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