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(bytes_zone_unusable);
 670 SPACE_INFO_ATTR(disk_used);
 671 SPACE_INFO_ATTR(disk_total);
 672 BTRFS_ATTR(space_info, total_bytes_pinned,
 673            btrfs_space_info_show_total_bytes_pinned);
 674
 675 static struct attribute *space_info_attrs[] = {
 676         BTRFS_ATTR_PTR(space_info, flags),
 677         BTRFS_ATTR_PTR(space_info, total_bytes),
 678         BTRFS_ATTR_PTR(space_info, bytes_used),
 679         BTRFS_ATTR_PTR(space_info, bytes_pinned),
 680         BTRFS_ATTR_PTR(space_info, bytes_reserved),
 681         BTRFS_ATTR_PTR(space_info, bytes_may_use),
 682         BTRFS_ATTR_PTR(space_info, bytes_readonly),
 683         BTRFS_ATTR_PTR(space_info, bytes_zone_unusable),
 684         BTRFS_ATTR_PTR(space_info, disk_used),
 685         BTRFS_ATTR_PTR(space_info, disk_total),
 686         BTRFS_ATTR_PTR(space_info, total_bytes_pinned),
 687         NULL,
 688 };
 689 ATTRIBUTE_GROUPS(space_info);
 690
 691 static void space_info_release(struct kobject *kobj)
 692 {
 693         struct btrfs_space_info *sinfo = to_space_info(kobj);
 694         percpu_counter_destroy(&sinfo->total_bytes_pinned);
 695         kfree(sinfo);
 696 }
 697
 698 static struct kobj_type space_info_ktype = {
 699         .sysfs_ops = &kobj_sysfs_ops,
 700         .release = space_info_release,
 701         .default_groups = space_info_groups,
 702 };
 703
 704 static const struct attribute *allocation_attrs[] = {
 705         BTRFS_ATTR_PTR(allocation, global_rsv_reserved),
 706         BTRFS_ATTR_PTR(allocation, global_rsv_size),
 707         NULL,
 708 };
 709
 710 static ssize_t btrfs_label_show(struct kobject *kobj,
 711                                 struct kobj_attribute *a, char *buf)
 712 {
 713         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 714         char *label = fs_info->super_copy->label;
 715         ssize_t ret;
 716
 717         spin_lock(&fs_info->super_lock);
 718         ret = scnprintf(buf, PAGE_SIZE, label[0] ? "%s\n" : "%s", label);
 719         spin_unlock(&fs_info->super_lock);
 720
 721         return ret;
 722 }
 723
 724 static ssize_t btrfs_label_store(struct kobject *kobj,
 725                                  struct kobj_attribute *a,
 726                                  const char *buf, size_t len)
 727 {
 728         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 729         size_t p_len;
 730
 731         if (!fs_info)
 732                 return -EPERM;
 733
 734         if (sb_rdonly(fs_info->sb))
 735                 return -EROFS;
 736
 737         /*
 738          * p_len is the len until the first occurrence of either
 739          * '\n' or '\0'
 740          */
 741         p_len = strcspn(buf, "\n");
 742
 743         if (p_len >= BTRFS_LABEL_SIZE)
 744                 return -EINVAL;
 745
 746         spin_lock(&fs_info->super_lock);
 747         memset(fs_info->super_copy->label, 0, BTRFS_LABEL_SIZE);
 748         memcpy(fs_info->super_copy->label, buf, p_len);
 749         spin_unlock(&fs_info->super_lock);
 750
 751         /*
 752          * We don't want to do full transaction commit from inside sysfs
 753          */
 754         btrfs_set_pending(fs_info, COMMIT);
 755         wake_up_process(fs_info->transaction_kthread);
 756
 757         return len;
 758 }
 759 BTRFS_ATTR_RW(, label, btrfs_label_show, btrfs_label_store);
 760
 761 static ssize_t btrfs_nodesize_show(struct kobject *kobj,
 762                                 struct kobj_attribute *a, char *buf)
 763 {
 764         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 765
 766         return scnprintf(buf, PAGE_SIZE, "%u\n", fs_info->super_copy->nodesize);
 767 }
 768
 769 BTRFS_ATTR(, nodesize, btrfs_nodesize_show);
 770
 771 static ssize_t btrfs_sectorsize_show(struct kobject *kobj,
 772                                 struct kobj_attribute *a, char *buf)
 773 {
 774         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 775
 776         return scnprintf(buf, PAGE_SIZE, "%u\n",
 777                          fs_info->super_copy->sectorsize);
 778 }
 779
 780 BTRFS_ATTR(, sectorsize, btrfs_sectorsize_show);
 781
 782 static ssize_t btrfs_clone_alignment_show(struct kobject *kobj,
 783                                 struct kobj_attribute *a, char *buf)
 784 {
 785         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 786
 787         return scnprintf(buf, PAGE_SIZE, "%u\n", fs_info->super_copy->sectorsize);
 788 }
 789
 790 BTRFS_ATTR(, clone_alignment, btrfs_clone_alignment_show);
 791
 792 static ssize_t quota_override_show(struct kobject *kobj,
 793                                    struct kobj_attribute *a, char *buf)
 794 {
 795         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 796         int quota_override;
 797
 798         quota_override = test_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
 799         return scnprintf(buf, PAGE_SIZE, "%d\n", quota_override);
 800 }
 801
 802 static ssize_t quota_override_store(struct kobject *kobj,
 803                                     struct kobj_attribute *a,
 804                                     const char *buf, size_t len)
 805 {
 806         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 807         unsigned long knob;
 808         int err;
 809
 810         if (!fs_info)
 811                 return -EPERM;
 812
 813         if (!capable(CAP_SYS_RESOURCE))
 814                 return -EPERM;
 815
 816         err = kstrtoul(buf, 10, &knob);
 817         if (err)
 818                 return err;
 819         if (knob > 1)
 820                 return -EINVAL;
 821
 822         if (knob)
 823                 set_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
 824         else
 825                 clear_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
 826
 827         return len;
 828 }
 829
 830 BTRFS_ATTR_RW(, quota_override, quota_override_show, quota_override_store);
 831
 832 static ssize_t btrfs_metadata_uuid_show(struct kobject *kobj,
 833                                 struct kobj_attribute *a, char *buf)
 834 {
 835         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 836
 837         return scnprintf(buf, PAGE_SIZE, "%pU\n",
 838                         fs_info->fs_devices->metadata_uuid);
 839 }
 840
 841 BTRFS_ATTR(, metadata_uuid, btrfs_metadata_uuid_show);
 842
 843 static ssize_t btrfs_checksum_show(struct kobject *kobj,
 844                                    struct kobj_attribute *a, char *buf)
 845 {
 846         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 847         u16 csum_type = btrfs_super_csum_type(fs_info->super_copy);
 848
 849         return scnprintf(buf, PAGE_SIZE, "%s (%s)\n",
 850                         btrfs_super_csum_name(csum_type),
 851                         crypto_shash_driver_name(fs_info->csum_shash));
 852 }
 853
 854 BTRFS_ATTR(, checksum, btrfs_checksum_show);
 855
 856 static ssize_t btrfs_exclusive_operation_show(struct kobject *kobj,
 857                 struct kobj_attribute *a, char *buf)
 858 {
 859         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 860         const char *str;
 861
 862         switch (READ_ONCE(fs_info->exclusive_operation)) {
 863                 case  BTRFS_EXCLOP_NONE:
 864                         str = "none\n";
 865                         break;
 866                 case BTRFS_EXCLOP_BALANCE:
 867                         str = "balance\n";
 868                         break;
 869                 case BTRFS_EXCLOP_DEV_ADD:
 870                         str = "device add\n";
 871                         break;
 872                 case BTRFS_EXCLOP_DEV_REMOVE:
 873                         str = "device remove\n";
 874                         break;
 875                 case BTRFS_EXCLOP_DEV_REPLACE:
 876                         str = "device replace\n";
 877                         break;
 878                 case BTRFS_EXCLOP_RESIZE:
 879                         str = "resize\n";
 880                         break;
 881                 case BTRFS_EXCLOP_SWAP_ACTIVATE:
 882                         str = "swap activate\n";
 883                         break;
 884                 default:
 885                         str = "UNKNOWN\n";
 886                         break;
 887         }
 888         return scnprintf(buf, PAGE_SIZE, "%s", str);
 889 }
 890 BTRFS_ATTR(, exclusive_operation, btrfs_exclusive_operation_show);
 891
 892 static ssize_t btrfs_generation_show(struct kobject *kobj,
 893                                      struct kobj_attribute *a, char *buf)
 894 {
 895         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 896
 897         return scnprintf(buf, PAGE_SIZE, "%llu\n", fs_info->generation);
 898 }
 899 BTRFS_ATTR(, generation, btrfs_generation_show);
 900
 901 /*
 902  * Look for an exact string @string in @buffer with possible leading or
 903  * trailing whitespace
 904  */
 905 static bool strmatch(const char *buffer, const char *string)
 906 {
 907         const size_t len = strlen(string);
 908
 909         /* Skip leading whitespace */
 910         buffer = skip_spaces(buffer);
 911
 912         /* Match entire string, check if the rest is whitespace or empty */
 913         if (strncmp(string, buffer, len) == 0 &&
 914             strlen(skip_spaces(buffer + len)) == 0)
 915                 return true;
 916
 917         return false;
 918 }
 919
 920 static const char * const btrfs_read_policy_name[] = { "pid" };
 921
 922 static ssize_t btrfs_read_policy_show(struct kobject *kobj,
 923                                       struct kobj_attribute *a, char *buf)
 924 {
 925         struct btrfs_fs_devices *fs_devices = to_fs_devs(kobj);
 926         ssize_t ret = 0;
 927         int i;
 928
 929         for (i = 0; i < BTRFS_NR_READ_POLICY; i++) {
 930                 if (fs_devices->read_policy == i)
 931                         ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s[%s]",
 932                                          (ret == 0 ? "" : " "),
 933                                          btrfs_read_policy_name[i]);
 934                 else
 935                         ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%s",
 936                                          (ret == 0 ? "" : " "),
 937                                          btrfs_read_policy_name[i]);
 938         }
 939
 940         ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
 941
 942         return ret;
 943 }
 944
 945 static ssize_t btrfs_read_policy_store(struct kobject *kobj,
 946                                        struct kobj_attribute *a,
 947                                        const char *buf, size_t len)
 948 {
 949         struct btrfs_fs_devices *fs_devices = to_fs_devs(kobj);
 950         int i;
 951
 952         for (i = 0; i < BTRFS_NR_READ_POLICY; i++) {
 953                 if (strmatch(buf, btrfs_read_policy_name[i])) {
 954                         if (i != fs_devices->read_policy) {
 955                                 fs_devices->read_policy = i;
 956                                 btrfs_info(fs_devices->fs_info,
 957                                            "read policy set to '%s'",
 958                                            btrfs_read_policy_name[i]);
 959                         }
 960                         return len;
 961                 }
 962         }
 963
 964         return -EINVAL;
 965 }
 966 BTRFS_ATTR_RW(, read_policy, btrfs_read_policy_show, btrfs_read_policy_store);
 967
 968 static const struct attribute *btrfs_attrs[] = {
 969         BTRFS_ATTR_PTR(, label),
 970         BTRFS_ATTR_PTR(, nodesize),
 971         BTRFS_ATTR_PTR(, sectorsize),
 972         BTRFS_ATTR_PTR(, clone_alignment),
 973         BTRFS_ATTR_PTR(, quota_override),
 974         BTRFS_ATTR_PTR(, metadata_uuid),
 975         BTRFS_ATTR_PTR(, checksum),
 976         BTRFS_ATTR_PTR(, exclusive_operation),
 977         BTRFS_ATTR_PTR(, generation),
 978         BTRFS_ATTR_PTR(, read_policy),
 979         NULL,
 980 };
 981
 982 static void btrfs_release_fsid_kobj(struct kobject *kobj)
 983 {
 984         struct btrfs_fs_devices *fs_devs = to_fs_devs(kobj);
 985
 986         memset(&fs_devs->fsid_kobj, 0, sizeof(struct kobject));
 987         complete(&fs_devs->kobj_unregister);
 988 }
 989
 990 static struct kobj_type btrfs_ktype = {
 991         .sysfs_ops      = &kobj_sysfs_ops,
 992         .release        = btrfs_release_fsid_kobj,
 993 };
 994
 995 static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj)
 996 {
 997         if (kobj->ktype != &btrfs_ktype)
 998                 return NULL;
 999         return container_of(kobj, struct btrfs_fs_devices, fsid_kobj);
1000 }
1001
1002 static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj)
1003 {
1004         if (kobj->ktype != &btrfs_ktype)
1005                 return NULL;
1006         return to_fs_devs(kobj)->fs_info;
1007 }
1008
1009 #define NUM_FEATURE_BITS 64
1010 #define BTRFS_FEATURE_NAME_MAX 13
1011 static char btrfs_unknown_feature_names[FEAT_MAX][NUM_FEATURE_BITS][BTRFS_FEATURE_NAME_MAX];
1012 static struct btrfs_feature_attr btrfs_feature_attrs[FEAT_MAX][NUM_FEATURE_BITS];
1013
1014 static const u64 supported_feature_masks[FEAT_MAX] = {
1015         [FEAT_COMPAT]    = BTRFS_FEATURE_COMPAT_SUPP,
1016         [FEAT_COMPAT_RO] = BTRFS_FEATURE_COMPAT_RO_SUPP,
1017         [FEAT_INCOMPAT]  = BTRFS_FEATURE_INCOMPAT_SUPP,
1018 };
1019
1020 static int addrm_unknown_feature_attrs(struct btrfs_fs_info *fs_info, bool add)
1021 {
1022         int set;
1023
1024         for (set = 0; set < FEAT_MAX; set++) {
1025                 int i;
1026                 struct attribute *attrs[2];
1027                 struct attribute_group agroup = {
1028                         .name = "features",
1029                         .attrs = attrs,
1030                 };
1031                 u64 features = get_features(fs_info, set);
1032                 features &= ~supported_feature_masks[set];
1033
1034                 if (!features)
1035                         continue;
1036
1037                 attrs[1] = NULL;
1038                 for (i = 0; i < NUM_FEATURE_BITS; i++) {
1039                         struct btrfs_feature_attr *fa;
1040
1041                         if (!(features & (1ULL << i)))
1042                                 continue;
1043
1044                         fa = &btrfs_feature_attrs[set][i];
1045                         attrs[0] = &fa->kobj_attr.attr;
1046                         if (add) {
1047                                 int ret;
1048                                 ret = sysfs_merge_group(&fs_info->fs_devices->fsid_kobj,
1049                                                         &agroup);
1050                                 if (ret)
1051                                         return ret;
1052                         } else
1053                                 sysfs_unmerge_group(&fs_info->fs_devices->fsid_kobj,
1054                                                     &agroup);
1055                 }
1056
1057         }
1058         return 0;
1059 }
1060
1061 static void __btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs)
1062 {
1063         if (fs_devs->devinfo_kobj) {
1064                 kobject_del(fs_devs->devinfo_kobj);
1065                 kobject_put(fs_devs->devinfo_kobj);
1066                 fs_devs->devinfo_kobj = NULL;
1067         }
1068
1069         if (fs_devs->devices_kobj) {
1070                 kobject_del(fs_devs->devices_kobj);
1071                 kobject_put(fs_devs->devices_kobj);
1072                 fs_devs->devices_kobj = NULL;
1073         }
1074
1075         if (fs_devs->fsid_kobj.state_initialized) {
1076                 kobject_del(&fs_devs->fsid_kobj);
1077                 kobject_put(&fs_devs->fsid_kobj);
1078                 wait_for_completion(&fs_devs->kobj_unregister);
1079         }
1080 }
1081
1082 /* when fs_devs is NULL it will remove all fsid kobject */
1083 void btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs)
1084 {
1085         struct list_head *fs_uuids = btrfs_get_fs_uuids();
1086
1087         if (fs_devs) {
1088                 __btrfs_sysfs_remove_fsid(fs_devs);
1089                 return;
1090         }
1091
1092         list_for_each_entry(fs_devs, fs_uuids, fs_list) {
1093                 __btrfs_sysfs_remove_fsid(fs_devs);
1094         }
1095 }
1096
1097 static void btrfs_sysfs_remove_fs_devices(struct btrfs_fs_devices *fs_devices)
1098 {
1099         struct btrfs_device *device;
1100         struct btrfs_fs_devices *seed;
1101
1102         list_for_each_entry(device, &fs_devices->devices, dev_list)
1103                 btrfs_sysfs_remove_device(device);
1104
1105         list_for_each_entry(seed, &fs_devices->seed_list, seed_list) {
1106                 list_for_each_entry(device, &seed->devices, dev_list)
1107                         btrfs_sysfs_remove_device(device);
1108         }
1109 }
1110
1111 void btrfs_sysfs_remove_mounted(struct btrfs_fs_info *fs_info)
1112 {
1113         struct kobject *fsid_kobj = &fs_info->fs_devices->fsid_kobj;
1114
1115         sysfs_remove_link(fsid_kobj, "bdi");
1116
1117         if (fs_info->space_info_kobj) {
1118                 sysfs_remove_files(fs_info->space_info_kobj, allocation_attrs);
1119                 kobject_del(fs_info->space_info_kobj);
1120                 kobject_put(fs_info->space_info_kobj);
1121         }
1122 #ifdef CONFIG_BTRFS_DEBUG
1123         if (fs_info->discard_debug_kobj) {
1124                 sysfs_remove_files(fs_info->discard_debug_kobj,
1125                                    discard_debug_attrs);
1126                 kobject_del(fs_info->discard_debug_kobj);
1127                 kobject_put(fs_info->discard_debug_kobj);
1128         }
1129         if (fs_info->debug_kobj) {
1130                 sysfs_remove_files(fs_info->debug_kobj, btrfs_debug_mount_attrs);
1131                 kobject_del(fs_info->debug_kobj);
1132                 kobject_put(fs_info->debug_kobj);
1133         }
1134 #endif
1135         addrm_unknown_feature_attrs(fs_info, false);
1136         sysfs_remove_group(fsid_kobj, &btrfs_feature_attr_group);
1137         sysfs_remove_files(fsid_kobj, btrfs_attrs);
1138         btrfs_sysfs_remove_fs_devices(fs_info->fs_devices);
1139 }
1140
1141 static const char * const btrfs_feature_set_names[FEAT_MAX] = {
1142         [FEAT_COMPAT]    = "compat",
1143         [FEAT_COMPAT_RO] = "compat_ro",
1144         [FEAT_INCOMPAT]  = "incompat",
1145 };
1146
1147 const char *btrfs_feature_set_name(enum btrfs_feature_set set)
1148 {
1149         return btrfs_feature_set_names[set];
1150 }
1151
1152 char *btrfs_printable_features(enum btrfs_feature_set set, u64 flags)
1153 {
1154         size_t bufsize = 4096; /* safe max, 64 names * 64 bytes */
1155         int len = 0;
1156         int i;
1157         char *str;
1158
1159         str = kmalloc(bufsize, GFP_KERNEL);
1160         if (!str)
1161                 return str;
1162
1163         for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
1164                 const char *name;
1165
1166                 if (!(flags & (1ULL << i)))
1167                         continue;
1168
1169                 name = btrfs_feature_attrs[set][i].kobj_attr.attr.name;
1170                 len += scnprintf(str + len, bufsize - len, "%s%s",
1171                                 len ? "," : "", name);
1172         }
1173
1174         return str;
1175 }
1176
1177 static void init_feature_attrs(void)
1178 {
1179         struct btrfs_feature_attr *fa;
1180         int set, i;
1181
1182         BUILD_BUG_ON(ARRAY_SIZE(btrfs_unknown_feature_names) !=
1183                      ARRAY_SIZE(btrfs_feature_attrs));
1184         BUILD_BUG_ON(ARRAY_SIZE(btrfs_unknown_feature_names[0]) !=
1185                      ARRAY_SIZE(btrfs_feature_attrs[0]));
1186
1187         memset(btrfs_feature_attrs, 0, sizeof(btrfs_feature_attrs));
1188         memset(btrfs_unknown_feature_names, 0,
1189                sizeof(btrfs_unknown_feature_names));
1190
1191         for (i = 0; btrfs_supported_feature_attrs[i]; i++) {
1192                 struct btrfs_feature_attr *sfa;
1193                 struct attribute *a = btrfs_supported_feature_attrs[i];
1194                 int bit;
1195                 sfa = attr_to_btrfs_feature_attr(a);
1196                 bit = ilog2(sfa->feature_bit);
1197                 fa = &btrfs_feature_attrs[sfa->feature_set][bit];
1198
1199                 fa->kobj_attr.attr.name = sfa->kobj_attr.attr.name;
1200         }
1201
1202         for (set = 0; set < FEAT_MAX; set++) {
1203                 for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
1204                         char *name = btrfs_unknown_feature_names[set][i];
1205                         fa = &btrfs_feature_attrs[set][i];
1206
1207                         if (fa->kobj_attr.attr.name)
1208                                 continue;
1209
1210                         snprintf(name, BTRFS_FEATURE_NAME_MAX, "%s:%u",
1211                                  btrfs_feature_set_names[set], i);
1212
1213                         fa->kobj_attr.attr.name = name;
1214                         fa->kobj_attr.attr.mode = S_IRUGO;
1215                         fa->feature_set = set;
1216                         fa->feature_bit = 1ULL << i;
1217                 }
1218         }
1219 }
1220
1221 /*
1222  * Create a sysfs entry for a given block group type at path
1223  * /sys/fs/btrfs/UUID/allocation/data/TYPE
1224  */
1225 void btrfs_sysfs_add_block_group_type(struct btrfs_block_group *cache)
1226 {
1227         struct btrfs_fs_info *fs_info = cache->fs_info;
1228         struct btrfs_space_info *space_info = cache->space_info;
1229         struct raid_kobject *rkobj;
1230         const int index = btrfs_bg_flags_to_raid_index(cache->flags);
1231         unsigned int nofs_flag;
1232         int ret;
1233
1234         /*
1235          * Setup a NOFS context because kobject_add(), deep in its call chain,
1236          * does GFP_KERNEL allocations, and we are often called in a context
1237          * where if reclaim is triggered we can deadlock (we are either holding
1238          * a transaction handle or some lock required for a transaction
1239          * commit).
1240          */
1241         nofs_flag = memalloc_nofs_save();
1242
1243         rkobj = kzalloc(sizeof(*rkobj), GFP_NOFS);
1244         if (!rkobj) {
1245                 memalloc_nofs_restore(nofs_flag);
1246                 btrfs_warn(cache->fs_info,
1247                                 "couldn't alloc memory for raid level kobject");
1248                 return;
1249         }
1250
1251         rkobj->flags = cache->flags;
1252         kobject_init(&rkobj->kobj, &btrfs_raid_ktype);
1253
1254         /*
1255          * We call this either on mount, or if we've created a block group for a
1256          * new index type while running (i.e. when restriping).  The running
1257          * case is tricky because we could race with other threads, so we need
1258          * to have this check to make sure we didn't already init the kobject.
1259          *
1260          * We don't have to protect on the free side because it only happens on
1261          * unmount.
1262          */
1263         spin_lock(&space_info->lock);
1264         if (space_info->block_group_kobjs[index]) {
1265                 spin_unlock(&space_info->lock);
1266                 kobject_put(&rkobj->kobj);
1267                 return;
1268         } else {
1269                 space_info->block_group_kobjs[index] = &rkobj->kobj;
1270         }
1271         spin_unlock(&space_info->lock);
1272
1273         ret = kobject_add(&rkobj->kobj, &space_info->kobj, "%s",
1274                           btrfs_bg_type_to_raid_name(rkobj->flags));
1275         memalloc_nofs_restore(nofs_flag);
1276         if (ret) {
1277                 spin_lock(&space_info->lock);
1278                 space_info->block_group_kobjs[index] = NULL;
1279                 spin_unlock(&space_info->lock);
1280                 kobject_put(&rkobj->kobj);
1281                 btrfs_warn(fs_info,
1282                         "failed to add kobject for block cache, ignoring");
1283                 return;
1284         }
1285 }
1286
1287 /*
1288  * Remove sysfs directories for all block group types of a given space info and
1289  * the space info as well
1290  */
1291 void btrfs_sysfs_remove_space_info(struct btrfs_space_info *space_info)
1292 {
1293         int i;
1294
1295         for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) {
1296                 struct kobject *kobj;
1297
1298                 kobj = space_info->block_group_kobjs[i];
1299                 space_info->block_group_kobjs[i] = NULL;
1300                 if (kobj) {
1301                         kobject_del(kobj);
1302                         kobject_put(kobj);
1303                 }
1304         }
1305         kobject_del(&space_info->kobj);
1306         kobject_put(&space_info->kobj);
1307 }
1308
1309 static const char *alloc_name(u64 flags)
1310 {
1311         switch (flags) {
1312         case BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA:
1313                 return "mixed";
1314         case BTRFS_BLOCK_GROUP_METADATA:
1315                 return "metadata";
1316         case BTRFS_BLOCK_GROUP_DATA:
1317                 return "data";
1318         case BTRFS_BLOCK_GROUP_SYSTEM:
1319                 return "system";
1320         default:
1321                 WARN_ON(1);
1322                 return "invalid-combination";
1323         }
1324 }
1325
1326 /*
1327  * Create a sysfs entry for a space info type at path
1328  * /sys/fs/btrfs/UUID/allocation/TYPE
1329  */
1330 int btrfs_sysfs_add_space_info_type(struct btrfs_fs_info *fs_info,
1331                                     struct btrfs_space_info *space_info)
1332 {
1333         int ret;
1334
1335         ret = kobject_init_and_add(&space_info->kobj, &space_info_ktype,
1336                                    fs_info->space_info_kobj, "%s",
1337                                    alloc_name(space_info->flags));
1338         if (ret) {
1339                 kobject_put(&space_info->kobj);
1340                 return ret;
1341         }
1342
1343         return 0;
1344 }
1345
1346 void btrfs_sysfs_remove_device(struct btrfs_device *device)
1347 {
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                 sysfs_remove_link(devices_kobj, bdev_kobj(device->bdev)->name);
1359
1360         if (device->devid_kobj.state_initialized) {
1361                 kobject_del(&device->devid_kobj);
1362                 kobject_put(&device->devid_kobj);
1363                 wait_for_completion(&device->kobj_unregister);
1364         }
1365 }
1366
1367 static ssize_t btrfs_devinfo_in_fs_metadata_show(struct kobject *kobj,
1368                                                  struct kobj_attribute *a,
1369                                                  char *buf)
1370 {
1371         int val;
1372         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1373                                                    devid_kobj);
1374
1375         val = !!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state);
1376
1377         return scnprintf(buf, PAGE_SIZE, "%d\n", val);
1378 }
1379 BTRFS_ATTR(devid, in_fs_metadata, btrfs_devinfo_in_fs_metadata_show);
1380
1381 static ssize_t btrfs_devinfo_missing_show(struct kobject *kobj,
1382                                         struct kobj_attribute *a, char *buf)
1383 {
1384         int val;
1385         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1386                                                    devid_kobj);
1387
1388         val = !!test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state);
1389
1390         return scnprintf(buf, PAGE_SIZE, "%d\n", val);
1391 }
1392 BTRFS_ATTR(devid, missing, btrfs_devinfo_missing_show);
1393
1394 static ssize_t btrfs_devinfo_replace_target_show(struct kobject *kobj,
1395                                                  struct kobj_attribute *a,
1396                                                  char *buf)
1397 {
1398         int val;
1399         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1400                                                    devid_kobj);
1401
1402         val = !!test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state);
1403
1404         return scnprintf(buf, PAGE_SIZE, "%d\n", val);
1405 }
1406 BTRFS_ATTR(devid, replace_target, btrfs_devinfo_replace_target_show);
1407
1408 static ssize_t btrfs_devinfo_writeable_show(struct kobject *kobj,
1409                                             struct kobj_attribute *a, char *buf)
1410 {
1411         int val;
1412         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1413                                                    devid_kobj);
1414
1415         val = !!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state);
1416
1417         return scnprintf(buf, PAGE_SIZE, "%d\n", val);
1418 }
1419 BTRFS_ATTR(devid, writeable, btrfs_devinfo_writeable_show);
1420
1421 static struct attribute *devid_attrs[] = {
1422         BTRFS_ATTR_PTR(devid, in_fs_metadata),
1423         BTRFS_ATTR_PTR(devid, missing),
1424         BTRFS_ATTR_PTR(devid, replace_target),
1425         BTRFS_ATTR_PTR(devid, writeable),
1426         NULL
1427 };
1428 ATTRIBUTE_GROUPS(devid);
1429
1430 static void btrfs_release_devid_kobj(struct kobject *kobj)
1431 {
1432         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1433                                                    devid_kobj);
1434
1435         memset(&device->devid_kobj, 0, sizeof(struct kobject));
1436         complete(&device->kobj_unregister);
1437 }
1438
1439 static struct kobj_type devid_ktype = {
1440         .sysfs_ops      = &kobj_sysfs_ops,
1441         .default_groups = devid_groups,
1442         .release        = btrfs_release_devid_kobj,
1443 };
1444
1445 int btrfs_sysfs_add_device(struct btrfs_device *device)
1446 {
1447         int ret;
1448         unsigned int nofs_flag;
1449         struct kobject *devices_kobj;
1450         struct kobject *devinfo_kobj;
1451
1452         /*
1453          * Make sure we use the fs_info::fs_devices to fetch the kobjects even
1454          * for the seed fs_devices
1455          */
1456         devices_kobj = device->fs_info->fs_devices->devices_kobj;
1457         devinfo_kobj = device->fs_info->fs_devices->devinfo_kobj;
1458         ASSERT(devices_kobj);
1459         ASSERT(devinfo_kobj);
1460
1461         nofs_flag = memalloc_nofs_save();
1462
1463         if (device->bdev) {
1464                 struct kobject *disk_kobj = bdev_kobj(device->bdev);
1465
1466                 ret = sysfs_create_link(devices_kobj, disk_kobj, disk_kobj->name);
1467                 if (ret) {
1468                         btrfs_warn(device->fs_info,
1469                                 "creating sysfs device link for devid %llu failed: %d",
1470                                 device->devid, ret);
1471                         goto out;
1472                 }
1473         }
1474
1475         init_completion(&device->kobj_unregister);
1476         ret = kobject_init_and_add(&device->devid_kobj, &devid_ktype,
1477                                    devinfo_kobj, "%llu", device->devid);
1478         if (ret) {
1479                 kobject_put(&device->devid_kobj);
1480                 btrfs_warn(device->fs_info,
1481                            "devinfo init for devid %llu failed: %d",
1482                            device->devid, ret);
1483         }
1484
1485 out:
1486         memalloc_nofs_restore(nofs_flag);
1487         return ret;
1488 }
1489
1490 static int btrfs_sysfs_add_fs_devices(struct btrfs_fs_devices *fs_devices)
1491 {
1492         int ret;
1493         struct btrfs_device *device;
1494         struct btrfs_fs_devices *seed;
1495
1496         list_for_each_entry(device, &fs_devices->devices, dev_list) {
1497                 ret = btrfs_sysfs_add_device(device);
1498                 if (ret)
1499                         goto fail;
1500         }
1501
1502         list_for_each_entry(seed, &fs_devices->seed_list, seed_list) {
1503                 list_for_each_entry(device, &seed->devices, dev_list) {
1504                         ret = btrfs_sysfs_add_device(device);
1505                         if (ret)
1506                                 goto fail;
1507                 }
1508         }
1509
1510         return 0;
1511
1512 fail:
1513         btrfs_sysfs_remove_fs_devices(fs_devices);
1514         return ret;
1515 }
1516
1517 void btrfs_kobject_uevent(struct block_device *bdev, enum kobject_action action)
1518 {
1519         int ret;
1520
1521         ret = kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, action);
1522         if (ret)
1523                 pr_warn("BTRFS: Sending event '%d' to kobject: '%s' (%p): failed\n",
1524                         action, kobject_name(&disk_to_dev(bdev->bd_disk)->kobj),
1525                         &disk_to_dev(bdev->bd_disk)->kobj);
1526 }
1527
1528 void btrfs_sysfs_update_sprout_fsid(struct btrfs_fs_devices *fs_devices)
1529
1530 {
1531         char fsid_buf[BTRFS_UUID_UNPARSED_SIZE];
1532
1533         /*
1534          * Sprouting changes fsid of the mounted filesystem, rename the fsid
1535          * directory
1536          */
1537         snprintf(fsid_buf, BTRFS_UUID_UNPARSED_SIZE, "%pU", fs_devices->fsid);
1538         if (kobject_rename(&fs_devices->fsid_kobj, fsid_buf))
1539                 btrfs_warn(fs_devices->fs_info,
1540                                 "sysfs: failed to create fsid for sprout");
1541 }
1542
1543 void btrfs_sysfs_update_devid(struct btrfs_device *device)
1544 {
1545         char tmp[24];
1546
1547         snprintf(tmp, sizeof(tmp), "%llu", device->devid);
1548
1549         if (kobject_rename(&device->devid_kobj, tmp))
1550                 btrfs_warn(device->fs_devices->fs_info,
1551                            "sysfs: failed to update devid for %llu",
1552                            device->devid);
1553 }
1554
1555 /* /sys/fs/btrfs/ entry */
1556 static struct kset *btrfs_kset;
1557
1558 /*
1559  * Creates:
1560  *              /sys/fs/btrfs/UUID
1561  *
1562  * Can be called by the device discovery thread.
1563  */
1564 int btrfs_sysfs_add_fsid(struct btrfs_fs_devices *fs_devs)
1565 {
1566         int error;
1567
1568         init_completion(&fs_devs->kobj_unregister);
1569         fs_devs->fsid_kobj.kset = btrfs_kset;
1570         error = kobject_init_and_add(&fs_devs->fsid_kobj, &btrfs_ktype, NULL,
1571                                      "%pU", fs_devs->fsid);
1572         if (error) {
1573                 kobject_put(&fs_devs->fsid_kobj);
1574                 return error;
1575         }
1576
1577         fs_devs->devices_kobj = kobject_create_and_add("devices",
1578                                                        &fs_devs->fsid_kobj);
1579         if (!fs_devs->devices_kobj) {
1580                 btrfs_err(fs_devs->fs_info,
1581                           "failed to init sysfs device interface");
1582                 btrfs_sysfs_remove_fsid(fs_devs);
1583                 return -ENOMEM;
1584         }
1585
1586         fs_devs->devinfo_kobj = kobject_create_and_add("devinfo",
1587                                                        &fs_devs->fsid_kobj);
1588         if (!fs_devs->devinfo_kobj) {
1589                 btrfs_err(fs_devs->fs_info,
1590                           "failed to init sysfs devinfo kobject");
1591                 btrfs_sysfs_remove_fsid(fs_devs);
1592                 return -ENOMEM;
1593         }
1594
1595         return 0;
1596 }
1597
1598 int btrfs_sysfs_add_mounted(struct btrfs_fs_info *fs_info)
1599 {
1600         int error;
1601         struct btrfs_fs_devices *fs_devs = fs_info->fs_devices;
1602         struct kobject *fsid_kobj = &fs_devs->fsid_kobj;
1603
1604         error = btrfs_sysfs_add_fs_devices(fs_devs);
1605         if (error)
1606                 return error;
1607
1608         error = sysfs_create_files(fsid_kobj, btrfs_attrs);
1609         if (error) {
1610                 btrfs_sysfs_remove_fs_devices(fs_devs);
1611                 return error;
1612         }
1613
1614         error = sysfs_create_group(fsid_kobj,
1615                                    &btrfs_feature_attr_group);
1616         if (error)
1617                 goto failure;
1618
1619 #ifdef CONFIG_BTRFS_DEBUG
1620         fs_info->debug_kobj = kobject_create_and_add("debug", fsid_kobj);
1621         if (!fs_info->debug_kobj) {
1622                 error = -ENOMEM;
1623                 goto failure;
1624         }
1625
1626         error = sysfs_create_files(fs_info->debug_kobj, btrfs_debug_mount_attrs);
1627         if (error)
1628                 goto failure;
1629
1630         /* Discard directory */
1631         fs_info->discard_debug_kobj = kobject_create_and_add("discard",
1632                                                      fs_info->debug_kobj);
1633         if (!fs_info->discard_debug_kobj) {
1634                 error = -ENOMEM;
1635                 goto failure;
1636         }
1637
1638         error = sysfs_create_files(fs_info->discard_debug_kobj,
1639                                    discard_debug_attrs);
1640         if (error)
1641                 goto failure;
1642 #endif
1643
1644         error = addrm_unknown_feature_attrs(fs_info, true);
1645         if (error)
1646                 goto failure;
1647
1648         error = sysfs_create_link(fsid_kobj, &fs_info->sb->s_bdi->dev->kobj, "bdi");
1649         if (error)
1650                 goto failure;
1651
1652         fs_info->space_info_kobj = kobject_create_and_add("allocation",
1653                                                   fsid_kobj);
1654         if (!fs_info->space_info_kobj) {
1655                 error = -ENOMEM;
1656                 goto failure;
1657         }
1658
1659         error = sysfs_create_files(fs_info->space_info_kobj, allocation_attrs);
1660         if (error)
1661                 goto failure;
1662
1663         return 0;
1664 failure:
1665         btrfs_sysfs_remove_mounted(fs_info);
1666         return error;
1667 }
1668
1669 static inline struct btrfs_fs_info *qgroup_kobj_to_fs_info(struct kobject *kobj)
1670 {
1671         return to_fs_info(kobj->parent->parent);
1672 }
1673
1674 #define QGROUP_ATTR(_member, _show_name)                                        \
1675 static ssize_t btrfs_qgroup_show_##_member(struct kobject *qgroup_kobj,         \
1676                                            struct kobj_attribute *a,            \
1677                                            char *buf)                           \
1678 {                                                                               \
1679         struct btrfs_fs_info *fs_info = qgroup_kobj_to_fs_info(qgroup_kobj);    \
1680         struct btrfs_qgroup *qgroup = container_of(qgroup_kobj,                 \
1681                         struct btrfs_qgroup, kobj);                             \
1682         return btrfs_show_u64(&qgroup->_member, &fs_info->qgroup_lock, buf);    \
1683 }                                                                               \
1684 BTRFS_ATTR(qgroup, _show_name, btrfs_qgroup_show_##_member)
1685
1686 #define QGROUP_RSV_ATTR(_name, _type)                                           \
1687 static ssize_t btrfs_qgroup_rsv_show_##_name(struct kobject *qgroup_kobj,       \
1688                                              struct kobj_attribute *a,          \
1689                                              char *buf)                         \
1690 {                                                                               \
1691         struct btrfs_fs_info *fs_info = qgroup_kobj_to_fs_info(qgroup_kobj);    \
1692         struct btrfs_qgroup *qgroup = container_of(qgroup_kobj,                 \
1693                         struct btrfs_qgroup, kobj);                             \
1694         return btrfs_show_u64(&qgroup->rsv.values[_type],                       \
1695                         &fs_info->qgroup_lock, buf);                            \
1696 }                                                                               \
1697 BTRFS_ATTR(qgroup, rsv_##_name, btrfs_qgroup_rsv_show_##_name)
1698
1699 QGROUP_ATTR(rfer, referenced);
1700 QGROUP_ATTR(excl, exclusive);
1701 QGROUP_ATTR(max_rfer, max_referenced);
1702 QGROUP_ATTR(max_excl, max_exclusive);
1703 QGROUP_ATTR(lim_flags, limit_flags);
1704 QGROUP_RSV_ATTR(data, BTRFS_QGROUP_RSV_DATA);
1705 QGROUP_RSV_ATTR(meta_pertrans, BTRFS_QGROUP_RSV_META_PERTRANS);
1706 QGROUP_RSV_ATTR(meta_prealloc, BTRFS_QGROUP_RSV_META_PREALLOC);
1707
1708 static struct attribute *qgroup_attrs[] = {
1709         BTRFS_ATTR_PTR(qgroup, referenced),
1710         BTRFS_ATTR_PTR(qgroup, exclusive),
1711         BTRFS_ATTR_PTR(qgroup, max_referenced),
1712         BTRFS_ATTR_PTR(qgroup, max_exclusive),
1713         BTRFS_ATTR_PTR(qgroup, limit_flags),
1714         BTRFS_ATTR_PTR(qgroup, rsv_data),
1715         BTRFS_ATTR_PTR(qgroup, rsv_meta_pertrans),
1716         BTRFS_ATTR_PTR(qgroup, rsv_meta_prealloc),
1717         NULL
1718 };
1719 ATTRIBUTE_GROUPS(qgroup);
1720
1721 static void qgroup_release(struct kobject *kobj)
1722 {
1723         struct btrfs_qgroup *qgroup = container_of(kobj, struct btrfs_qgroup, kobj);
1724
1725         memset(&qgroup->kobj, 0, sizeof(*kobj));
1726 }
1727
1728 static struct kobj_type qgroup_ktype = {
1729         .sysfs_ops = &kobj_sysfs_ops,
1730         .release = qgroup_release,
1731         .default_groups = qgroup_groups,
1732 };
1733
1734 int btrfs_sysfs_add_one_qgroup(struct btrfs_fs_info *fs_info,
1735                                 struct btrfs_qgroup *qgroup)
1736 {
1737         struct kobject *qgroups_kobj = fs_info->qgroups_kobj;
1738         int ret;
1739
1740         if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
1741                 return 0;
1742         if (qgroup->kobj.state_initialized)
1743                 return 0;
1744         if (!qgroups_kobj)
1745                 return -EINVAL;
1746
1747         ret = kobject_init_and_add(&qgroup->kobj, &qgroup_ktype, qgroups_kobj,
1748                         "%hu_%llu", btrfs_qgroup_level(qgroup->qgroupid),
1749                         btrfs_qgroup_subvolid(qgroup->qgroupid));
1750         if (ret < 0)
1751                 kobject_put(&qgroup->kobj);
1752
1753         return ret;
1754 }
1755
1756 void btrfs_sysfs_del_qgroups(struct btrfs_fs_info *fs_info)
1757 {
1758         struct btrfs_qgroup *qgroup;
1759         struct btrfs_qgroup *next;
1760
1761         if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
1762                 return;
1763
1764         rbtree_postorder_for_each_entry_safe(qgroup, next,
1765                                              &fs_info->qgroup_tree, node)
1766                 btrfs_sysfs_del_one_qgroup(fs_info, qgroup);
1767         if (fs_info->qgroups_kobj) {
1768                 kobject_del(fs_info->qgroups_kobj);
1769                 kobject_put(fs_info->qgroups_kobj);
1770                 fs_info->qgroups_kobj = NULL;
1771         }
1772 }
1773
1774 /* Called when qgroups get initialized, thus there is no need for locking */
1775 int btrfs_sysfs_add_qgroups(struct btrfs_fs_info *fs_info)
1776 {
1777         struct kobject *fsid_kobj = &fs_info->fs_devices->fsid_kobj;
1778         struct btrfs_qgroup *qgroup;
1779         struct btrfs_qgroup *next;
1780         int ret = 0;
1781
1782         if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
1783                 return 0;
1784
1785         ASSERT(fsid_kobj);
1786         if (fs_info->qgroups_kobj)
1787                 return 0;
1788
1789         fs_info->qgroups_kobj = kobject_create_and_add("qgroups", fsid_kobj);
1790         if (!fs_info->qgroups_kobj) {
1791                 ret = -ENOMEM;
1792                 goto out;
1793         }
1794         rbtree_postorder_for_each_entry_safe(qgroup, next,
1795                                              &fs_info->qgroup_tree, node) {
1796                 ret = btrfs_sysfs_add_one_qgroup(fs_info, qgroup);
1797                 if (ret < 0)
1798                         goto out;
1799         }
1800
1801 out:
1802         if (ret < 0)
1803                 btrfs_sysfs_del_qgroups(fs_info);
1804         return ret;
1805 }
1806
1807 void btrfs_sysfs_del_one_qgroup(struct btrfs_fs_info *fs_info,
1808                                 struct btrfs_qgroup *qgroup)
1809 {
1810         if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
1811                 return;
1812
1813         if (qgroup->kobj.state_initialized) {
1814                 kobject_del(&qgroup->kobj);
1815                 kobject_put(&qgroup->kobj);
1816         }
1817 }
1818
1819 /*
1820  * Change per-fs features in /sys/fs/btrfs/UUID/features to match current
1821  * values in superblock. Call after any changes to incompat/compat_ro flags
1822  */
1823 void btrfs_sysfs_feature_update(struct btrfs_fs_info *fs_info,
1824                 u64 bit, enum btrfs_feature_set set)
1825 {
1826         struct btrfs_fs_devices *fs_devs;
1827         struct kobject *fsid_kobj;
1828         u64 __maybe_unused features;
1829         int __maybe_unused ret;
1830
1831         if (!fs_info)
1832                 return;
1833
1834         /*
1835          * See 14e46e04958df74 and e410e34fad913dd, feature bit updates are not
1836          * safe when called from some contexts (eg. balance)
1837          */
1838         features = get_features(fs_info, set);
1839         ASSERT(bit & supported_feature_masks[set]);
1840
1841         fs_devs = fs_info->fs_devices;
1842         fsid_kobj = &fs_devs->fsid_kobj;
1843
1844         if (!fsid_kobj->state_initialized)
1845                 return;
1846
1847         /*
1848          * FIXME: this is too heavy to update just one value, ideally we'd like
1849          * to use sysfs_update_group but some refactoring is needed first.
1850          */
1851         sysfs_remove_group(fsid_kobj, &btrfs_feature_attr_group);
1852         ret = sysfs_create_group(fsid_kobj, &btrfs_feature_attr_group);
1853 }
1854
1855 int __init btrfs_init_sysfs(void)
1856 {
1857         int ret;
1858
1859         btrfs_kset = kset_create_and_add("btrfs", NULL, fs_kobj);
1860         if (!btrfs_kset)
1861                 return -ENOMEM;
1862
1863         init_feature_attrs();
1864         ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
1865         if (ret)
1866                 goto out2;
1867         ret = sysfs_merge_group(&btrfs_kset->kobj,
1868                                 &btrfs_static_feature_attr_group);
1869         if (ret)
1870                 goto out_remove_group;
1871
1872 #ifdef CONFIG_BTRFS_DEBUG
1873         ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_debug_feature_attr_group);
1874         if (ret)
1875                 goto out2;
1876 #endif
1877
1878         return 0;
1879
1880 out_remove_group:
1881         sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
1882 out2:
1883         kset_unregister(btrfs_kset);
1884
1885         return ret;
1886 }
1887
1888 void __cold btrfs_exit_sysfs(void)
1889 {
1890         sysfs_unmerge_group(&btrfs_kset->kobj,
1891                             &btrfs_static_feature_attr_group);
1892         sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
1893 #ifdef CONFIG_BTRFS_DEBUG
1894         sysfs_remove_group(&btrfs_kset->kobj, &btrfs_debug_feature_attr_group);
1895 #endif
1896         kset_unregister(btrfs_kset);
1897 }
1898