fs/btrfs/sysfs.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2007 Oracle.  All rights reserved.
   4  */
   5
   6 #include <linux/sched.h>
   7 #include <linux/sched/mm.h>
   8 #include <linux/slab.h>
   9 #include <linux/spinlock.h>
  10 #include <linux/completion.h>
  11 #include <linux/bug.h>
  12 #include <crypto/hash.h>
  13
  14 #include "ctree.h"
  15 #include "discard.h"
  16 #include "disk-io.h"
  17 #include "send.h"
  18 #include "transaction.h"
  19 #include "sysfs.h"
  20 #include "volumes.h"
  21 #include "space-info.h"
  22 #include "block-group.h"
  23 #include "qgroup.h"
  24
  25 struct btrfs_feature_attr {
  26         struct kobj_attribute kobj_attr;
  27         enum btrfs_feature_set feature_set;
  28         u64 feature_bit;
  29 };
  30
  31 /* For raid type sysfs entries */
  32 struct raid_kobject {
  33         u64 flags;
  34         struct kobject kobj;
  35 };
  36
  37 #define __INIT_KOBJ_ATTR(_name, _mode, _show, _store)                   \
  38 {                                                                       \
  39         .attr   = { .name = __stringify(_name), .mode = _mode },        \
  40         .show   = _show,                                                \
  41         .store  = _store,                                               \
  42 }
  43
  44 #define BTRFS_ATTR_RW(_prefix, _name, _show, _store)                    \
  45         static struct kobj_attribute btrfs_attr_##_prefix##_##_name =   \
  46                         __INIT_KOBJ_ATTR(_name, 0644, _show, _store)
  47
  48 #define BTRFS_ATTR(_prefix, _name, _show)                               \
  49         static struct kobj_attribute btrfs_attr_##_prefix##_##_name =   \
  50                         __INIT_KOBJ_ATTR(_name, 0444, _show, NULL)
  51
  52 #define BTRFS_ATTR_PTR(_prefix, _name)                                  \
  53         (&btrfs_attr_##_prefix##_##_name.attr)
  54
  55 #define BTRFS_FEAT_ATTR(_name, _feature_set, _feature_prefix, _feature_bit)  \
  56 static struct btrfs_feature_attr btrfs_attr_features_##_name = {             \
  57         .kobj_attr = __INIT_KOBJ_ATTR(_name, S_IRUGO,                        \
  58                                       btrfs_feature_attr_show,               \
  59                                       btrfs_feature_attr_store),             \
  60         .feature_set    = _feature_set,                                      \
  61         .feature_bit    = _feature_prefix ##_## _feature_bit,                \
  62 }
  63 #define BTRFS_FEAT_ATTR_PTR(_name)                                           \
  64         (&btrfs_attr_features_##_name.kobj_attr.attr)
  65
  66 #define BTRFS_FEAT_ATTR_COMPAT(name, feature) \
  67         BTRFS_FEAT_ATTR(name, FEAT_COMPAT, BTRFS_FEATURE_COMPAT, feature)
  68 #define BTRFS_FEAT_ATTR_COMPAT_RO(name, feature) \
  69         BTRFS_FEAT_ATTR(name, FEAT_COMPAT_RO, BTRFS_FEATURE_COMPAT_RO, feature)
  70 #define BTRFS_FEAT_ATTR_INCOMPAT(name, feature) \
  71         BTRFS_FEAT_ATTR(name, FEAT_INCOMPAT, BTRFS_FEATURE_INCOMPAT, feature)
  72
  73 static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj);
  74 static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj);
  75
  76 static struct btrfs_feature_attr *to_btrfs_feature_attr(struct kobj_attribute *a)
  77 {
  78         return container_of(a, struct btrfs_feature_attr, kobj_attr);
  79 }
  80
  81 static struct kobj_attribute *attr_to_btrfs_attr(struct attribute *attr)
  82 {
  83         return container_of(attr, struct kobj_attribute, attr);
  84 }
  85
  86 static struct btrfs_feature_attr *attr_to_btrfs_feature_attr(
  87                 struct attribute *attr)
  88 {
  89         return to_btrfs_feature_attr(attr_to_btrfs_attr(attr));
  90 }
  91
  92 static u64 get_features(struct btrfs_fs_info *fs_info,
  93                         enum btrfs_feature_set set)
  94 {
  95         struct btrfs_super_block *disk_super = fs_info->super_copy;
  96         if (set == FEAT_COMPAT)
  97                 return btrfs_super_compat_flags(disk_super);
  98         else if (set == FEAT_COMPAT_RO)
  99                 return btrfs_super_compat_ro_flags(disk_super);
 100         else
 101                 return btrfs_super_incompat_flags(disk_super);
 102 }
 103
 104 static void set_features(struct btrfs_fs_info *fs_info,
 105                          enum btrfs_feature_set set, u64 features)
 106 {
 107         struct btrfs_super_block *disk_super = fs_info->super_copy;
 108         if (set == FEAT_COMPAT)
 109                 btrfs_set_super_compat_flags(disk_super, features);
 110         else if (set == FEAT_COMPAT_RO)
 111                 btrfs_set_super_compat_ro_flags(disk_super, features);
 112         else
 113                 btrfs_set_super_incompat_flags(disk_super, features);
 114 }
 115
 116 static int can_modify_feature(struct btrfs_feature_attr *fa)
 117 {
 118         int val = 0;
 119         u64 set, clear;
 120         switch (fa->feature_set) {
 121         case FEAT_COMPAT:
 122                 set = BTRFS_FEATURE_COMPAT_SAFE_SET;
 123                 clear = BTRFS_FEATURE_COMPAT_SAFE_CLEAR;
 124                 break;
 125         case FEAT_COMPAT_RO:
 126                 set = BTRFS_FEATURE_COMPAT_RO_SAFE_SET;
 127                 clear = BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR;
 128                 break;
 129         case FEAT_INCOMPAT:
 130                 set = BTRFS_FEATURE_INCOMPAT_SAFE_SET;
 131                 clear = BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR;
 132                 break;
 133         default:
 134                 pr_warn("btrfs: sysfs: unknown feature set %d\n",
 135                                 fa->feature_set);
 136                 return 0;
 137         }
 138
 139         if (set & fa->feature_bit)
 140                 val |= 1;
 141         if (clear & fa->feature_bit)
 142                 val |= 2;
 143
 144         return val;
 145 }
 146
 147 static ssize_t btrfs_feature_attr_show(struct kobject *kobj,
 148                                        struct kobj_attribute *a, char *buf)
 149 {
 150         int val = 0;
 151         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 152         struct btrfs_feature_attr *fa = to_btrfs_feature_attr(a);
 153         if (fs_info) {
 154                 u64 features = get_features(fs_info, fa->feature_set);
 155                 if (features & fa->feature_bit)
 156                         val = 1;
 157         } else
 158                 val = can_modify_feature(fa);
 159
 160         return scnprintf(buf, PAGE_SIZE, "%d\n", val);
 161 }
 162
 163 static ssize_t btrfs_feature_attr_store(struct kobject *kobj,
 164                                         struct kobj_attribute *a,
 165                                         const char *buf, size_t count)
 166 {
 167         struct btrfs_fs_info *fs_info;
 168         struct btrfs_feature_attr *fa = to_btrfs_feature_attr(a);
 169         u64 features, set, clear;
 170         unsigned long val;
 171         int ret;
 172
 173         fs_info = to_fs_info(kobj);
 174         if (!fs_info)
 175                 return -EPERM;
 176
 177         if (sb_rdonly(fs_info->sb))
 178                 return -EROFS;
 179
 180         ret = kstrtoul(skip_spaces(buf), 0, &val);
 181         if (ret)
 182                 return ret;
 183
 184         if (fa->feature_set == FEAT_COMPAT) {
 185                 set = BTRFS_FEATURE_COMPAT_SAFE_SET;
 186                 clear = BTRFS_FEATURE_COMPAT_SAFE_CLEAR;
 187         } else if (fa->feature_set == FEAT_COMPAT_RO) {
 188                 set = BTRFS_FEATURE_COMPAT_RO_SAFE_SET;
 189                 clear = BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR;
 190         } else {
 191                 set = BTRFS_FEATURE_INCOMPAT_SAFE_SET;
 192                 clear = BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR;
 193         }
 194
 195         features = get_features(fs_info, fa->feature_set);
 196
 197         /* Nothing to do */
 198         if ((val && (features & fa->feature_bit)) ||
 199             (!val && !(features & fa->feature_bit)))
 200                 return count;
 201
 202         if ((val && !(set & fa->feature_bit)) ||
 203             (!val && !(clear & fa->feature_bit))) {
 204                 btrfs_info(fs_info,
 205                         "%sabling feature %s on mounted fs is not supported.",
 206                         val ? "En" : "Dis", fa->kobj_attr.attr.name);
 207                 return -EPERM;
 208         }
 209
 210         btrfs_info(fs_info, "%s %s feature flag",
 211                    val ? "Setting" : "Clearing", fa->kobj_attr.attr.name);
 212
 213         spin_lock(&fs_info->super_lock);
 214         features = get_features(fs_info, fa->feature_set);
 215         if (val)
 216                 features |= fa->feature_bit;
 217         else
 218                 features &= ~fa->feature_bit;
 219         set_features(fs_info, fa->feature_set, features);
 220         spin_unlock(&fs_info->super_lock);
 221
 222         /*
 223          * We don't want to do full transaction commit from inside sysfs
 224          */
 225         btrfs_set_pending(fs_info, COMMIT);
 226         wake_up_process(fs_info->transaction_kthread);
 227
 228         return count;
 229 }
 230
 231 static umode_t btrfs_feature_visible(struct kobject *kobj,
 232                                      struct attribute *attr, int unused)
 233 {
 234         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 235         umode_t mode = attr->mode;
 236
 237         if (fs_info) {
 238                 struct btrfs_feature_attr *fa;
 239                 u64 features;
 240
 241                 fa = attr_to_btrfs_feature_attr(attr);
 242                 features = get_features(fs_info, fa->feature_set);
 243
 244                 if (can_modify_feature(fa))
 245                         mode |= S_IWUSR;
 246                 else if (!(features & fa->feature_bit))
 247                         mode = 0;
 248         }
 249
 250         return mode;
 251 }
 252
 253 BTRFS_FEAT_ATTR_INCOMPAT(mixed_backref, MIXED_BACKREF);
 254 BTRFS_FEAT_ATTR_INCOMPAT(default_subvol, DEFAULT_SUBVOL);
 255 BTRFS_FEAT_ATTR_INCOMPAT(mixed_groups, MIXED_GROUPS);
 256 BTRFS_FEAT_ATTR_INCOMPAT(compress_lzo, COMPRESS_LZO);
 257 BTRFS_FEAT_ATTR_INCOMPAT(compress_zstd, COMPRESS_ZSTD);
 258 BTRFS_FEAT_ATTR_INCOMPAT(big_metadata, BIG_METADATA);
 259 BTRFS_FEAT_ATTR_INCOMPAT(extended_iref, EXTENDED_IREF);
 260 BTRFS_FEAT_ATTR_INCOMPAT(raid56, RAID56);
 261 BTRFS_FEAT_ATTR_INCOMPAT(skinny_metadata, SKINNY_METADATA);
 262 BTRFS_FEAT_ATTR_INCOMPAT(no_holes, NO_HOLES);
 263 BTRFS_FEAT_ATTR_INCOMPAT(metadata_uuid, METADATA_UUID);
 264 BTRFS_FEAT_ATTR_COMPAT_RO(free_space_tree, FREE_SPACE_TREE);
 265 BTRFS_FEAT_ATTR_INCOMPAT(raid1c34, RAID1C34);
 266 /* Remove once support for zoned allocation is feature complete */
 267 #ifdef CONFIG_BTRFS_DEBUG
 268 BTRFS_FEAT_ATTR_INCOMPAT(zoned, ZONED);
 269 #endif
 270
 271 static struct attribute *btrfs_supported_feature_attrs[] = {
 272         BTRFS_FEAT_ATTR_PTR(mixed_backref),
 273         BTRFS_FEAT_ATTR_PTR(default_subvol),
 274         BTRFS_FEAT_ATTR_PTR(mixed_groups),
 275         BTRFS_FEAT_ATTR_PTR(compress_lzo),
 276         BTRFS_FEAT_ATTR_PTR(compress_zstd),
 277         BTRFS_FEAT_ATTR_PTR(big_metadata),
 278         BTRFS_FEAT_ATTR_PTR(extended_iref),
 279         BTRFS_FEAT_ATTR_PTR(raid56),
 280         BTRFS_FEAT_ATTR_PTR(skinny_metadata),
 281         BTRFS_FEAT_ATTR_PTR(no_holes),
 282         BTRFS_FEAT_ATTR_PTR(metadata_uuid),
 283         BTRFS_FEAT_ATTR_PTR(free_space_tree),
 284         BTRFS_FEAT_ATTR_PTR(raid1c34),
 285 #ifdef CONFIG_BTRFS_DEBUG
 286         BTRFS_FEAT_ATTR_PTR(zoned),
 287 #endif
 288         NULL
 289 };
 290
 291 /*
 292  * Features which depend on feature bits and may differ between each fs.
 293  *
 294  * /sys/fs/btrfs/features lists all available features of this kernel while
 295  * /sys/fs/btrfs/UUID/features shows features of the fs which are enabled or
 296  * can be changed online.
 297  */
 298 static const struct attribute_group btrfs_feature_attr_group = {
 299         .name = "features",
 300         .is_visible = btrfs_feature_visible,
 301         .attrs = btrfs_supported_feature_attrs,
 302 };
 303
 304 static ssize_t rmdir_subvol_show(struct kobject *kobj,
 305                                  struct kobj_attribute *ka, char *buf)
 306 {
 307         return scnprintf(buf, PAGE_SIZE, "0\n");
 308 }
 309 BTRFS_ATTR(static_feature, rmdir_subvol, rmdir_subvol_show);
 310
 311 static ssize_t supported_checksums_show(struct kobject *kobj,
 312                                         struct kobj_attribute *a, char *buf)
 313 {
 314         ssize_t ret = 0;
 315         int i;
 316
 317         for (i = 0; i < btrfs_get_num_csums(); i++) {
 318                 /*
 319                  * This "trick" only works as long as 'enum btrfs_csum_type' has
 320                  * no holes in it
 321                  */
 322                 ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%s",
 323                                 (i == 0 ? "" : " "), btrfs_super_csum_name(i));
 324
 325         }
 326
 327         ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
 328         return ret;
 329 }
 330 BTRFS_ATTR(static_feature, supported_checksums, supported_checksums_show);
 331
 332 static ssize_t send_stream_version_show(struct kobject *kobj,
 333                                         struct kobj_attribute *ka, char *buf)
 334 {
 335         return snprintf(buf, PAGE_SIZE, "%d\n", BTRFS_SEND_STREAM_VERSION);
 336 }
 337 BTRFS_ATTR(static_feature, send_stream_version, send_stream_version_show);
 338
 339 static const char *rescue_opts[] = {
 340         "usebackuproot",
 341         "nologreplay",
 342         "ignorebadroots",
 343         "ignoredatacsums",
 344         "all",
 345 };
 346
 347 static ssize_t supported_rescue_options_show(struct kobject *kobj,
 348                                              struct kobj_attribute *a,
 349                                              char *buf)
 350 {
 351         ssize_t ret = 0;
 352         int i;
 353
 354         for (i = 0; i < ARRAY_SIZE(rescue_opts); i++)
 355                 ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%s",
 356                                  (i ? " " : ""), rescue_opts[i]);
 357         ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
 358         return ret;
 359 }
 360 BTRFS_ATTR(static_feature, supported_rescue_options,
 361            supported_rescue_options_show);
 362
 363 static struct attribute *btrfs_supported_static_feature_attrs[] = {
 364         BTRFS_ATTR_PTR(static_feature, rmdir_subvol),
 365         BTRFS_ATTR_PTR(static_feature, supported_checksums),
 366         BTRFS_ATTR_PTR(static_feature, send_stream_version),
 367         BTRFS_ATTR_PTR(static_feature, supported_rescue_options),
 368         NULL
 369 };
 370
 371 /*
 372  * Features which only depend on kernel version.
 373  *
 374  * These are listed in /sys/fs/btrfs/features along with
 375  * btrfs_feature_attr_group
 376  */
 377 static const struct attribute_group btrfs_static_feature_attr_group = {
 378         .name = "features",
 379         .attrs = btrfs_supported_static_feature_attrs,
 380 };
 381
 382 #ifdef CONFIG_BTRFS_DEBUG
 383
 384 /*
 385  * Discard statistics and tunables
 386  */
 387 #define discard_to_fs_info(_kobj)       to_fs_info((_kobj)->parent->parent)
 388
 389 static ssize_t btrfs_discardable_bytes_show(struct kobject *kobj,
 390                                             struct kobj_attribute *a,
 391                                             char *buf)
 392 {
 393         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 394
 395         return scnprintf(buf, PAGE_SIZE, "%lld\n",
 396                         atomic64_read(&fs_info->discard_ctl.discardable_bytes));
 397 }
 398 BTRFS_ATTR(discard, discardable_bytes, btrfs_discardable_bytes_show);
 399
 400 static ssize_t btrfs_discardable_extents_show(struct kobject *kobj,
 401                                               struct kobj_attribute *a,
 402                                               char *buf)
 403 {
 404         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 405
 406         return scnprintf(buf, PAGE_SIZE, "%d\n",
 407                         atomic_read(&fs_info->discard_ctl.discardable_extents));
 408 }
 409 BTRFS_ATTR(discard, discardable_extents, btrfs_discardable_extents_show);
 410
 411 static ssize_t btrfs_discard_bitmap_bytes_show(struct kobject *kobj,
 412                                                struct kobj_attribute *a,
 413                                                char *buf)
 414 {
 415         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 416
 417         return scnprintf(buf, PAGE_SIZE, "%lld\n",
 418                         fs_info->discard_ctl.discard_bitmap_bytes);
 419 }
 420 BTRFS_ATTR(discard, discard_bitmap_bytes, btrfs_discard_bitmap_bytes_show);
 421
 422 static ssize_t btrfs_discard_bytes_saved_show(struct kobject *kobj,
 423                                               struct kobj_attribute *a,
 424                                               char *buf)
 425 {
 426         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 427
 428         return scnprintf(buf, PAGE_SIZE, "%lld\n",
 429                 atomic64_read(&fs_info->discard_ctl.discard_bytes_saved));
 430 }
 431 BTRFS_ATTR(discard, discard_bytes_saved, btrfs_discard_bytes_saved_show);
 432
 433 static ssize_t btrfs_discard_extent_bytes_show(struct kobject *kobj,
 434                                                struct kobj_attribute *a,
 435                                                char *buf)
 436 {
 437         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 438
 439         return scnprintf(buf, PAGE_SIZE, "%lld\n",
 440                         fs_info->discard_ctl.discard_extent_bytes);
 441 }
 442 BTRFS_ATTR(discard, discard_extent_bytes, btrfs_discard_extent_bytes_show);
 443
 444 static ssize_t btrfs_discard_iops_limit_show(struct kobject *kobj,
 445                                              struct kobj_attribute *a,
 446                                              char *buf)
 447 {
 448         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 449
 450         return scnprintf(buf, PAGE_SIZE, "%u\n",
 451                         READ_ONCE(fs_info->discard_ctl.iops_limit));
 452 }
 453
 454 static ssize_t btrfs_discard_iops_limit_store(struct kobject *kobj,
 455                                               struct kobj_attribute *a,
 456                                               const char *buf, size_t len)
 457 {
 458         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 459         struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
 460         u32 iops_limit;
 461         int ret;
 462
 463         ret = kstrtou32(buf, 10, &iops_limit);
 464         if (ret)
 465                 return -EINVAL;
 466
 467         WRITE_ONCE(discard_ctl->iops_limit, iops_limit);
 468         btrfs_discard_calc_delay(discard_ctl);
 469         btrfs_discard_schedule_work(discard_ctl, true);
 470         return len;
 471 }
 472 BTRFS_ATTR_RW(discard, iops_limit, btrfs_discard_iops_limit_show,
 473               btrfs_discard_iops_limit_store);
 474
 475 static ssize_t btrfs_discard_kbps_limit_show(struct kobject *kobj,
 476                                              struct kobj_attribute *a,
 477                                              char *buf)
 478 {
 479         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 480
 481         return scnprintf(buf, PAGE_SIZE, "%u\n",
 482                         READ_ONCE(fs_info->discard_ctl.kbps_limit));
 483 }
 484
 485 static ssize_t btrfs_discard_kbps_limit_store(struct kobject *kobj,
 486                                               struct kobj_attribute *a,
 487                                               const char *buf, size_t len)
 488 {
 489         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 490         struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
 491         u32 kbps_limit;
 492         int ret;
 493
 494         ret = kstrtou32(buf, 10, &kbps_limit);
 495         if (ret)
 496                 return -EINVAL;
 497
 498         WRITE_ONCE(discard_ctl->kbps_limit, kbps_limit);
 499         btrfs_discard_schedule_work(discard_ctl, true);
 500         return len;
 501 }
 502 BTRFS_ATTR_RW(discard, kbps_limit, btrfs_discard_kbps_limit_show,
 503               btrfs_discard_kbps_limit_store);
 504
 505 static ssize_t btrfs_discard_max_discard_size_show(struct kobject *kobj,
 506                                                    struct kobj_attribute *a,
 507                                                    char *buf)
 508 {
 509         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 510
 511         return scnprintf(buf, PAGE_SIZE, "%llu\n",
 512                         READ_ONCE(fs_info->discard_ctl.max_discard_size));
 513 }
 514
 515 static ssize_t btrfs_discard_max_discard_size_store(struct kobject *kobj,
 516                                                     struct kobj_attribute *a,
 517                                                     const char *buf, size_t len)
 518 {
 519         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 520         struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
 521         u64 max_discard_size;
 522         int ret;
 523
 524         ret = kstrtou64(buf, 10, &max_discard_size);
 525         if (ret)
 526                 return -EINVAL;
 527
 528         WRITE_ONCE(discard_ctl->max_discard_size, max_discard_size);
 529
 530         return len;
 531 }
 532 BTRFS_ATTR_RW(discard, max_discard_size, btrfs_discard_max_discard_size_show,
 533               btrfs_discard_max_discard_size_store);
 534
 535 static const struct attribute *discard_debug_attrs[] = {
 536         BTRFS_ATTR_PTR(discard, discardable_bytes),
 537         BTRFS_ATTR_PTR(discard, discardable_extents),
 538         BTRFS_ATTR_PTR(discard, discard_bitmap_bytes),
 539         BTRFS_ATTR_PTR(discard, discard_bytes_saved),
 540         BTRFS_ATTR_PTR(discard, discard_extent_bytes),
 541         BTRFS_ATTR_PTR(discard, iops_limit),
 542         BTRFS_ATTR_PTR(discard, kbps_limit),
 543         BTRFS_ATTR_PTR(discard, max_discard_size),
 544         NULL,
 545 };
 546
 547 /*
 548  * Runtime debugging exported via sysfs
 549  *
 550  * /sys/fs/btrfs/debug - applies to module or all filesystems
 551  * /sys/fs/btrfs/UUID  - applies only to the given filesystem
 552  */
 553 static const struct attribute *btrfs_debug_mount_attrs[] = {
 554         NULL,
 555 };
 556
 557 static struct attribute *btrfs_debug_feature_attrs[] = {
 558         NULL
 559 };
 560
 561 static const struct attribute_group btrfs_debug_feature_attr_group = {
 562         .name = "debug",
 563         .attrs = btrfs_debug_feature_attrs,
 564 };
 565
 566 #endif
 567
 568 static ssize_t btrfs_show_u64(u64 *value_ptr, spinlock_t *lock, char *buf)
 569 {
 570         u64 val;
 571         if (lock)
 572                 spin_lock(lock);
 573         val = *value_ptr;
 574         if (lock)
 575                 spin_unlock(lock);
 576         return scnprintf(buf, PAGE_SIZE, "%llu\n", val);
 577 }
 578
 579 static ssize_t global_rsv_size_show(struct kobject *kobj,
 580                                     struct kobj_attribute *ka, char *buf)
 581 {
 582         struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent);
 583         struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
 584         return btrfs_show_u64(&block_rsv->size, &block_rsv->lock, buf);
 585 }
 586 BTRFS_ATTR(allocation, global_rsv_size, global_rsv_size_show);
 587
 588 static ssize_t global_rsv_reserved_show(struct kobject *kobj,
 589                                         struct kobj_attribute *a, char *buf)
 590 {
 591         struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent);
 592         struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
 593         return btrfs_show_u64(&block_rsv->reserved, &block_rsv->lock, buf);
 594 }
 595 BTRFS_ATTR(allocation, global_rsv_reserved, global_rsv_reserved_show);
 596
 597 #define to_space_info(_kobj) container_of(_kobj, struct btrfs_space_info, kobj)
 598 #define to_raid_kobj(_kobj) container_of(_kobj, struct raid_kobject, kobj)
 599
 600 static ssize_t raid_bytes_show(struct kobject *kobj,
 601                                struct kobj_attribute *attr, char *buf);
 602 BTRFS_ATTR(raid, total_bytes, raid_bytes_show);
 603 BTRFS_ATTR(raid, used_bytes, raid_bytes_show);
 604
 605 static ssize_t raid_bytes_show(struct kobject *kobj,
 606                                struct kobj_attribute *attr, char *buf)
 607
 608 {
 609         struct btrfs_space_info *sinfo = to_space_info(kobj->parent);
 610         struct btrfs_block_group *block_group;
 611         int index = btrfs_bg_flags_to_raid_index(to_raid_kobj(kobj)->flags);
 612         u64 val = 0;
 613
 614         down_read(&sinfo->groups_sem);
 615         list_for_each_entry(block_group, &sinfo->block_groups[index], list) {
 616                 if (&attr->attr == BTRFS_ATTR_PTR(raid, total_bytes))
 617                         val += block_group->length;
 618                 else
 619                         val += block_group->used;
 620         }
 621         up_read(&sinfo->groups_sem);
 622         return scnprintf(buf, PAGE_SIZE, "%llu\n", val);
 623 }
 624
 625 static struct attribute *raid_attrs[] = {
 626         BTRFS_ATTR_PTR(raid, total_bytes),
 627         BTRFS_ATTR_PTR(raid, used_bytes),
 628         NULL
 629 };
 630 ATTRIBUTE_GROUPS(raid);
 631
 632 static void release_raid_kobj(struct kobject *kobj)
 633 {
 634         kfree(to_raid_kobj(kobj));
 635 }
 636
 637 static struct kobj_type btrfs_raid_ktype = {
 638         .sysfs_ops = &kobj_sysfs_ops,
 639         .release = release_raid_kobj,
 640         .default_groups = raid_groups,
 641 };
 642
 643 #define SPACE_INFO_ATTR(field)                                          \
 644 static ssize_t btrfs_space_info_show_##field(struct kobject *kobj,      \
 645                                              struct kobj_attribute *a,  \
 646                                              char *buf)                 \
 647 {                                                                       \
 648         struct btrfs_space_info *sinfo = to_space_info(kobj);           \
 649         return btrfs_show_u64(&sinfo->field, &sinfo->lock, buf);        \
 650 }                                                                       \
 651 BTRFS_ATTR(space_info, field, btrfs_space_info_show_##field)
 652
 653 static ssize_t btrfs_space_info_show_total_bytes_pinned(struct kobject *kobj,
 654                                                        struct kobj_attribute *a,
 655                                                        char *buf)
 656 {
 657         struct btrfs_space_info *sinfo = to_space_info(kobj);
 658         s64 val = percpu_counter_sum(&sinfo->total_bytes_pinned);
 659         return scnprintf(buf, PAGE_SIZE, "%lld\n", val);
 660 }
 661
 662 SPACE_INFO_ATTR(flags);
 663 SPACE_INFO_ATTR(total_bytes);
 664 SPACE_INFO_ATTR(bytes_used);
 665 SPACE_INFO_ATTR(bytes_pinned);
 666 SPACE_INFO_ATTR(bytes_reserved);
 667 SPACE_INFO_ATTR(bytes_may_use);
 668 SPACE_INFO_ATTR(bytes_readonly);
 669 SPACE_INFO_ATTR(disk_used);
 670 SPACE_INFO_ATTR(disk_total);
 671 BTRFS_ATTR(space_info, total_bytes_pinned,
 672            btrfs_space_info_show_total_bytes_pinned);
 673
 674 static struct attribute *space_info_attrs[] = {
 675         BTRFS_ATTR_PTR(space_info, flags),
 676         BTRFS_ATTR_PTR(space_info, total_bytes),
 677         BTRFS_ATTR_PTR(space_info, bytes_used),
 678         BTRFS_ATTR_PTR(space_info, bytes_pinned),
 679         BTRFS_ATTR_PTR(space_info, bytes_reserved),
 680         BTRFS_ATTR_PTR(space_info, bytes_may_use),
 681         BTRFS_ATTR_PTR(space_info, bytes_readonly),
 682         BTRFS_ATTR_PTR(space_info, disk_used),
 683         BTRFS_ATTR_PTR(space_info, disk_total),
 684         BTRFS_ATTR_PTR(space_info, total_bytes_pinned),
 685         NULL,
 686 };
 687 ATTRIBUTE_GROUPS(space_info);
 688
 689 static void space_info_release(struct kobject *kobj)
 690 {
 691         struct btrfs_space_info *sinfo = to_space_info(kobj);
 692         percpu_counter_destroy(&sinfo->total_bytes_pinned);
 693         kfree(sinfo);
 694 }
 695
 696 static struct kobj_type space_info_ktype = {
 697         .sysfs_ops = &kobj_sysfs_ops,
 698         .release = space_info_release,
 699         .default_groups = space_info_groups,
 700 };
 701
 702 static const struct attribute *allocation_attrs[] = {
 703         BTRFS_ATTR_PTR(allocation, global_rsv_reserved),
 704         BTRFS_ATTR_PTR(allocation, global_rsv_size),
 705         NULL,
 706 };
 707
 708 static ssize_t btrfs_label_show(struct kobject *kobj,
 709                                 struct kobj_attribute *a, char *buf)
 710 {
 711         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 712         char *label = fs_info->super_copy->label;
 713         ssize_t ret;
 714
 715         spin_lock(&fs_info->super_lock);
 716         ret = scnprintf(buf, PAGE_SIZE, label[0] ? "%s\n" : "%s", label);
 717         spin_unlock(&fs_info->super_lock);
 718
 719         return ret;
 720 }
 721
 722 static ssize_t btrfs_label_store(struct kobject *kobj,
 723                                  struct kobj_attribute *a,
 724                                  const char *buf, size_t len)
 725 {
 726         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 727         size_t p_len;
 728
 729         if (!fs_info)
 730                 return -EPERM;
 731
 732         if (sb_rdonly(fs_info->sb))
 733                 return -EROFS;
 734
 735         /*
 736          * p_len is the len until the first occurrence of either
 737          * '\n' or '\0'
 738          */
 739         p_len = strcspn(buf, "\n");
 740
 741         if (p_len >= BTRFS_LABEL_SIZE)
 742                 return -EINVAL;
 743
 744         spin_lock(&fs_info->super_lock);
 745         memset(fs_info->super_copy->label, 0, BTRFS_LABEL_SIZE);
 746         memcpy(fs_info->super_copy->label, buf, p_len);
 747         spin_unlock(&fs_info->super_lock);
 748
 749         /*
 750          * We don't want to do full transaction commit from inside sysfs
 751          */
 752         btrfs_set_pending(fs_info, COMMIT);
 753         wake_up_process(fs_info->transaction_kthread);
 754
 755         return len;
 756 }
 757 BTRFS_ATTR_RW(, label, btrfs_label_show, btrfs_label_store);
 758
 759 static ssize_t btrfs_nodesize_show(struct kobject *kobj,
 760                                 struct kobj_attribute *a, char *buf)
 761 {
 762         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 763
 764         return scnprintf(buf, PAGE_SIZE, "%u\n", fs_info->super_copy->nodesize);
 765 }
 766
 767 BTRFS_ATTR(, nodesize, btrfs_nodesize_show);
 768
 769 static ssize_t btrfs_sectorsize_show(struct kobject *kobj,
 770                                 struct kobj_attribute *a, char *buf)
 771 {
 772         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 773
 774         return scnprintf(buf, PAGE_SIZE, "%u\n",
 775                          fs_info->super_copy->sectorsize);
 776 }
 777
 778 BTRFS_ATTR(, sectorsize, btrfs_sectorsize_show);
 779
 780 static ssize_t btrfs_clone_alignment_show(struct kobject *kobj,
 781                                 struct kobj_attribute *a, char *buf)
 782 {
 783         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 784
 785         return scnprintf(buf, PAGE_SIZE, "%u\n", fs_info->super_copy->sectorsize);
 786 }
 787
 788 BTRFS_ATTR(, clone_alignment, btrfs_clone_alignment_show);
 789
 790 static ssize_t quota_override_show(struct kobject *kobj,
 791                                    struct kobj_attribute *a, char *buf)
 792 {
 793         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 794         int quota_override;
 795
 796         quota_override = test_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
 797         return scnprintf(buf, PAGE_SIZE, "%d\n", quota_override);
 798 }
 799
 800 static ssize_t quota_override_store(struct kobject *kobj,
 801                                     struct kobj_attribute *a,
 802                                     const char *buf, size_t len)
 803 {
 804         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 805         unsigned long knob;
 806         int err;
 807
 808         if (!fs_info)
 809                 return -EPERM;
 810
 811         if (!capable(CAP_SYS_RESOURCE))
 812                 return -EPERM;
 813
 814         err = kstrtoul(buf, 10, &knob);
 815         if (err)
 816                 return err;
 817         if (knob > 1)
 818                 return -EINVAL;
 819
 820         if (knob)
 821                 set_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
 822         else
 823                 clear_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
 824
 825         return len;
 826 }
 827
 828 BTRFS_ATTR_RW(, quota_override, quota_override_show, quota_override_store);
 829
 830 static ssize_t btrfs_metadata_uuid_show(struct kobject *kobj,
 831                                 struct kobj_attribute *a, char *buf)
 832 {
 833         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 834
 835         return scnprintf(buf, PAGE_SIZE, "%pU\n",
 836                         fs_info->fs_devices->metadata_uuid);
 837 }
 838
 839 BTRFS_ATTR(, metadata_uuid, btrfs_metadata_uuid_show);
 840
 841 static ssize_t btrfs_checksum_show(struct kobject *kobj,
 842                                    struct kobj_attribute *a, char *buf)
 843 {
 844         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 845         u16 csum_type = btrfs_super_csum_type(fs_info->super_copy);
 846
 847         return scnprintf(buf, PAGE_SIZE, "%s (%s)\n",
 848                         btrfs_super_csum_name(csum_type),
 849                         crypto_shash_driver_name(fs_info->csum_shash));
 850 }
 851
 852 BTRFS_ATTR(, checksum, btrfs_checksum_show);
 853
 854 static ssize_t btrfs_exclusive_operation_show(struct kobject *kobj,
 855                 struct kobj_attribute *a, char *buf)
 856 {
 857         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 858         const char *str;
 859
 860         switch (READ_ONCE(fs_info->exclusive_operation)) {
 861                 case  BTRFS_EXCLOP_NONE:
 862                         str = "none\n";
 863                         break;
 864                 case BTRFS_EXCLOP_BALANCE:
 865                         str = "balance\n";
 866                         break;
 867                 case BTRFS_EXCLOP_DEV_ADD:
 868                         str = "device add\n";
 869                         break;
 870                 case BTRFS_EXCLOP_DEV_REMOVE:
 871                         str = "device remove\n";
 872                         break;
 873                 case BTRFS_EXCLOP_DEV_REPLACE:
 874                         str = "device replace\n";
 875                         break;
 876                 case BTRFS_EXCLOP_RESIZE:
 877                         str = "resize\n";
 878                         break;
 879                 case BTRFS_EXCLOP_SWAP_ACTIVATE:
 880                         str = "swap activate\n";
 881                         break;
 882                 default:
 883                         str = "UNKNOWN\n";
 884                         break;
 885         }
 886         return scnprintf(buf, PAGE_SIZE, "%s", str);
 887 }
 888 BTRFS_ATTR(, exclusive_operation, btrfs_exclusive_operation_show);
 889
 890 static ssize_t btrfs_generation_show(struct kobject *kobj,
 891                                      struct kobj_attribute *a, char *buf)
 892 {
 893         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 894
 895         return scnprintf(buf, PAGE_SIZE, "%llu\n", fs_info->generation);
 896 }
 897 BTRFS_ATTR(, generation, btrfs_generation_show);
 898
 899 /*
 900  * Look for an exact string @string in @buffer with possible leading or
 901  * trailing whitespace
 902  */
 903 static bool strmatch(const char *buffer, const char *string)
 904 {
 905         const size_t len = strlen(string);
 906
 907         /* Skip leading whitespace */
 908         buffer = skip_spaces(buffer);
 909
 910         /* Match entire string, check if the rest is whitespace or empty */
 911         if (strncmp(string, buffer, len) == 0 &&
 912             strlen(skip_spaces(buffer + len)) == 0)
 913                 return true;
 914
 915         return false;
 916 }
 917
 918 static const char * const btrfs_read_policy_name[] = { "pid" };
 919
 920 static ssize_t btrfs_read_policy_show(struct kobject *kobj,
 921                                       struct kobj_attribute *a, char *buf)
 922 {
 923         struct btrfs_fs_devices *fs_devices = to_fs_devs(kobj);
 924         ssize_t ret = 0;
 925         int i;
 926
 927         for (i = 0; i < BTRFS_NR_READ_POLICY; i++) {
 928                 if (fs_devices->read_policy == i)
 929                         ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s[%s]",
 930                                          (ret == 0 ? "" : " "),
 931                                          btrfs_read_policy_name[i]);
 932                 else
 933                         ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%s",
 934                                          (ret == 0 ? "" : " "),
 935                                          btrfs_read_policy_name[i]);
 936         }
 937
 938         ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
 939
 940         return ret;
 941 }
 942
 943 static ssize_t btrfs_read_policy_store(struct kobject *kobj,
 944                                        struct kobj_attribute *a,
 945                                        const char *buf, size_t len)
 946 {
 947         struct btrfs_fs_devices *fs_devices = to_fs_devs(kobj);
 948         int i;
 949
 950         for (i = 0; i < BTRFS_NR_READ_POLICY; i++) {
 951                 if (strmatch(buf, btrfs_read_policy_name[i])) {
 952                         if (i != fs_devices->read_policy) {
 953                                 fs_devices->read_policy = i;
 954                                 btrfs_info(fs_devices->fs_info,
 955                                            "read policy set to '%s'",
 956                                            btrfs_read_policy_name[i]);
 957                         }
 958                         return len;
 959                 }
 960         }
 961
 962         return -EINVAL;
 963 }
 964 BTRFS_ATTR_RW(, read_policy, btrfs_read_policy_show, btrfs_read_policy_store);
 965
 966 static const struct attribute *btrfs_attrs[] = {
 967         BTRFS_ATTR_PTR(, label),
 968         BTRFS_ATTR_PTR(, nodesize),
 969         BTRFS_ATTR_PTR(, sectorsize),
 970         BTRFS_ATTR_PTR(, clone_alignment),
 971         BTRFS_ATTR_PTR(, quota_override),
 972         BTRFS_ATTR_PTR(, metadata_uuid),
 973         BTRFS_ATTR_PTR(, checksum),
 974         BTRFS_ATTR_PTR(, exclusive_operation),
 975         BTRFS_ATTR_PTR(, generation),
 976         BTRFS_ATTR_PTR(, read_policy),
 977         NULL,
 978 };
 979
 980 static void btrfs_release_fsid_kobj(struct kobject *kobj)
 981 {
 982         struct btrfs_fs_devices *fs_devs = to_fs_devs(kobj);
 983
 984         memset(&fs_devs->fsid_kobj, 0, sizeof(struct kobject));
 985         complete(&fs_devs->kobj_unregister);
 986 }
 987
 988 static struct kobj_type btrfs_ktype = {
 989         .sysfs_ops      = &kobj_sysfs_ops,
 990         .release        = btrfs_release_fsid_kobj,
 991 };
 992
 993 static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj)
 994 {
 995         if (kobj->ktype != &btrfs_ktype)
 996                 return NULL;
 997         return container_of(kobj, struct btrfs_fs_devices, fsid_kobj);
 998 }
 999
1000 static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj)
1001 {
1002         if (kobj->ktype != &btrfs_ktype)
1003                 return NULL;
1004         return to_fs_devs(kobj)->fs_info;
1005 }
1006
1007 #define NUM_FEATURE_BITS 64
1008 #define BTRFS_FEATURE_NAME_MAX 13
1009 static char btrfs_unknown_feature_names[FEAT_MAX][NUM_FEATURE_BITS][BTRFS_FEATURE_NAME_MAX];
1010 static struct btrfs_feature_attr btrfs_feature_attrs[FEAT_MAX][NUM_FEATURE_BITS];
1011
1012 static const u64 supported_feature_masks[FEAT_MAX] = {
1013         [FEAT_COMPAT]    = BTRFS_FEATURE_COMPAT_SUPP,
1014         [FEAT_COMPAT_RO] = BTRFS_FEATURE_COMPAT_RO_SUPP,
1015         [FEAT_INCOMPAT]  = BTRFS_FEATURE_INCOMPAT_SUPP,
1016 };
1017
1018 static int addrm_unknown_feature_attrs(struct btrfs_fs_info *fs_info, bool add)
1019 {
1020         int set;
1021
1022         for (set = 0; set < FEAT_MAX; set++) {
1023                 int i;
1024                 struct attribute *attrs[2];
1025                 struct attribute_group agroup = {
1026                         .name = "features",
1027                         .attrs = attrs,
1028                 };
1029                 u64 features = get_features(fs_info, set);
1030                 features &= ~supported_feature_masks[set];
1031
1032                 if (!features)
1033                         continue;
1034
1035                 attrs[1] = NULL;
1036                 for (i = 0; i < NUM_FEATURE_BITS; i++) {
1037                         struct btrfs_feature_attr *fa;
1038
1039                         if (!(features & (1ULL << i)))
1040                                 continue;
1041
1042                         fa = &btrfs_feature_attrs[set][i];
1043                         attrs[0] = &fa->kobj_attr.attr;
1044                         if (add) {
1045                                 int ret;
1046                                 ret = sysfs_merge_group(&fs_info->fs_devices->fsid_kobj,
1047                                                         &agroup);
1048                                 if (ret)
1049                                         return ret;
1050                         } else
1051                                 sysfs_unmerge_group(&fs_info->fs_devices->fsid_kobj,
1052                                                     &agroup);
1053                 }
1054
1055         }
1056         return 0;
1057 }
1058
1059 static void __btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs)
1060 {
1061         if (fs_devs->devinfo_kobj) {
1062                 kobject_del(fs_devs->devinfo_kobj);
1063                 kobject_put(fs_devs->devinfo_kobj);
1064                 fs_devs->devinfo_kobj = NULL;
1065         }
1066
1067         if (fs_devs->devices_kobj) {
1068                 kobject_del(fs_devs->devices_kobj);
1069                 kobject_put(fs_devs->devices_kobj);
1070                 fs_devs->devices_kobj = NULL;
1071         }
1072
1073         if (fs_devs->fsid_kobj.state_initialized) {
1074                 kobject_del(&fs_devs->fsid_kobj);
1075                 kobject_put(&fs_devs->fsid_kobj);
1076                 wait_for_completion(&fs_devs->kobj_unregister);
1077         }
1078 }
1079
1080 /* when fs_devs is NULL it will remove all fsid kobject */
1081 void btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs)
1082 {
1083         struct list_head *fs_uuids = btrfs_get_fs_uuids();
1084
1085         if (fs_devs) {
1086                 __btrfs_sysfs_remove_fsid(fs_devs);
1087                 return;
1088         }
1089
1090         list_for_each_entry(fs_devs, fs_uuids, fs_list) {
1091                 __btrfs_sysfs_remove_fsid(fs_devs);
1092         }
1093 }
1094
1095 static void btrfs_sysfs_remove_fs_devices(struct btrfs_fs_devices *fs_devices)
1096 {
1097         struct btrfs_device *device;
1098         struct btrfs_fs_devices *seed;
1099
1100         list_for_each_entry(device, &fs_devices->devices, dev_list)
1101                 btrfs_sysfs_remove_device(device);
1102
1103         list_for_each_entry(seed, &fs_devices->seed_list, seed_list) {
1104                 list_for_each_entry(device, &seed->devices, dev_list)
1105                         btrfs_sysfs_remove_device(device);
1106         }
1107 }
1108
1109 void btrfs_sysfs_remove_mounted(struct btrfs_fs_info *fs_info)
1110 {
1111         struct kobject *fsid_kobj = &fs_info->fs_devices->fsid_kobj;
1112
1113         sysfs_remove_link(fsid_kobj, "bdi");
1114
1115         if (fs_info->space_info_kobj) {
1116                 sysfs_remove_files(fs_info->space_info_kobj, allocation_attrs);
1117                 kobject_del(fs_info->space_info_kobj);
1118                 kobject_put(fs_info->space_info_kobj);
1119         }
1120 #ifdef CONFIG_BTRFS_DEBUG
1121         if (fs_info->discard_debug_kobj) {
1122                 sysfs_remove_files(fs_info->discard_debug_kobj,
1123                                    discard_debug_attrs);
1124                 kobject_del(fs_info->discard_debug_kobj);
1125                 kobject_put(fs_info->discard_debug_kobj);
1126         }
1127         if (fs_info->debug_kobj) {
1128                 sysfs_remove_files(fs_info->debug_kobj, btrfs_debug_mount_attrs);
1129                 kobject_del(fs_info->debug_kobj);
1130                 kobject_put(fs_info->debug_kobj);
1131         }
1132 #endif
1133         addrm_unknown_feature_attrs(fs_info, false);
1134         sysfs_remove_group(fsid_kobj, &btrfs_feature_attr_group);
1135         sysfs_remove_files(fsid_kobj, btrfs_attrs);
1136         btrfs_sysfs_remove_fs_devices(fs_info->fs_devices);
1137 }
1138
1139 static const char * const btrfs_feature_set_names[FEAT_MAX] = {
1140         [FEAT_COMPAT]    = "compat",
1141         [FEAT_COMPAT_RO] = "compat_ro",
1142         [FEAT_INCOMPAT]  = "incompat",
1143 };
1144
1145 const char *btrfs_feature_set_name(enum btrfs_feature_set set)
1146 {
1147         return btrfs_feature_set_names[set];
1148 }
1149
1150 char *btrfs_printable_features(enum btrfs_feature_set set, u64 flags)
1151 {
1152         size_t bufsize = 4096; /* safe max, 64 names * 64 bytes */
1153         int len = 0;
1154         int i;
1155         char *str;
1156
1157         str = kmalloc(bufsize, GFP_KERNEL);
1158         if (!str)
1159                 return str;
1160
1161         for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
1162                 const char *name;
1163
1164                 if (!(flags & (1ULL << i)))
1165                         continue;
1166
1167                 name = btrfs_feature_attrs[set][i].kobj_attr.attr.name;
1168                 len += scnprintf(str + len, bufsize - len, "%s%s",
1169                                 len ? "," : "", name);
1170         }
1171
1172         return str;
1173 }
1174
1175 static void init_feature_attrs(void)
1176 {
1177         struct btrfs_feature_attr *fa;
1178         int set, i;
1179
1180         BUILD_BUG_ON(ARRAY_SIZE(btrfs_unknown_feature_names) !=
1181                      ARRAY_SIZE(btrfs_feature_attrs));
1182         BUILD_BUG_ON(ARRAY_SIZE(btrfs_unknown_feature_names[0]) !=
1183                      ARRAY_SIZE(btrfs_feature_attrs[0]));
1184
1185         memset(btrfs_feature_attrs, 0, sizeof(btrfs_feature_attrs));
1186         memset(btrfs_unknown_feature_names, 0,
1187                sizeof(btrfs_unknown_feature_names));
1188
1189         for (i = 0; btrfs_supported_feature_attrs[i]; i++) {
1190                 struct btrfs_feature_attr *sfa;
1191                 struct attribute *a = btrfs_supported_feature_attrs[i];
1192                 int bit;
1193                 sfa = attr_to_btrfs_feature_attr(a);
1194                 bit = ilog2(sfa->feature_bit);
1195                 fa = &btrfs_feature_attrs[sfa->feature_set][bit];
1196
1197                 fa->kobj_attr.attr.name = sfa->kobj_attr.attr.name;
1198         }
1199
1200         for (set = 0; set < FEAT_MAX; set++) {
1201                 for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
1202                         char *name = btrfs_unknown_feature_names[set][i];
1203                         fa = &btrfs_feature_attrs[set][i];
1204
1205                         if (fa->kobj_attr.attr.name)
1206                                 continue;
1207
1208                         snprintf(name, BTRFS_FEATURE_NAME_MAX, "%s:%u",
1209                                  btrfs_feature_set_names[set], i);
1210
1211                         fa->kobj_attr.attr.name = name;
1212                         fa->kobj_attr.attr.mode = S_IRUGO;
1213                         fa->feature_set = set;
1214                         fa->feature_bit = 1ULL << i;
1215                 }
1216         }
1217 }
1218
1219 /*
1220  * Create a sysfs entry for a given block group type at path
1221  * /sys/fs/btrfs/UUID/allocation/data/TYPE
1222  */
1223 void btrfs_sysfs_add_block_group_type(struct btrfs_block_group *cache)
1224 {
1225         struct btrfs_fs_info *fs_info = cache->fs_info;
1226         struct btrfs_space_info *space_info = cache->space_info;
1227         struct raid_kobject *rkobj;
1228         const int index = btrfs_bg_flags_to_raid_index(cache->flags);
1229         unsigned int nofs_flag;
1230         int ret;
1231
1232         /*
1233          * Setup a NOFS context because kobject_add(), deep in its call chain,
1234          * does GFP_KERNEL allocations, and we are often called in a context
1235          * where if reclaim is triggered we can deadlock (we are either holding
1236          * a transaction handle or some lock required for a transaction
1237          * commit).
1238          */
1239         nofs_flag = memalloc_nofs_save();
1240
1241         rkobj = kzalloc(sizeof(*rkobj), GFP_NOFS);
1242         if (!rkobj) {
1243                 memalloc_nofs_restore(nofs_flag);
1244                 btrfs_warn(cache->fs_info,
1245                                 "couldn't alloc memory for raid level kobject");
1246                 return;
1247         }
1248
1249         rkobj->flags = cache->flags;
1250         kobject_init(&rkobj->kobj, &btrfs_raid_ktype);
1251
1252         /*
1253          * We call this either on mount, or if we've created a block group for a
1254          * new index type while running (i.e. when restriping).  The running
1255          * case is tricky because we could race with other threads, so we need
1256          * to have this check to make sure we didn't already init the kobject.
1257          *
1258          * We don't have to protect on the free side because it only happens on
1259          * unmount.
1260          */
1261         spin_lock(&space_info->lock);
1262         if (space_info->block_group_kobjs[index]) {
1263                 spin_unlock(&space_info->lock);
1264                 kobject_put(&rkobj->kobj);
1265                 return;
1266         } else {
1267                 space_info->block_group_kobjs[index] = &rkobj->kobj;
1268         }
1269         spin_unlock(&space_info->lock);
1270
1271         ret = kobject_add(&rkobj->kobj, &space_info->kobj, "%s",
1272                           btrfs_bg_type_to_raid_name(rkobj->flags));
1273         memalloc_nofs_restore(nofs_flag);
1274         if (ret) {
1275                 spin_lock(&space_info->lock);
1276                 space_info->block_group_kobjs[index] = NULL;
1277                 spin_unlock(&space_info->lock);
1278                 kobject_put(&rkobj->kobj);
1279                 btrfs_warn(fs_info,
1280                         "failed to add kobject for block cache, ignoring");
1281                 return;
1282         }
1283 }
1284
1285 /*
1286  * Remove sysfs directories for all block group types of a given space info and
1287  * the space info as well
1288  */
1289 void btrfs_sysfs_remove_space_info(struct btrfs_space_info *space_info)
1290 {
1291         int i;
1292
1293         for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) {
1294                 struct kobject *kobj;
1295
1296                 kobj = space_info->block_group_kobjs[i];
1297                 space_info->block_group_kobjs[i] = NULL;
1298                 if (kobj) {
1299                         kobject_del(kobj);
1300                         kobject_put(kobj);
1301                 }
1302         }
1303         kobject_del(&space_info->kobj);
1304         kobject_put(&space_info->kobj);
1305 }
1306
1307 static const char *alloc_name(u64 flags)
1308 {
1309         switch (flags) {
1310         case BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA:
1311                 return "mixed";
1312         case BTRFS_BLOCK_GROUP_METADATA:
1313                 return "metadata";
1314         case BTRFS_BLOCK_GROUP_DATA:
1315                 return "data";
1316         case BTRFS_BLOCK_GROUP_SYSTEM:
1317                 return "system";
1318         default:
1319                 WARN_ON(1);
1320                 return "invalid-combination";
1321         }
1322 }
1323
1324 /*
1325  * Create a sysfs entry for a space info type at path
1326  * /sys/fs/btrfs/UUID/allocation/TYPE
1327  */
1328 int btrfs_sysfs_add_space_info_type(struct btrfs_fs_info *fs_info,
1329                                     struct btrfs_space_info *space_info)
1330 {
1331         int ret;
1332
1333         ret = kobject_init_and_add(&space_info->kobj, &space_info_ktype,
1334                                    fs_info->space_info_kobj, "%s",
1335                                    alloc_name(space_info->flags));
1336         if (ret) {
1337                 kobject_put(&space_info->kobj);
1338                 return ret;
1339         }
1340
1341         return 0;
1342 }
1343
1344 void btrfs_sysfs_remove_device(struct btrfs_device *device)
1345 {
1346         struct hd_struct *disk;
1347         struct kobject *disk_kobj;
1348         struct kobject *devices_kobj;
1349
1350         /*
1351          * Seed fs_devices devices_kobj aren't used, fetch kobject from the
1352          * fs_info::fs_devices.
1353          */
1354         devices_kobj = device->fs_info->fs_devices->devices_kobj;
1355         ASSERT(devices_kobj);
1356
1357         if (device->bdev) {
1358                 disk = device->bdev->bd_part;
1359                 disk_kobj = &part_to_dev(disk)->kobj;
1360                 sysfs_remove_link(devices_kobj, disk_kobj->name);
1361         }
1362
1363         if (device->devid_kobj.state_initialized) {
1364                 kobject_del(&device->devid_kobj);
1365                 kobject_put(&device->devid_kobj);
1366                 wait_for_completion(&device->kobj_unregister);
1367         }
1368 }
1369
1370 static ssize_t btrfs_devinfo_in_fs_metadata_show(struct kobject *kobj,
1371                                                  struct kobj_attribute *a,
1372                                                  char *buf)
1373 {
1374         int val;
1375         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1376                                                    devid_kobj);
1377
1378         val = !!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state);
1379
1380         return scnprintf(buf, PAGE_SIZE, "%d\n", val);
1381 }
1382 BTRFS_ATTR(devid, in_fs_metadata, btrfs_devinfo_in_fs_metadata_show);
1383
1384 static ssize_t btrfs_devinfo_missing_show(struct kobject *kobj,
1385                                         struct kobj_attribute *a, char *buf)
1386 {
1387         int val;
1388         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1389                                                    devid_kobj);
1390
1391         val = !!test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state);
1392
1393         return scnprintf(buf, PAGE_SIZE, "%d\n", val);
1394 }
1395 BTRFS_ATTR(devid, missing, btrfs_devinfo_missing_show);
1396
1397 static ssize_t btrfs_devinfo_replace_target_show(struct kobject *kobj,
1398                                                  struct kobj_attribute *a,
1399                                                  char *buf)
1400 {
1401         int val;
1402         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1403                                                    devid_kobj);
1404
1405         val = !!test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state);
1406
1407         return scnprintf(buf, PAGE_SIZE, "%d\n", val);
1408 }
1409 BTRFS_ATTR(devid, replace_target, btrfs_devinfo_replace_target_show);
1410
1411 static ssize_t btrfs_devinfo_writeable_show(struct kobject *kobj,
1412                                             struct kobj_attribute *a, char *buf)
1413 {
1414         int val;
1415         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1416                                                    devid_kobj);
1417
1418         val = !!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state);
1419
1420         return scnprintf(buf, PAGE_SIZE, "%d\n", val);
1421 }
1422 BTRFS_ATTR(devid, writeable, btrfs_devinfo_writeable_show);
1423
1424 static struct attribute *devid_attrs[] = {
1425         BTRFS_ATTR_PTR(devid, in_fs_metadata),
1426         BTRFS_ATTR_PTR(devid, missing),
1427         BTRFS_ATTR_PTR(devid, replace_target),
1428         BTRFS_ATTR_PTR(devid, writeable),
1429         NULL
1430 };
1431 ATTRIBUTE_GROUPS(devid);
1432
1433 static void btrfs_release_devid_kobj(struct kobject *kobj)
1434 {
1435         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1436                                                    devid_kobj);
1437
1438         memset(&device->devid_kobj, 0, sizeof(struct kobject));
1439         complete(&device->kobj_unregister);
1440 }
1441
1442 static struct kobj_type devid_ktype = {
1443         .sysfs_ops      = &kobj_sysfs_ops,
1444         .default_groups = devid_groups,
1445         .release        = btrfs_release_devid_kobj,
1446 };
1447
1448 int btrfs_sysfs_add_device(struct btrfs_device *device)
1449 {
1450         int ret;
1451         unsigned int nofs_flag;
1452         struct kobject *devices_kobj;
1453         struct kobject *devinfo_kobj;
1454
1455         /*
1456          * Make sure we use the fs_info::fs_devices to fetch the kobjects even
1457          * for the seed fs_devices
1458          */
1459         devices_kobj = device->fs_info->fs_devices->devices_kobj;
1460         devinfo_kobj = device->fs_info->fs_devices->devinfo_kobj;
1461         ASSERT(devices_kobj);
1462         ASSERT(devinfo_kobj);
1463
1464         nofs_flag = memalloc_nofs_save();
1465
1466         if (device->bdev) {
1467                 struct hd_struct *disk;
1468                 struct kobject *disk_kobj;
1469
1470                 disk = device->bdev->bd_part;
1471                 disk_kobj = &part_to_dev(disk)->kobj;
1472
1473                 ret = sysfs_create_link(devices_kobj, disk_kobj, disk_kobj->name);
1474                 if (ret) {
1475                         btrfs_warn(device->fs_info,
1476                                 "creating sysfs device link for devid %llu failed: %d",
1477                                 device->devid, ret);
1478                         goto out;
1479                 }
1480         }
1481
1482         init_completion(&device->kobj_unregister);
1483         ret = kobject_init_and_add(&device->devid_kobj, &devid_ktype,
1484                                    devinfo_kobj, "%llu", device->devid);
1485         if (ret) {
1486                 kobject_put(&device->devid_kobj);
1487                 btrfs_warn(device->fs_info,
1488                            "devinfo init for devid %llu failed: %d",
1489                            device->devid, ret);
1490         }
1491
1492 out:
1493         memalloc_nofs_restore(nofs_flag);
1494         return ret;
1495 }
1496
1497 static int btrfs_sysfs_add_fs_devices(struct btrfs_fs_devices *fs_devices)
1498 {
1499         int ret;
1500         struct btrfs_device *device;
1501         struct btrfs_fs_devices *seed;
1502
1503         list_for_each_entry(device, &fs_devices->devices, dev_list) {
1504                 ret = btrfs_sysfs_add_device(device);
1505                 if (ret)
1506                         goto fail;
1507         }
1508
1509         list_for_each_entry(seed, &fs_devices->seed_list, seed_list) {
1510                 list_for_each_entry(device, &seed->devices, dev_list) {
1511                         ret = btrfs_sysfs_add_device(device);
1512                         if (ret)
1513                                 goto fail;
1514                 }
1515         }
1516
1517         return 0;
1518
1519 fail:
1520         btrfs_sysfs_remove_fs_devices(fs_devices);
1521         return ret;
1522 }
1523
1524 void btrfs_kobject_uevent(struct block_device *bdev, enum kobject_action action)
1525 {
1526         int ret;
1527
1528         ret = kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, action);
1529         if (ret)
1530                 pr_warn("BTRFS: Sending event '%d' to kobject: '%s' (%p): failed\n",
1531                         action, kobject_name(&disk_to_dev(bdev->bd_disk)->kobj),
1532                         &disk_to_dev(bdev->bd_disk)->kobj);
1533 }
1534
1535 void btrfs_sysfs_update_sprout_fsid(struct btrfs_fs_devices *fs_devices)
1536
1537 {
1538         char fsid_buf[BTRFS_UUID_UNPARSED_SIZE];
1539
1540         /*
1541          * Sprouting changes fsid of the mounted filesystem, rename the fsid
1542          * directory
1543          */
1544         snprintf(fsid_buf, BTRFS_UUID_UNPARSED_SIZE, "%pU", fs_devices->fsid);
1545         if (kobject_rename(&fs_devices->fsid_kobj, fsid_buf))
1546                 btrfs_warn(fs_devices->fs_info,
1547                                 "sysfs: failed to create fsid for sprout");
1548 }
1549
1550 void btrfs_sysfs_update_devid(struct btrfs_device *device)
1551 {
1552         char tmp[24];
1553
1554         snprintf(tmp, sizeof(tmp), "%llu", device->devid);
1555
1556         if (kobject_rename(&device->devid_kobj, tmp))
1557                 btrfs_warn(device->fs_devices->fs_info,
1558                            "sysfs: failed to update devid for %llu",
1559                            device->devid);
1560 }
1561
1562 /* /sys/fs/btrfs/ entry */
1563 static struct kset *btrfs_kset;
1564
1565 /*
1566  * Creates:
1567  *              /sys/fs/btrfs/UUID
1568  *
1569  * Can be called by the device discovery thread.
1570  */
1571 int btrfs_sysfs_add_fsid(struct btrfs_fs_devices *fs_devs)
1572 {
1573         int error;
1574
1575         init_completion(&fs_devs->kobj_unregister);
1576         fs_devs->fsid_kobj.kset = btrfs_kset;
1577         error = kobject_init_and_add(&fs_devs->fsid_kobj, &btrfs_ktype, NULL,
1578                                      "%pU", fs_devs->fsid);
1579         if (error) {
1580                 kobject_put(&fs_devs->fsid_kobj);
1581                 return error;
1582         }
1583
1584         fs_devs->devices_kobj = kobject_create_and_add("devices",
1585                                                        &fs_devs->fsid_kobj);
1586         if (!fs_devs->devices_kobj) {
1587                 btrfs_err(fs_devs->fs_info,
1588                           "failed to init sysfs device interface");
1589                 btrfs_sysfs_remove_fsid(fs_devs);
1590                 return -ENOMEM;
1591         }
1592
1593         fs_devs->devinfo_kobj = kobject_create_and_add("devinfo",
1594                                                        &fs_devs->fsid_kobj);
1595         if (!fs_devs->devinfo_kobj) {
1596                 btrfs_err(fs_devs->fs_info,
1597                           "failed to init sysfs devinfo kobject");
1598                 btrfs_sysfs_remove_fsid(fs_devs);
1599                 return -ENOMEM;
1600         }
1601
1602         return 0;
1603 }
1604
1605 int btrfs_sysfs_add_mounted(struct btrfs_fs_info *fs_info)
1606 {
1607         int error;
1608         struct btrfs_fs_devices *fs_devs = fs_info->fs_devices;
1609         struct kobject *fsid_kobj = &fs_devs->fsid_kobj;
1610
1611         error = btrfs_sysfs_add_fs_devices(fs_devs);
1612         if (error)
1613                 return error;
1614
1615         error = sysfs_create_files(fsid_kobj, btrfs_attrs);
1616         if (error) {
1617                 btrfs_sysfs_remove_fs_devices(fs_devs);
1618                 return error;
1619         }
1620
1621         error = sysfs_create_group(fsid_kobj,
1622                                    &btrfs_feature_attr_group);
1623         if (error)
1624                 goto failure;
1625
1626 #ifdef CONFIG_BTRFS_DEBUG
1627         fs_info->debug_kobj = kobject_create_and_add("debug", fsid_kobj);
1628         if (!fs_info->debug_kobj) {
1629                 error = -ENOMEM;
1630                 goto failure;
1631         }
1632
1633         error = sysfs_create_files(fs_info->debug_kobj, btrfs_debug_mount_attrs);
1634         if (error)
1635                 goto failure;
1636
1637         /* Discard directory */
1638         fs_info->discard_debug_kobj = kobject_create_and_add("discard",
1639                                                      fs_info->debug_kobj);
1640         if (!fs_info->discard_debug_kobj) {
1641                 error = -ENOMEM;
1642                 goto failure;
1643         }
1644
1645         error = sysfs_create_files(fs_info->discard_debug_kobj,
1646                                    discard_debug_attrs);
1647         if (error)
1648                 goto failure;
1649 #endif
1650
1651         error = addrm_unknown_feature_attrs(fs_info, true);
1652         if (error)
1653                 goto failure;
1654
1655         error = sysfs_create_link(fsid_kobj, &fs_info->sb->s_bdi->dev->kobj, "bdi");
1656         if (error)
1657                 goto failure;
1658
1659         fs_info->space_info_kobj = kobject_create_and_add("allocation",
1660                                                   fsid_kobj);
1661         if (!fs_info->space_info_kobj) {
1662                 error = -ENOMEM;
1663                 goto failure;
1664         }
1665
1666         error = sysfs_create_files(fs_info->space_info_kobj, allocation_attrs);
1667         if (error)
1668                 goto failure;
1669
1670         return 0;
1671 failure:
1672         btrfs_sysfs_remove_mounted(fs_info);
1673         return error;
1674 }
1675
1676 static inline struct btrfs_fs_info *qgroup_kobj_to_fs_info(struct kobject *kobj)
1677 {
1678         return to_fs_info(kobj->parent->parent);
1679 }
1680
1681 #define QGROUP_ATTR(_member, _show_name)                                        \
1682 static ssize_t btrfs_qgroup_show_##_member(struct kobject *qgroup_kobj,         \
1683                                            struct kobj_attribute *a,            \
1684                                            char *buf)                           \
1685 {                                                                               \
1686         struct btrfs_fs_info *fs_info = qgroup_kobj_to_fs_info(qgroup_kobj);    \
1687         struct btrfs_qgroup *qgroup = container_of(qgroup_kobj,                 \
1688                         struct btrfs_qgroup, kobj);                             \
1689         return btrfs_show_u64(&qgroup->_member, &fs_info->qgroup_lock, buf);    \
1690 }                                                                               \
1691 BTRFS_ATTR(qgroup, _show_name, btrfs_qgroup_show_##_member)
1692
1693 #define QGROUP_RSV_ATTR(_name, _type)                                           \
1694 static ssize_t btrfs_qgroup_rsv_show_##_name(struct kobject *qgroup_kobj,       \
1695                                              struct kobj_attribute *a,          \
1696                                              char *buf)                         \
1697 {                                                                               \
1698         struct btrfs_fs_info *fs_info = qgroup_kobj_to_fs_info(qgroup_kobj);    \
1699         struct btrfs_qgroup *qgroup = container_of(qgroup_kobj,                 \
1700                         struct btrfs_qgroup, kobj);                             \
1701         return btrfs_show_u64(&qgroup->rsv.values[_type],                       \
1702                         &fs_info->qgroup_lock, buf);                            \
1703 }                                                                               \
1704 BTRFS_ATTR(qgroup, rsv_##_name, btrfs_qgroup_rsv_show_##_name)
1705
1706 QGROUP_ATTR(rfer, referenced);
1707 QGROUP_ATTR(excl, exclusive);
1708 QGROUP_ATTR(max_rfer, max_referenced);
1709 QGROUP_ATTR(max_excl, max_exclusive);
1710 QGROUP_ATTR(lim_flags, limit_flags);
1711 QGROUP_RSV_ATTR(data, BTRFS_QGROUP_RSV_DATA);
1712 QGROUP_RSV_ATTR(meta_pertrans, BTRFS_QGROUP_RSV_META_PERTRANS);
1713 QGROUP_RSV_ATTR(meta_prealloc, BTRFS_QGROUP_RSV_META_PREALLOC);
1714
1715 static struct attribute *qgroup_attrs[] = {
1716         BTRFS_ATTR_PTR(qgroup, referenced),
1717         BTRFS_ATTR_PTR(qgroup, exclusive),
1718         BTRFS_ATTR_PTR(qgroup, max_referenced),
1719         BTRFS_ATTR_PTR(qgroup, max_exclusive),
1720         BTRFS_ATTR_PTR(qgroup, limit_flags),
1721         BTRFS_ATTR_PTR(qgroup, rsv_data),
1722         BTRFS_ATTR_PTR(qgroup, rsv_meta_pertrans),
1723         BTRFS_ATTR_PTR(qgroup, rsv_meta_prealloc),
1724         NULL
1725 };
1726 ATTRIBUTE_GROUPS(qgroup);
1727
1728 static void qgroup_release(struct kobject *kobj)
1729 {
1730         struct btrfs_qgroup *qgroup = container_of(kobj, struct btrfs_qgroup, kobj);
1731
1732         memset(&qgroup->kobj, 0, sizeof(*kobj));
1733 }
1734
1735 static struct kobj_type qgroup_ktype = {
1736         .sysfs_ops = &kobj_sysfs_ops,
1737         .release = qgroup_release,
1738         .default_groups = qgroup_groups,
1739 };
1740
1741 int btrfs_sysfs_add_one_qgroup(struct btrfs_fs_info *fs_info,
1742                                 struct btrfs_qgroup *qgroup)
1743 {
1744         struct kobject *qgroups_kobj = fs_info->qgroups_kobj;
1745         int ret;
1746
1747         if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
1748                 return 0;
1749         if (qgroup->kobj.state_initialized)
1750                 return 0;
1751         if (!qgroups_kobj)
1752                 return -EINVAL;
1753
1754         ret = kobject_init_and_add(&qgroup->kobj, &qgroup_ktype, qgroups_kobj,
1755                         "%hu_%llu", btrfs_qgroup_level(qgroup->qgroupid),
1756                         btrfs_qgroup_subvolid(qgroup->qgroupid));
1757         if (ret < 0)
1758                 kobject_put(&qgroup->kobj);
1759
1760         return ret;
1761 }
1762
1763 void btrfs_sysfs_del_qgroups(struct btrfs_fs_info *fs_info)
1764 {
1765         struct btrfs_qgroup *qgroup;
1766         struct btrfs_qgroup *next;
1767
1768         if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
1769                 return;
1770
1771         rbtree_postorder_for_each_entry_safe(qgroup, next,
1772                                              &fs_info->qgroup_tree, node)
1773                 btrfs_sysfs_del_one_qgroup(fs_info, qgroup);
1774         if (fs_info->qgroups_kobj) {
1775                 kobject_del(fs_info->qgroups_kobj);
1776                 kobject_put(fs_info->qgroups_kobj);
1777                 fs_info->qgroups_kobj = NULL;
1778         }
1779 }
1780
1781 /* Called when qgroups get initialized, thus there is no need for locking */
1782 int btrfs_sysfs_add_qgroups(struct btrfs_fs_info *fs_info)
1783 {
1784         struct kobject *fsid_kobj = &fs_info->fs_devices->fsid_kobj;
1785         struct btrfs_qgroup *qgroup;
1786         struct btrfs_qgroup *next;
1787         int ret = 0;
1788
1789         if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
1790                 return 0;
1791
1792         ASSERT(fsid_kobj);
1793         if (fs_info->qgroups_kobj)
1794                 return 0;
1795
1796         fs_info->qgroups_kobj = kobject_create_and_add("qgroups", fsid_kobj);
1797         if (!fs_info->qgroups_kobj) {
1798                 ret = -ENOMEM;
1799                 goto out;
1800         }
1801         rbtree_postorder_for_each_entry_safe(qgroup, next,
1802                                              &fs_info->qgroup_tree, node) {
1803                 ret = btrfs_sysfs_add_one_qgroup(fs_info, qgroup);
1804                 if (ret < 0)
1805                         goto out;
1806         }
1807
1808 out:
1809         if (ret < 0)
1810                 btrfs_sysfs_del_qgroups(fs_info);
1811         return ret;
1812 }
1813
1814 void btrfs_sysfs_del_one_qgroup(struct btrfs_fs_info *fs_info,
1815                                 struct btrfs_qgroup *qgroup)
1816 {
1817         if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
1818                 return;
1819
1820         if (qgroup->kobj.state_initialized) {
1821                 kobject_del(&qgroup->kobj);
1822                 kobject_put(&qgroup->kobj);
1823         }
1824 }
1825
1826 /*
1827  * Change per-fs features in /sys/fs/btrfs/UUID/features to match current
1828  * values in superblock. Call after any changes to incompat/compat_ro flags
1829  */
1830 void btrfs_sysfs_feature_update(struct btrfs_fs_info *fs_info,
1831                 u64 bit, enum btrfs_feature_set set)
1832 {
1833         struct btrfs_fs_devices *fs_devs;
1834         struct kobject *fsid_kobj;
1835         u64 __maybe_unused features;
1836         int __maybe_unused ret;
1837
1838         if (!fs_info)
1839                 return;
1840
1841         /*
1842          * See 14e46e04958df74 and e410e34fad913dd, feature bit updates are not
1843          * safe when called from some contexts (eg. balance)
1844          */
1845         features = get_features(fs_info, set);
1846         ASSERT(bit & supported_feature_masks[set]);
1847
1848         fs_devs = fs_info->fs_devices;
1849         fsid_kobj = &fs_devs->fsid_kobj;
1850
1851         if (!fsid_kobj->state_initialized)
1852                 return;
1853
1854         /*
1855          * FIXME: this is too heavy to update just one value, ideally we'd like
1856          * to use sysfs_update_group but some refactoring is needed first.
1857          */
1858         sysfs_remove_group(fsid_kobj, &btrfs_feature_attr_group);
1859         ret = sysfs_create_group(fsid_kobj, &btrfs_feature_attr_group);
1860 }
1861
1862 int __init btrfs_init_sysfs(void)
1863 {
1864         int ret;
1865
1866         btrfs_kset = kset_create_and_add("btrfs", NULL, fs_kobj);
1867         if (!btrfs_kset)
1868                 return -ENOMEM;
1869
1870         init_feature_attrs();
1871         ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
1872         if (ret)
1873                 goto out2;
1874         ret = sysfs_merge_group(&btrfs_kset->kobj,
1875                                 &btrfs_static_feature_attr_group);
1876         if (ret)
1877                 goto out_remove_group;
1878
1879 #ifdef CONFIG_BTRFS_DEBUG
1880         ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_debug_feature_attr_group);
1881         if (ret)
1882                 goto out2;
1883 #endif
1884
1885         return 0;
1886
1887 out_remove_group:
1888         sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
1889 out2:
1890         kset_unregister(btrfs_kset);
1891
1892         return ret;
1893 }
1894
1895 void __cold btrfs_exit_sysfs(void)
1896 {
1897         sysfs_unmerge_group(&btrfs_kset->kobj,
1898                             &btrfs_static_feature_attr_group);
1899         sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
1900 #ifdef CONFIG_BTRFS_DEBUG
1901         sysfs_remove_group(&btrfs_kset->kobj, &btrfs_debug_feature_attr_group);
1902 #endif
1903         kset_unregister(btrfs_kset);
1904 }
1905