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 "transaction.h"
  18 #include "sysfs.h"
  19 #include "volumes.h"
  20 #include "space-info.h"
  21 #include "block-group.h"
  22
  23 struct btrfs_feature_attr {
  24         struct kobj_attribute kobj_attr;
  25         enum btrfs_feature_set feature_set;
  26         u64 feature_bit;
  27 };
  28
  29 /* For raid type sysfs entries */
  30 struct raid_kobject {
  31         u64 flags;
  32         struct kobject kobj;
  33 };
  34
  35 #define __INIT_KOBJ_ATTR(_name, _mode, _show, _store)                   \
  36 {                                                                       \
  37         .attr   = { .name = __stringify(_name), .mode = _mode },        \
  38         .show   = _show,                                                \
  39         .store  = _store,                                               \
  40 }
  41
  42 #define BTRFS_ATTR_RW(_prefix, _name, _show, _store)                    \
  43         static struct kobj_attribute btrfs_attr_##_prefix##_##_name =   \
  44                         __INIT_KOBJ_ATTR(_name, 0644, _show, _store)
  45
  46 #define BTRFS_ATTR(_prefix, _name, _show)                               \
  47         static struct kobj_attribute btrfs_attr_##_prefix##_##_name =   \
  48                         __INIT_KOBJ_ATTR(_name, 0444, _show, NULL)
  49
  50 #define BTRFS_ATTR_PTR(_prefix, _name)                                  \
  51         (&btrfs_attr_##_prefix##_##_name.attr)
  52
  53 #define BTRFS_FEAT_ATTR(_name, _feature_set, _feature_prefix, _feature_bit)  \
  54 static struct btrfs_feature_attr btrfs_attr_features_##_name = {             \
  55         .kobj_attr = __INIT_KOBJ_ATTR(_name, S_IRUGO,                        \
  56                                       btrfs_feature_attr_show,               \
  57                                       btrfs_feature_attr_store),             \
  58         .feature_set    = _feature_set,                                      \
  59         .feature_bit    = _feature_prefix ##_## _feature_bit,                \
  60 }
  61 #define BTRFS_FEAT_ATTR_PTR(_name)                                           \
  62         (&btrfs_attr_features_##_name.kobj_attr.attr)
  63
  64 #define BTRFS_FEAT_ATTR_COMPAT(name, feature) \
  65         BTRFS_FEAT_ATTR(name, FEAT_COMPAT, BTRFS_FEATURE_COMPAT, feature)
  66 #define BTRFS_FEAT_ATTR_COMPAT_RO(name, feature) \
  67         BTRFS_FEAT_ATTR(name, FEAT_COMPAT_RO, BTRFS_FEATURE_COMPAT_RO, feature)
  68 #define BTRFS_FEAT_ATTR_INCOMPAT(name, feature) \
  69         BTRFS_FEAT_ATTR(name, FEAT_INCOMPAT, BTRFS_FEATURE_INCOMPAT, feature)
  70
  71 static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj);
  72 static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj);
  73
  74 static struct btrfs_feature_attr *to_btrfs_feature_attr(struct kobj_attribute *a)
  75 {
  76         return container_of(a, struct btrfs_feature_attr, kobj_attr);
  77 }
  78
  79 static struct kobj_attribute *attr_to_btrfs_attr(struct attribute *attr)
  80 {
  81         return container_of(attr, struct kobj_attribute, attr);
  82 }
  83
  84 static struct btrfs_feature_attr *attr_to_btrfs_feature_attr(
  85                 struct attribute *attr)
  86 {
  87         return to_btrfs_feature_attr(attr_to_btrfs_attr(attr));
  88 }
  89
  90 static u64 get_features(struct btrfs_fs_info *fs_info,
  91                         enum btrfs_feature_set set)
  92 {
  93         struct btrfs_super_block *disk_super = fs_info->super_copy;
  94         if (set == FEAT_COMPAT)
  95                 return btrfs_super_compat_flags(disk_super);
  96         else if (set == FEAT_COMPAT_RO)
  97                 return btrfs_super_compat_ro_flags(disk_super);
  98         else
  99                 return btrfs_super_incompat_flags(disk_super);
 100 }
 101
 102 static void set_features(struct btrfs_fs_info *fs_info,
 103                          enum btrfs_feature_set set, u64 features)
 104 {
 105         struct btrfs_super_block *disk_super = fs_info->super_copy;
 106         if (set == FEAT_COMPAT)
 107                 btrfs_set_super_compat_flags(disk_super, features);
 108         else if (set == FEAT_COMPAT_RO)
 109                 btrfs_set_super_compat_ro_flags(disk_super, features);
 110         else
 111                 btrfs_set_super_incompat_flags(disk_super, features);
 112 }
 113
 114 static int can_modify_feature(struct btrfs_feature_attr *fa)
 115 {
 116         int val = 0;
 117         u64 set, clear;
 118         switch (fa->feature_set) {
 119         case FEAT_COMPAT:
 120                 set = BTRFS_FEATURE_COMPAT_SAFE_SET;
 121                 clear = BTRFS_FEATURE_COMPAT_SAFE_CLEAR;
 122                 break;
 123         case FEAT_COMPAT_RO:
 124                 set = BTRFS_FEATURE_COMPAT_RO_SAFE_SET;
 125                 clear = BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR;
 126                 break;
 127         case FEAT_INCOMPAT:
 128                 set = BTRFS_FEATURE_INCOMPAT_SAFE_SET;
 129                 clear = BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR;
 130                 break;
 131         default:
 132                 pr_warn("btrfs: sysfs: unknown feature set %d\n",
 133                                 fa->feature_set);
 134                 return 0;
 135         }
 136
 137         if (set & fa->feature_bit)
 138                 val |= 1;
 139         if (clear & fa->feature_bit)
 140                 val |= 2;
 141
 142         return val;
 143 }
 144
 145 static ssize_t btrfs_feature_attr_show(struct kobject *kobj,
 146                                        struct kobj_attribute *a, char *buf)
 147 {
 148         int val = 0;
 149         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 150         struct btrfs_feature_attr *fa = to_btrfs_feature_attr(a);
 151         if (fs_info) {
 152                 u64 features = get_features(fs_info, fa->feature_set);
 153                 if (features & fa->feature_bit)
 154                         val = 1;
 155         } else
 156                 val = can_modify_feature(fa);
 157
 158         return snprintf(buf, PAGE_SIZE, "%d\n", val);
 159 }
 160
 161 static ssize_t btrfs_feature_attr_store(struct kobject *kobj,
 162                                         struct kobj_attribute *a,
 163                                         const char *buf, size_t count)
 164 {
 165         struct btrfs_fs_info *fs_info;
 166         struct btrfs_feature_attr *fa = to_btrfs_feature_attr(a);
 167         u64 features, set, clear;
 168         unsigned long val;
 169         int ret;
 170
 171         fs_info = to_fs_info(kobj);
 172         if (!fs_info)
 173                 return -EPERM;
 174
 175         if (sb_rdonly(fs_info->sb))
 176                 return -EROFS;
 177
 178         ret = kstrtoul(skip_spaces(buf), 0, &val);
 179         if (ret)
 180                 return ret;
 181
 182         if (fa->feature_set == FEAT_COMPAT) {
 183                 set = BTRFS_FEATURE_COMPAT_SAFE_SET;
 184                 clear = BTRFS_FEATURE_COMPAT_SAFE_CLEAR;
 185         } else if (fa->feature_set == FEAT_COMPAT_RO) {
 186                 set = BTRFS_FEATURE_COMPAT_RO_SAFE_SET;
 187                 clear = BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR;
 188         } else {
 189                 set = BTRFS_FEATURE_INCOMPAT_SAFE_SET;
 190                 clear = BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR;
 191         }
 192
 193         features = get_features(fs_info, fa->feature_set);
 194
 195         /* Nothing to do */
 196         if ((val && (features & fa->feature_bit)) ||
 197             (!val && !(features & fa->feature_bit)))
 198                 return count;
 199
 200         if ((val && !(set & fa->feature_bit)) ||
 201             (!val && !(clear & fa->feature_bit))) {
 202                 btrfs_info(fs_info,
 203                         "%sabling feature %s on mounted fs is not supported.",
 204                         val ? "En" : "Dis", fa->kobj_attr.attr.name);
 205                 return -EPERM;
 206         }
 207
 208         btrfs_info(fs_info, "%s %s feature flag",
 209                    val ? "Setting" : "Clearing", fa->kobj_attr.attr.name);
 210
 211         spin_lock(&fs_info->super_lock);
 212         features = get_features(fs_info, fa->feature_set);
 213         if (val)
 214                 features |= fa->feature_bit;
 215         else
 216                 features &= ~fa->feature_bit;
 217         set_features(fs_info, fa->feature_set, features);
 218         spin_unlock(&fs_info->super_lock);
 219
 220         /*
 221          * We don't want to do full transaction commit from inside sysfs
 222          */
 223         btrfs_set_pending(fs_info, COMMIT);
 224         wake_up_process(fs_info->transaction_kthread);
 225
 226         return count;
 227 }
 228
 229 static umode_t btrfs_feature_visible(struct kobject *kobj,
 230                                      struct attribute *attr, int unused)
 231 {
 232         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 233         umode_t mode = attr->mode;
 234
 235         if (fs_info) {
 236                 struct btrfs_feature_attr *fa;
 237                 u64 features;
 238
 239                 fa = attr_to_btrfs_feature_attr(attr);
 240                 features = get_features(fs_info, fa->feature_set);
 241
 242                 if (can_modify_feature(fa))
 243                         mode |= S_IWUSR;
 244                 else if (!(features & fa->feature_bit))
 245                         mode = 0;
 246         }
 247
 248         return mode;
 249 }
 250
 251 BTRFS_FEAT_ATTR_INCOMPAT(mixed_backref, MIXED_BACKREF);
 252 BTRFS_FEAT_ATTR_INCOMPAT(default_subvol, DEFAULT_SUBVOL);
 253 BTRFS_FEAT_ATTR_INCOMPAT(mixed_groups, MIXED_GROUPS);
 254 BTRFS_FEAT_ATTR_INCOMPAT(compress_lzo, COMPRESS_LZO);
 255 BTRFS_FEAT_ATTR_INCOMPAT(compress_zstd, COMPRESS_ZSTD);
 256 BTRFS_FEAT_ATTR_INCOMPAT(big_metadata, BIG_METADATA);
 257 BTRFS_FEAT_ATTR_INCOMPAT(extended_iref, EXTENDED_IREF);
 258 BTRFS_FEAT_ATTR_INCOMPAT(raid56, RAID56);
 259 BTRFS_FEAT_ATTR_INCOMPAT(skinny_metadata, SKINNY_METADATA);
 260 BTRFS_FEAT_ATTR_INCOMPAT(no_holes, NO_HOLES);
 261 BTRFS_FEAT_ATTR_INCOMPAT(metadata_uuid, METADATA_UUID);
 262 BTRFS_FEAT_ATTR_COMPAT_RO(free_space_tree, FREE_SPACE_TREE);
 263 BTRFS_FEAT_ATTR_INCOMPAT(raid1c34, RAID1C34);
 264
 265 static struct attribute *btrfs_supported_feature_attrs[] = {
 266         BTRFS_FEAT_ATTR_PTR(mixed_backref),
 267         BTRFS_FEAT_ATTR_PTR(default_subvol),
 268         BTRFS_FEAT_ATTR_PTR(mixed_groups),
 269         BTRFS_FEAT_ATTR_PTR(compress_lzo),
 270         BTRFS_FEAT_ATTR_PTR(compress_zstd),
 271         BTRFS_FEAT_ATTR_PTR(big_metadata),
 272         BTRFS_FEAT_ATTR_PTR(extended_iref),
 273         BTRFS_FEAT_ATTR_PTR(raid56),
 274         BTRFS_FEAT_ATTR_PTR(skinny_metadata),
 275         BTRFS_FEAT_ATTR_PTR(no_holes),
 276         BTRFS_FEAT_ATTR_PTR(metadata_uuid),
 277         BTRFS_FEAT_ATTR_PTR(free_space_tree),
 278         BTRFS_FEAT_ATTR_PTR(raid1c34),
 279         NULL
 280 };
 281
 282 /*
 283  * Features which depend on feature bits and may differ between each fs.
 284  *
 285  * /sys/fs/btrfs/features lists all available features of this kernel while
 286  * /sys/fs/btrfs/UUID/features shows features of the fs which are enabled or
 287  * can be changed online.
 288  */
 289 static const struct attribute_group btrfs_feature_attr_group = {
 290         .name = "features",
 291         .is_visible = btrfs_feature_visible,
 292         .attrs = btrfs_supported_feature_attrs,
 293 };
 294
 295 static ssize_t rmdir_subvol_show(struct kobject *kobj,
 296                                  struct kobj_attribute *ka, char *buf)
 297 {
 298         return snprintf(buf, PAGE_SIZE, "0\n");
 299 }
 300 BTRFS_ATTR(static_feature, rmdir_subvol, rmdir_subvol_show);
 301
 302 static ssize_t supported_checksums_show(struct kobject *kobj,
 303                                         struct kobj_attribute *a, char *buf)
 304 {
 305         ssize_t ret = 0;
 306         int i;
 307
 308         for (i = 0; i < btrfs_get_num_csums(); i++) {
 309                 /*
 310                  * This "trick" only works as long as 'enum btrfs_csum_type' has
 311                  * no holes in it
 312                  */
 313                 ret += snprintf(buf + ret, PAGE_SIZE - ret, "%s%s",
 314                                 (i == 0 ? "" : " "), btrfs_super_csum_name(i));
 315
 316         }
 317
 318         ret += snprintf(buf + ret, PAGE_SIZE - ret, "\n");
 319         return ret;
 320 }
 321 BTRFS_ATTR(static_feature, supported_checksums, supported_checksums_show);
 322
 323 static struct attribute *btrfs_supported_static_feature_attrs[] = {
 324         BTRFS_ATTR_PTR(static_feature, rmdir_subvol),
 325         BTRFS_ATTR_PTR(static_feature, supported_checksums),
 326         NULL
 327 };
 328
 329 /*
 330  * Features which only depend on kernel version.
 331  *
 332  * These are listed in /sys/fs/btrfs/features along with
 333  * btrfs_feature_attr_group
 334  */
 335 static const struct attribute_group btrfs_static_feature_attr_group = {
 336         .name = "features",
 337         .attrs = btrfs_supported_static_feature_attrs,
 338 };
 339
 340 #ifdef CONFIG_BTRFS_DEBUG
 341
 342 /*
 343  * Discard statistics and tunables
 344  */
 345 #define discard_to_fs_info(_kobj)       to_fs_info((_kobj)->parent->parent)
 346
 347 static ssize_t btrfs_discardable_bytes_show(struct kobject *kobj,
 348                                             struct kobj_attribute *a,
 349                                             char *buf)
 350 {
 351         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 352
 353         return snprintf(buf, PAGE_SIZE, "%lld\n",
 354                         atomic64_read(&fs_info->discard_ctl.discardable_bytes));
 355 }
 356 BTRFS_ATTR(discard, discardable_bytes, btrfs_discardable_bytes_show);
 357
 358 static ssize_t btrfs_discardable_extents_show(struct kobject *kobj,
 359                                               struct kobj_attribute *a,
 360                                               char *buf)
 361 {
 362         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 363
 364         return snprintf(buf, PAGE_SIZE, "%d\n",
 365                         atomic_read(&fs_info->discard_ctl.discardable_extents));
 366 }
 367 BTRFS_ATTR(discard, discardable_extents, btrfs_discardable_extents_show);
 368
 369 static ssize_t btrfs_discard_iops_limit_show(struct kobject *kobj,
 370                                              struct kobj_attribute *a,
 371                                              char *buf)
 372 {
 373         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 374
 375         return snprintf(buf, PAGE_SIZE, "%u\n",
 376                         READ_ONCE(fs_info->discard_ctl.iops_limit));
 377 }
 378
 379 static ssize_t btrfs_discard_iops_limit_store(struct kobject *kobj,
 380                                               struct kobj_attribute *a,
 381                                               const char *buf, size_t len)
 382 {
 383         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 384         struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
 385         u32 iops_limit;
 386         int ret;
 387
 388         ret = kstrtou32(buf, 10, &iops_limit);
 389         if (ret)
 390                 return -EINVAL;
 391
 392         WRITE_ONCE(discard_ctl->iops_limit, iops_limit);
 393
 394         return len;
 395 }
 396 BTRFS_ATTR_RW(discard, iops_limit, btrfs_discard_iops_limit_show,
 397               btrfs_discard_iops_limit_store);
 398
 399 static ssize_t btrfs_discard_kbps_limit_show(struct kobject *kobj,
 400                                              struct kobj_attribute *a,
 401                                              char *buf)
 402 {
 403         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 404
 405         return snprintf(buf, PAGE_SIZE, "%u\n",
 406                         READ_ONCE(fs_info->discard_ctl.kbps_limit));
 407 }
 408
 409 static ssize_t btrfs_discard_kbps_limit_store(struct kobject *kobj,
 410                                               struct kobj_attribute *a,
 411                                               const char *buf, size_t len)
 412 {
 413         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 414         struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
 415         u32 kbps_limit;
 416         int ret;
 417
 418         ret = kstrtou32(buf, 10, &kbps_limit);
 419         if (ret)
 420                 return -EINVAL;
 421
 422         WRITE_ONCE(discard_ctl->kbps_limit, kbps_limit);
 423
 424         return len;
 425 }
 426 BTRFS_ATTR_RW(discard, kbps_limit, btrfs_discard_kbps_limit_show,
 427               btrfs_discard_kbps_limit_store);
 428
 429 static const struct attribute *discard_debug_attrs[] = {
 430         BTRFS_ATTR_PTR(discard, discardable_bytes),
 431         BTRFS_ATTR_PTR(discard, discardable_extents),
 432         BTRFS_ATTR_PTR(discard, iops_limit),
 433         BTRFS_ATTR_PTR(discard, kbps_limit),
 434         NULL,
 435 };
 436
 437 /*
 438  * Runtime debugging exported via sysfs
 439  *
 440  * /sys/fs/btrfs/debug - applies to module or all filesystems
 441  * /sys/fs/btrfs/UUID  - applies only to the given filesystem
 442  */
 443 static const struct attribute *btrfs_debug_mount_attrs[] = {
 444         NULL,
 445 };
 446
 447 static struct attribute *btrfs_debug_feature_attrs[] = {
 448         NULL
 449 };
 450
 451 static const struct attribute_group btrfs_debug_feature_attr_group = {
 452         .name = "debug",
 453         .attrs = btrfs_debug_feature_attrs,
 454 };
 455
 456 #endif
 457
 458 static ssize_t btrfs_show_u64(u64 *value_ptr, spinlock_t *lock, char *buf)
 459 {
 460         u64 val;
 461         if (lock)
 462                 spin_lock(lock);
 463         val = *value_ptr;
 464         if (lock)
 465                 spin_unlock(lock);
 466         return snprintf(buf, PAGE_SIZE, "%llu\n", val);
 467 }
 468
 469 static ssize_t global_rsv_size_show(struct kobject *kobj,
 470                                     struct kobj_attribute *ka, char *buf)
 471 {
 472         struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent);
 473         struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
 474         return btrfs_show_u64(&block_rsv->size, &block_rsv->lock, buf);
 475 }
 476 BTRFS_ATTR(allocation, global_rsv_size, global_rsv_size_show);
 477
 478 static ssize_t global_rsv_reserved_show(struct kobject *kobj,
 479                                         struct kobj_attribute *a, char *buf)
 480 {
 481         struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent);
 482         struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
 483         return btrfs_show_u64(&block_rsv->reserved, &block_rsv->lock, buf);
 484 }
 485 BTRFS_ATTR(allocation, global_rsv_reserved, global_rsv_reserved_show);
 486
 487 #define to_space_info(_kobj) container_of(_kobj, struct btrfs_space_info, kobj)
 488 #define to_raid_kobj(_kobj) container_of(_kobj, struct raid_kobject, kobj)
 489
 490 static ssize_t raid_bytes_show(struct kobject *kobj,
 491                                struct kobj_attribute *attr, char *buf);
 492 BTRFS_ATTR(raid, total_bytes, raid_bytes_show);
 493 BTRFS_ATTR(raid, used_bytes, raid_bytes_show);
 494
 495 static ssize_t raid_bytes_show(struct kobject *kobj,
 496                                struct kobj_attribute *attr, char *buf)
 497
 498 {
 499         struct btrfs_space_info *sinfo = to_space_info(kobj->parent);
 500         struct btrfs_block_group *block_group;
 501         int index = btrfs_bg_flags_to_raid_index(to_raid_kobj(kobj)->flags);
 502         u64 val = 0;
 503
 504         down_read(&sinfo->groups_sem);
 505         list_for_each_entry(block_group, &sinfo->block_groups[index], list) {
 506                 if (&attr->attr == BTRFS_ATTR_PTR(raid, total_bytes))
 507                         val += block_group->length;
 508                 else
 509                         val += block_group->used;
 510         }
 511         up_read(&sinfo->groups_sem);
 512         return snprintf(buf, PAGE_SIZE, "%llu\n", val);
 513 }
 514
 515 static struct attribute *raid_attrs[] = {
 516         BTRFS_ATTR_PTR(raid, total_bytes),
 517         BTRFS_ATTR_PTR(raid, used_bytes),
 518         NULL
 519 };
 520 ATTRIBUTE_GROUPS(raid);
 521
 522 static void release_raid_kobj(struct kobject *kobj)
 523 {
 524         kfree(to_raid_kobj(kobj));
 525 }
 526
 527 static struct kobj_type btrfs_raid_ktype = {
 528         .sysfs_ops = &kobj_sysfs_ops,
 529         .release = release_raid_kobj,
 530         .default_groups = raid_groups,
 531 };
 532
 533 #define SPACE_INFO_ATTR(field)                                          \
 534 static ssize_t btrfs_space_info_show_##field(struct kobject *kobj,      \
 535                                              struct kobj_attribute *a,  \
 536                                              char *buf)                 \
 537 {                                                                       \
 538         struct btrfs_space_info *sinfo = to_space_info(kobj);           \
 539         return btrfs_show_u64(&sinfo->field, &sinfo->lock, buf);        \
 540 }                                                                       \
 541 BTRFS_ATTR(space_info, field, btrfs_space_info_show_##field)
 542
 543 static ssize_t btrfs_space_info_show_total_bytes_pinned(struct kobject *kobj,
 544                                                        struct kobj_attribute *a,
 545                                                        char *buf)
 546 {
 547         struct btrfs_space_info *sinfo = to_space_info(kobj);
 548         s64 val = percpu_counter_sum(&sinfo->total_bytes_pinned);
 549         return snprintf(buf, PAGE_SIZE, "%lld\n", val);
 550 }
 551
 552 SPACE_INFO_ATTR(flags);
 553 SPACE_INFO_ATTR(total_bytes);
 554 SPACE_INFO_ATTR(bytes_used);
 555 SPACE_INFO_ATTR(bytes_pinned);
 556 SPACE_INFO_ATTR(bytes_reserved);
 557 SPACE_INFO_ATTR(bytes_may_use);
 558 SPACE_INFO_ATTR(bytes_readonly);
 559 SPACE_INFO_ATTR(disk_used);
 560 SPACE_INFO_ATTR(disk_total);
 561 BTRFS_ATTR(space_info, total_bytes_pinned,
 562            btrfs_space_info_show_total_bytes_pinned);
 563
 564 static struct attribute *space_info_attrs[] = {
 565         BTRFS_ATTR_PTR(space_info, flags),
 566         BTRFS_ATTR_PTR(space_info, total_bytes),
 567         BTRFS_ATTR_PTR(space_info, bytes_used),
 568         BTRFS_ATTR_PTR(space_info, bytes_pinned),
 569         BTRFS_ATTR_PTR(space_info, bytes_reserved),
 570         BTRFS_ATTR_PTR(space_info, bytes_may_use),
 571         BTRFS_ATTR_PTR(space_info, bytes_readonly),
 572         BTRFS_ATTR_PTR(space_info, disk_used),
 573         BTRFS_ATTR_PTR(space_info, disk_total),
 574         BTRFS_ATTR_PTR(space_info, total_bytes_pinned),
 575         NULL,
 576 };
 577 ATTRIBUTE_GROUPS(space_info);
 578
 579 static void space_info_release(struct kobject *kobj)
 580 {
 581         struct btrfs_space_info *sinfo = to_space_info(kobj);
 582         percpu_counter_destroy(&sinfo->total_bytes_pinned);
 583         kfree(sinfo);
 584 }
 585
 586 static struct kobj_type space_info_ktype = {
 587         .sysfs_ops = &kobj_sysfs_ops,
 588         .release = space_info_release,
 589         .default_groups = space_info_groups,
 590 };
 591
 592 static const struct attribute *allocation_attrs[] = {
 593         BTRFS_ATTR_PTR(allocation, global_rsv_reserved),
 594         BTRFS_ATTR_PTR(allocation, global_rsv_size),
 595         NULL,
 596 };
 597
 598 static ssize_t btrfs_label_show(struct kobject *kobj,
 599                                 struct kobj_attribute *a, char *buf)
 600 {
 601         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 602         char *label = fs_info->super_copy->label;
 603         ssize_t ret;
 604
 605         spin_lock(&fs_info->super_lock);
 606         ret = snprintf(buf, PAGE_SIZE, label[0] ? "%s\n" : "%s", label);
 607         spin_unlock(&fs_info->super_lock);
 608
 609         return ret;
 610 }
 611
 612 static ssize_t btrfs_label_store(struct kobject *kobj,
 613                                  struct kobj_attribute *a,
 614                                  const char *buf, size_t len)
 615 {
 616         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 617         size_t p_len;
 618
 619         if (!fs_info)
 620                 return -EPERM;
 621
 622         if (sb_rdonly(fs_info->sb))
 623                 return -EROFS;
 624
 625         /*
 626          * p_len is the len until the first occurrence of either
 627          * '\n' or '\0'
 628          */
 629         p_len = strcspn(buf, "\n");
 630
 631         if (p_len >= BTRFS_LABEL_SIZE)
 632                 return -EINVAL;
 633
 634         spin_lock(&fs_info->super_lock);
 635         memset(fs_info->super_copy->label, 0, BTRFS_LABEL_SIZE);
 636         memcpy(fs_info->super_copy->label, buf, p_len);
 637         spin_unlock(&fs_info->super_lock);
 638
 639         /*
 640          * We don't want to do full transaction commit from inside sysfs
 641          */
 642         btrfs_set_pending(fs_info, COMMIT);
 643         wake_up_process(fs_info->transaction_kthread);
 644
 645         return len;
 646 }
 647 BTRFS_ATTR_RW(, label, btrfs_label_show, btrfs_label_store);
 648
 649 static ssize_t btrfs_nodesize_show(struct kobject *kobj,
 650                                 struct kobj_attribute *a, char *buf)
 651 {
 652         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 653
 654         return snprintf(buf, PAGE_SIZE, "%u\n", fs_info->super_copy->nodesize);
 655 }
 656
 657 BTRFS_ATTR(, nodesize, btrfs_nodesize_show);
 658
 659 static ssize_t btrfs_sectorsize_show(struct kobject *kobj,
 660                                 struct kobj_attribute *a, char *buf)
 661 {
 662         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 663
 664         return snprintf(buf, PAGE_SIZE, "%u\n",
 665                         fs_info->super_copy->sectorsize);
 666 }
 667
 668 BTRFS_ATTR(, sectorsize, btrfs_sectorsize_show);
 669
 670 static ssize_t btrfs_clone_alignment_show(struct kobject *kobj,
 671                                 struct kobj_attribute *a, char *buf)
 672 {
 673         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 674
 675         return snprintf(buf, PAGE_SIZE, "%u\n",
 676                         fs_info->super_copy->sectorsize);
 677 }
 678
 679 BTRFS_ATTR(, clone_alignment, btrfs_clone_alignment_show);
 680
 681 static ssize_t quota_override_show(struct kobject *kobj,
 682                                    struct kobj_attribute *a, char *buf)
 683 {
 684         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 685         int quota_override;
 686
 687         quota_override = test_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
 688         return snprintf(buf, PAGE_SIZE, "%d\n", quota_override);
 689 }
 690
 691 static ssize_t quota_override_store(struct kobject *kobj,
 692                                     struct kobj_attribute *a,
 693                                     const char *buf, size_t len)
 694 {
 695         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 696         unsigned long knob;
 697         int err;
 698
 699         if (!fs_info)
 700                 return -EPERM;
 701
 702         if (!capable(CAP_SYS_RESOURCE))
 703                 return -EPERM;
 704
 705         err = kstrtoul(buf, 10, &knob);
 706         if (err)
 707                 return err;
 708         if (knob > 1)
 709                 return -EINVAL;
 710
 711         if (knob)
 712                 set_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
 713         else
 714                 clear_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
 715
 716         return len;
 717 }
 718
 719 BTRFS_ATTR_RW(, quota_override, quota_override_show, quota_override_store);
 720
 721 static ssize_t btrfs_metadata_uuid_show(struct kobject *kobj,
 722                                 struct kobj_attribute *a, char *buf)
 723 {
 724         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 725
 726         return snprintf(buf, PAGE_SIZE, "%pU\n",
 727                         fs_info->fs_devices->metadata_uuid);
 728 }
 729
 730 BTRFS_ATTR(, metadata_uuid, btrfs_metadata_uuid_show);
 731
 732 static ssize_t btrfs_checksum_show(struct kobject *kobj,
 733                                    struct kobj_attribute *a, char *buf)
 734 {
 735         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 736         u16 csum_type = btrfs_super_csum_type(fs_info->super_copy);
 737
 738         return snprintf(buf, PAGE_SIZE, "%s (%s)\n",
 739                         btrfs_super_csum_name(csum_type),
 740                         crypto_shash_driver_name(fs_info->csum_shash));
 741 }
 742
 743 BTRFS_ATTR(, checksum, btrfs_checksum_show);
 744
 745 static const struct attribute *btrfs_attrs[] = {
 746         BTRFS_ATTR_PTR(, label),
 747         BTRFS_ATTR_PTR(, nodesize),
 748         BTRFS_ATTR_PTR(, sectorsize),
 749         BTRFS_ATTR_PTR(, clone_alignment),
 750         BTRFS_ATTR_PTR(, quota_override),
 751         BTRFS_ATTR_PTR(, metadata_uuid),
 752         BTRFS_ATTR_PTR(, checksum),
 753         NULL,
 754 };
 755
 756 static void btrfs_release_fsid_kobj(struct kobject *kobj)
 757 {
 758         struct btrfs_fs_devices *fs_devs = to_fs_devs(kobj);
 759
 760         memset(&fs_devs->fsid_kobj, 0, sizeof(struct kobject));
 761         complete(&fs_devs->kobj_unregister);
 762 }
 763
 764 static struct kobj_type btrfs_ktype = {
 765         .sysfs_ops      = &kobj_sysfs_ops,
 766         .release        = btrfs_release_fsid_kobj,
 767 };
 768
 769 static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj)
 770 {
 771         if (kobj->ktype != &btrfs_ktype)
 772                 return NULL;
 773         return container_of(kobj, struct btrfs_fs_devices, fsid_kobj);
 774 }
 775
 776 static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj)
 777 {
 778         if (kobj->ktype != &btrfs_ktype)
 779                 return NULL;
 780         return to_fs_devs(kobj)->fs_info;
 781 }
 782
 783 #define NUM_FEATURE_BITS 64
 784 #define BTRFS_FEATURE_NAME_MAX 13
 785 static char btrfs_unknown_feature_names[FEAT_MAX][NUM_FEATURE_BITS][BTRFS_FEATURE_NAME_MAX];
 786 static struct btrfs_feature_attr btrfs_feature_attrs[FEAT_MAX][NUM_FEATURE_BITS];
 787
 788 static const u64 supported_feature_masks[FEAT_MAX] = {
 789         [FEAT_COMPAT]    = BTRFS_FEATURE_COMPAT_SUPP,
 790         [FEAT_COMPAT_RO] = BTRFS_FEATURE_COMPAT_RO_SUPP,
 791         [FEAT_INCOMPAT]  = BTRFS_FEATURE_INCOMPAT_SUPP,
 792 };
 793
 794 static int addrm_unknown_feature_attrs(struct btrfs_fs_info *fs_info, bool add)
 795 {
 796         int set;
 797
 798         for (set = 0; set < FEAT_MAX; set++) {
 799                 int i;
 800                 struct attribute *attrs[2];
 801                 struct attribute_group agroup = {
 802                         .name = "features",
 803                         .attrs = attrs,
 804                 };
 805                 u64 features = get_features(fs_info, set);
 806                 features &= ~supported_feature_masks[set];
 807
 808                 if (!features)
 809                         continue;
 810
 811                 attrs[1] = NULL;
 812                 for (i = 0; i < NUM_FEATURE_BITS; i++) {
 813                         struct btrfs_feature_attr *fa;
 814
 815                         if (!(features & (1ULL << i)))
 816                                 continue;
 817
 818                         fa = &btrfs_feature_attrs[set][i];
 819                         attrs[0] = &fa->kobj_attr.attr;
 820                         if (add) {
 821                                 int ret;
 822                                 ret = sysfs_merge_group(&fs_info->fs_devices->fsid_kobj,
 823                                                         &agroup);
 824                                 if (ret)
 825                                         return ret;
 826                         } else
 827                                 sysfs_unmerge_group(&fs_info->fs_devices->fsid_kobj,
 828                                                     &agroup);
 829                 }
 830
 831         }
 832         return 0;
 833 }
 834
 835 static void __btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs)
 836 {
 837         if (fs_devs->devices_kobj) {
 838                 kobject_del(fs_devs->devices_kobj);
 839                 kobject_put(fs_devs->devices_kobj);
 840                 fs_devs->devices_kobj = NULL;
 841         }
 842
 843         if (fs_devs->fsid_kobj.state_initialized) {
 844                 kobject_del(&fs_devs->fsid_kobj);
 845                 kobject_put(&fs_devs->fsid_kobj);
 846                 wait_for_completion(&fs_devs->kobj_unregister);
 847         }
 848 }
 849
 850 /* when fs_devs is NULL it will remove all fsid kobject */
 851 void btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs)
 852 {
 853         struct list_head *fs_uuids = btrfs_get_fs_uuids();
 854
 855         if (fs_devs) {
 856                 __btrfs_sysfs_remove_fsid(fs_devs);
 857                 return;
 858         }
 859
 860         list_for_each_entry(fs_devs, fs_uuids, fs_list) {
 861                 __btrfs_sysfs_remove_fsid(fs_devs);
 862         }
 863 }
 864
 865 void btrfs_sysfs_remove_mounted(struct btrfs_fs_info *fs_info)
 866 {
 867         btrfs_reset_fs_info_ptr(fs_info);
 868
 869         if (fs_info->space_info_kobj) {
 870                 sysfs_remove_files(fs_info->space_info_kobj, allocation_attrs);
 871                 kobject_del(fs_info->space_info_kobj);
 872                 kobject_put(fs_info->space_info_kobj);
 873         }
 874 #ifdef CONFIG_BTRFS_DEBUG
 875         if (fs_info->discard_debug_kobj) {
 876                 sysfs_remove_files(fs_info->discard_debug_kobj,
 877                                    discard_debug_attrs);
 878                 kobject_del(fs_info->discard_debug_kobj);
 879                 kobject_put(fs_info->discard_debug_kobj);
 880         }
 881         if (fs_info->debug_kobj) {
 882                 sysfs_remove_files(fs_info->debug_kobj, btrfs_debug_mount_attrs);
 883                 kobject_del(fs_info->debug_kobj);
 884                 kobject_put(fs_info->debug_kobj);
 885         }
 886 #endif
 887         addrm_unknown_feature_attrs(fs_info, false);
 888         sysfs_remove_group(&fs_info->fs_devices->fsid_kobj, &btrfs_feature_attr_group);
 889         sysfs_remove_files(&fs_info->fs_devices->fsid_kobj, btrfs_attrs);
 890         btrfs_sysfs_rm_device_link(fs_info->fs_devices, NULL);
 891 }
 892
 893 static const char * const btrfs_feature_set_names[FEAT_MAX] = {
 894         [FEAT_COMPAT]    = "compat",
 895         [FEAT_COMPAT_RO] = "compat_ro",
 896         [FEAT_INCOMPAT]  = "incompat",
 897 };
 898
 899 const char * const btrfs_feature_set_name(enum btrfs_feature_set set)
 900 {
 901         return btrfs_feature_set_names[set];
 902 }
 903
 904 char *btrfs_printable_features(enum btrfs_feature_set set, u64 flags)
 905 {
 906         size_t bufsize = 4096; /* safe max, 64 names * 64 bytes */
 907         int len = 0;
 908         int i;
 909         char *str;
 910
 911         str = kmalloc(bufsize, GFP_KERNEL);
 912         if (!str)
 913                 return str;
 914
 915         for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
 916                 const char *name;
 917
 918                 if (!(flags & (1ULL << i)))
 919                         continue;
 920
 921                 name = btrfs_feature_attrs[set][i].kobj_attr.attr.name;
 922                 len += snprintf(str + len, bufsize - len, "%s%s",
 923                                 len ? "," : "", name);
 924         }
 925
 926         return str;
 927 }
 928
 929 static void init_feature_attrs(void)
 930 {
 931         struct btrfs_feature_attr *fa;
 932         int set, i;
 933
 934         BUILD_BUG_ON(ARRAY_SIZE(btrfs_unknown_feature_names) !=
 935                      ARRAY_SIZE(btrfs_feature_attrs));
 936         BUILD_BUG_ON(ARRAY_SIZE(btrfs_unknown_feature_names[0]) !=
 937                      ARRAY_SIZE(btrfs_feature_attrs[0]));
 938
 939         memset(btrfs_feature_attrs, 0, sizeof(btrfs_feature_attrs));
 940         memset(btrfs_unknown_feature_names, 0,
 941                sizeof(btrfs_unknown_feature_names));
 942
 943         for (i = 0; btrfs_supported_feature_attrs[i]; i++) {
 944                 struct btrfs_feature_attr *sfa;
 945                 struct attribute *a = btrfs_supported_feature_attrs[i];
 946                 int bit;
 947                 sfa = attr_to_btrfs_feature_attr(a);
 948                 bit = ilog2(sfa->feature_bit);
 949                 fa = &btrfs_feature_attrs[sfa->feature_set][bit];
 950
 951                 fa->kobj_attr.attr.name = sfa->kobj_attr.attr.name;
 952         }
 953
 954         for (set = 0; set < FEAT_MAX; set++) {
 955                 for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
 956                         char *name = btrfs_unknown_feature_names[set][i];
 957                         fa = &btrfs_feature_attrs[set][i];
 958
 959                         if (fa->kobj_attr.attr.name)
 960                                 continue;
 961
 962                         snprintf(name, BTRFS_FEATURE_NAME_MAX, "%s:%u",
 963                                  btrfs_feature_set_names[set], i);
 964
 965                         fa->kobj_attr.attr.name = name;
 966                         fa->kobj_attr.attr.mode = S_IRUGO;
 967                         fa->feature_set = set;
 968                         fa->feature_bit = 1ULL << i;
 969                 }
 970         }
 971 }
 972
 973 /*
 974  * Create a sysfs entry for a given block group type at path
 975  * /sys/fs/btrfs/UUID/allocation/data/TYPE
 976  */
 977 void btrfs_sysfs_add_block_group_type(struct btrfs_block_group *cache)
 978 {
 979         struct btrfs_fs_info *fs_info = cache->fs_info;
 980         struct btrfs_space_info *space_info = cache->space_info;
 981         struct raid_kobject *rkobj;
 982         const int index = btrfs_bg_flags_to_raid_index(cache->flags);
 983         unsigned int nofs_flag;
 984         int ret;
 985
 986         /*
 987          * Setup a NOFS context because kobject_add(), deep in its call chain,
 988          * does GFP_KERNEL allocations, and we are often called in a context
 989          * where if reclaim is triggered we can deadlock (we are either holding
 990          * a transaction handle or some lock required for a transaction
 991          * commit).
 992          */
 993         nofs_flag = memalloc_nofs_save();
 994
 995         rkobj = kzalloc(sizeof(*rkobj), GFP_NOFS);
 996         if (!rkobj) {
 997                 memalloc_nofs_restore(nofs_flag);
 998                 btrfs_warn(cache->fs_info,
 999                                 "couldn't alloc memory for raid level kobject");
1000                 return;
1001         }
1002
1003         rkobj->flags = cache->flags;
1004         kobject_init(&rkobj->kobj, &btrfs_raid_ktype);
1005         ret = kobject_add(&rkobj->kobj, &space_info->kobj, "%s",
1006                           btrfs_bg_type_to_raid_name(rkobj->flags));
1007         memalloc_nofs_restore(nofs_flag);
1008         if (ret) {
1009                 kobject_put(&rkobj->kobj);
1010                 btrfs_warn(fs_info,
1011                         "failed to add kobject for block cache, ignoring");
1012                 return;
1013         }
1014
1015         space_info->block_group_kobjs[index] = &rkobj->kobj;
1016 }
1017
1018 /*
1019  * Remove sysfs directories for all block group types of a given space info and
1020  * the space info as well
1021  */
1022 void btrfs_sysfs_remove_space_info(struct btrfs_space_info *space_info)
1023 {
1024         int i;
1025
1026         for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) {
1027                 struct kobject *kobj;
1028
1029                 kobj = space_info->block_group_kobjs[i];
1030                 space_info->block_group_kobjs[i] = NULL;
1031                 if (kobj) {
1032                         kobject_del(kobj);
1033                         kobject_put(kobj);
1034                 }
1035         }
1036         kobject_del(&space_info->kobj);
1037         kobject_put(&space_info->kobj);
1038 }
1039
1040 static const char *alloc_name(u64 flags)
1041 {
1042         switch (flags) {
1043         case BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA:
1044                 return "mixed";
1045         case BTRFS_BLOCK_GROUP_METADATA:
1046                 return "metadata";
1047         case BTRFS_BLOCK_GROUP_DATA:
1048                 return "data";
1049         case BTRFS_BLOCK_GROUP_SYSTEM:
1050                 return "system";
1051         default:
1052                 WARN_ON(1);
1053                 return "invalid-combination";
1054         };
1055 }
1056
1057 /*
1058  * Create a sysfs entry for a space info type at path
1059  * /sys/fs/btrfs/UUID/allocation/TYPE
1060  */
1061 int btrfs_sysfs_add_space_info_type(struct btrfs_fs_info *fs_info,
1062                                     struct btrfs_space_info *space_info)
1063 {
1064         int ret;
1065
1066         ret = kobject_init_and_add(&space_info->kobj, &space_info_ktype,
1067                                    fs_info->space_info_kobj, "%s",
1068                                    alloc_name(space_info->flags));
1069         if (ret) {
1070                 kobject_put(&space_info->kobj);
1071                 return ret;
1072         }
1073
1074         return 0;
1075 }
1076
1077 /* when one_device is NULL, it removes all device links */
1078
1079 int btrfs_sysfs_rm_device_link(struct btrfs_fs_devices *fs_devices,
1080                 struct btrfs_device *one_device)
1081 {
1082         struct hd_struct *disk;
1083         struct kobject *disk_kobj;
1084
1085         if (!fs_devices->devices_kobj)
1086                 return -EINVAL;
1087
1088         if (one_device && one_device->bdev) {
1089                 disk = one_device->bdev->bd_part;
1090                 disk_kobj = &part_to_dev(disk)->kobj;
1091
1092                 sysfs_remove_link(fs_devices->devices_kobj, disk_kobj->name);
1093         }
1094
1095         if (one_device)
1096                 return 0;
1097
1098         list_for_each_entry(one_device,
1099                         &fs_devices->devices, dev_list) {
1100                 if (!one_device->bdev)
1101                         continue;
1102                 disk = one_device->bdev->bd_part;
1103                 disk_kobj = &part_to_dev(disk)->kobj;
1104
1105                 sysfs_remove_link(fs_devices->devices_kobj, disk_kobj->name);
1106         }
1107
1108         return 0;
1109 }
1110
1111 int btrfs_sysfs_add_device_link(struct btrfs_fs_devices *fs_devices,
1112                                 struct btrfs_device *one_device)
1113 {
1114         int error = 0;
1115         struct btrfs_device *dev;
1116
1117         list_for_each_entry(dev, &fs_devices->devices, dev_list) {
1118                 struct hd_struct *disk;
1119                 struct kobject *disk_kobj;
1120
1121                 if (!dev->bdev)
1122                         continue;
1123
1124                 if (one_device && one_device != dev)
1125                         continue;
1126
1127                 disk = dev->bdev->bd_part;
1128                 disk_kobj = &part_to_dev(disk)->kobj;
1129
1130                 error = sysfs_create_link(fs_devices->devices_kobj,
1131                                           disk_kobj, disk_kobj->name);
1132                 if (error)
1133                         break;
1134         }
1135
1136         return error;
1137 }
1138
1139 void btrfs_kobject_uevent(struct block_device *bdev, enum kobject_action action)
1140 {
1141         int ret;
1142
1143         ret = kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, action);
1144         if (ret)
1145                 pr_warn("BTRFS: Sending event '%d' to kobject: '%s' (%p): failed\n",
1146                         action, kobject_name(&disk_to_dev(bdev->bd_disk)->kobj),
1147                         &disk_to_dev(bdev->bd_disk)->kobj);
1148 }
1149
1150 void btrfs_sysfs_update_sprout_fsid(struct btrfs_fs_devices *fs_devices,
1151                                     const u8 *fsid)
1152 {
1153         char fsid_buf[BTRFS_UUID_UNPARSED_SIZE];
1154
1155         /*
1156          * Sprouting changes fsid of the mounted filesystem, rename the fsid
1157          * directory
1158          */
1159         snprintf(fsid_buf, BTRFS_UUID_UNPARSED_SIZE, "%pU", fsid);
1160         if (kobject_rename(&fs_devices->fsid_kobj, fsid_buf))
1161                 btrfs_warn(fs_devices->fs_info,
1162                                 "sysfs: failed to create fsid for sprout");
1163 }
1164
1165 /* /sys/fs/btrfs/ entry */
1166 static struct kset *btrfs_kset;
1167
1168 /*
1169  * Creates:
1170  *              /sys/fs/btrfs/UUID
1171  *
1172  * Can be called by the device discovery thread.
1173  */
1174 int btrfs_sysfs_add_fsid(struct btrfs_fs_devices *fs_devs)
1175 {
1176         int error;
1177
1178         init_completion(&fs_devs->kobj_unregister);
1179         fs_devs->fsid_kobj.kset = btrfs_kset;
1180         error = kobject_init_and_add(&fs_devs->fsid_kobj, &btrfs_ktype, NULL,
1181                                      "%pU", fs_devs->fsid);
1182         if (error) {
1183                 kobject_put(&fs_devs->fsid_kobj);
1184                 return error;
1185         }
1186
1187         fs_devs->devices_kobj = kobject_create_and_add("devices",
1188                                                        &fs_devs->fsid_kobj);
1189         if (!fs_devs->devices_kobj) {
1190                 btrfs_err(fs_devs->fs_info,
1191                           "failed to init sysfs device interface");
1192                 kobject_put(&fs_devs->fsid_kobj);
1193                 return -ENOMEM;
1194         }
1195
1196         return 0;
1197 }
1198
1199 int btrfs_sysfs_add_mounted(struct btrfs_fs_info *fs_info)
1200 {
1201         int error;
1202         struct btrfs_fs_devices *fs_devs = fs_info->fs_devices;
1203         struct kobject *fsid_kobj = &fs_devs->fsid_kobj;
1204
1205         btrfs_set_fs_info_ptr(fs_info);
1206
1207         error = btrfs_sysfs_add_device_link(fs_devs, NULL);
1208         if (error)
1209                 return error;
1210
1211         error = sysfs_create_files(fsid_kobj, btrfs_attrs);
1212         if (error) {
1213                 btrfs_sysfs_rm_device_link(fs_devs, NULL);
1214                 return error;
1215         }
1216
1217         error = sysfs_create_group(fsid_kobj,
1218                                    &btrfs_feature_attr_group);
1219         if (error)
1220                 goto failure;
1221
1222 #ifdef CONFIG_BTRFS_DEBUG
1223         fs_info->debug_kobj = kobject_create_and_add("debug", fsid_kobj);
1224         if (!fs_info->debug_kobj) {
1225                 error = -ENOMEM;
1226                 goto failure;
1227         }
1228
1229         error = sysfs_create_files(fs_info->debug_kobj, btrfs_debug_mount_attrs);
1230         if (error)
1231                 goto failure;
1232
1233         /* Discard directory */
1234         fs_info->discard_debug_kobj = kobject_create_and_add("discard",
1235                                                      fs_info->debug_kobj);
1236         if (!fs_info->discard_debug_kobj) {
1237                 error = -ENOMEM;
1238                 goto failure;
1239         }
1240
1241         error = sysfs_create_files(fs_info->discard_debug_kobj,
1242                                    discard_debug_attrs);
1243         if (error)
1244                 goto failure;
1245 #endif
1246
1247         error = addrm_unknown_feature_attrs(fs_info, true);
1248         if (error)
1249                 goto failure;
1250
1251         fs_info->space_info_kobj = kobject_create_and_add("allocation",
1252                                                   fsid_kobj);
1253         if (!fs_info->space_info_kobj) {
1254                 error = -ENOMEM;
1255                 goto failure;
1256         }
1257
1258         error = sysfs_create_files(fs_info->space_info_kobj, allocation_attrs);
1259         if (error)
1260                 goto failure;
1261
1262         return 0;
1263 failure:
1264         btrfs_sysfs_remove_mounted(fs_info);
1265         return error;
1266 }
1267
1268
1269 /*
1270  * Change per-fs features in /sys/fs/btrfs/UUID/features to match current
1271  * values in superblock. Call after any changes to incompat/compat_ro flags
1272  */
1273 void btrfs_sysfs_feature_update(struct btrfs_fs_info *fs_info,
1274                 u64 bit, enum btrfs_feature_set set)
1275 {
1276         struct btrfs_fs_devices *fs_devs;
1277         struct kobject *fsid_kobj;
1278         u64 features;
1279         int ret;
1280
1281         if (!fs_info)
1282                 return;
1283
1284         features = get_features(fs_info, set);
1285         ASSERT(bit & supported_feature_masks[set]);
1286
1287         fs_devs = fs_info->fs_devices;
1288         fsid_kobj = &fs_devs->fsid_kobj;
1289
1290         if (!fsid_kobj->state_initialized)
1291                 return;
1292
1293         /*
1294          * FIXME: this is too heavy to update just one value, ideally we'd like
1295          * to use sysfs_update_group but some refactoring is needed first.
1296          */
1297         sysfs_remove_group(fsid_kobj, &btrfs_feature_attr_group);
1298         ret = sysfs_create_group(fsid_kobj, &btrfs_feature_attr_group);
1299 }
1300
1301 int __init btrfs_init_sysfs(void)
1302 {
1303         int ret;
1304
1305         btrfs_kset = kset_create_and_add("btrfs", NULL, fs_kobj);
1306         if (!btrfs_kset)
1307                 return -ENOMEM;
1308
1309         init_feature_attrs();
1310         ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
1311         if (ret)
1312                 goto out2;
1313         ret = sysfs_merge_group(&btrfs_kset->kobj,
1314                                 &btrfs_static_feature_attr_group);
1315         if (ret)
1316                 goto out_remove_group;
1317
1318 #ifdef CONFIG_BTRFS_DEBUG
1319         ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_debug_feature_attr_group);
1320         if (ret)
1321                 goto out2;
1322 #endif
1323
1324         return 0;
1325
1326 out_remove_group:
1327         sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
1328 out2:
1329         kset_unregister(btrfs_kset);
1330
1331         return ret;
1332 }
1333
1334 void __cold btrfs_exit_sysfs(void)
1335 {
1336         sysfs_unmerge_group(&btrfs_kset->kobj,
1337                             &btrfs_static_feature_attr_group);
1338         sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
1339 #ifdef CONFIG_BTRFS_DEBUG
1340         sysfs_remove_group(&btrfs_kset->kobj, &btrfs_debug_feature_attr_group);
1341 #endif
1342         kset_unregister(btrfs_kset);
1343 }
1344