates:
1559  *              /sys/fs/btrfs/UUID
1560  *
1561  * Can be called by the device discovery thread.
1562  */
1563 int btrfs_sysfs_add_fsid(struct btrfs_fs_devices *fs_devs)
1564 {
1565         int error;
1566
1567         init_completion(&fs_devs->kobj_unregister);
1568         fs_devs->fsid_kobj.kset = btrfs_kset;
1569         error = kobject_init_and_add(&fs_devs->fsid_kobj, &btrfs_ktype, NULL,
1570                                      "%pU", fs_devs->fsid);
1571         if (error) {
1572                 kobject_put(&fs_devs->fsid_kobj);
1573                 return error;
1574         }
1575
1576         fs_devs->devices_kobj = kobject_create_and_add("devices",
1577                                                        &fs_devs->fsid_kobj);
1578         if (!fs_devs->devices_kobj) {
1579                 btrfs_err(fs_devs->fs_info,
1580                           "failed to init sysfs device interface");
1581                 btrfs_sysfs_remove_fsid(fs_devs);
1582                 return -ENOMEM;
1583         }
1584
1585         fs_devs->devinfo_kobj = kobject_create_and_add("devinfo",
1586                                                        &fs_devs->fsid_kobj);
1587         if (!fs_devs->devinfo_kobj) {
1588                 btrfs_err(fs_devs->fs_info,
1589                           "failed to init sysfs devinfo kobject");
1590                 btrfs_sysfs_remove_fsid(fs_devs);
1591                 return -ENOMEM;
1592         }
1593
1594         return 0;
1595 }
1596
1597 int btrfs_sysfs_add_mounted(struct btrfs_fs_info *fs_info)
1598 {
1599         int error;
1600         struct btrfs_fs_devices *fs_devs = fs_info->fs_devices;
1601         struct kobject *fsid_kobj = &fs_devs->fsid_kobj;
1602
1603         error = btrfs_sysfs_add_fs_devices(fs_devs);
1604         if (error)
1605                 return error;
1606
1607         error = sysfs_create_files(fsid_kobj, btrfs_attrs);
1608         if (error) {
1609                 btrfs_sysfs_remove_fs_devices(fs_devs);
1610                 return error;
1611         }
1612
1613         error = sysfs_create_group(fsid_kobj,
1614                                    &btrfs_feature_attr_group);
1615         if (error)
1616                 goto failure;
1617
1618 #ifdef CONFIG_BTRFS_DEBUG
1619         fs_info->debug_kobj = kobject_create_and_add("debug", fsid_kobj);
1620         if (!fs_info->debug_kobj) {
1621                 error = -ENOMEM;
1622                 goto failure;
1623         }
1624
1625         error = sysfs_create_files(fs_info->debug_kobj, btrfs_debug_mount_attrs);
1626         if (error)
1627                 goto failure;
1628
1629         /* Discard directory */
1630         fs_info->discard_debug_kobj = kobject_create_and_add("discard",
1631                                                      fs_info->debug_kobj);
1632         if (!fs_info->discard_debug_kobj) {
1633                 error = -ENOMEM;
1634                 goto failure;
1635         }
1636
1637         error = sysfs_create_files(fs_info->discard_debug_kobj,
1638                                    discard_debug_attrs);
1639         if (error)
1640                 goto failure;
1641 #endif
1642
1643         error = addrm_unknown_feature_attrs(fs_info, true);
1644         if (error)
1645                 goto failure;
1646
1647         error = sysfs_create_link(fsid_kobj, &fs_info->sb->s_bdi->dev->kobj, "bdi");
1648         if (error)
1649                 goto failure;
1650
1651         fs_info->space_info_kobj = kobject_create_and_add("allocation",
1652                                                   fsid_kobj);
1653         if (!fs_info->space_info_kobj) {
1654                 error = -ENOMEM;
1655                 goto failure;
1656         }
1657
1658         error = sysfs_create_files(fs_info->space_info_kobj, allocation_attrs);
1659         if (error)
1660                 goto failure;
1661
1662         return 0;
1663 failure:
1664         btrfs_sysfs_remove_mounted(fs_info);
1665         return error;
1666 }
1667
1668 static inline struct btrfs_fs_info *qgroup_kobj_to_fs_info(struct kobject *kobj)
1669 {
1670         return to_fs_info(kobj->parent->parent);
1671 }
1672
1673 #define QGROUP_ATTR(_member, _show_name)                                        \
1674 static ssize_t btrfs_qgroup_show_##_member(struct kobject *qgroup_kobj,         \
1675                                            struct kobj_attribute *a,            \
1676                                            char *buf)                           \
1677 {                                                                               \
1678         struct btrfs_fs_info *fs_info = qgroup_kobj_to_fs_info(qgroup_kobj);    \
1679         struct btrfs_qgroup *qgroup = container_of(qgroup_kobj,                 \
1680                         struct btrfs_qgroup, kobj);                             \
1681         return btrfs_show_u64(&qgroup->_member, &fs_info->qgroup_lock, buf);    \
1682 }                                                                               \
1683 BTRFS_ATTR(qgroup, _show_name, btrfs_qgroup_show_##_member)
1684
1685 #define QGROUP_RSV_ATTR(_name, _type)                                           \
1686 static ssize_t btrfs_qgroup_rsv_show_##_name(struct kobject *qgroup_kobj,       \
1687                                              struct kobj_attribute *a,          \
1688                                              char *buf)                         \
1689 {                                                                               \
1690         struct btrfs_fs_info *fs_info = qgroup_kobj_to_fs_info(qgroup_kobj);    \
1691         struct btrfs_qgroup *qgroup = container_of(qgroup_kobj,                 \
1692                         struct btrfs_qgroup, kobj);                             \
1693         return btrfs_show_u64(&qgroup->rsv.values[_type],                       \
1694                         &fs_info->qgroup_lock, buf);                            \
1695 }                                                                               \
1696 BTRFS_ATTR(qgroup, rsv_##_name, btrfs_qgroup_rsv_show_##_name)
1697
1698 QGROUP_ATTR(rfer, referenced);
1699 QGROUP_ATTR(excl, exclusive);
1700 QGROUP_ATTR(max_rfer, max_referenced);
1701 QGROUP_ATTR(max_excl, max_exclusive);
1702 QGROUP_ATTR(lim_flags, limit_flags);
1703 QGROUP_RSV_ATTR(data, BTRFS_QGROUP_RSV_DATA);
1704 QGROUP_RSV_ATTR(meta_pertrans, BTRFS_QGROUP_RSV_META_PERTRANS);
1705 QGROUP_RSV_ATTR(meta_prealloc, BTRFS_QGROUP_RSV_META_PREALLOC);
1706
1707 static struct attribute *qgroup_attrs[] = {
1708         BTRFS_ATTR_PTR(qgroup, referenced),
1709         BTRFS_ATTR_PTR(qgroup, exclusive),
1710         BTRFS_ATTR_PTR(qgroup, max_referenced),
1711         BTRFS_ATTR_PTR(qgroup, max_exclusive),
1712         BTRFS_ATTR_PTR(qgroup, limit_flags),
1713         BTRFS_ATTR_PTR(qgroup, rsv_data),
1714         BTRFS_ATTR_PTR(qgroup, rsv_meta_pertrans),
1715         BTRFS_ATTR_PTR(qgroup, rsv_meta_prealloc),
1716         NULL
1717 };
1718 ATTRIBUTE_GROUPS(qgroup);
1719
1720 static void qgroup_release(struct kobject *kobj)
1721 {
1722         struct btrfs_qgroup *qgroup = container_of(kobj, struct btrfs_qgroup, kobj);
1723
1724         memset(&qgroup->kobj, 0, sizeof(*kobj));
1725 }
1726
1727 static struct kobj_type qgroup_ktype = {
1728         .sysfs_ops = &kobj_sysfs_ops,
1729         .release = qgroup_release,
1730         .default_groups = qgroup_groups,
1731 };
1732
1733 int btrfs_sysfs_add_one_qgroup(struct btrfs_fs_info *fs_info,
1734                                 struct btrfs_qgroup *qgroup)
1735 {
1736         struct kobject *qgroups_kobj = fs_info->qgroups_kobj;
1737         int ret;
1738
1739         if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
1740                 return 0;
1741         if (qgroup->kobj.state_initialized)
1742                 return 0;
1743         if (!qgroups_kobj)
1744                 return -EINVAL;
1745
1746         ret = kobject_init_and_add(&qgroup->kobj, &qgroup_ktype, qgroups_kobj,
1747                         "%hu_%llu", btrfs_qgroup_level(qgroup->qgroupid),
1748                         btrfs_qgroup_subvolid(qgroup->qgroupid));
1749         if (ret < 0)
1750                 kobject_put(&qgroup->kobj);
1751
1752         return ret;
1753 }
1754
1755 void btrfs_sysfs_del_qgroups(struct btrfs_fs_info *fs_info)
1756 {
1757         struct btrfs_qgroup *qgroup;
1758         struct btrfs_qgroup *next;
1759
1760         if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
1761                 return;
1762
1763         rbtree_postorder_for_each_entry_safe(qgroup, next,
1764                                              &fs_info->qgroup_tree, node)
1765                 btrfs_sysfs_del_one_qgroup(fs_info, qgroup);
1766         if (fs_info->qgroups_kobj) {
1767                 kobject_del(fs_info->qgroups_kobj);
1768                 kobject_put(fs_info->qgroups_kobj);
1769                 fs_info->qgroups_kobj = NULL;
1770         }
1771 }
1772
1773 /* Called when qgroups get initialized, thus there is no need for locking */
1774 int btrfs_sysfs_add_qgroups(struct btrfs_fs_info *fs_info)
1775 {
1776         struct kobject *fsid_kobj = &fs_info->fs_devices->fsid_kobj;
1777         struct btrfs_qgroup *qgroup;
1778         struct btrfs_qgroup *next;
1779         int ret = 0;
1780
1781         if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
1782                 return 0;
1783
1784         ASSERT(fsid_kobj);
1785         if (fs_info->qgroups_kobj)
1786                 return 0;
1787
1788         fs_info->qgroups_kobj = kobject_create_and_add("qgroups", fsid_kobj);
1789         if (!fs_info->qgroups_kobj) {
1790                 ret = -ENOMEM;
1791                 goto out;
1792         }
1793         rbtree_postorder_for_each_entry_safe(qgroup, next,
1794                                              &fs_info->qgroup_tree, node) {
1795                 ret = btrfs_sysfs_add_one_qgroup(fs_info, qgroup);
1796                 if (ret < 0)
1797                         goto out;
1798         }
1799
1800 out:
1801         if (ret < 0)
1802                 btrfs_sysfs_del_qgroups(fs_info);
1803         return ret;
1804 }
1805
1806 void btrfs_sysfs_del_one_qgroup(struct btrfs_fs_info *fs_info,
1807                                 struct btrfs_qgroup *qgroup)
1808 {
1809         if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
1810                 return;
1811
1812         if (qgroup->kobj.state_initialized) {
1813                 kobject_del(&qgroup->kobj);
1814                 kobject_put(&qgroup->kobj);
1815         }
1816 }
1817
1818 /*
1819  * Change per-fs features in /sys/fs/btrfs/UUID/features to match current
1820  * values in superblock. Call after any changes to incompat/compat_ro flags
1821  */
1822 void btrfs_sysfs_feature_update(struct btrfs_fs_info *fs_info,
1823                 u64 bit, enum btrfs_feature_set set)
1824 {
1825         struct btrfs_fs_devices *fs_devs;
1826         struct kobject *fsid_kobj;
1827         u64 __maybe_unused features;
1828         int __maybe_unused ret;
1829
1830         if (!fs_info)
1831                 return;
1832
1833         /*
1834          * See 14e46e04958df74 and e410e34fad913dd, feature bit updates are not
1835          * safe when called from some contexts (eg. balance)
1836          */
1837         features = get_features(fs_info, set);
1838         ASSERT(bit & supported_feature_masks[set]);
1839
1840         fs_devs = fs_info->fs_devices;
1841         fsid_kobj = &fs_devs->fsid_kobj;
1842
1843         if (!fsid_kobj->state_initialized)
1844                 return;
1845
1846         /*
1847          * FIXME: this is too heavy to update just one value, ideally we'd like
1848          * to use sysfs_update_group but some refactoring is needed first.
1849          */
1850         sysfs_remove_group(fsid_kobj, &btrfs_feature_attr_group);
1851         ret = sysfs_create_group(fsid_kobj, &btrfs_feature_attr_group);
1852 }
1853
1854 int __init btrfs_init_sysfs(void)
1855 {
1856         int ret;
1857
1858         btrfs_kset = kset_create_and_add("btrfs", NULL, fs_kobj);
1859         if (!btrfs_kset)
1860                 return -ENOMEM;
1861
1862         init_feature_attrs();
1863         ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
1864         if (ret)
1865                 goto out2;
1866         ret = sysfs_merge_group(&btrfs_kset->kobj,
1867                                 &btrfs_static_feature_attr_group);
1868         if (ret)
1869                 goto out_remove_group;
1870
1871 #ifdef CONFIG_BTRFS_DEBUG
1872         ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_debug_feature_attr_group);
1873         if (ret)
1874                 goto out2;
1875 #endif
1876
1877         return 0;
1878
1879 out_remove_group:
1880         sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
1881 out2:
1882         kset_unregister(btrfs_kset);
1883
1884         return ret;
1885 }
1886
1887 void __cold btrfs_exit_sysfs(void)
1888 {
1889         sysfs_unmerge_group(&btrfs_kset->kobj,
1890                             &btrfs_static_feature_attr_group);
1891         sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
1892 #ifdef CONFIG_BTRFS_DEBUG
1893         sysfs_remove_group(&btrfs_kset->kobj, &btrfs_debug_feature_attr_group);
1894 #endif
1895         kset_unregister(btrfs_kset);
1896 }
1897