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 <linux/list.h>
  13 #include <crypto/hash.h>
  14 #include "messages.h"
  15 #include "ctree.h"
  16 #include "discard.h"
  17 #include "disk-io.h"
  18 #include "send.h"
  19 #include "transaction.h"
  20 #include "sysfs.h"
  21 #include "volumes.h"
  22 #include "space-info.h"
  23 #include "block-group.h"
  24 #include "qgroup.h"
  25 #include "misc.h"
  26 #include "fs.h"
  27 #include "accessors.h"
  28
  29 /*
  30  * Structure name                       Path
  31  * --------------------------------------------------------------------------
  32  * btrfs_supported_static_feature_attrs /sys/fs/btrfs/features
  33  * btrfs_supported_feature_attrs        /sys/fs/btrfs/features and
  34  *                                      /sys/fs/btrfs/<uuid>/features
  35  * btrfs_attrs                          /sys/fs/btrfs/<uuid>
  36  * devid_attrs                          /sys/fs/btrfs/<uuid>/devinfo/<devid>
  37  * allocation_attrs                     /sys/fs/btrfs/<uuid>/allocation
  38  * qgroup_attrs                         /sys/fs/btrfs/<uuid>/qgroups/<level>_<qgroupid>
  39  * space_info_attrs                     /sys/fs/btrfs/<uuid>/allocation/<bg-type>
  40  * raid_attrs                           /sys/fs/btrfs/<uuid>/allocation/<bg-type>/<bg-profile>
  41  * discard_attrs                        /sys/fs/btrfs/<uuid>/discard
  42  *
  43  * When built with BTRFS_CONFIG_DEBUG:
  44  *
  45  * btrfs_debug_feature_attrs            /sys/fs/btrfs/debug
  46  * btrfs_debug_mount_attrs              /sys/fs/btrfs/<uuid>/debug
  47  */
  48
  49 struct btrfs_feature_attr {
  50         struct kobj_attribute kobj_attr;
  51         enum btrfs_feature_set feature_set;
  52         u64 feature_bit;
  53 };
  54
  55 /* For raid type sysfs entries */
  56 struct raid_kobject {
  57         u64 flags;
  58         struct kobject kobj;
  59 };
  60
  61 #define __INIT_KOBJ_ATTR(_name, _mode, _show, _store)                   \
  62 {                                                                       \
  63         .attr   = { .name = __stringify(_name), .mode = _mode },        \
  64         .show   = _show,                                                \
  65         .store  = _store,                                               \
  66 }
  67
  68 #define BTRFS_ATTR_W(_prefix, _name, _store)                            \
  69         static struct kobj_attribute btrfs_attr_##_prefix##_##_name =   \
  70                         __INIT_KOBJ_ATTR(_name, 0200, NULL, _store)
  71
  72 #define BTRFS_ATTR_RW(_prefix, _name, _show, _store)                    \
  73         static struct kobj_attribute btrfs_attr_##_prefix##_##_name =   \
  74                         __INIT_KOBJ_ATTR(_name, 0644, _show, _store)
  75
  76 #define BTRFS_ATTR(_prefix, _name, _show)                               \
  77         static struct kobj_attribute btrfs_attr_##_prefix##_##_name =   \
  78                         __INIT_KOBJ_ATTR(_name, 0444, _show, NULL)
  79
  80 #define BTRFS_ATTR_PTR(_prefix, _name)                                  \
  81         (&btrfs_attr_##_prefix##_##_name.attr)
  82
  83 #define BTRFS_FEAT_ATTR(_name, _feature_set, _feature_prefix, _feature_bit)  \
  84 static struct btrfs_feature_attr btrfs_attr_features_##_name = {             \
  85         .kobj_attr = __INIT_KOBJ_ATTR(_name, S_IRUGO,                        \
  86                                       btrfs_feature_attr_show,               \
  87                                       btrfs_feature_attr_store),             \
  88         .feature_set    = _feature_set,                                      \
  89         .feature_bit    = _feature_prefix ##_## _feature_bit,                \
  90 }
  91 #define BTRFS_FEAT_ATTR_PTR(_name)                                           \
  92         (&btrfs_attr_features_##_name.kobj_attr.attr)
  93
  94 #define BTRFS_FEAT_ATTR_COMPAT(name, feature) \
  95         BTRFS_FEAT_ATTR(name, FEAT_COMPAT, BTRFS_FEATURE_COMPAT, feature)
  96 #define BTRFS_FEAT_ATTR_COMPAT_RO(name, feature) \
  97         BTRFS_FEAT_ATTR(name, FEAT_COMPAT_RO, BTRFS_FEATURE_COMPAT_RO, feature)
  98 #define BTRFS_FEAT_ATTR_INCOMPAT(name, feature) \
  99         BTRFS_FEAT_ATTR(name, FEAT_INCOMPAT, BTRFS_FEATURE_INCOMPAT, feature)
 100
 101 static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj);
 102 static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj);
 103 static struct kobject *get_btrfs_kobj(struct kobject *kobj);
 104
 105 static struct btrfs_feature_attr *to_btrfs_feature_attr(struct kobj_attribute *a)
 106 {
 107         return container_of(a, struct btrfs_feature_attr, kobj_attr);
 108 }
 109
 110 static struct kobj_attribute *attr_to_btrfs_attr(struct attribute *attr)
 111 {
 112         return container_of(attr, struct kobj_attribute, attr);
 113 }
 114
 115 static struct btrfs_feature_attr *attr_to_btrfs_feature_attr(
 116                 struct attribute *attr)
 117 {
 118         return to_btrfs_feature_attr(attr_to_btrfs_attr(attr));
 119 }
 120
 121 static u64 get_features(struct btrfs_fs_info *fs_info,
 122                         enum btrfs_feature_set set)
 123 {
 124         struct btrfs_super_block *disk_super = fs_info->super_copy;
 125         if (set == FEAT_COMPAT)
 126                 return btrfs_super_compat_flags(disk_super);
 127         else if (set == FEAT_COMPAT_RO)
 128                 return btrfs_super_compat_ro_flags(disk_super);
 129         else
 130                 return btrfs_super_incompat_flags(disk_super);
 131 }
 132
 133 static void set_features(struct btrfs_fs_info *fs_info,
 134                          enum btrfs_feature_set set, u64 features)
 135 {
 136         struct btrfs_super_block *disk_super = fs_info->super_copy;
 137         if (set == FEAT_COMPAT)
 138                 btrfs_set_super_compat_flags(disk_super, features);
 139         else if (set == FEAT_COMPAT_RO)
 140                 btrfs_set_super_compat_ro_flags(disk_super, features);
 141         else
 142                 btrfs_set_super_incompat_flags(disk_super, features);
 143 }
 144
 145 static int can_modify_feature(struct btrfs_feature_attr *fa)
 146 {
 147         int val = 0;
 148         u64 set, clear;
 149         switch (fa->feature_set) {
 150         case FEAT_COMPAT:
 151                 set = BTRFS_FEATURE_COMPAT_SAFE_SET;
 152                 clear = BTRFS_FEATURE_COMPAT_SAFE_CLEAR;
 153                 break;
 154         case FEAT_COMPAT_RO:
 155                 set = BTRFS_FEATURE_COMPAT_RO_SAFE_SET;
 156                 clear = BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR;
 157                 break;
 158         case FEAT_INCOMPAT:
 159                 set = BTRFS_FEATURE_INCOMPAT_SAFE_SET;
 160                 clear = BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR;
 161                 break;
 162         default:
 163                 pr_warn("btrfs: sysfs: unknown feature set %d\n",
 164                                 fa->feature_set);
 165                 return 0;
 166         }
 167
 168         if (set & fa->feature_bit)
 169                 val |= 1;
 170         if (clear & fa->feature_bit)
 171                 val |= 2;
 172
 173         return val;
 174 }
 175
 176 static ssize_t btrfs_feature_attr_show(struct kobject *kobj,
 177                                        struct kobj_attribute *a, char *buf)
 178 {
 179         int val = 0;
 180         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 181         struct btrfs_feature_attr *fa = to_btrfs_feature_attr(a);
 182         if (fs_info) {
 183                 u64 features = get_features(fs_info, fa->feature_set);
 184                 if (features & fa->feature_bit)
 185                         val = 1;
 186         } else
 187                 val = can_modify_feature(fa);
 188
 189         return sysfs_emit(buf, "%d\n", val);
 190 }
 191
 192 static ssize_t btrfs_feature_attr_store(struct kobject *kobj,
 193                                         struct kobj_attribute *a,
 194                                         const char *buf, size_t count)
 195 {
 196         struct btrfs_fs_info *fs_info;
 197         struct btrfs_feature_attr *fa = to_btrfs_feature_attr(a);
 198         u64 features, set, clear;
 199         unsigned long val;
 200         int ret;
 201
 202         fs_info = to_fs_info(kobj);
 203         if (!fs_info)
 204                 return -EPERM;
 205
 206         if (sb_rdonly(fs_info->sb))
 207                 return -EROFS;
 208
 209         ret = kstrtoul(skip_spaces(buf), 0, &val);
 210         if (ret)
 211                 return ret;
 212
 213         if (fa->feature_set == FEAT_COMPAT) {
 214                 set = BTRFS_FEATURE_COMPAT_SAFE_SET;
 215                 clear = BTRFS_FEATURE_COMPAT_SAFE_CLEAR;
 216         } else if (fa->feature_set == FEAT_COMPAT_RO) {
 217                 set = BTRFS_FEATURE_COMPAT_RO_SAFE_SET;
 218                 clear = BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR;
 219         } else {
 220                 set = BTRFS_FEATURE_INCOMPAT_SAFE_SET;
 221                 clear = BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR;
 222         }
 223
 224         features = get_features(fs_info, fa->feature_set);
 225
 226         /* Nothing to do */
 227         if ((val && (features & fa->feature_bit)) ||
 228             (!val && !(features & fa->feature_bit)))
 229                 return count;
 230
 231         if ((val && !(set & fa->feature_bit)) ||
 232             (!val && !(clear & fa->feature_bit))) {
 233                 btrfs_info(fs_info,
 234                         "%sabling feature %s on mounted fs is not supported.",
 235                         val ? "En" : "Dis", fa->kobj_attr.attr.name);
 236                 return -EPERM;
 237         }
 238
 239         btrfs_info(fs_info, "%s %s feature flag",
 240                    val ? "Setting" : "Clearing", fa->kobj_attr.attr.name);
 241
 242         spin_lock(&fs_info->super_lock);
 243         features = get_features(fs_info, fa->feature_set);
 244         if (val)
 245                 features |= fa->feature_bit;
 246         else
 247                 features &= ~fa->feature_bit;
 248         set_features(fs_info, fa->feature_set, features);
 249         spin_unlock(&fs_info->super_lock);
 250
 251         /*
 252          * We don't want to do full transaction commit from inside sysfs
 253          */
 254         set_bit(BTRFS_FS_NEED_TRANS_COMMIT, &fs_info->flags);
 255         wake_up_process(fs_info->transaction_kthread);
 256
 257         return count;
 258 }
 259
 260 static umode_t btrfs_feature_visible(struct kobject *kobj,
 261                                      struct attribute *attr, int unused)
 262 {
 263         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 264         umode_t mode = attr->mode;
 265
 266         if (fs_info) {
 267                 struct btrfs_feature_attr *fa;
 268                 u64 features;
 269
 270                 fa = attr_to_btrfs_feature_attr(attr);
 271                 features = get_features(fs_info, fa->feature_set);
 272
 273                 if (can_modify_feature(fa))
 274                         mode |= S_IWUSR;
 275                 else if (!(features & fa->feature_bit))
 276                         mode = 0;
 277         }
 278
 279         return mode;
 280 }
 281
 282 BTRFS_FEAT_ATTR_INCOMPAT(default_subvol, DEFAULT_SUBVOL);
 283 BTRFS_FEAT_ATTR_INCOMPAT(mixed_groups, MIXED_GROUPS);
 284 BTRFS_FEAT_ATTR_INCOMPAT(compress_lzo, COMPRESS_LZO);
 285 BTRFS_FEAT_ATTR_INCOMPAT(compress_zstd, COMPRESS_ZSTD);
 286 BTRFS_FEAT_ATTR_INCOMPAT(extended_iref, EXTENDED_IREF);
 287 BTRFS_FEAT_ATTR_INCOMPAT(raid56, RAID56);
 288 BTRFS_FEAT_ATTR_INCOMPAT(skinny_metadata, SKINNY_METADATA);
 289 BTRFS_FEAT_ATTR_INCOMPAT(no_holes, NO_HOLES);
 290 BTRFS_FEAT_ATTR_INCOMPAT(metadata_uuid, METADATA_UUID);
 291 BTRFS_FEAT_ATTR_COMPAT_RO(free_space_tree, FREE_SPACE_TREE);
 292 BTRFS_FEAT_ATTR_COMPAT_RO(block_group_tree, BLOCK_GROUP_TREE);
 293 BTRFS_FEAT_ATTR_INCOMPAT(raid1c34, RAID1C34);
 294 BTRFS_FEAT_ATTR_INCOMPAT(simple_quota, SIMPLE_QUOTA);
 295 #ifdef CONFIG_BLK_DEV_ZONED
 296 BTRFS_FEAT_ATTR_INCOMPAT(zoned, ZONED);
 297 #endif
 298 #ifdef CONFIG_BTRFS_DEBUG
 299 /* Remove once support for extent tree v2 is feature complete */
 300 BTRFS_FEAT_ATTR_INCOMPAT(extent_tree_v2, EXTENT_TREE_V2);
 301 /* Remove once support for raid stripe tree is feature complete. */
 302 BTRFS_FEAT_ATTR_INCOMPAT(raid_stripe_tree, RAID_STRIPE_TREE);
 303 #endif
 304 #ifdef CONFIG_FS_VERITY
 305 BTRFS_FEAT_ATTR_COMPAT_RO(verity, VERITY);
 306 #endif
 307
 308 /*
 309  * Features which depend on feature bits and may differ between each fs.
 310  *
 311  * /sys/fs/btrfs/features      - all available features implemented by this version
 312  * /sys/fs/btrfs/UUID/features - features of the fs which are enabled or
 313  *                               can be changed on a mounted filesystem.
 314  */
 315 static struct attribute *btrfs_supported_feature_attrs[] = {
 316         BTRFS_FEAT_ATTR_PTR(default_subvol),
 317         BTRFS_FEAT_ATTR_PTR(mixed_groups),
 318         BTRFS_FEAT_ATTR_PTR(compress_lzo),
 319         BTRFS_FEAT_ATTR_PTR(compress_zstd),
 320         BTRFS_FEAT_ATTR_PTR(extended_iref),
 321         BTRFS_FEAT_ATTR_PTR(raid56),
 322         BTRFS_FEAT_ATTR_PTR(skinny_metadata),
 323         BTRFS_FEAT_ATTR_PTR(no_holes),
 324         BTRFS_FEAT_ATTR_PTR(metadata_uuid),
 325         BTRFS_FEAT_ATTR_PTR(free_space_tree),
 326         BTRFS_FEAT_ATTR_PTR(raid1c34),
 327         BTRFS_FEAT_ATTR_PTR(block_group_tree),
 328         BTRFS_FEAT_ATTR_PTR(simple_quota),
 329 #ifdef CONFIG_BLK_DEV_ZONED
 330         BTRFS_FEAT_ATTR_PTR(zoned),
 331 #endif
 332 #ifdef CONFIG_BTRFS_DEBUG
 333         BTRFS_FEAT_ATTR_PTR(extent_tree_v2),
 334         BTRFS_FEAT_ATTR_PTR(raid_stripe_tree),
 335 #endif
 336 #ifdef CONFIG_FS_VERITY
 337         BTRFS_FEAT_ATTR_PTR(verity),
 338 #endif
 339         NULL
 340 };
 341
 342 static const struct attribute_group btrfs_feature_attr_group = {
 343         .name = "features",
 344         .is_visible = btrfs_feature_visible,
 345         .attrs = btrfs_supported_feature_attrs,
 346 };
 347
 348 static ssize_t rmdir_subvol_show(struct kobject *kobj,
 349                                  struct kobj_attribute *ka, char *buf)
 350 {
 351         return sysfs_emit(buf, "0\n");
 352 }
 353 BTRFS_ATTR(static_feature, rmdir_subvol, rmdir_subvol_show);
 354
 355 static ssize_t supported_checksums_show(struct kobject *kobj,
 356                                         struct kobj_attribute *a, char *buf)
 357 {
 358         ssize_t ret = 0;
 359         int i;
 360
 361         for (i = 0; i < btrfs_get_num_csums(); i++) {
 362                 /*
 363                  * This "trick" only works as long as 'enum btrfs_csum_type' has
 364                  * no holes in it
 365                  */
 366                 ret += sysfs_emit_at(buf, ret, "%s%s", (i == 0 ? "" : " "),
 367                                      btrfs_super_csum_name(i));
 368
 369         }
 370
 371         ret += sysfs_emit_at(buf, ret, "\n");
 372         return ret;
 373 }
 374 BTRFS_ATTR(static_feature, supported_checksums, supported_checksums_show);
 375
 376 static ssize_t send_stream_version_show(struct kobject *kobj,
 377                                         struct kobj_attribute *ka, char *buf)
 378 {
 379         return sysfs_emit(buf, "%d\n", BTRFS_SEND_STREAM_VERSION);
 380 }
 381 BTRFS_ATTR(static_feature, send_stream_version, send_stream_version_show);
 382
 383 static const char *rescue_opts[] = {
 384         "usebackuproot",
 385         "nologreplay",
 386         "ignorebadroots",
 387         "ignoredatacsums",
 388         "all",
 389 };
 390
 391 static ssize_t supported_rescue_options_show(struct kobject *kobj,
 392                                              struct kobj_attribute *a,
 393                                              char *buf)
 394 {
 395         ssize_t ret = 0;
 396         int i;
 397
 398         for (i = 0; i < ARRAY_SIZE(rescue_opts); i++)
 399                 ret += sysfs_emit_at(buf, ret, "%s%s", (i ? " " : ""), rescue_opts[i]);
 400         ret += sysfs_emit_at(buf, ret, "\n");
 401         return ret;
 402 }
 403 BTRFS_ATTR(static_feature, supported_rescue_options,
 404            supported_rescue_options_show);
 405
 406 static ssize_t supported_sectorsizes_show(struct kobject *kobj,
 407                                           struct kobj_attribute *a,
 408                                           char *buf)
 409 {
 410         ssize_t ret = 0;
 411
 412         /* An artificial limit to only support 4K and PAGE_SIZE */
 413         if (PAGE_SIZE > SZ_4K)
 414                 ret += sysfs_emit_at(buf, ret, "%u ", SZ_4K);
 415         ret += sysfs_emit_at(buf, ret, "%lu\n", PAGE_SIZE);
 416
 417         return ret;
 418 }
 419 BTRFS_ATTR(static_feature, supported_sectorsizes,
 420            supported_sectorsizes_show);
 421
 422 static ssize_t acl_show(struct kobject *kobj, struct kobj_attribute *a, char *buf)
 423 {
 424         return sysfs_emit(buf, "%d\n", !!IS_ENABLED(CONFIG_BTRFS_FS_POSIX_ACL));
 425 }
 426 BTRFS_ATTR(static_feature, acl, acl_show);
 427
 428 static ssize_t temp_fsid_supported_show(struct kobject *kobj,
 429                                         struct kobj_attribute *a, char *buf)
 430 {
 431         return sysfs_emit(buf, "0\n");
 432 }
 433 BTRFS_ATTR(static_feature, temp_fsid, temp_fsid_supported_show);
 434
 435 /*
 436  * Features which only depend on kernel version.
 437  *
 438  * These are listed in /sys/fs/btrfs/features along with
 439  * btrfs_supported_feature_attrs.
 440  */
 441 static struct attribute *btrfs_supported_static_feature_attrs[] = {
 442         BTRFS_ATTR_PTR(static_feature, acl),
 443         BTRFS_ATTR_PTR(static_feature, rmdir_subvol),
 444         BTRFS_ATTR_PTR(static_feature, supported_checksums),
 445         BTRFS_ATTR_PTR(static_feature, send_stream_version),
 446         BTRFS_ATTR_PTR(static_feature, supported_rescue_options),
 447         BTRFS_ATTR_PTR(static_feature, supported_sectorsizes),
 448         BTRFS_ATTR_PTR(static_feature, temp_fsid),
 449         NULL
 450 };
 451
 452 static const struct attribute_group btrfs_static_feature_attr_group = {
 453         .name = "features",
 454         .attrs = btrfs_supported_static_feature_attrs,
 455 };
 456
 457 /*
 458  * Discard statistics and tunables
 459  */
 460 #define discard_to_fs_info(_kobj)       to_fs_info(get_btrfs_kobj(_kobj))
 461
 462 static ssize_t btrfs_discardable_bytes_show(struct kobject *kobj,
 463                                             struct kobj_attribute *a,
 464                                             char *buf)
 465 {
 466         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 467
 468         return sysfs_emit(buf, "%lld\n",
 469                         atomic64_read(&fs_info->discard_ctl.discardable_bytes));
 470 }
 471 BTRFS_ATTR(discard, discardable_bytes, btrfs_discardable_bytes_show);
 472
 473 static ssize_t btrfs_discardable_extents_show(struct kobject *kobj,
 474                                               struct kobj_attribute *a,
 475                                               char *buf)
 476 {
 477         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 478
 479         return sysfs_emit(buf, "%d\n",
 480                         atomic_read(&fs_info->discard_ctl.discardable_extents));
 481 }
 482 BTRFS_ATTR(discard, discardable_extents, btrfs_discardable_extents_show);
 483
 484 static ssize_t btrfs_discard_bitmap_bytes_show(struct kobject *kobj,
 485                                                struct kobj_attribute *a,
 486                                                char *buf)
 487 {
 488         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 489
 490         return sysfs_emit(buf, "%llu\n",
 491                           fs_info->discard_ctl.discard_bitmap_bytes);
 492 }
 493 BTRFS_ATTR(discard, discard_bitmap_bytes, btrfs_discard_bitmap_bytes_show);
 494
 495 static ssize_t btrfs_discard_bytes_saved_show(struct kobject *kobj,
 496                                               struct kobj_attribute *a,
 497                                               char *buf)
 498 {
 499         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 500
 501         return sysfs_emit(buf, "%lld\n",
 502                 atomic64_read(&fs_info->discard_ctl.discard_bytes_saved));
 503 }
 504 BTRFS_ATTR(discard, discard_bytes_saved, btrfs_discard_bytes_saved_show);
 505
 506 static ssize_t btrfs_discard_extent_bytes_show(struct kobject *kobj,
 507                                                struct kobj_attribute *a,
 508                                                char *buf)
 509 {
 510         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 511
 512         return sysfs_emit(buf, "%llu\n",
 513                           fs_info->discard_ctl.discard_extent_bytes);
 514 }
 515 BTRFS_ATTR(discard, discard_extent_bytes, btrfs_discard_extent_bytes_show);
 516
 517 static ssize_t btrfs_discard_iops_limit_show(struct kobject *kobj,
 518                                              struct kobj_attribute *a,
 519                                              char *buf)
 520 {
 521         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 522
 523         return sysfs_emit(buf, "%u\n",
 524                           READ_ONCE(fs_info->discard_ctl.iops_limit));
 525 }
 526
 527 static ssize_t btrfs_discard_iops_limit_store(struct kobject *kobj,
 528                                               struct kobj_attribute *a,
 529                                               const char *buf, size_t len)
 530 {
 531         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 532         struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
 533         u32 iops_limit;
 534         int ret;
 535
 536         ret = kstrtou32(buf, 10, &iops_limit);
 537         if (ret)
 538                 return -EINVAL;
 539
 540         WRITE_ONCE(discard_ctl->iops_limit, iops_limit);
 541         btrfs_discard_calc_delay(discard_ctl);
 542         btrfs_discard_schedule_work(discard_ctl, true);
 543         return len;
 544 }
 545 BTRFS_ATTR_RW(discard, iops_limit, btrfs_discard_iops_limit_show,
 546               btrfs_discard_iops_limit_store);
 547
 548 static ssize_t btrfs_discard_kbps_limit_show(struct kobject *kobj,
 549                                              struct kobj_attribute *a,
 550                                              char *buf)
 551 {
 552         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 553
 554         return sysfs_emit(buf, "%u\n",
 555                           READ_ONCE(fs_info->discard_ctl.kbps_limit));
 556 }
 557
 558 static ssize_t btrfs_discard_kbps_limit_store(struct kobject *kobj,
 559                                               struct kobj_attribute *a,
 560                                               const char *buf, size_t len)
 561 {
 562         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 563         struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
 564         u32 kbps_limit;
 565         int ret;
 566
 567         ret = kstrtou32(buf, 10, &kbps_limit);
 568         if (ret)
 569                 return -EINVAL;
 570
 571         WRITE_ONCE(discard_ctl->kbps_limit, kbps_limit);
 572         btrfs_discard_schedule_work(discard_ctl, true);
 573         return len;
 574 }
 575 BTRFS_ATTR_RW(discard, kbps_limit, btrfs_discard_kbps_limit_show,
 576               btrfs_discard_kbps_limit_store);
 577
 578 static ssize_t btrfs_discard_max_discard_size_show(struct kobject *kobj,
 579                                                    struct kobj_attribute *a,
 580                                                    char *buf)
 581 {
 582         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 583
 584         return sysfs_emit(buf, "%llu\n",
 585                           READ_ONCE(fs_info->discard_ctl.max_discard_size));
 586 }
 587
 588 static ssize_t btrfs_discard_max_discard_size_store(struct kobject *kobj,
 589                                                     struct kobj_attribute *a,
 590                                                     const char *buf, size_t len)
 591 {
 592         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 593         struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
 594         u64 max_discard_size;
 595         int ret;
 596
 597         ret = kstrtou64(buf, 10, &max_discard_size);
 598         if (ret)
 599                 return -EINVAL;
 600
 601         WRITE_ONCE(discard_ctl->max_discard_size, max_discard_size);
 602
 603         return len;
 604 }
 605 BTRFS_ATTR_RW(discard, max_discard_size, btrfs_discard_max_discard_size_show,
 606               btrfs_discard_max_discard_size_store);
 607
 608 /*
 609  * Per-filesystem stats for discard (when mounted with discard=async).
 610  *
 611  * Path: /sys/fs/btrfs/<uuid>/discard/
 612  */
 613 static const struct attribute *discard_attrs[] = {
 614         BTRFS_ATTR_PTR(discard, discardable_bytes),
 615         BTRFS_ATTR_PTR(discard, discardable_extents),
 616         BTRFS_ATTR_PTR(discard, discard_bitmap_bytes),
 617         BTRFS_ATTR_PTR(discard, discard_bytes_saved),
 618         BTRFS_ATTR_PTR(discard, discard_extent_bytes),
 619         BTRFS_ATTR_PTR(discard, iops_limit),
 620         BTRFS_ATTR_PTR(discard, kbps_limit),
 621         BTRFS_ATTR_PTR(discard, max_discard_size),
 622         NULL,
 623 };
 624
 625 #ifdef CONFIG_BTRFS_DEBUG
 626
 627 /*
 628  * Per-filesystem runtime debugging exported via sysfs.
 629  *
 630  * Path: /sys/fs/btrfs/UUID/debug/
 631  */
 632 static const struct attribute *btrfs_debug_mount_attrs[] = {
 633         NULL,
 634 };
 635
 636 /*
 637  * Runtime debugging exported via sysfs, applies to all mounted filesystems.
 638  *
 639  * Path: /sys/fs/btrfs/debug
 640  */
 641 static struct attribute *btrfs_debug_feature_attrs[] = {
 642         NULL
 643 };
 644
 645 static const struct attribute_group btrfs_debug_feature_attr_group = {
 646         .name = "debug",
 647         .attrs = btrfs_debug_feature_attrs,
 648 };
 649
 650 #endif
 651
 652 static ssize_t btrfs_show_u64(u64 *value_ptr, spinlock_t *lock, char *buf)
 653 {
 654         u64 val;
 655         if (lock)
 656                 spin_lock(lock);
 657         val = *value_ptr;
 658         if (lock)
 659                 spin_unlock(lock);
 660         return sysfs_emit(buf, "%llu\n", val);
 661 }
 662
 663 static ssize_t global_rsv_size_show(struct kobject *kobj,
 664                                     struct kobj_attribute *ka, char *buf)
 665 {
 666         struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent);
 667         struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
 668         return btrfs_show_u64(&block_rsv->size, &block_rsv->lock, buf);
 669 }
 670 BTRFS_ATTR(allocation, global_rsv_size, global_rsv_size_show);
 671
 672 static ssize_t global_rsv_reserved_show(struct kobject *kobj,
 673                                         struct kobj_attribute *a, char *buf)
 674 {
 675         struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent);
 676         struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
 677         return btrfs_show_u64(&block_rsv->reserved, &block_rsv->lock, buf);
 678 }
 679 BTRFS_ATTR(allocation, global_rsv_reserved, global_rsv_reserved_show);
 680
 681 #define to_space_info(_kobj) container_of(_kobj, struct btrfs_space_info, kobj)
 682 #define to_raid_kobj(_kobj) container_of(_kobj, struct raid_kobject, kobj)
 683
 684 static ssize_t raid_bytes_show(struct kobject *kobj,
 685                                struct kobj_attribute *attr, char *buf);
 686 BTRFS_ATTR(raid, total_bytes, raid_bytes_show);
 687 BTRFS_ATTR(raid, used_bytes, raid_bytes_show);
 688
 689 static ssize_t raid_bytes_show(struct kobject *kobj,
 690                                struct kobj_attribute *attr, char *buf)
 691
 692 {
 693         struct btrfs_space_info *sinfo = to_space_info(kobj->parent);
 694         struct btrfs_block_group *block_group;
 695         int index = btrfs_bg_flags_to_raid_index(to_raid_kobj(kobj)->flags);
 696         u64 val = 0;
 697
 698         down_read(&sinfo->groups_sem);
 699         list_for_each_entry(block_group, &sinfo->block_groups[index], list) {
 700                 if (&attr->attr == BTRFS_ATTR_PTR(raid, total_bytes))
 701                         val += block_group->length;
 702                 else
 703                         val += block_group->used;
 704         }
 705         up_read(&sinfo->groups_sem);
 706         return sysfs_emit(buf, "%llu\n", val);
 707 }
 708
 709 /*
 710  * Allocation information about block group profiles.
 711  *
 712  * Path: /sys/fs/btrfs/<uuid>/allocation/<bg-type>/<bg-profile>/
 713  */
 714 static struct attribute *raid_attrs[] = {
 715         BTRFS_ATTR_PTR(raid, total_bytes),
 716         BTRFS_ATTR_PTR(raid, used_bytes),
 717         NULL
 718 };
 719 ATTRIBUTE_GROUPS(raid);
 720
 721 static void release_raid_kobj(struct kobject *kobj)
 722 {
 723         kfree(to_raid_kobj(kobj));
 724 }
 725
 726 static const struct kobj_type btrfs_raid_ktype = {
 727         .sysfs_ops = &kobj_sysfs_ops,
 728         .release = release_raid_kobj,
 729         .default_groups = raid_groups,
 730 };
 731
 732 #define SPACE_INFO_ATTR(field)                                          \
 733 static ssize_t btrfs_space_info_show_##field(struct kobject *kobj,      \
 734                                              struct kobj_attribute *a,  \
 735                                              char *buf)                 \
 736 {                                                                       \
 737         struct btrfs_space_info *sinfo = to_space_info(kobj);           \
 738         return btrfs_show_u64(&sinfo->field, &sinfo->lock, buf);        \
 739 }                                                                       \
 740 BTRFS_ATTR(space_info, field, btrfs_space_info_show_##field)
 741
 742 static ssize_t btrfs_chunk_size_show(struct kobject *kobj,
 743                                      struct kobj_attribute *a, char *buf)
 744 {
 745         struct btrfs_space_info *sinfo = to_space_info(kobj);
 746
 747         return sysfs_emit(buf, "%llu\n", READ_ONCE(sinfo->chunk_size));
 748 }
 749
 750 /*
 751  * Store new chunk size in space info. Can be called on a read-only filesystem.
 752  *
 753  * If the new chunk size value is larger than 10% of free space it is reduced
 754  * to match that limit. Alignment must be to 256M and the system chunk size
 755  * cannot be set.
 756  */
 757 static ssize_t btrfs_chunk_size_store(struct kobject *kobj,
 758                                       struct kobj_attribute *a,
 759                                       const char *buf, size_t len)
 760 {
 761         struct btrfs_space_info *space_info = to_space_info(kobj);
 762         struct btrfs_fs_info *fs_info = to_fs_info(get_btrfs_kobj(kobj));
 763         char *retptr;
 764         u64 val;
 765
 766         if (!capable(CAP_SYS_ADMIN))
 767                 return -EPERM;
 768
 769         if (!fs_info->fs_devices)
 770                 return -EINVAL;
 771
 772         if (btrfs_is_zoned(fs_info))
 773                 return -EINVAL;
 774
 775         /* System block type must not be changed. */
 776         if (space_info->flags & BTRFS_BLOCK_GROUP_SYSTEM)
 777                 return -EPERM;
 778
 779         val = memparse(buf, &retptr);
 780         /* There could be trailing '\n', also catch any typos after the value */
 781         retptr = skip_spaces(retptr);
 782         if (*retptr != 0 || val == 0)
 783                 return -EINVAL;
 784
 785         val = min(val, BTRFS_MAX_DATA_CHUNK_SIZE);
 786
 787         /* Limit stripe size to 10% of available space. */
 788         val = min(mult_perc(fs_info->fs_devices->total_rw_bytes, 10), val);
 789
 790         /* Must be multiple of 256M. */
 791         val &= ~((u64)SZ_256M - 1);
 792
 793         /* Must be at least 256M. */
 794         if (val < SZ_256M)
 795                 return -EINVAL;
 796
 797         btrfs_update_space_info_chunk_size(space_info, val);
 798
 799         return len;
 800 }
 801
 802 static ssize_t btrfs_size_classes_show(struct kobject *kobj,
 803                                        struct kobj_attribute *a, char *buf)
 804 {
 805         struct btrfs_space_info *sinfo = to_space_info(kobj);
 806         struct btrfs_block_group *bg;
 807         u32 none = 0;
 808         u32 small = 0;
 809         u32 medium = 0;
 810         u32 large = 0;
 811
 812         for (int i = 0; i < BTRFS_NR_RAID_TYPES; ++i) {
 813                 down_read(&sinfo->groups_sem);
 814                 list_for_each_entry(bg, &sinfo->block_groups[i], list) {
 815                         if (!btrfs_block_group_should_use_size_class(bg))
 816                                 continue;
 817                         switch (bg->size_class) {
 818                         case BTRFS_BG_SZ_NONE:
 819                                 none++;
 820                                 break;
 821                         case BTRFS_BG_SZ_SMALL:
 822                                 small++;
 823                                 break;
 824                         case BTRFS_BG_SZ_MEDIUM:
 825                                 medium++;
 826                                 break;
 827                         case BTRFS_BG_SZ_LARGE:
 828                                 large++;
 829                                 break;
 830                         }
 831                 }
 832                 up_read(&sinfo->groups_sem);
 833         }
 834         return sysfs_emit(buf, "none %u\n"
 835                                "small %u\n"
 836                                "medium %u\n"
 837                                "large %u\n",
 838                                none, small, medium, large);
 839 }
 840
 841 #ifdef CONFIG_BTRFS_DEBUG
 842 /*
 843  * Request chunk allocation with current chunk size.
 844  */
 845 static ssize_t btrfs_force_chunk_alloc_store(struct kobject *kobj,
 846                                              struct kobj_attribute *a,
 847                                              const char *buf, size_t len)
 848 {
 849         struct btrfs_space_info *space_info = to_space_info(kobj);
 850         struct btrfs_fs_info *fs_info = to_fs_info(get_btrfs_kobj(kobj));
 851         struct btrfs_trans_handle *trans;
 852         bool val;
 853         int ret;
 854
 855         if (!capable(CAP_SYS_ADMIN))
 856                 return -EPERM;
 857
 858         if (sb_rdonly(fs_info->sb))
 859                 return -EROFS;
 860
 861         ret = kstrtobool(buf, &val);
 862         if (ret)
 863                 return ret;
 864
 865         if (!val)
 866                 return -EINVAL;
 867
 868         /*
 869          * This is unsafe to be called from sysfs context and may cause
 870          * unexpected problems.
 871          */
 872         trans = btrfs_start_transaction(fs_info->tree_root, 0);
 873         if (IS_ERR(trans))
 874                 return PTR_ERR(trans);
 875         ret = btrfs_force_chunk_alloc(trans, space_info->flags);
 876         btrfs_end_transaction(trans);
 877
 878         if (ret == 1)
 879                 return len;
 880
 881         return -ENOSPC;
 882 }
 883 BTRFS_ATTR_W(space_info, force_chunk_alloc, btrfs_force_chunk_alloc_store);
 884
 885 #endif
 886
 887 SPACE_INFO_ATTR(flags);
 888 SPACE_INFO_ATTR(total_bytes);
 889 SPACE_INFO_ATTR(bytes_used);
 890 SPACE_INFO_ATTR(bytes_pinned);
 891 SPACE_INFO_ATTR(bytes_reserved);
 892 SPACE_INFO_ATTR(bytes_may_use);
 893 SPACE_INFO_ATTR(bytes_readonly);
 894 SPACE_INFO_ATTR(bytes_zone_unusable);
 895 SPACE_INFO_ATTR(disk_used);
 896 SPACE_INFO_ATTR(disk_total);
 897 BTRFS_ATTR_RW(space_info, chunk_size, btrfs_chunk_size_show, btrfs_chunk_size_store);
 898 BTRFS_ATTR(space_info, size_classes, btrfs_size_classes_show);
 899
 900 static ssize_t btrfs_sinfo_bg_reclaim_threshold_show(struct kobject *kobj,
 901                                                      struct kobj_attribute *a,
 902                                                      char *buf)
 903 {
 904         struct btrfs_space_info *space_info = to_space_info(kobj);
 905
 906         return sysfs_emit(buf, "%d\n", READ_ONCE(space_info->bg_reclaim_threshold));
 907 }
 908
 909 static ssize_t btrfs_sinfo_bg_reclaim_threshold_store(struct kobject *kobj,
 910                                                       struct kobj_attribute *a,
 911                                                       const char *buf, size_t len)
 912 {
 913         struct btrfs_space_info *space_info = to_space_info(kobj);
 914         int thresh;
 915         int ret;
 916
 917         ret = kstrtoint(buf, 10, &thresh);
 918         if (ret)
 919                 return ret;
 920
 921         if (thresh < 0 || thresh > 100)
 922                 return -EINVAL;
 923
 924         WRITE_ONCE(space_info->bg_reclaim_threshold, thresh);
 925
 926         return len;
 927 }
 928
 929 BTRFS_ATTR_RW(space_info, bg_reclaim_threshold,
 930               btrfs_sinfo_bg_reclaim_threshold_show,
 931               btrfs_sinfo_bg_reclaim_threshold_store);
 932
 933 /*
 934  * Allocation information about block group types.
 935  *
 936  * Path: /sys/fs/btrfs/<uuid>/allocation/<bg-type>/
 937  */
 938 static struct attribute *space_info_attrs[] = {
 939         BTRFS_ATTR_PTR(space_info, flags),
 940         BTRFS_ATTR_PTR(space_info, total_bytes),
 941         BTRFS_ATTR_PTR(space_info, bytes_used),
 942         BTRFS_ATTR_PTR(space_info, bytes_pinned),
 943         BTRFS_ATTR_PTR(space_info, bytes_reserved),
 944         BTRFS_ATTR_PTR(space_info, bytes_may_use),
 945         BTRFS_ATTR_PTR(space_info, bytes_readonly),
 946         BTRFS_ATTR_PTR(space_info, bytes_zone_unusable),
 947         BTRFS_ATTR_PTR(space_info, disk_used),
 948         BTRFS_ATTR_PTR(space_info, disk_total),
 949         BTRFS_ATTR_PTR(space_info, bg_reclaim_threshold),
 950         BTRFS_ATTR_PTR(space_info, chunk_size),
 951         BTRFS_ATTR_PTR(space_info, size_classes),
 952 #ifdef CONFIG_BTRFS_DEBUG
 953         BTRFS_ATTR_PTR(space_info, force_chunk_alloc),
 954 #endif
 955         NULL,
 956 };
 957 ATTRIBUTE_GROUPS(space_info);
 958
 959 static void space_info_release(struct kobject *kobj)
 960 {
 961         struct btrfs_space_info *sinfo = to_space_info(kobj);
 962         kfree(sinfo);
 963 }
 964
 965 static const struct kobj_type space_info_ktype = {
 966         .sysfs_ops = &kobj_sysfs_ops,
 967         .release = space_info_release,
 968         .default_groups = space_info_groups,
 969 };
 970
 971 /*
 972  * Allocation information about block groups.
 973  *
 974  * Path: /sys/fs/btrfs/<uuid>/allocation/
 975  */
 976 static const struct attribute *allocation_attrs[] = {
 977         BTRFS_ATTR_PTR(allocation, global_rsv_reserved),
 978         BTRFS_ATTR_PTR(allocation, global_rsv_size),
 979         NULL,
 980 };
 981
 982 static ssize_t btrfs_label_show(struct kobject *kobj,
 983                                 struct kobj_attribute *a, char *buf)
 984 {
 985         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 986         char *label = fs_info->super_copy->label;
 987         ssize_t ret;
 988
 989         spin_lock(&fs_info->super_lock);
 990         ret = sysfs_emit(buf, label[0] ? "%s\n" : "%s", label);
 991         spin_unlock(&fs_info->super_lock);
 992
 993         return ret;
 994 }
 995
 996 static ssize_t btrfs_label_store(struct kobject *kobj,
 997                                  struct kobj_attribute *a,
 998                                  const char *buf, size_t len)
 999 {
1000         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1001         size_t p_len;
1002
1003         if (!fs_info)
1004                 return -EPERM;
1005
1006         if (sb_rdonly(fs_info->sb))
1007                 return -EROFS;
1008
1009         /*
1010          * p_len is the len until the first occurrence of either
1011          * '\n' or '\0'
1012          */
1013         p_len = strcspn(buf, "\n");
1014
1015         if (p_len >= BTRFS_LABEL_SIZE)
1016                 return -EINVAL;
1017
1018         spin_lock(&fs_info->super_lock);
1019         memset(fs_info->super_copy->label, 0, BTRFS_LABEL_SIZE);
1020         memcpy(fs_info->super_copy->label, buf, p_len);
1021         spin_unlock(&fs_info->super_lock);
1022
1023         /*
1024          * We don't want to do full transaction commit from inside sysfs
1025          */
1026         set_bit(BTRFS_FS_NEED_TRANS_COMMIT, &fs_info->flags);
1027         wake_up_process(fs_info->transaction_kthread);
1028
1029         return len;
1030 }
1031 BTRFS_ATTR_RW(, label, btrfs_label_show, btrfs_label_store);
1032
1033 static ssize_t btrfs_nodesize_show(struct kobject *kobj,
1034                                 struct kobj_attribute *a, char *buf)
1035 {
1036         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1037
1038         return sysfs_emit(buf, "%u\n", fs_info->super_copy->nodesize);
1039 }
1040
1041 BTRFS_ATTR(, nodesize, btrfs_nodesize_show);
1042
1043 static ssize_t btrfs_sectorsize_show(struct kobject *kobj,
1044                                 struct kobj_attribute *a, char *buf)
1045 {
1046         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1047
1048         return sysfs_emit(buf, "%u\n", fs_info->super_copy->sectorsize);
1049 }
1050
1051 BTRFS_ATTR(, sectorsize, btrfs_sectorsize_show);
1052
1053 static ssize_t btrfs_commit_stats_show(struct kobject *kobj,
1054                                        struct kobj_attribute *a, char *buf)
1055 {
1056         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1057
1058         return sysfs_emit(buf,
1059                 "commits %llu\n"
1060                 "last_commit_ms %llu\n"
1061                 "max_commit_ms %llu\n"
1062                 "total_commit_ms %llu\n",
1063                 fs_info->commit_stats.commit_count,
1064                 div_u64(fs_info->commit_stats.last_commit_dur, NSEC_PER_MSEC),
1065                 div_u64(fs_info->commit_stats.max_commit_dur, NSEC_PER_MSEC),
1066                 div_u64(fs_info->commit_stats.total_commit_dur, NSEC_PER_MSEC));
1067 }
1068
1069 static ssize_t btrfs_commit_stats_store(struct kobject *kobj,
1070                                         struct kobj_attribute *a,
1071                                         const char *buf, size_t len)
1072 {
1073         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1074         unsigned long val;
1075         int ret;
1076
1077         if (!fs_info)
1078                 return -EPERM;
1079
1080         if (!capable(CAP_SYS_RESOURCE))
1081                 return -EPERM;
1082
1083         ret = kstrtoul(buf, 10, &val);
1084         if (ret)
1085                 return ret;
1086         if (val)
1087                 return -EINVAL;
1088
1089         WRITE_ONCE(fs_info->commit_stats.max_commit_dur, 0);
1090
1091         return len;
1092 }
1093 BTRFS_ATTR_RW(, commit_stats, btrfs_commit_stats_show, btrfs_commit_stats_store);
1094
1095 static ssize_t btrfs_clone_alignment_show(struct kobject *kobj,
1096                                 struct kobj_attribute *a, char *buf)
1097 {
1098         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1099
1100         return sysfs_emit(buf, "%u\n", fs_info->super_copy->sectorsize);
1101 }
1102
1103 BTRFS_ATTR(, clone_alignment, btrfs_clone_alignment_show);
1104
1105 static ssize_t quota_override_show(struct kobject *kobj,
1106                                    struct kobj_attribute *a, char *buf)
1107 {
1108         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1109         int quota_override;
1110
1111         quota_override = test_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
1112         return sysfs_emit(buf, "%d\n", quota_override);
1113 }
1114
1115 static ssize_t quota_override_store(struct kobject *kobj,
1116                                     struct kobj_attribute *a,
1117                                     const char *buf, size_t len)
1118 {
1119         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1120         unsigned long knob;
1121         int err;
1122
1123         if (!fs_info)
1124                 return -EPERM;
1125
1126         if (!capable(CAP_SYS_RESOURCE))
1127                 return -EPERM;
1128
1129         err = kstrtoul(buf, 10, &knob);
1130         if (err)
1131                 return err;
1132         if (knob > 1)
1133                 return -EINVAL;
1134
1135         if (knob)
1136                 set_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
1137         else
1138                 clear_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
1139
1140         return len;
1141 }
1142
1143 BTRFS_ATTR_RW(, quota_override, quota_override_show, quota_override_store);
1144
1145 static ssize_t btrfs_metadata_uuid_show(struct kobject *kobj,
1146                                 struct kobj_attribute *a, char *buf)
1147 {
1148         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1149
1150         return sysfs_emit(buf, "%pU\n", fs_info->fs_devices->metadata_uuid);
1151 }
1152
1153 BTRFS_ATTR(, metadata_uuid, btrfs_metadata_uuid_show);
1154
1155 static ssize_t btrfs_checksum_show(struct kobject *kobj,
1156                                    struct kobj_attribute *a, char *buf)
1157 {
1158         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1159         u16 csum_type = btrfs_super_csum_type(fs_info->super_copy);
1160
1161         return sysfs_emit(buf, "%s (%s)\n",
1162                           btrfs_super_csum_name(csum_type),
1163                           crypto_shash_driver_name(fs_info->csum_shash));
1164 }
1165
1166 BTRFS_ATTR(, checksum, btrfs_checksum_show);
1167
1168 static ssize_t btrfs_exclusive_operation_show(struct kobject *kobj,
1169                 struct kobj_attribute *a, char *buf)
1170 {
1171         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1172         const char *str;
1173
1174         switch (READ_ONCE(fs_info->exclusive_operation)) {
1175                 case  BTRFS_EXCLOP_NONE:
1176                         str = "none\n";
1177                         break;
1178                 case BTRFS_EXCLOP_BALANCE:
1179                         str = "balance\n";
1180                         break;
1181                 case BTRFS_EXCLOP_BALANCE_PAUSED:
1182                         str = "balance paused\n";
1183                         break;
1184                 case BTRFS_EXCLOP_DEV_ADD:
1185                         str = "device add\n";
1186                         break;
1187                 case BTRFS_EXCLOP_DEV_REMOVE:
1188                         str = "device remove\n";
1189                         break;
1190                 case BTRFS_EXCLOP_DEV_REPLACE:
1191                         str = "device replace\n";
1192                         break;
1193                 case BTRFS_EXCLOP_RESIZE:
1194                         str = "resize\n";
1195                         break;
1196                 case BTRFS_EXCLOP_SWAP_ACTIVATE:
1197                         str = "swap activate\n";
1198                         break;
1199                 default:
1200                         str = "UNKNOWN\n";
1201                         break;
1202         }
1203         return sysfs_emit(buf, "%s", str);
1204 }
1205 BTRFS_ATTR(, exclusive_operation, btrfs_exclusive_operation_show);
1206
1207 static ssize_t btrfs_generation_show(struct kobject *kobj,
1208                                      struct kobj_attribute *a, char *buf)
1209 {
1210         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1211
1212         return sysfs_emit(buf, "%llu\n", btrfs_get_fs_generation(fs_info));
1213 }
1214 BTRFS_ATTR(, generation, btrfs_generation_show);
1215
1216 static ssize_t btrfs_temp_fsid_show(struct kobject *kobj,
1217                                     struct kobj_attribute *a, char *buf)
1218 {
1219         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1220
1221         return sysfs_emit(buf, "%d\n", fs_info->fs_devices->temp_fsid);
1222 }
1223 BTRFS_ATTR(, temp_fsid, btrfs_temp_fsid_show);
1224
1225 static const char * const btrfs_read_policy_name[] = { "pid" };
1226
1227 static ssize_t btrfs_read_policy_show(struct kobject *kobj,
1228                                       struct kobj_attribute *a, char *buf)
1229 {
1230         struct btrfs_fs_devices *fs_devices = to_fs_devs(kobj);
1231         ssize_t ret = 0;
1232         int i;
1233
1234         for (i = 0; i < BTRFS_NR_READ_POLICY; i++) {
1235                 if (fs_devices->read_policy == i)
1236                         ret += sysfs_emit_at(buf, ret, "%s[%s]",
1237                                          (ret == 0 ? "" : " "),
1238                                          btrfs_read_policy_name[i]);
1239                 else
1240                         ret += sysfs_emit_at(buf, ret, "%s%s",
1241                                          (ret == 0 ? "" : " "),
1242                                          btrfs_read_policy_name[i]);
1243         }
1244
1245         ret += sysfs_emit_at(buf, ret, "\n");
1246
1247         return ret;
1248 }
1249
1250 static ssize_t btrfs_read_policy_store(struct kobject *kobj,
1251                                        struct kobj_attribute *a,
1252                                        const char *buf, size_t len)
1253 {
1254         struct btrfs_fs_devices *fs_devices = to_fs_devs(kobj);
1255         int i;
1256
1257         for (i = 0; i < BTRFS_NR_READ_POLICY; i++) {
1258                 if (sysfs_streq(buf, btrfs_read_policy_name[i])) {
1259                         if (i != fs_devices->read_policy) {
1260                                 fs_devices->read_policy = i;
1261                                 btrfs_info(fs_devices->fs_info,
1262                                            "read policy set to '%s'",
1263                                            btrfs_read_policy_name[i]);
1264                         }
1265                         return len;
1266                 }
1267         }
1268
1269         return -EINVAL;
1270 }
1271 BTRFS_ATTR_RW(, read_policy, btrfs_read_policy_show, btrfs_read_policy_store);
1272
1273 static ssize_t btrfs_bg_reclaim_threshold_show(struct kobject *kobj,
1274                                                struct kobj_attribute *a,
1275                                                char *buf)
1276 {
1277         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1278
1279         return sysfs_emit(buf, "%d\n", READ_ONCE(fs_info->bg_reclaim_threshold));
1280 }
1281
1282 static ssize_t btrfs_bg_reclaim_threshold_store(struct kobject *kobj,
1283                                                 struct kobj_attribute *a,
1284                                                 const char *buf, size_t len)
1285 {
1286         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1287         int thresh;
1288         int ret;
1289
1290         ret = kstrtoint(buf, 10, &thresh);
1291         if (ret)
1292                 return ret;
1293
1294 #ifdef CONFIG_BTRFS_DEBUG
1295         if (thresh != 0 && (thresh > 100))
1296                 return -EINVAL;
1297 #else
1298         if (thresh != 0 && (thresh <= 50 || thresh > 100))
1299                 return -EINVAL;
1300 #endif
1301
1302         WRITE_ONCE(fs_info->bg_reclaim_threshold, thresh);
1303
1304         return len;
1305 }
1306 BTRFS_ATTR_RW(, bg_reclaim_threshold, btrfs_bg_reclaim_threshold_show,
1307               btrfs_bg_reclaim_threshold_store);
1308
1309 /*
1310  * Per-filesystem information and stats.
1311  *
1312  * Path: /sys/fs/btrfs/<uuid>/
1313  */
1314 static const struct attribute *btrfs_attrs[] = {
1315         BTRFS_ATTR_PTR(, label),
1316         BTRFS_ATTR_PTR(, nodesize),
1317         BTRFS_ATTR_PTR(, sectorsize),
1318         BTRFS_ATTR_PTR(, clone_alignment),
1319         BTRFS_ATTR_PTR(, quota_override),
1320         BTRFS_ATTR_PTR(, metadata_uuid),
1321         BTRFS_ATTR_PTR(, checksum),
1322         BTRFS_ATTR_PTR(, exclusive_operation),
1323         BTRFS_ATTR_PTR(, generation),
1324         BTRFS_ATTR_PTR(, read_policy),
1325         BTRFS_ATTR_PTR(, bg_reclaim_threshold),
1326         BTRFS_ATTR_PTR(, commit_stats),
1327         BTRFS_ATTR_PTR(, temp_fsid),
1328         NULL,
1329 };
1330
1331 static void btrfs_release_fsid_kobj(struct kobject *kobj)
1332 {
1333         struct btrfs_fs_devices *fs_devs = to_fs_devs(kobj);
1334
1335         memset(&fs_devs->fsid_kobj, 0, sizeof(struct kobject));
1336         complete(&fs_devs->kobj_unregister);
1337 }
1338
1339 static const struct kobj_type btrfs_ktype = {
1340         .sysfs_ops      = &kobj_sysfs_ops,
1341         .release        = btrfs_release_fsid_kobj,
1342 };
1343
1344 static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj)
1345 {
1346         if (kobj->ktype != &btrfs_ktype)
1347                 return NULL;
1348         return container_of(kobj, struct btrfs_fs_devices, fsid_kobj);
1349 }
1350
1351 static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj)
1352 {
1353         if (kobj->ktype != &btrfs_ktype)
1354                 return NULL;
1355         return to_fs_devs(kobj)->fs_info;
1356 }
1357
1358 static struct kobject *get_btrfs_kobj(struct kobject *kobj)
1359 {
1360         while (kobj) {
1361                 if (kobj->ktype == &btrfs_ktype)
1362                         return kobj;
1363                 kobj = kobj->parent;
1364         }
1365         return NULL;
1366 }
1367
1368 #define NUM_FEATURE_BITS 64
1369 #define BTRFS_FEATURE_NAME_MAX 13
1370 static char btrfs_unknown_feature_names[FEAT_MAX][NUM_FEATURE_BITS][BTRFS_FEATURE_NAME_MAX];
1371 static struct btrfs_feature_attr btrfs_feature_attrs[FEAT_MAX][NUM_FEATURE_BITS];
1372
1373 static_assert(ARRAY_SIZE(btrfs_unknown_feature_names) ==
1374               ARRAY_SIZE(btrfs_feature_attrs));
1375 static_assert(ARRAY_SIZE(btrfs_unknown_feature_names[0]) ==
1376               ARRAY_SIZE(btrfs_feature_attrs[0]));
1377
1378 static const u64 supported_feature_masks[FEAT_MAX] = {
1379         [FEAT_COMPAT]    = BTRFS_FEATURE_COMPAT_SUPP,
1380         [FEAT_COMPAT_RO] = BTRFS_FEATURE_COMPAT_RO_SUPP,
1381         [FEAT_INCOMPAT]  = BTRFS_FEATURE_INCOMPAT_SUPP,
1382 };
1383
1384 static int addrm_unknown_feature_attrs(struct btrfs_fs_info *fs_info, bool add)
1385 {
1386         int set;
1387
1388         for (set = 0; set < FEAT_MAX; set++) {
1389                 int i;
1390                 struct attribute *attrs[2];
1391                 struct attribute_group agroup = {
1392                         .name = "features",
1393                         .attrs = attrs,
1394                 };
1395                 u64 features = get_features(fs_info, set);
1396                 features &= ~supported_feature_masks[set];
1397
1398                 if (!features)
1399                         continue;
1400
1401                 attrs[1] = NULL;
1402                 for (i = 0; i < NUM_FEATURE_BITS; i++) {
1403                         struct btrfs_feature_attr *fa;
1404
1405                         if (!(features & (1ULL << i)))
1406                                 continue;
1407
1408                         fa = &btrfs_feature_attrs[set][i];
1409                         attrs[0] = &fa->kobj_attr.attr;
1410                         if (add) {
1411                                 int ret;
1412                                 ret = sysfs_merge_group(&fs_info->fs_devices->fsid_kobj,
1413                                                         &agroup);
1414                                 if (ret)
1415                                         return ret;
1416                         } else
1417                                 sysfs_unmerge_group(&fs_info->fs_devices->fsid_kobj,
1418                                                     &agroup);
1419                 }
1420
1421         }
1422         return 0;
1423 }
1424
1425 static void __btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs)
1426 {
1427         if (fs_devs->devinfo_kobj) {
1428                 kobject_del(fs_devs->devinfo_kobj);
1429                 kobject_put(fs_devs->devinfo_kobj);
1430                 fs_devs->devinfo_kobj = NULL;
1431         }
1432
1433         if (fs_devs->devices_kobj) {
1434                 kobject_del(fs_devs->devices_kobj);
1435                 kobject_put(fs_devs->devices_kobj);
1436                 fs_devs->devices_kobj = NULL;
1437         }
1438
1439         if (fs_devs->fsid_kobj.state_initialized) {
1440                 kobject_del(&fs_devs->fsid_kobj);
1441                 kobject_put(&fs_devs->fsid_kobj);
1442                 wait_for_completion(&fs_devs->kobj_unregister);
1443         }
1444 }
1445
1446 /* when fs_devs is NULL it will remove all fsid kobject */
1447 void btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs)
1448 {
1449         struct list_head *fs_uuids = btrfs_get_fs_uuids();
1450
1451         if (fs_devs) {
1452                 __btrfs_sysfs_remove_fsid(fs_devs);
1453                 return;
1454         }
1455
1456         list_for_each_entry(fs_devs, fs_uuids, fs_list) {
1457                 __btrfs_sysfs_remove_fsid(fs_devs);
1458         }
1459 }
1460
1461 static void btrfs_sysfs_remove_fs_devices(struct btrfs_fs_devices *fs_devices)
1462 {
1463         struct btrfs_device *device;
1464         struct btrfs_fs_devices *seed;
1465
1466         list_for_each_entry(device, &fs_devices->devices, dev_list)
1467                 btrfs_sysfs_remove_device(device);
1468
1469         list_for_each_entry(seed, &fs_devices->seed_list, seed_list) {
1470                 list_for_each_entry(device, &seed->devices, dev_list)
1471                         btrfs_sysfs_remove_device(device);
1472         }
1473 }
1474
1475 void btrfs_sysfs_remove_mounted(struct btrfs_fs_info *fs_info)
1476 {
1477         struct kobject *fsid_kobj = &fs_info->fs_devices->fsid_kobj;
1478
1479         sysfs_remove_link(fsid_kobj, "bdi");
1480
1481         if (fs_info->space_info_kobj) {
1482                 sysfs_remove_files(fs_info->space_info_kobj, allocation_attrs);
1483                 kobject_del(fs_info->space_info_kobj);
1484                 kobject_put(fs_info->space_info_kobj);
1485         }
1486         if (fs_info->discard_kobj) {
1487                 sysfs_remove_files(fs_info->discard_kobj, discard_attrs);
1488                 kobject_del(fs_info->discard_kobj);
1489                 kobject_put(fs_info->discard_kobj);
1490         }
1491 #ifdef CONFIG_BTRFS_DEBUG
1492         if (fs_info->debug_kobj) {
1493                 sysfs_remove_files(fs_info->debug_kobj, btrfs_debug_mount_attrs);
1494                 kobject_del(fs_info->debug_kobj);
1495                 kobject_put(fs_info->debug_kobj);
1496         }
1497 #endif
1498         addrm_unknown_feature_attrs(fs_info, false);
1499         sysfs_remove_group(fsid_kobj, &btrfs_feature_attr_group);
1500         sysfs_remove_files(fsid_kobj, btrfs_attrs);
1501         btrfs_sysfs_remove_fs_devices(fs_info->fs_devices);
1502 }
1503
1504 static const char * const btrfs_feature_set_names[FEAT_MAX] = {
1505         [FEAT_COMPAT]    = "compat",
1506         [FEAT_COMPAT_RO] = "compat_ro",
1507         [FEAT_INCOMPAT]  = "incompat",
1508 };
1509
1510 const char *btrfs_feature_set_name(enum btrfs_feature_set set)
1511 {
1512         return btrfs_feature_set_names[set];
1513 }
1514
1515 char *btrfs_printable_features(enum btrfs_feature_set set, u64 flags)
1516 {
1517         size_t bufsize = 4096; /* safe max, 64 names * 64 bytes */
1518         int len = 0;
1519         int i;
1520         char *str;
1521
1522         str = kmalloc(bufsize, GFP_KERNEL);
1523         if (!str)
1524                 return str;
1525
1526         for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
1527                 const char *name;
1528
1529                 if (!(flags & (1ULL << i)))
1530                         continue;
1531
1532                 name = btrfs_feature_attrs[set][i].kobj_attr.attr.name;
1533                 len += scnprintf(str + len, bufsize - len, "%s%s",
1534                                 len ? "," : "", name);
1535         }
1536
1537         return str;
1538 }
1539
1540 static void init_feature_attrs(void)
1541 {
1542         struct btrfs_feature_attr *fa;
1543         int set, i;
1544
1545         memset(btrfs_feature_attrs, 0, sizeof(btrfs_feature_attrs));
1546         memset(btrfs_unknown_feature_names, 0,
1547                sizeof(btrfs_unknown_feature_names));
1548
1549         for (i = 0; btrfs_supported_feature_attrs[i]; i++) {
1550                 struct btrfs_feature_attr *sfa;
1551                 struct attribute *a = btrfs_supported_feature_attrs[i];
1552                 int bit;
1553                 sfa = attr_to_btrfs_feature_attr(a);
1554                 bit = ilog2(sfa->feature_bit);
1555                 fa = &btrfs_feature_attrs[sfa->feature_set][bit];
1556
1557                 fa->kobj_attr.attr.name = sfa->kobj_attr.attr.name;
1558         }
1559
1560         for (set = 0; set < FEAT_MAX; set++) {
1561                 for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
1562                         char *name = btrfs_unknown_feature_names[set][i];
1563                         fa = &btrfs_feature_attrs[set][i];
1564
1565                         if (fa->kobj_attr.attr.name)
1566                                 continue;
1567
1568                         snprintf(name, BTRFS_FEATURE_NAME_MAX, "%s:%u",
1569                                  btrfs_feature_set_names[set], i);
1570
1571                         fa->kobj_attr.attr.name = name;
1572                         fa->kobj_attr.attr.mode = S_IRUGO;
1573                         fa->feature_set = set;
1574                         fa->feature_bit = 1ULL << i;
1575                 }
1576         }
1577 }
1578
1579 /*
1580  * Create a sysfs entry for a given block group type at path
1581  * /sys/fs/btrfs/UUID/allocation/data/TYPE
1582  */
1583 void btrfs_sysfs_add_block_group_type(struct btrfs_block_group *cache)
1584 {
1585         struct btrfs_fs_info *fs_info = cache->fs_info;
1586         struct btrfs_space_info *space_info = cache->space_info;
1587         struct raid_kobject *rkobj;
1588         const int index = btrfs_bg_flags_to_raid_index(cache->flags);
1589         unsigned int nofs_flag;
1590         int ret;
1591
1592         /*
1593          * Setup a NOFS context because kobject_add(), deep in its call chain,
1594          * does GFP_KERNEL allocations, and we are often called in a context
1595          * where if reclaim is triggered we can deadlock (we are either holding
1596          * a transaction handle or some lock required for a transaction
1597          * commit).
1598          */
1599         nofs_flag = memalloc_nofs_save();
1600
1601         rkobj = kzalloc(sizeof(*rkobj), GFP_NOFS);
1602         if (!rkobj) {
1603                 memalloc_nofs_restore(nofs_flag);
1604                 btrfs_warn(cache->fs_info,
1605                                 "couldn't alloc memory for raid level kobject");
1606                 return;
1607         }
1608
1609         rkobj->flags = cache->flags;
1610         kobject_init(&rkobj->kobj, &btrfs_raid_ktype);
1611
1612         /*
1613          * We call this either on mount, or if we've created a block group for a
1614          * new index type while running (i.e. when restriping).  The running
1615          * case is tricky because we could race with other threads, so we need
1616          * to have this check to make sure we didn't already init the kobject.
1617          *
1618          * We don't have to protect on the free side because it only happens on
1619          * unmount.
1620          */
1621         spin_lock(&space_info->lock);
1622         if (space_info->block_group_kobjs[index]) {
1623                 spin_unlock(&space_info->lock);
1624                 kobject_put(&rkobj->kobj);
1625                 return;
1626         } else {
1627                 space_info->block_group_kobjs[index] = &rkobj->kobj;
1628         }
1629         spin_unlock(&space_info->lock);
1630
1631         ret = kobject_add(&rkobj->kobj, &space_info->kobj, "%s",
1632                           btrfs_bg_type_to_raid_name(rkobj->flags));
1633         memalloc_nofs_restore(nofs_flag);
1634         if (ret) {
1635                 spin_lock(&space_info->lock);
1636                 space_info->block_group_kobjs[index] = NULL;
1637                 spin_unlock(&space_info->lock);
1638                 kobject_put(&rkobj->kobj);
1639                 btrfs_warn(fs_info,
1640                         "failed to add kobject for block cache, ignoring");
1641                 return;
1642         }
1643 }
1644
1645 /*
1646  * Remove sysfs directories for all block group types of a given space info and
1647  * the space info as well
1648  */
1649 void btrfs_sysfs_remove_space_info(struct btrfs_space_info *space_info)
1650 {
1651         int i;
1652
1653         for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) {
1654                 struct kobject *kobj;
1655
1656                 kobj = space_info->block_group_kobjs[i];
1657                 space_info->block_group_kobjs[i] = NULL;
1658                 if (kobj) {
1659                         kobject_del(kobj);
1660                         kobject_put(kobj);
1661                 }
1662         }
1663         kobject_del(&space_info->kobj);
1664         kobject_put(&space_info->kobj);
1665 }
1666
1667 static const char *alloc_name(u64 flags)
1668 {
1669         switch (flags) {
1670         case BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA:
1671                 return "mixed";
1672         case BTRFS_BLOCK_GROUP_METADATA:
1673                 return "metadata";
1674         case BTRFS_BLOCK_GROUP_DATA:
1675                 return "data";
1676         case BTRFS_BLOCK_GROUP_SYSTEM:
1677                 return "system";
1678         default:
1679                 WARN_ON(1);
1680                 return "invalid-combination";
1681         }
1682 }
1683
1684 /*
1685  * Create a sysfs entry for a space info type at path
1686  * /sys/fs/btrfs/UUID/allocation/TYPE
1687  */
1688 int btrfs_sysfs_add_space_info_type(struct btrfs_fs_info *fs_info,
1689                                     struct btrfs_space_info *space_info)
1690 {
1691         int ret;
1692
1693         ret = kobject_init_and_add(&space_info->kobj, &space_info_ktype,
1694                                    fs_info->space_info_kobj, "%s",
1695                                    alloc_name(space_info->flags));
1696         if (ret) {
1697                 kobject_put(&space_info->kobj);
1698                 return ret;
1699         }
1700
1701         return 0;
1702 }
1703
1704 void btrfs_sysfs_remove_device(struct btrfs_device *device)
1705 {
1706         struct kobject *devices_kobj;
1707
1708         /*
1709          * Seed fs_devices devices_kobj aren't used, fetch kobject from the
1710          * fs_info::fs_devices.
1711          */
1712         devices_kobj = device->fs_info->fs_devices->devices_kobj;
1713         ASSERT(devices_kobj);
1714
1715         if (device->bdev)
1716                 sysfs_remove_link(devices_kobj, bdev_kobj(device->bdev)->name);
1717
1718         if (device->devid_kobj.state_initialized) {
1719                 kobject_del(&device->devid_kobj);
1720                 kobject_put(&device->devid_kobj);
1721                 wait_for_completion(&device->kobj_unregister);
1722         }
1723 }
1724
1725 static ssize_t btrfs_devinfo_in_fs_metadata_show(struct kobject *kobj,
1726                                                  struct kobj_attribute *a,
1727                                                  char *buf)
1728 {
1729         int val;
1730         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1731                                                    devid_kobj);
1732
1733         val = !!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state);
1734
1735         return sysfs_emit(buf, "%d\n", val);
1736 }
1737 BTRFS_ATTR(devid, in_fs_metadata, btrfs_devinfo_in_fs_metadata_show);
1738
1739 static ssize_t btrfs_devinfo_missing_show(struct kobject *kobj,
1740                                         struct kobj_attribute *a, char *buf)
1741 {
1742         int val;
1743         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1744                                                    devid_kobj);
1745
1746         val = !!test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state);
1747
1748         return sysfs_emit(buf, "%d\n", val);
1749 }
1750 BTRFS_ATTR(devid, missing, btrfs_devinfo_missing_show);
1751
1752 static ssize_t btrfs_devinfo_replace_target_show(struct kobject *kobj,
1753                                                  struct kobj_attribute *a,
1754                                                  char *buf)
1755 {
1756         int val;
1757         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1758                                                    devid_kobj);
1759
1760         val = !!test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state);
1761
1762         return sysfs_emit(buf, "%d\n", val);
1763 }
1764 BTRFS_ATTR(devid, replace_target, btrfs_devinfo_replace_target_show);
1765
1766 static ssize_t btrfs_devinfo_scrub_speed_max_show(struct kobject *kobj,
1767                                              struct kobj_attribute *a,
1768                                              char *buf)
1769 {
1770         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1771                                                    devid_kobj);
1772
1773         return sysfs_emit(buf, "%llu\n", READ_ONCE(device->scrub_speed_max));
1774 }
1775
1776 static ssize_t btrfs_devinfo_scrub_speed_max_store(struct kobject *kobj,
1777                                               struct kobj_attribute *a,
1778                                               const char *buf, size_t len)
1779 {
1780         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1781                                                    devid_kobj);
1782         char *endptr;
1783         unsigned long long limit;
1784
1785         limit = memparse(buf, &endptr);
1786         /* There could be trailing '\n', also catch any typos after the value. */
1787         endptr = skip_spaces(endptr);
1788         if (*endptr != 0)
1789                 return -EINVAL;
1790         WRITE_ONCE(device->scrub_speed_max, limit);
1791         return len;
1792 }
1793 BTRFS_ATTR_RW(devid, scrub_speed_max, btrfs_devinfo_scrub_speed_max_show,
1794               btrfs_devinfo_scrub_speed_max_store);
1795
1796 static ssize_t btrfs_devinfo_writeable_show(struct kobject *kobj,
1797                                             struct kobj_attribute *a, char *buf)
1798 {
1799         int val;
1800         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1801                                                    devid_kobj);
1802
1803         val = !!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state);
1804
1805         return sysfs_emit(buf, "%d\n", val);
1806 }
1807 BTRFS_ATTR(devid, writeable, btrfs_devinfo_writeable_show);
1808
1809 static ssize_t btrfs_devinfo_fsid_show(struct kobject *kobj,
1810                                        struct kobj_attribute *a, char *buf)
1811 {
1812         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1813                                                    devid_kobj);
1814
1815         return sysfs_emit(buf, "%pU\n", device->fs_devices->fsid);
1816 }
1817 BTRFS_ATTR(devid, fsid, btrfs_devinfo_fsid_show);
1818
1819 static ssize_t btrfs_devinfo_error_stats_show(struct kobject *kobj,
1820                 struct kobj_attribute *a, char *buf)
1821 {
1822         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1823                                                    devid_kobj);
1824
1825         if (!device->dev_stats_valid)
1826                 return sysfs_emit(buf, "invalid\n");
1827
1828         /*
1829          * Print all at once so we get a snapshot of all values from the same
1830          * time. Keep them in sync and in order of definition of
1831          * btrfs_dev_stat_values.
1832          */
1833         return sysfs_emit(buf,
1834                 "write_errs %d\n"
1835                 "read_errs %d\n"
1836                 "flush_errs %d\n"
1837                 "corruption_errs %d\n"
1838                 "generation_errs %d\n",
1839                 btrfs_dev_stat_read(device, BTRFS_DEV_STAT_WRITE_ERRS),
1840                 btrfs_dev_stat_read(device, BTRFS_DEV_STAT_READ_ERRS),
1841                 btrfs_dev_stat_read(device, BTRFS_DEV_STAT_FLUSH_ERRS),
1842                 btrfs_dev_stat_read(device, BTRFS_DEV_STAT_CORRUPTION_ERRS),
1843                 btrfs_dev_stat_read(device, BTRFS_DEV_STAT_GENERATION_ERRS));
1844 }
1845 BTRFS_ATTR(devid, error_stats, btrfs_devinfo_error_stats_show);
1846
1847 /*
1848  * Information about one device.
1849  *
1850  * Path: /sys/fs/btrfs/<uuid>/devinfo/<devid>/
1851  */
1852 static struct attribute *devid_attrs[] = {
1853         BTRFS_ATTR_PTR(devid, error_stats),
1854         BTRFS_ATTR_PTR(devid, fsid),
1855         BTRFS_ATTR_PTR(devid, in_fs_metadata),
1856         BTRFS_ATTR_PTR(devid, missing),
1857         BTRFS_ATTR_PTR(devid, replace_target),
1858         BTRFS_ATTR_PTR(devid, scrub_speed_max),
1859         BTRFS_ATTR_PTR(devid, writeable),
1860         NULL
1861 };
1862 ATTRIBUTE_GROUPS(devid);
1863
1864 static void btrfs_release_devid_kobj(struct kobject *kobj)
1865 {
1866         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1867                                                    devid_kobj);
1868
1869         memset(&device->devid_kobj, 0, sizeof(struct kobject));
1870         complete(&device->kobj_unregister);
1871 }
1872
1873 static const struct kobj_type devid_ktype = {
1874         .sysfs_ops      = &kobj_sysfs_ops,
1875         .default_groups = devid_groups,
1876         .release        = btrfs_release_devid_kobj,
1877 };
1878
1879 int btrfs_sysfs_add_device(struct btrfs_device *device)
1880 {
1881         int ret;
1882         unsigned int nofs_flag;
1883         struct kobject *devices_kobj;
1884         struct kobject *devinfo_kobj;
1885
1886         /*
1887          * Make sure we use the fs_info::fs_devices to fetch the kobjects even
1888          * for the seed fs_devices
1889          */
1890         devices_kobj = device->fs_info->fs_devices->devices_kobj;
1891         devinfo_kobj = device->fs_info->fs_devices->devinfo_kobj;
1892         ASSERT(devices_kobj);
1893         ASSERT(devinfo_kobj);
1894
1895         nofs_flag = memalloc_nofs_save();
1896
1897         if (device->bdev) {
1898                 struct kobject *disk_kobj = bdev_kobj(device->bdev);
1899
1900                 ret = sysfs_create_link(devices_kobj, disk_kobj, disk_kobj->name);
1901                 if (ret) {
1902                         btrfs_warn(device->fs_info,
1903                                 "creating sysfs device link for devid %llu failed: %d",
1904                                 device->devid, ret);
1905                         goto out;
1906                 }
1907         }
1908
1909         init_completion(&device->kobj_unregister);
1910         ret = kobject_init_and_add(&device->devid_kobj, &devid_ktype,
1911                                    devinfo_kobj, "%llu", device->devid);
1912         if (ret) {
1913                 kobject_put(&device->devid_kobj);
1914                 btrfs_warn(device->fs_info,
1915                            "devinfo init for devid %llu failed: %d",
1916                            device->devid, ret);
1917         }
1918
1919 out:
1920         memalloc_nofs_restore(nofs_flag);
1921         return ret;
1922 }
1923
1924 static int btrfs_sysfs_add_fs_devices(struct btrfs_fs_devices *fs_devices)
1925 {
1926         int ret;
1927         struct btrfs_device *device;
1928         struct btrfs_fs_devices *seed;
1929
1930         list_for_each_entry(device, &fs_devices->devices, dev_list) {
1931                 ret = btrfs_sysfs_add_device(device);
1932                 if (ret)
1933                         goto fail;
1934         }
1935
1936         list_for_each_entry(seed, &fs_devices->seed_list, seed_list) {
1937                 list_for_each_entry(device, &seed->devices, dev_list) {
1938                         ret = btrfs_sysfs_add_device(device);
1939                         if (ret)
1940                                 goto fail;
1941                 }
1942         }
1943
1944         return 0;
1945
1946 fail:
1947         btrfs_sysfs_remove_fs_devices(fs_devices);
1948         return ret;
1949 }
1950
1951 void btrfs_kobject_uevent(struct block_device *bdev, enum kobject_action action)
1952 {
1953         int ret;
1954
1955         ret = kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, action);
1956         if (ret)
1957                 pr_warn("BTRFS: Sending event '%d' to kobject: '%s' (%p): failed\n",
1958                         action, kobject_name(&disk_to_dev(bdev->bd_disk)->kobj),
1959                         &disk_to_dev(bdev->bd_disk)->kobj);
1960 }
1961
1962 void btrfs_sysfs_update_sprout_fsid(struct btrfs_fs_devices *fs_devices)
1963
1964 {
1965         char fsid_buf[BTRFS_UUID_UNPARSED_SIZE];
1966
1967         /*
1968          * Sprouting changes fsid of the mounted filesystem, rename the fsid
1969          * directory
1970          */
1971         snprintf(fsid_buf, BTRFS_UUID_UNPARSED_SIZE, "%pU", fs_devices->fsid);
1972         if (kobject_rename(&fs_devices->fsid_kobj, fsid_buf))
1973                 btrfs_warn(fs_devices->fs_info,
1974                                 "sysfs: failed to create fsid for sprout");
1975 }
1976
1977 void btrfs_sysfs_update_devid(struct btrfs_device *device)
1978 {
1979         char tmp[24];
1980
1981         snprintf(tmp, sizeof(tmp), "%llu", device->devid);
1982
1983         if (kobject_rename(&device->devid_kobj, tmp))
1984                 btrfs_warn(device->fs_devices->fs_info,
1985                            "sysfs: failed to update devid for %llu",
1986                            device->devid);
1987 }
1988
1989 /* /sys/fs/btrfs/ entry */
1990 static struct kset *btrfs_kset;
1991
1992 /*
1993  * Creates:
1994  *              /sys/fs/btrfs/UUID
1995  *
1996  * Can be called by the device discovery thread.
1997  */
1998 int btrfs_sysfs_add_fsid(struct btrfs_fs_devices *fs_devs)
1999 {
2000         int error;
2001
2002         init_completion(&fs_devs->kobj_unregister);
2003         fs_devs->fsid_kobj.kset = btrfs_kset;
2004         error = kobject_init_and_add(&fs_devs->fsid_kobj, &btrfs_ktype, NULL,
2005                                      "%pU", fs_devs->fsid);
2006         if (error) {
2007                 kobject_put(&fs_devs->fsid_kobj);
2008                 return error;
2009         }
2010
2011         fs_devs->devices_kobj = kobject_create_and_add("devices",
2012                                                        &fs_devs->fsid_kobj);
2013         if (!fs_devs->devices_kobj) {
2014                 btrfs_err(fs_devs->fs_info,
2015                           "failed to init sysfs device interface");
2016                 btrfs_sysfs_remove_fsid(fs_devs);
2017                 return -ENOMEM;
2018         }
2019
2020         fs_devs->devinfo_kobj = kobject_create_and_add("devinfo",
2021                                                        &fs_devs->fsid_kobj);
2022         if (!fs_devs->devinfo_kobj) {
2023                 btrfs_err(fs_devs->fs_info,
2024                           "failed to init sysfs devinfo kobject");
2025                 btrfs_sysfs_remove_fsid(fs_devs);
2026                 return -ENOMEM;
2027         }
2028
2029         return 0;
2030 }
2031
2032 int btrfs_sysfs_add_mounted(struct btrfs_fs_info *fs_info)
2033 {
2034         int error;
2035         struct btrfs_fs_devices *fs_devs = fs_info->fs_devices;
2036         struct kobject *fsid_kobj = &fs_devs->fsid_kobj;
2037
2038         error = btrfs_sysfs_add_fs_devices(fs_devs);
2039         if (error)
2040                 return error;
2041
2042         error = sysfs_create_files(fsid_kobj, btrfs_attrs);
2043         if (error) {
2044                 btrfs_sysfs_remove_fs_devices(fs_devs);
2045                 return error;
2046         }
2047
2048         error = sysfs_create_group(fsid_kobj,
2049                                    &btrfs_feature_attr_group);
2050         if (error)
2051                 goto failure;
2052
2053 #ifdef CONFIG_BTRFS_DEBUG
2054         fs_info->debug_kobj = kobject_create_and_add("debug", fsid_kobj);
2055         if (!fs_info->debug_kobj) {
2056                 error = -ENOMEM;
2057                 goto failure;
2058         }
2059
2060         error = sysfs_create_files(fs_info->debug_kobj, btrfs_debug_mount_attrs);
2061         if (error)
2062                 goto failure;
2063 #endif
2064
2065         /* Discard directory */
2066         fs_info->discard_kobj = kobject_create_and_add("discard", fsid_kobj);
2067         if (!fs_info->discard_kobj) {
2068                 error = -ENOMEM;
2069                 goto failure;
2070         }
2071
2072         error = sysfs_create_files(fs_info->discard_kobj, discard_attrs);
2073         if (error)
2074                 goto failure;
2075
2076         error = addrm_unknown_feature_attrs(fs_info, true);
2077         if (error)
2078                 goto failure;
2079
2080         error = sysfs_create_link(fsid_kobj, &fs_info->sb->s_bdi->dev->kobj, "bdi");
2081         if (error)
2082                 goto failure;
2083
2084         fs_info->space_info_kobj = kobject_create_and_add("allocation",
2085                                                   fsid_kobj);
2086         if (!fs_info->space_info_kobj) {
2087                 error = -ENOMEM;
2088                 goto failure;
2089         }
2090
2091         error = sysfs_create_files(fs_info->space_info_kobj, allocation_attrs);
2092         if (error)
2093                 goto failure;
2094
2095         return 0;
2096 failure:
2097         btrfs_sysfs_remove_mounted(fs_info);
2098         return error;
2099 }
2100
2101 static ssize_t qgroup_enabled_show(struct kobject *qgroups_kobj,
2102                                    struct kobj_attribute *a,
2103                                    char *buf)
2104 {
2105         struct btrfs_fs_info *fs_info = to_fs_info(qgroups_kobj->parent);
2106         bool enabled;
2107
2108         spin_lock(&fs_info->qgroup_lock);
2109         enabled = fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_ON;
2110         spin_unlock(&fs_info->qgroup_lock);
2111
2112         return sysfs_emit(buf, "%d\n", enabled);
2113 }
2114 BTRFS_ATTR(qgroups, enabled, qgroup_enabled_show);
2115
2116 static ssize_t qgroup_mode_show(struct kobject *qgroups_kobj,
2117                                 struct kobj_attribute *a,
2118                                 char *buf)
2119 {
2120         struct btrfs_fs_info *fs_info = to_fs_info(qgroups_kobj->parent);
2121         ssize_t ret = 0;
2122
2123         spin_lock(&fs_info->qgroup_lock);
2124         ASSERT(btrfs_qgroup_enabled(fs_info));
2125         switch (btrfs_qgroup_mode(fs_info)) {
2126         case BTRFS_QGROUP_MODE_FULL:
2127                 ret = sysfs_emit(buf, "qgroup\n");
2128                 break;
2129         case BTRFS_QGROUP_MODE_SIMPLE:
2130                 ret = sysfs_emit(buf, "squota\n");
2131                 break;
2132         default:
2133                 btrfs_warn(fs_info, "unexpected qgroup mode %d\n",
2134                            btrfs_qgroup_mode(fs_info));
2135                 break;
2136         }
2137         spin_unlock(&fs_info->qgroup_lock);
2138
2139         return ret;
2140 }
2141 BTRFS_ATTR(qgroups, mode, qgroup_mode_show);
2142
2143 static ssize_t qgroup_inconsistent_show(struct kobject *qgroups_kobj,
2144                                         struct kobj_attribute *a,
2145                                         char *buf)
2146 {
2147         struct btrfs_fs_info *fs_info = to_fs_info(qgroups_kobj->parent);
2148         bool inconsistent;
2149
2150         spin_lock(&fs_info->qgroup_lock);
2151         inconsistent = (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT);
2152         spin_unlock(&fs_info->qgroup_lock);
2153
2154         return sysfs_emit(buf, "%d\n", inconsistent);
2155 }
2156 BTRFS_ATTR(qgroups, inconsistent, qgroup_inconsistent_show);
2157
2158 static ssize_t qgroup_drop_subtree_thres_show(struct kobject *qgroups_kobj,
2159                                               struct kobj_attribute *a,
2160                                               char *buf)
2161 {
2162         struct btrfs_fs_info *fs_info = to_fs_info(qgroups_kobj->parent);
2163         u8 result;
2164
2165         spin_lock(&fs_info->qgroup_lock);
2166         result = fs_info->qgroup_drop_subtree_thres;
2167         spin_unlock(&fs_info->qgroup_lock);
2168
2169         return sysfs_emit(buf, "%d\n", result);
2170 }
2171
2172 static ssize_t qgroup_drop_subtree_thres_store(struct kobject *qgroups_kobj,
2173                                                struct kobj_attribute *a,
2174                                                const char *buf, size_t len)
2175 {
2176         struct btrfs_fs_info *fs_info = to_fs_info(qgroups_kobj->parent);
2177         u8 new_thres;
2178         int ret;
2179
2180         ret = kstrtou8(buf, 10, &new_thres);
2181         if (ret)
2182                 return -EINVAL;
2183
2184         if (new_thres > BTRFS_MAX_LEVEL)
2185                 return -EINVAL;
2186
2187         spin_lock(&fs_info->qgroup_lock);
2188         fs_info->qgroup_drop_subtree_thres = new_thres;
2189         spin_unlock(&fs_info->qgroup_lock);
2190
2191         return len;
2192 }
2193 BTRFS_ATTR_RW(qgroups, drop_subtree_threshold, qgroup_drop_subtree_thres_show,
2194               qgroup_drop_subtree_thres_store);
2195
2196 /*
2197  * Qgroups global info
2198  *
2199  * Path: /sys/fs/btrfs/<uuid>/qgroups/
2200  */
2201 static struct attribute *qgroups_attrs[] = {
2202         BTRFS_ATTR_PTR(qgroups, enabled),
2203         BTRFS_ATTR_PTR(qgroups, inconsistent),
2204         BTRFS_ATTR_PTR(qgroups, drop_subtree_threshold),
2205         BTRFS_ATTR_PTR(qgroups, mode),
2206         NULL
2207 };
2208 ATTRIBUTE_GROUPS(qgroups);
2209
2210 static void qgroups_release(struct kobject *kobj)
2211 {
2212         kfree(kobj);
2213 }
2214
2215 static const struct kobj_type qgroups_ktype = {
2216         .sysfs_ops = &kobj_sysfs_ops,
2217         .default_groups = qgroups_groups,
2218         .release = qgroups_release,
2219 };
2220
2221 static inline struct btrfs_fs_info *qgroup_kobj_to_fs_info(struct kobject *kobj)
2222 {
2223         return to_fs_info(kobj->parent->parent);
2224 }
2225
2226 #define QGROUP_ATTR(_member, _show_name)                                        \
2227 static ssize_t btrfs_qgroup_show_##_member(struct kobject *qgroup_kobj,         \
2228                                            struct kobj_attribute *a,            \
2229                                            char *buf)                           \
2230 {                                                                               \
2231         struct btrfs_fs_info *fs_info = qgroup_kobj_to_fs_info(qgroup_kobj);    \
2232         struct btrfs_qgroup *qgroup = container_of(qgroup_kobj,                 \
2233                         struct btrfs_qgroup, kobj);                             \
2234         return btrfs_show_u64(&qgroup->_member, &fs_info->qgroup_lock, buf);    \
2235 }                                                                               \
2236 BTRFS_ATTR(qgroup, _show_name, btrfs_qgroup_show_##_member)
2237
2238 #define QGROUP_RSV_ATTR(_name, _type)                                           \
2239 static ssize_t btrfs_qgroup_rsv_show_##_name(struct kobject *qgroup_kobj,       \
2240                                              struct kobj_attribute *a,          \
2241                                              char *buf)                         \
2242 {                                                                               \
2243         struct btrfs_fs_info *fs_info = qgroup_kobj_to_fs_info(qgroup_kobj);    \
2244         struct btrfs_qgroup *qgroup = container_of(qgroup_kobj,                 \
2245                         struct btrfs_qgroup, kobj);                             \
2246         return btrfs_show_u64(&qgroup->rsv.values[_type],                       \
2247                         &fs_info->qgroup_lock, buf);                            \
2248 }                                                                               \
2249 BTRFS_ATTR(qgroup, rsv_##_name, btrfs_qgroup_rsv_show_##_name)
2250
2251 QGROUP_ATTR(rfer, referenced);
2252 QGROUP_ATTR(excl, exclusive);
2253 QGROUP_ATTR(max_rfer, max_referenced);
2254 QGROUP_ATTR(max_excl, max_exclusive);
2255 QGROUP_ATTR(lim_flags, limit_flags);
2256 QGROUP_RSV_ATTR(data, BTRFS_QGROUP_RSV_DATA);
2257 QGROUP_RSV_ATTR(meta_pertrans, BTRFS_QGROUP_RSV_META_PERTRANS);
2258 QGROUP_RSV_ATTR(meta_prealloc, BTRFS_QGROUP_RSV_META_PREALLOC);
2259
2260 /*
2261  * Qgroup information.
2262  *
2263  * Path: /sys/fs/btrfs/<uuid>/qgroups/<level>_<qgroupid>/
2264  */
2265 static struct attribute *qgroup_attrs[] = {
2266         BTRFS_ATTR_PTR(qgroup, referenced),
2267         BTRFS_ATTR_PTR(qgroup, exclusive),
2268         BTRFS_ATTR_PTR(qgroup, max_referenced),
2269         BTRFS_ATTR_PTR(qgroup, max_exclusive),
2270         BTRFS_ATTR_PTR(qgroup, limit_flags),
2271         BTRFS_ATTR_PTR(qgroup, rsv_data),
2272         BTRFS_ATTR_PTR(qgroup, rsv_meta_pertrans),
2273         BTRFS_ATTR_PTR(qgroup, rsv_meta_prealloc),
2274         NULL
2275 };
2276 ATTRIBUTE_GROUPS(qgroup);
2277
2278 static void qgroup_release(struct kobject *kobj)
2279 {
2280         struct btrfs_qgroup *qgroup = container_of(kobj, struct btrfs_qgroup, kobj);
2281
2282         memset(&qgroup->kobj, 0, sizeof(*kobj));
2283 }
2284
2285 static const struct kobj_type qgroup_ktype = {
2286         .sysfs_ops = &kobj_sysfs_ops,
2287         .release = qgroup_release,
2288         .default_groups = qgroup_groups,
2289 };
2290
2291 int btrfs_sysfs_add_one_qgroup(struct btrfs_fs_info *fs_info,
2292                                 struct btrfs_qgroup *qgroup)
2293 {
2294         struct kobject *qgroups_kobj = fs_info->qgroups_kobj;
2295         int ret;
2296
2297         if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
2298                 return 0;
2299         if (qgroup->kobj.state_initialized)
2300                 return 0;
2301         if (!qgroups_kobj)
2302                 return -EINVAL;
2303
2304         ret = kobject_init_and_add(&qgroup->kobj, &qgroup_ktype, qgroups_kobj,
2305                         "%hu_%llu", btrfs_qgroup_level(qgroup->qgroupid),
2306                         btrfs_qgroup_subvolid(qgroup->qgroupid));
2307         if (ret < 0)
2308                 kobject_put(&qgroup->kobj);
2309
2310         return ret;
2311 }
2312
2313 void btrfs_sysfs_del_qgroups(struct btrfs_fs_info *fs_info)
2314 {
2315         struct btrfs_qgroup *qgroup;
2316         struct btrfs_qgroup *next;
2317
2318         if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
2319                 return;
2320
2321         rbtree_postorder_for_each_entry_safe(qgroup, next,
2322                                              &fs_info->qgroup_tree, node)
2323                 btrfs_sysfs_del_one_qgroup(fs_info, qgroup);
2324         if (fs_info->qgroups_kobj) {
2325                 kobject_del(fs_info->qgroups_kobj);
2326                 kobject_put(fs_info->qgroups_kobj);
2327                 fs_info->qgroups_kobj = NULL;
2328         }
2329 }
2330
2331 /* Called when qgroups get initialized, thus there is no need for locking */
2332 int btrfs_sysfs_add_qgroups(struct btrfs_fs_info *fs_info)
2333 {
2334         struct kobject *fsid_kobj = &fs_info->fs_devices->fsid_kobj;
2335         struct btrfs_qgroup *qgroup;
2336         struct btrfs_qgroup *next;
2337         int ret = 0;
2338
2339         if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
2340                 return 0;
2341
2342         ASSERT(fsid_kobj);
2343         if (fs_info->qgroups_kobj)
2344                 return 0;
2345
2346         fs_info->qgroups_kobj = kzalloc(sizeof(struct kobject), GFP_KERNEL);
2347         if (!fs_info->qgroups_kobj)
2348                 return -ENOMEM;
2349
2350         ret = kobject_init_and_add(fs_info->qgroups_kobj, &qgroups_ktype,
2351                                    fsid_kobj, "qgroups");
2352         if (ret < 0)
2353                 goto out;
2354
2355         rbtree_postorder_for_each_entry_safe(qgroup, next,
2356                                              &fs_info->qgroup_tree, node) {
2357                 ret = btrfs_sysfs_add_one_qgroup(fs_info, qgroup);
2358                 if (ret < 0)
2359                         goto out;
2360         }
2361
2362 out:
2363         if (ret < 0)
2364                 btrfs_sysfs_del_qgroups(fs_info);
2365         return ret;
2366 }
2367
2368 void btrfs_sysfs_del_one_qgroup(struct btrfs_fs_info *fs_info,
2369                                 struct btrfs_qgroup *qgroup)
2370 {
2371         if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
2372                 return;
2373
2374         if (qgroup->kobj.state_initialized) {
2375                 kobject_del(&qgroup->kobj);
2376                 kobject_put(&qgroup->kobj);
2377         }
2378 }
2379
2380 /*
2381  * Change per-fs features in /sys/fs/btrfs/UUID/features to match current
2382  * values in superblock. Call after any changes to incompat/compat_ro flags
2383  */
2384 void btrfs_sysfs_feature_update(struct btrfs_fs_info *fs_info)
2385 {
2386         struct kobject *fsid_kobj;
2387         int ret;
2388
2389         if (!fs_info)
2390                 return;
2391
2392         fsid_kobj = &fs_info->fs_devices->fsid_kobj;
2393         if (!fsid_kobj->state_initialized)
2394                 return;
2395
2396         ret = sysfs_update_group(fsid_kobj, &btrfs_feature_attr_group);
2397         if (ret < 0)
2398                 btrfs_warn(fs_info,
2399                            "failed to update /sys/fs/btrfs/%pU/features: %d",
2400                            fs_info->fs_devices->fsid, ret);
2401 }
2402
2403 int __init btrfs_init_sysfs(void)
2404 {
2405         int ret;
2406
2407         btrfs_kset = kset_create_and_add("btrfs", NULL, fs_kobj);
2408         if (!btrfs_kset)
2409                 return -ENOMEM;
2410
2411         init_feature_attrs();
2412         ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
2413         if (ret)
2414                 goto out2;
2415         ret = sysfs_merge_group(&btrfs_kset->kobj,
2416                                 &btrfs_static_feature_attr_group);
2417         if (ret)
2418                 goto out_remove_group;
2419
2420 #ifdef CONFIG_BTRFS_DEBUG
2421         ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_debug_feature_attr_group);
2422         if (ret) {
2423                 sysfs_unmerge_group(&btrfs_kset->kobj,
2424                                     &btrfs_static_feature_attr_group);
2425                 goto out_remove_group;
2426         }
2427 #endif
2428
2429         return 0;
2430
2431 out_remove_group:
2432         sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
2433 out2:
2434         kset_unregister(btrfs_kset);
2435
2436         return ret;
2437 }
2438
2439 void __cold btrfs_exit_sysfs(void)
2440 {
2441         sysfs_unmerge_group(&btrfs_kset->kobj,
2442                             &btrfs_static_feature_attr_group);
2443         sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
2444 #ifdef CONFIG_BTRFS_DEBUG
2445         sysfs_remove_group(&btrfs_kset->kobj, &btrfs_debug_feature_attr_group);
2446 #endif
2447         kset_unregister(btrfs_kset);
2448 }