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 ssize_t supported_sectorsizes_show(struct kobject *kobj,
 364                                           struct kobj_attribute *a,
 365                                           char *buf)
 366 {
 367         ssize_t ret = 0;
 368
 369         /* Only sectorsize == PAGE_SIZE is now supported */
 370         ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%lu\n", PAGE_SIZE);
 371
 372         return ret;
 373 }
 374 BTRFS_ATTR(static_feature, supported_sectorsizes,
 375            supported_sectorsizes_show);
 376
 377 static struct attribute *btrfs_supported_static_feature_attrs[] = {
 378         BTRFS_ATTR_PTR(static_feature, rmdir_subvol),
 379         BTRFS_ATTR_PTR(static_feature, supported_checksums),
 380         BTRFS_ATTR_PTR(static_feature, send_stream_version),
 381         BTRFS_ATTR_PTR(static_feature, supported_rescue_options),
 382         BTRFS_ATTR_PTR(static_feature, supported_sectorsizes),
 383         NULL
 384 };
 385
 386 /*
 387  * Features which only depend on kernel version.
 388  *
 389  * These are listed in /sys/fs/btrfs/features along with
 390  * btrfs_feature_attr_group
 391  */
 392 static const struct attribute_group btrfs_static_feature_attr_group = {
 393         .name = "features",
 394         .attrs = btrfs_supported_static_feature_attrs,
 395 };
 396
 397 #ifdef CONFIG_BTRFS_DEBUG
 398
 399 /*
 400  * Discard statistics and tunables
 401  */
 402 #define discard_to_fs_info(_kobj)       to_fs_info((_kobj)->parent->parent)
 403
 404 static ssize_t btrfs_discardable_bytes_show(struct kobject *kobj,
 405                                             struct kobj_attribute *a,
 406                                             char *buf)
 407 {
 408         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 409
 410         return scnprintf(buf, PAGE_SIZE, "%lld\n",
 411                         atomic64_read(&fs_info->discard_ctl.discardable_bytes));
 412 }
 413 BTRFS_ATTR(discard, discardable_bytes, btrfs_discardable_bytes_show);
 414
 415 static ssize_t btrfs_discardable_extents_show(struct kobject *kobj,
 416                                               struct kobj_attribute *a,
 417                                               char *buf)
 418 {
 419         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 420
 421         return scnprintf(buf, PAGE_SIZE, "%d\n",
 422                         atomic_read(&fs_info->discard_ctl.discardable_extents));
 423 }
 424 BTRFS_ATTR(discard, discardable_extents, btrfs_discardable_extents_show);
 425
 426 static ssize_t btrfs_discard_bitmap_bytes_show(struct kobject *kobj,
 427                                                struct kobj_attribute *a,
 428                                                char *buf)
 429 {
 430         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 431
 432         return scnprintf(buf, PAGE_SIZE, "%llu\n",
 433                         fs_info->discard_ctl.discard_bitmap_bytes);
 434 }
 435 BTRFS_ATTR(discard, discard_bitmap_bytes, btrfs_discard_bitmap_bytes_show);
 436
 437 static ssize_t btrfs_discard_bytes_saved_show(struct kobject *kobj,
 438                                               struct kobj_attribute *a,
 439                                               char *buf)
 440 {
 441         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 442
 443         return scnprintf(buf, PAGE_SIZE, "%lld\n",
 444                 atomic64_read(&fs_info->discard_ctl.discard_bytes_saved));
 445 }
 446 BTRFS_ATTR(discard, discard_bytes_saved, btrfs_discard_bytes_saved_show);
 447
 448 static ssize_t btrfs_discard_extent_bytes_show(struct kobject *kobj,
 449                                                struct kobj_attribute *a,
 450                                                char *buf)
 451 {
 452         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 453
 454         return scnprintf(buf, PAGE_SIZE, "%llu\n",
 455                         fs_info->discard_ctl.discard_extent_bytes);
 456 }
 457 BTRFS_ATTR(discard, discard_extent_bytes, btrfs_discard_extent_bytes_show);
 458
 459 static ssize_t btrfs_discard_iops_limit_show(struct kobject *kobj,
 460                                              struct kobj_attribute *a,
 461                                              char *buf)
 462 {
 463         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 464
 465         return scnprintf(buf, PAGE_SIZE, "%u\n",
 466                         READ_ONCE(fs_info->discard_ctl.iops_limit));
 467 }
 468
 469 static ssize_t btrfs_discard_iops_limit_store(struct kobject *kobj,
 470                                               struct kobj_attribute *a,
 471                                               const char *buf, size_t len)
 472 {
 473         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 474         struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
 475         u32 iops_limit;
 476         int ret;
 477
 478         ret = kstrtou32(buf, 10, &iops_limit);
 479         if (ret)
 480                 return -EINVAL;
 481
 482         WRITE_ONCE(discard_ctl->iops_limit, iops_limit);
 483         btrfs_discard_calc_delay(discard_ctl);
 484         btrfs_discard_schedule_work(discard_ctl, true);
 485         return len;
 486 }
 487 BTRFS_ATTR_RW(discard, iops_limit, btrfs_discard_iops_limit_show,
 488               btrfs_discard_iops_limit_store);
 489
 490 static ssize_t btrfs_discard_kbps_limit_show(struct kobject *kobj,
 491                                              struct kobj_attribute *a,
 492                                              char *buf)
 493 {
 494         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 495
 496         return scnprintf(buf, PAGE_SIZE, "%u\n",
 497                         READ_ONCE(fs_info->discard_ctl.kbps_limit));
 498 }
 499
 500 static ssize_t btrfs_discard_kbps_limit_store(struct kobject *kobj,
 501                                               struct kobj_attribute *a,
 502                                               const char *buf, size_t len)
 503 {
 504         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 505         struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
 506         u32 kbps_limit;
 507         int ret;
 508
 509         ret = kstrtou32(buf, 10, &kbps_limit);
 510         if (ret)
 511                 return -EINVAL;
 512
 513         WRITE_ONCE(discard_ctl->kbps_limit, kbps_limit);
 514         btrfs_discard_schedule_work(discard_ctl, true);
 515         return len;
 516 }
 517 BTRFS_ATTR_RW(discard, kbps_limit, btrfs_discard_kbps_limit_show,
 518               btrfs_discard_kbps_limit_store);
 519
 520 static ssize_t btrfs_discard_max_discard_size_show(struct kobject *kobj,
 521                                                    struct kobj_attribute *a,
 522                                                    char *buf)
 523 {
 524         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 525
 526         return scnprintf(buf, PAGE_SIZE, "%llu\n",
 527                         READ_ONCE(fs_info->discard_ctl.max_discard_size));
 528 }
 529
 530 static ssize_t btrfs_discard_max_discard_size_store(struct kobject *kobj,
 531                                                     struct kobj_attribute *a,
 532                                                     const char *buf, size_t len)
 533 {
 534         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 535         struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
 536         u64 max_discard_size;
 537         int ret;
 538
 539         ret = kstrtou64(buf, 10, &max_discard_size);
 540         if (ret)
 541                 return -EINVAL;
 542
 543         WRITE_ONCE(discard_ctl->max_discard_size, max_discard_size);
 544
 545         return len;
 546 }
 547 BTRFS_ATTR_RW(discard, max_discard_size, btrfs_discard_max_discard_size_show,
 548               btrfs_discard_max_discard_size_store);
 549
 550 static const struct attribute *discard_debug_attrs[] = {
 551         BTRFS_ATTR_PTR(discard, discardable_bytes),
 552         BTRFS_ATTR_PTR(discard, discardable_extents),
 553         BTRFS_ATTR_PTR(discard, discard_bitmap_bytes),
 554         BTRFS_ATTR_PTR(discard, discard_bytes_saved),
 555         BTRFS_ATTR_PTR(discard, discard_extent_bytes),
 556         BTRFS_ATTR_PTR(discard, iops_limit),
 557         BTRFS_ATTR_PTR(discard, kbps_limit),
 558         BTRFS_ATTR_PTR(discard, max_discard_size),
 559         NULL,
 560 };
 561
 562 /*
 563  * Runtime debugging exported via sysfs
 564  *
 565  * /sys/fs/btrfs/debug - applies to module or all filesystems
 566  * /sys/fs/btrfs/UUID  - applies only to the given filesystem
 567  */
 568 static const struct attribute *btrfs_debug_mount_attrs[] = {
 569         NULL,
 570 };
 571
 572 static struct attribute *btrfs_debug_feature_attrs[] = {
 573         NULL
 574 };
 575
 576 static const struct attribute_group btrfs_debug_feature_attr_group = {
 577         .name = "debug",
 578         .attrs = btrfs_debug_feature_attrs,
 579 };
 580
 581 #endif
 582
 583 static ssize_t btrfs_show_u64(u64 *value_ptr, spinlock_t *lock, char *buf)
 584 {
 585         u64 val;
 586         if (lock)
 587                 spin_lock(lock);
 588         val = *value_ptr;
 589         if (lock)
 590                 spin_unlock(lock);
 591         return scnprintf(buf, PAGE_SIZE, "%llu\n", val);
 592 }
 593
 594 static ssize_t global_rsv_size_show(struct kobject *kobj,
 595                                     struct kobj_attribute *ka, char *buf)
 596 {
 597         struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent);
 598         struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
 599         return btrfs_show_u64(&block_rsv->size, &block_rsv->lock, buf);
 600 }
 601 BTRFS_ATTR(allocation, global_rsv_size, global_rsv_size_show);
 602
 603 static ssize_t global_rsv_reserved_show(struct kobject *kobj,
 604                                         struct kobj_attribute *a, char *buf)
 605 {
 606         struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent);
 607         struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
 608         return btrfs_show_u64(&block_rsv->reserved, &block_rsv->lock, buf);
 609 }
 610 BTRFS_ATTR(allocation, global_rsv_reserved, global_rsv_reserved_show);
 611
 612 #define to_space_info(_kobj) container_of(_kobj, struct btrfs_space_info, kobj)
 613 #define to_raid_kobj(_kobj) container_of(_kobj, struct raid_kobject, kobj)
 614
 615 static ssize_t raid_bytes_show(struct kobject *kobj,
 616                                struct kobj_attribute *attr, char *buf);
 617 BTRFS_ATTR(raid, total_bytes, raid_bytes_show);
 618 BTRFS_ATTR(raid, used_bytes, raid_bytes_show);
 619
 620 static ssize_t raid_bytes_show(struct kobject *kobj,
 621                                struct kobj_attribute *attr, char *buf)
 622
 623 {
 624         struct btrfs_space_info *sinfo = to_space_info(kobj->parent);
 625         struct btrfs_block_group *block_group;
 626         int index = btrfs_bg_flags_to_raid_index(to_raid_kobj(kobj)->flags);
 627         u64 val = 0;
 628
 629         down_read(&sinfo->groups_sem);
 630         list_for_each_entry(block_group, &sinfo->block_groups[index], list) {
 631                 if (&attr->attr == BTRFS_ATTR_PTR(raid, total_bytes))
 632                         val += block_group->length;
 633                 else
 634                         val += block_group->used;
 635         }
 636         up_read(&sinfo->groups_sem);
 637         return scnprintf(buf, PAGE_SIZE, "%llu\n", val);
 638 }
 639
 640 static struct attribute *raid_attrs[] = {
 641         BTRFS_ATTR_PTR(raid, total_bytes),
 642         BTRFS_ATTR_PTR(raid, used_bytes),
 643         NULL
 644 };
 645 ATTRIBUTE_GROUPS(raid);
 646
 647 static void release_raid_kobj(struct kobject *kobj)
 648 {
 649         kfree(to_raid_kobj(kobj));
 650 }
 651
 652 static struct kobj_type btrfs_raid_ktype = {
 653         .sysfs_ops = &kobj_sysfs_ops,
 654         .release = release_raid_kobj,
 655         .default_groups = raid_groups,
 656 };
 657
 658 #define SPACE_INFO_ATTR(field)                                          \
 659 static ssize_t btrfs_space_info_show_##field(struct kobject *kobj,      \
 660                                              struct kobj_attribute *a,  \
 661                                              char *buf)                 \
 662 {                                                                       \
 663         struct btrfs_space_info *sinfo = to_space_info(kobj);           \
 664         return btrfs_show_u64(&sinfo->field, &sinfo->lock, buf);        \
 665 }                                                                       \
 666 BTRFS_ATTR(space_info, field, btrfs_space_info_show_##field)
 667
 668 static ssize_t btrfs_space_info_show_total_bytes_pinned(struct kobject *kobj,
 669                                                        struct kobj_attribute *a,
 670                                                        char *buf)
 671 {
 672         struct btrfs_space_info *sinfo = to_space_info(kobj);
 673         s64 val = percpu_counter_sum(&sinfo->total_bytes_pinned);
 674         return scnprintf(buf, PAGE_SIZE, "%lld\n", val);
 675 }
 676
 677 SPACE_INFO_ATTR(flags);
 678 SPACE_INFO_ATTR(total_bytes);
 679 SPACE_INFO_ATTR(bytes_used);
 680 SPACE_INFO_ATTR(bytes_pinned);
 681 SPACE_INFO_ATTR(bytes_reserved);
 682 SPACE_INFO_ATTR(bytes_may_use);
 683 SPACE_INFO_ATTR(bytes_readonly);
 684 SPACE_INFO_ATTR(bytes_zone_unusable);
 685 SPACE_INFO_ATTR(disk_used);
 686 SPACE_INFO_ATTR(disk_total);
 687 BTRFS_ATTR(space_info, total_bytes_pinned,
 688            btrfs_space_info_show_total_bytes_pinned);
 689
 690 static struct attribute *space_info_attrs[] = {
 691         BTRFS_ATTR_PTR(space_info, flags),
 692         BTRFS_ATTR_PTR(space_info, total_bytes),
 693         BTRFS_ATTR_PTR(space_info, bytes_used),
 694         BTRFS_ATTR_PTR(space_info, bytes_pinned),
 695         BTRFS_ATTR_PTR(space_info, bytes_reserved),
 696         BTRFS_ATTR_PTR(space_info, bytes_may_use),
 697         BTRFS_ATTR_PTR(space_info, bytes_readonly),
 698         BTRFS_ATTR_PTR(space_info, bytes_zone_unusable),
 699         BTRFS_ATTR_PTR(space_info, disk_used),
 700         BTRFS_ATTR_PTR(space_info, disk_total),
 701         BTRFS_ATTR_PTR(space_info, total_bytes_pinned),
 702         NULL,
 703 };
 704 ATTRIBUTE_GROUPS(space_info);
 705
 706 static void space_info_release(struct kobject *kobj)
 707 {
 708         struct btrfs_space_info *sinfo = to_space_info(kobj);
 709         percpu_counter_destroy(&sinfo->total_bytes_pinned);
 710         kfree(sinfo);
 711 }
 712
 713 static struct kobj_type space_info_ktype = {
 714         .sysfs_ops = &kobj_sysfs_ops,
 715         .release = space_info_release,
 716         .default_groups = space_info_groups,
 717 };
 718
 719 static const struct attribute *allocation_attrs[] = {
 720         BTRFS_ATTR_PTR(allocation, global_rsv_reserved),
 721         BTRFS_ATTR_PTR(allocation, global_rsv_size),
 722         NULL,
 723 };
 724
 725 static ssize_t btrfs_label_show(struct kobject *kobj,
 726                                 struct kobj_attribute *a, char *buf)
 727 {
 728         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 729         char *label = fs_info->super_copy->label;
 730         ssize_t ret;
 731
 732         spin_lock(&fs_info->super_lock);
 733         ret = scnprintf(buf, PAGE_SIZE, label[0] ? "%s\n" : "%s", label);
 734         spin_unlock(&fs_info->super_lock);
 735
 736         return ret;
 737 }
 738
 739 static ssize_t btrfs_label_store(struct kobject *kobj,
 740                                  struct kobj_attribute *a,
 741                                  const char *buf, size_t len)
 742 {
 743         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 744         size_t p_len;
 745
 746         if (!fs_info)
 747                 return -EPERM;
 748
 749         if (sb_rdonly(fs_info->sb))
 750                 return -EROFS;
 751
 752         /*
 753          * p_len is the len until the first occurrence of either
 754          * '\n' or '\0'
 755          */
 756         p_len = strcspn(buf, "\n");
 757
 758         if (p_len >= BTRFS_LABEL_SIZE)
 759                 return -EINVAL;
 760
 761         spin_lock(&fs_info->super_lock);
 762         memset(fs_info->super_copy->label, 0, BTRFS_LABEL_SIZE);
 763         memcpy(fs_info->super_copy->label, buf, p_len);
 764         spin_unlock(&fs_info->super_lock);
 765
 766         /*
 767          * We don't want to do full transaction commit from inside sysfs
 768          */
 769         btrfs_set_pending(fs_info, COMMIT);
 770         wake_up_process(fs_info->transaction_kthread);
 771
 772         return len;
 773 }
 774 BTRFS_ATTR_RW(, label, btrfs_label_show, btrfs_label_store);
 775
 776 static ssize_t btrfs_nodesize_show(struct kobject *kobj,
 777                                 struct kobj_attribute *a, char *buf)
 778 {
 779         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 780
 781         return scnprintf(buf, PAGE_SIZE, "%u\n", fs_info->super_copy->nodesize);
 782 }
 783
 784 BTRFS_ATTR(, nodesize, btrfs_nodesize_show);
 785
 786 static ssize_t btrfs_sectorsize_show(struct kobject *kobj,
 787                                 struct kobj_attribute *a, char *buf)
 788 {
 789         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 790
 791         return scnprintf(buf, PAGE_SIZE, "%u\n",
 792                          fs_info->super_copy->sectorsize);
 793 }
 794
 795 BTRFS_ATTR(, sectorsize, btrfs_sectorsize_show);
 796
 797 static ssize_t btrfs_clone_alignment_show(struct kobject *kobj,
 798                                 struct kobj_attribute *a, char *buf)
 799 {
 800         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 801
 802         return scnprintf(buf, PAGE_SIZE, "%u\n", fs_info->super_copy->sectorsize);
 803 }
 804
 805 BTRFS_ATTR(, clone_alignment, btrfs_clone_alignment_show);
 806
 807 static ssize_t quota_override_show(struct kobject *kobj,
 808                                    struct kobj_attribute *a, char *buf)
 809 {
 810         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 811         int quota_override;
 812
 813         quota_override = test_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
 814         return scnprintf(buf, PAGE_SIZE, "%d\n", quota_override);
 815 }
 816
 817 static ssize_t quota_override_store(struct kobject *kobj,
 818                                     struct kobj_attribute *a,
 819                                     const char *buf, size_t len)
 820 {
 821         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 822         unsigned long knob;
 823         int err;
 824
 825         if (!fs_info)
 826                 return -EPERM;
 827
 828         if (!capable(CAP_SYS_RESOURCE))
 829                 return -EPERM;
 830
 831         err = kstrtoul(buf, 10, &knob);
 832         if (err)
 833                 return err;
 834         if (knob > 1)
 835                 return -EINVAL;
 836
 837         if (knob)
 838                 set_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
 839         else
 840                 clear_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
 841
 842         return len;
 843 }
 844
 845 BTRFS_ATTR_RW(, quota_override, quota_override_show, quota_override_store);
 846
 847 static ssize_t btrfs_metadata_uuid_show(struct kobject *kobj,
 848                                 struct kobj_attribute *a, char *buf)
 849 {
 850         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 851
 852         return scnprintf(buf, PAGE_SIZE, "%pU\n",
 853                         fs_info->fs_devices->metadata_uuid);
 854 }
 855
 856 BTRFS_ATTR(, metadata_uuid, btrfs_metadata_uuid_show);
 857
 858 static ssize_t btrfs_checksum_show(struct kobject *kobj,
 859                                    struct kobj_attribute *a, char *buf)
 860 {
 861         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 862         u16 csum_type = btrfs_super_csum_type(fs_info->super_copy);
 863
 864         return scnprintf(buf, PAGE_SIZE, "%s (%s)\n",
 865                         btrfs_super_csum_name(csum_type),
 866                         crypto_shash_driver_name(fs_info->csum_shash));
 867 }
 868
 869 BTRFS_ATTR(, checksum, btrfs_checksum_show);
 870
 871 static ssize_t btrfs_exclusive_operation_show(struct kobject *kobj,
 872                 struct kobj_attribute *a, char *buf)
 873 {
 874         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 875         const char *str;
 876
 877         switch (READ_ONCE(fs_info->exclusive_operation)) {
 878                 case  BTRFS_EXCLOP_NONE:
 879                         str = "none\n";
 880                         break;
 881                 case BTRFS_EXCLOP_BALANCE:
 882                         str = "balance\n";
 883                         break;
 884                 case BTRFS_EXCLOP_DEV_ADD:
 885                         str = "device add\n";
 886                         break;
 887                 case BTRFS_EXCLOP_DEV_REMOVE:
 888                         str = "device remove\n";
 889                         break;
 890                 case BTRFS_EXCLOP_DEV_REPLACE:
 891                         str = "device replace\n";
 892                         break;
 893                 case BTRFS_EXCLOP_RESIZE:
 894                         str = "resize\n";
 895                         break;
 896                 case BTRFS_EXCLOP_SWAP_ACTIVATE:
 897                         str = "swap activate\n";
 898                         break;
 899                 default:
 900                         str = "UNKNOWN\n";
 901                         break;
 902         }
 903         return scnprintf(buf, PAGE_SIZE, "%s", str);
 904 }
 905 BTRFS_ATTR(, exclusive_operation, btrfs_exclusive_operation_show);
 906
 907 static ssize_t btrfs_generation_show(struct kobject *kobj,
 908                                      struct kobj_attribute *a, char *buf)
 909 {
 910         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 911
 912         return scnprintf(buf, PAGE_SIZE, "%llu\n", fs_info->generation);
 913 }
 914 BTRFS_ATTR(, generation, btrfs_generation_show);
 915
 916 /*
 917  * Look for an exact string @string in @buffer with possible leading or
 918  * trailing whitespace
 919  */
 920 static bool strmatch(const char *buffer, const char *string)
 921 {
 922         const size_t len = strlen(string);
 923
 924         /* Skip leading whitespace */
 925         buffer = skip_spaces(buffer);
 926
 927         /* Match entire string, check if the rest is whitespace or empty */
 928         if (strncmp(string, buffer, len) == 0 &&
 929             strlen(skip_spaces(buffer + len)) == 0)
 930                 return true;
 931
 932         return false;
 933 }
 934
 935 static const char * const btrfs_read_policy_name[] = { "pid" };
 936
 937 static ssize_t btrfs_read_policy_show(struct kobject *kobj,
 938                                       struct kobj_attribute *a, char *buf)
 939 {
 940         struct btrfs_fs_devices *fs_devices = to_fs_devs(kobj);
 941         ssize_t ret = 0;
 942         int i;
 943
 944         for (i = 0; i < BTRFS_NR_READ_POLICY; i++) {
 945                 if (fs_devices->read_policy == i)
 946                         ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s[%s]",
 947                                          (ret == 0 ? "" : " "),
 948                                          btrfs_read_policy_name[i]);
 949                 else
 950                         ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%s",
 951                                          (ret == 0 ? "" : " "),
 952                                          btrfs_read_policy_name[i]);
 953         }
 954
 955         ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
 956
 957         return ret;
 958 }
 959
 960 static ssize_t btrfs_read_policy_store(struct kobject *kobj,
 961                                        struct kobj_attribute *a,
 962                                        const char *buf, size_t len)
 963 {
 964         struct btrfs_fs_devices *fs_devices = to_fs_devs(kobj);
 965         int i;
 966
 967         for (i = 0; i < BTRFS_NR_READ_POLICY; i++) {
 968                 if (strmatch(buf, btrfs_read_policy_name[i])) {
 969                         if (i != fs_devices->read_policy) {
 970                                 fs_devices->read_policy = i;
 971                                 btrfs_info(fs_devices->fs_info,
 972                                            "read policy set to '%s'",
 973                                            btrfs_read_policy_name[i]);
 974                         }
 975                         return len;
 976                 }
 977         }
 978
 979         return -EINVAL;
 980 }
 981 BTRFS_ATTR_RW(, read_policy, btrfs_read_policy_show, btrfs_read_policy_store);
 982
 983 static ssize_t btrfs_bg_reclaim_threshold_show(struct kobject *kobj,
 984                                                struct kobj_attribute *a,
 985                                                char *buf)
 986 {
 987         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 988         ssize_t ret;
 989
 990         ret = scnprintf(buf, PAGE_SIZE, "%d\n", fs_info->bg_reclaim_threshold);
 991
 992         return ret;
 993 }
 994
 995 static ssize_t btrfs_bg_reclaim_threshold_store(struct kobject *kobj,
 996                                                 struct kobj_attribute *a,
 997                                                 const char *buf, size_t len)
 998 {
 999         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1000         int thresh;
1001         int ret;
1002
1003         ret = kstrtoint(buf, 10, &thresh);
1004         if (ret)
1005                 return ret;
1006
1007         if (thresh <= 50 || thresh > 100)
1008                 return -EINVAL;
1009
1010         fs_info->bg_reclaim_threshold = thresh;
1011
1012         return len;
1013 }
1014 BTRFS_ATTR_RW(, bg_reclaim_threshold, btrfs_bg_reclaim_threshold_show,
1015               btrfs_bg_reclaim_threshold_store);
1016
1017 static const struct attribute *btrfs_attrs[] = {
1018         BTRFS_ATTR_PTR(, label),
1019         BTRFS_ATTR_PTR(, nodesize),
1020         BTRFS_ATTR_PTR(, sectorsize),
1021         BTRFS_ATTR_PTR(, clone_alignment),
1022         BTRFS_ATTR_PTR(, quota_override),
1023         BTRFS_ATTR_PTR(, metadata_uuid),
1024         BTRFS_ATTR_PTR(, checksum),
1025         BTRFS_ATTR_PTR(, exclusive_operation),
1026         BTRFS_ATTR_PTR(, generation),
1027         BTRFS_ATTR_PTR(, read_policy),
1028         BTRFS_ATTR_PTR(, bg_reclaim_threshold),
1029         NULL,
1030 };
1031
1032 static void btrfs_release_fsid_kobj(struct kobject *kobj)
1033 {
1034         struct btrfs_fs_devices *fs_devs = to_fs_devs(kobj);
1035
1036         memset(&fs_devs->fsid_kobj, 0, sizeof(struct kobject));
1037         complete(&fs_devs->kobj_unregister);
1038 }
1039
1040 static struct kobj_type btrfs_ktype = {
1041         .sysfs_ops      = &kobj_sysfs_ops,
1042         .release        = btrfs_release_fsid_kobj,
1043 };
1044
1045 static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj)
1046 {
1047         if (kobj->ktype != &btrfs_ktype)
1048                 return NULL;
1049         return container_of(kobj, struct btrfs_fs_devices, fsid_kobj);
1050 }
1051
1052 static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj)
1053 {
1054         if (kobj->ktype != &btrfs_ktype)
1055                 return NULL;
1056         return to_fs_devs(kobj)->fs_info;
1057 }
1058
1059 #define NUM_FEATURE_BITS 64
1060 #define BTRFS_FEATURE_NAME_MAX 13
1061 static char btrfs_unknown_feature_names[FEAT_MAX][NUM_FEATURE_BITS][BTRFS_FEATURE_NAME_MAX];
1062 static struct btrfs_feature_attr btrfs_feature_attrs[FEAT_MAX][NUM_FEATURE_BITS];
1063
1064 static const u64 supported_feature_masks[FEAT_MAX] = {
1065         [FEAT_COMPAT]    = BTRFS_FEATURE_COMPAT_SUPP,
1066         [FEAT_COMPAT_RO] = BTRFS_FEATURE_COMPAT_RO_SUPP,
1067         [FEAT_INCOMPAT]  = BTRFS_FEATURE_INCOMPAT_SUPP,
1068 };
1069
1070 static int addrm_unknown_feature_attrs(struct btrfs_fs_info *fs_info, bool add)
1071 {
1072         int set;
1073
1074         for (set = 0; set < FEAT_MAX; set++) {
1075                 int i;
1076                 struct attribute *attrs[2];
1077                 struct attribute_group agroup = {
1078                         .name = "features",
1079                         .attrs = attrs,
1080                 };
1081                 u64 features = get_features(fs_info, set);
1082                 features &= ~supported_feature_masks[set];
1083
1084                 if (!features)
1085                         continue;
1086
1087                 attrs[1] = NULL;
1088                 for (i = 0; i < NUM_FEATURE_BITS; i++) {
1089                         struct btrfs_feature_attr *fa;
1090
1091                         if (!(features & (1ULL << i)))
1092                                 continue;
1093
1094                         fa = &btrfs_feature_attrs[set][i];
1095                         attrs[0] = &fa->kobj_attr.attr;
1096                         if (add) {
1097                                 int ret;
1098                                 ret = sysfs_merge_group(&fs_info->fs_devices->fsid_kobj,
1099                                                         &agroup);
1100                                 if (ret)
1101                                         return ret;
1102                         } else
1103                                 sysfs_unmerge_group(&fs_info->fs_devices->fsid_kobj,
1104                                                     &agroup);
1105                 }
1106
1107         }
1108         return 0;
1109 }
1110
1111 static void __btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs)
1112 {
1113         if (fs_devs->devinfo_kobj) {
1114                 kobject_del(fs_devs->devinfo_kobj);
1115                 kobject_put(fs_devs->devinfo_kobj);
1116                 fs_devs->devinfo_kobj = NULL;
1117         }
1118
1119         if (fs_devs->devices_kobj) {
1120                 kobject_del(fs_devs->devices_kobj);
1121                 kobject_put(fs_devs->devices_kobj);
1122                 fs_devs->devices_kobj = NULL;
1123         }
1124
1125         if (fs_devs->fsid_kobj.state_initialized) {
1126                 kobject_del(&fs_devs->fsid_kobj);
1127                 kobject_put(&fs_devs->fsid_kobj);
1128                 wait_for_completion(&fs_devs->kobj_unregister);
1129         }
1130 }
1131
1132 /* when fs_devs is NULL it will remove all fsid kobject */
1133 void btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs)
1134 {
1135         struct list_head *fs_uuids = btrfs_get_fs_uuids();
1136
1137         if (fs_devs) {
1138                 __btrfs_sysfs_remove_fsid(fs_devs);
1139                 return;
1140         }
1141
1142         list_for_each_entry(fs_devs, fs_uuids, fs_list) {
1143                 __btrfs_sysfs_remove_fsid(fs_devs);
1144         }
1145 }
1146
1147 static void btrfs_sysfs_remove_fs_devices(struct btrfs_fs_devices *fs_devices)
1148 {
1149         struct btrfs_device *device;
1150         struct btrfs_fs_devices *seed;
1151
1152         list_for_each_entry(device, &fs_devices->devices, dev_list)
1153                 btrfs_sysfs_remove_device(device);
1154
1155         list_for_each_entry(seed, &fs_devices->seed_list, seed_list) {
1156                 list_for_each_entry(device, &seed->devices, dev_list)
1157                         btrfs_sysfs_remove_device(device);
1158         }
1159 }
1160
1161 void btrfs_sysfs_remove_mounted(struct btrfs_fs_info *fs_info)
1162 {
1163         struct kobject *fsid_kobj = &fs_info->fs_devices->fsid_kobj;
1164
1165         sysfs_remove_link(fsid_kobj, "bdi");
1166
1167         if (fs_info->space_info_kobj) {
1168                 sysfs_remove_files(fs_info->space_info_kobj, allocation_attrs);
1169                 kobject_del(fs_info->space_info_kobj);
1170                 kobject_put(fs_info->space_info_kobj);
1171         }
1172 #ifdef CONFIG_BTRFS_DEBUG
1173         if (fs_info->discard_debug_kobj) {
1174                 sysfs_remove_files(fs_info->discard_debug_kobj,
1175                                    discard_debug_attrs);
1176                 kobject_del(fs_info->discard_debug_kobj);
1177                 kobject_put(fs_info->discard_debug_kobj);
1178         }
1179         if (fs_info->debug_kobj) {
1180                 sysfs_remove_files(fs_info->debug_kobj, btrfs_debug_mount_attrs);
1181                 kobject_del(fs_info->debug_kobj);
1182                 kobject_put(fs_info->debug_kobj);
1183         }
1184 #endif
1185         addrm_unknown_feature_attrs(fs_info, false);
1186         sysfs_remove_group(fsid_kobj, &btrfs_feature_attr_group);
1187         sysfs_remove_files(fsid_kobj, btrfs_attrs);
1188         btrfs_sysfs_remove_fs_devices(fs_info->fs_devices);
1189 }
1190
1191 static const char * const btrfs_feature_set_names[FEAT_MAX] = {
1192         [FEAT_COMPAT]    = "compat",
1193         [FEAT_COMPAT_RO] = "compat_ro",
1194         [FEAT_INCOMPAT]  = "incompat",
1195 };
1196
1197 const char *btrfs_feature_set_name(enum btrfs_feature_set set)
1198 {
1199         return btrfs_feature_set_names[set];
1200 }
1201
1202 char *btrfs_printable_features(enum btrfs_feature_set set, u64 flags)
1203 {
1204         size_t bufsize = 4096; /* safe max, 64 names * 64 bytes */
1205         int len = 0;
1206         int i;
1207         char *str;
1208
1209         str = kmalloc(bufsize, GFP_KERNEL);
1210         if (!str)
1211                 return str;
1212
1213         for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
1214                 const char *name;
1215
1216                 if (!(flags & (1ULL << i)))
1217                         continue;
1218
1219                 name = btrfs_feature_attrs[set][i].kobj_attr.attr.name;
1220                 len += scnprintf(str + len, bufsize - len, "%s%s",
1221                                 len ? "," : "", name);
1222         }
1223
1224         return str;
1225 }
1226
1227 static void init_feature_attrs(void)
1228 {
1229         struct btrfs_feature_attr *fa;
1230         int set, i;
1231
1232         BUILD_BUG_ON(ARRAY_SIZE(btrfs_unknown_feature_names) !=
1233                      ARRAY_SIZE(btrfs_feature_attrs));
1234         BUILD_BUG_ON(ARRAY_SIZE(btrfs_unknown_feature_names[0]) !=
1235                      ARRAY_SIZE(btrfs_feature_attrs[0]));
1236
1237         memset(btrfs_feature_attrs, 0, sizeof(btrfs_feature_attrs));
1238         memset(btrfs_unknown_feature_names, 0,
1239                sizeof(btrfs_unknown_feature_names));
1240
1241         for (i = 0; btrfs_supported_feature_attrs[i]; i++) {
1242                 struct btrfs_feature_attr *sfa;
1243                 struct attribute *a = btrfs_supported_feature_attrs[i];
1244                 int bit;
1245                 sfa = attr_to_btrfs_feature_attr(a);
1246                 bit = ilog2(sfa->feature_bit);
1247                 fa = &btrfs_feature_attrs[sfa->feature_set][bit];
1248
1249                 fa->kobj_attr.attr.name = sfa->kobj_attr.attr.name;
1250         }
1251
1252         for (set = 0; set < FEAT_MAX; set++) {
1253                 for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
1254                         char *name = btrfs_unknown_feature_names[set][i];
1255                         fa = &btrfs_feature_attrs[set][i];
1256
1257                         if (fa->kobj_attr.attr.name)
1258                                 continue;
1259
1260                         snprintf(name, BTRFS_FEATURE_NAME_MAX, "%s:%u",
1261                                  btrfs_feature_set_names[set], i);
1262
1263                         fa->kobj_attr.attr.name = name;
1264                         fa->kobj_attr.attr.mode = S_IRUGO;
1265                         fa->feature_set = set;
1266                         fa->feature_bit = 1ULL << i;
1267                 }
1268         }
1269 }
1270
1271 /*
1272  * Create a sysfs entry for a given block group type at path
1273  * /sys/fs/btrfs/UUID/allocation/data/TYPE
1274  */
1275 void btrfs_sysfs_add_block_group_type(struct btrfs_block_group *cache)
1276 {
1277         struct btrfs_fs_info *fs_info = cache->fs_info;
1278         struct btrfs_space_info *space_info = cache->space_info;
1279         struct raid_kobject *rkobj;
1280         const int index = btrfs_bg_flags_to_raid_index(cache->flags);
1281         unsigned int nofs_flag;
1282         int ret;
1283
1284         /*
1285          * Setup a NOFS context because kobject_add(), deep in its call chain,
1286          * does GFP_KERNEL allocations, and we are often called in a context
1287          * where if reclaim is triggered we can deadlock (we are either holding
1288          * a transaction handle or some lock required for a transaction
1289          * commit).
1290          */
1291         nofs_flag = memalloc_nofs_save();
1292
1293         rkobj = kzalloc(sizeof(*rkobj), GFP_NOFS);
1294         if (!rkobj) {
1295                 memalloc_nofs_restore(nofs_flag);
1296                 btrfs_warn(cache->fs_info,
1297                                 "couldn't alloc memory for raid level kobject");
1298                 return;
1299         }
1300
1301         rkobj->flags = cache->flags;
1302         kobject_init(&rkobj->kobj, &btrfs_raid_ktype);
1303
1304         /*
1305          * We call this either on mount, or if we've created a block group for a
1306          * new index type while running (i.e. when restriping).  The running
1307          * case is tricky because we could race with other threads, so we need
1308          * to have this check to make sure we didn't already init the kobject.
1309          *
1310          * We don't have to protect on the free side because it only happens on
1311          * unmount.
1312          */
1313         spin_lock(&space_info->lock);
1314         if (space_info->block_group_kobjs[index]) {
1315                 spin_unlock(&space_info->lock);
1316                 kobject_put(&rkobj->kobj);
1317                 return;
1318         } else {
1319                 space_info->block_group_kobjs[index] = &rkobj->kobj;
1320         }
1321         spin_unlock(&space_info->lock);
1322
1323         ret = kobject_add(&rkobj->kobj, &space_info->kobj, "%s",
1324                           btrfs_bg_type_to_raid_name(rkobj->flags));
1325         memalloc_nofs_restore(nofs_flag);
1326         if (ret) {
1327                 spin_lock(&space_info->lock);
1328                 space_info->block_group_kobjs[index] = NULL;
1329                 spin_unlock(&space_info->lock);
1330                 kobject_put(&rkobj->kobj);
1331                 btrfs_warn(fs_info,
1332                         "failed to add kobject for block cache, ignoring");
1333                 return;
1334         }
1335 }
1336
1337 /*
1338  * Remove sysfs directories for all block group types of a given space info and
1339  * the space info as well
1340  */
1341 void btrfs_sysfs_remove_space_info(struct btrfs_space_info *space_info)
1342 {
1343         int i;
1344
1345         for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) {
1346                 struct kobject *kobj;
1347
1348                 kobj = space_info->block_group_kobjs[i];
1349                 space_info->block_group_kobjs[i] = NULL;
1350                 if (kobj) {
1351                         kobject_del(kobj);
1352                         kobject_put(kobj);
1353                 }
1354         }
1355         kobject_del(&space_info->kobj);
1356         kobject_put(&space_info->kobj);
1357 }
1358
1359 static const char *alloc_name(u64 flags)
1360 {
1361         switch (flags) {
1362         case BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA:
1363                 return "mixed";
1364         case BTRFS_BLOCK_GROUP_METADATA:
1365                 return "metadata";
1366         case BTRFS_BLOCK_GROUP_DATA:
1367                 return "data";
1368         case BTRFS_BLOCK_GROUP_SYSTEM:
1369                 return "system";
1370         default:
1371                 WARN_ON(1);
1372                 return "invalid-combination";
1373         }
1374 }
1375
1376 /*
1377  * Create a sysfs entry for a space info type at path
1378  * /sys/fs/btrfs/UUID/allocation/TYPE
1379  */
1380 int btrfs_sysfs_add_space_info_type(struct btrfs_fs_info *fs_info,
1381                                     struct btrfs_space_info *space_info)
1382 {
1383         int ret;
1384
1385         ret = kobject_init_and_add(&space_info->kobj, &space_info_ktype,
1386                                    fs_info->space_info_kobj, "%s",
1387                                    alloc_name(space_info->flags));
1388         if (ret) {
1389                 kobject_put(&space_info->kobj);
1390                 return ret;
1391         }
1392
1393         return 0;
1394 }
1395
1396 void btrfs_sysfs_remove_device(struct btrfs_device *device)
1397 {
1398         struct kobject *devices_kobj;
1399
1400         /*
1401          * Seed fs_devices devices_kobj aren't used, fetch kobject from the
1402          * fs_info::fs_devices.
1403          */
1404         devices_kobj = device->fs_info->fs_devices->devices_kobj;
1405         ASSERT(devices_kobj);
1406
1407         if (device->bdev)
1408                 sysfs_remove_link(devices_kobj, bdev_kobj(device->bdev)->name);
1409
1410         if (device->devid_kobj.state_initialized) {
1411                 kobject_del(&device->devid_kobj);
1412                 kobject_put(&device->devid_kobj);
1413                 wait_for_completion(&device->kobj_unregister);
1414         }
1415 }
1416
1417 static ssize_t btrfs_devinfo_in_fs_metadata_show(struct kobject *kobj,
1418                                                  struct kobj_attribute *a,
1419                                                  char *buf)
1420 {
1421         int val;
1422         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1423                                                    devid_kobj);
1424
1425         val = !!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state);
1426
1427         return scnprintf(buf, PAGE_SIZE, "%d\n", val);
1428 }
1429 BTRFS_ATTR(devid, in_fs_metadata, btrfs_devinfo_in_fs_metadata_show);
1430
1431 static ssize_t btrfs_devinfo_missing_show(struct kobject *kobj,
1432                                         struct kobj_attribute *a, char *buf)
1433 {
1434         int val;
1435         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1436                                                    devid_kobj);
1437
1438         val = !!test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state);
1439
1440         return scnprintf(buf, PAGE_SIZE, "%d\n", val);
1441 }
1442 BTRFS_ATTR(devid, missing, btrfs_devinfo_missing_show);
1443
1444 static ssize_t btrfs_devinfo_replace_target_show(struct kobject *kobj,
1445                                                  struct kobj_attribute *a,
1446                                                  char *buf)
1447 {
1448         int val;
1449         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1450                                                    devid_kobj);
1451
1452         val = !!test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state);
1453
1454         return scnprintf(buf, PAGE_SIZE, "%d\n", val);
1455 }
1456 BTRFS_ATTR(devid, replace_target, btrfs_devinfo_replace_target_show);
1457
1458 static ssize_t btrfs_devinfo_scrub_speed_max_show(struct kobject *kobj,
1459                                              struct kobj_attribute *a,
1460                                              char *buf)
1461 {
1462         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1463                                                    devid_kobj);
1464
1465         return scnprintf(buf, PAGE_SIZE, "%llu\n",
1466                          READ_ONCE(device->scrub_speed_max));
1467 }
1468
1469 static ssize_t btrfs_devinfo_scrub_speed_max_store(struct kobject *kobj,
1470                                               struct kobj_attribute *a,
1471                                               const char *buf, size_t len)
1472 {
1473         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1474                                                    devid_kobj);
1475         char *endptr;
1476         unsigned long long limit;
1477
1478         limit = memparse(buf, &endptr);
1479         WRITE_ONCE(device->scrub_speed_max, limit);
1480         return len;
1481 }
1482 BTRFS_ATTR_RW(devid, scrub_speed_max, btrfs_devinfo_scrub_speed_max_show,
1483               btrfs_devinfo_scrub_speed_max_store);
1484
1485 static ssize_t btrfs_devinfo_writeable_show(struct kobject *kobj,
1486                                             struct kobj_attribute *a, char *buf)
1487 {
1488         int val;
1489         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1490                                                    devid_kobj);
1491
1492         val = !!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state);
1493
1494         return scnprintf(buf, PAGE_SIZE, "%d\n", val);
1495 }
1496 BTRFS_ATTR(devid, writeable, btrfs_devinfo_writeable_show);
1497
1498 static ssize_t btrfs_devinfo_error_stats_show(struct kobject *kobj,
1499                 struct kobj_attribute *a, char *buf)
1500 {
1501         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1502                                                    devid_kobj);
1503
1504         if (!device->dev_stats_valid)
1505                 return scnprintf(buf, PAGE_SIZE, "invalid\n");
1506
1507         /*
1508          * Print all at once so we get a snapshot of all values from the same
1509          * time. Keep them in sync and in order of definition of
1510          * btrfs_dev_stat_values.
1511          */
1512         return scnprintf(buf, PAGE_SIZE,
1513                 "write_errs %d\n"
1514                 "read_errs %d\n"
1515                 "flush_errs %d\n"
1516                 "corruption_errs %d\n"
1517                 "generation_errs %d\n",
1518                 btrfs_dev_stat_read(device, BTRFS_DEV_STAT_WRITE_ERRS),
1519                 btrfs_dev_stat_read(device, BTRFS_DEV_STAT_READ_ERRS),
1520                 btrfs_dev_stat_read(device, BTRFS_DEV_STAT_FLUSH_ERRS),
1521                 btrfs_dev_stat_read(device, BTRFS_DEV_STAT_CORRUPTION_ERRS),
1522                 btrfs_dev_stat_read(device, BTRFS_DEV_STAT_GENERATION_ERRS));
1523 }
1524 BTRFS_ATTR(devid, error_stats, btrfs_devinfo_error_stats_show);
1525
1526 static struct attribute *devid_attrs[] = {
1527         BTRFS_ATTR_PTR(devid, error_stats),
1528         BTRFS_ATTR_PTR(devid, in_fs_metadata),
1529         BTRFS_ATTR_PTR(devid, missing),
1530         BTRFS_ATTR_PTR(devid, replace_target),
1531         BTRFS_ATTR_PTR(devid, scrub_speed_max),
1532         BTRFS_ATTR_PTR(devid, writeable),
1533         NULL
1534 };
1535 ATTRIBUTE_GROUPS(devid);
1536
1537 static void btrfs_release_devid_kobj(struct kobject *kobj)
1538 {
1539         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1540                                                    devid_kobj);
1541
1542         memset(&device->devid_kobj, 0, sizeof(struct kobject));
1543         complete(&device->kobj_unregister);
1544 }
1545
1546 static struct kobj_type devid_ktype = {
1547         .sysfs_ops      = &kobj_sysfs_ops,
1548         .default_groups = devid_groups,
1549         .release        = btrfs_release_devid_kobj,
1550 };
1551
1552 int btrfs_sysfs_add_device(struct btrfs_device *device)
1553 {
1554         int ret;
1555         unsigned int nofs_flag;
1556         struct kobject *devices_kobj;
1557         struct kobject *devinfo_kobj;
1558
1559         /*
1560          * Make sure we use the fs_info::fs_devices to fetch the kobjects even
1561          * for the seed fs_devices
1562          */
1563         devices_kobj = device->fs_info->fs_devices->devices_kobj;
1564         devinfo_kobj = device->fs_info->fs_devices->devinfo_kobj;
1565         ASSERT(devices_kobj);
1566         ASSERT(devinfo_kobj);
1567
1568         nofs_flag = memalloc_nofs_save();
1569
1570         if (device->bdev) {
1571                 struct kobject *disk_kobj = bdev_kobj(device->bdev);
1572
1573                 ret = sysfs_create_link(devices_kobj, disk_kobj, disk_kobj->name);
1574                 if (ret) {
1575                         btrfs_warn(device->fs_info,
1576                                 "creating sysfs device link for devid %llu failed: %d",
1577                                 device->devid, ret);
1578                         goto out;
1579                 }
1580         }
1581
1582         init_completion(&device->kobj_unregister);
1583         ret = kobject_init_and_add(&device->devid_kobj, &devid_ktype,
1584                                    devinfo_kobj, "%llu", device->devid);
1585         if (ret) {
1586                 kobject_put(&device->devid_kobj);
1587                 btrfs_warn(device->fs_info,
1588                            "devinfo init for devid %llu failed: %d",
1589                            device->devid, ret);
1590         }
1591
1592 out:
1593         memalloc_nofs_restore(nofs_flag);
1594         return ret;
1595 }
1596
1597 static int btrfs_sysfs_add_fs_devices(struct btrfs_fs_devices *fs_devices)
1598 {
1599         int ret;
1600         struct btrfs_device *device;
1601         struct btrfs_fs_devices *seed;
1602
1603         list_for_each_entry(device, &fs_devices->devices, dev_list) {
1604                 ret = btrfs_sysfs_add_device(device);
1605                 if (ret)
1606                         goto fail;
1607         }
1608
1609         list_for_each_entry(seed, &fs_devices->seed_list, seed_list) {
1610                 list_for_each_entry(device, &seed->devices, dev_list) {
1611                         ret = btrfs_sysfs_add_device(device);
1612                         if (ret)
1613                                 goto fail;
1614                 }
1615         }
1616
1617         return 0;
1618
1619 fail:
1620         btrfs_sysfs_remove_fs_devices(fs_devices);
1621         return ret;
1622 }
1623
1624 void btrfs_kobject_uevent(struct block_device *bdev, enum kobject_action action)
1625 {
1626         int ret;
1627
1628         ret = kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, action);
1629         if (ret)
1630                 pr_warn("BTRFS: Sending event '%d' to kobject: '%s' (%p): failed\n",
1631                         action, kobject_name(&disk_to_dev(bdev->bd_disk)->kobj),
1632                         &disk_to_dev(bdev->bd_disk)->kobj);
1633 }
1634
1635 void btrfs_sysfs_update_sprout_fsid(struct btrfs_fs_devices *fs_devices)
1636
1637 {
1638         char fsid_buf[BTRFS_UUID_UNPARSED_SIZE];
1639
1640         /*
1641          * Sprouting changes fsid of the mounted filesystem, rename the fsid
1642          * directory
1643          */
1644         snprintf(fsid_buf, BTRFS_UUID_UNPARSED_SIZE, "%pU", fs_devices->fsid);
1645         if (kobject_rename(&fs_devices->fsid_kobj, fsid_buf))
1646                 btrfs_warn(fs_devices->fs_info,
1647                                 "sysfs: failed to create fsid for sprout");
1648 }
1649
1650 void btrfs_sysfs_update_devid(struct btrfs_device *device)
1651 {
1652         char tmp[24];
1653
1654         snprintf(tmp, sizeof(tmp), "%llu", device->devid);
1655
1656         if (kobject_rename(&device->devid_kobj, tmp))
1657                 btrfs_warn(device->fs_devices->fs_info,
1658                            "sysfs: failed to update devid for %llu",
1659                            device->devid);
1660 }
1661
1662 /* /sys/fs/btrfs/ entry */
1663 static struct kset *btrfs_kset;
1664
1665 /*
1666  * Creates:
1667  *              /sys/fs/btrfs/UUID
1668  *
1669  * Can be called by the device discovery thread.
1670  */
1671 int btrfs_sysfs_add_fsid(struct btrfs_fs_devices *fs_devs)
1672 {
1673         int error;
1674
1675         init_completion(&fs_devs->kobj_unregister);
1676         fs_devs->fsid_kobj.kset = btrfs_kset;
1677         error = kobject_init_and_add(&fs_devs->fsid_kobj, &btrfs_ktype, NULL,
1678                                      "%pU", fs_devs->fsid);
1679         if (error) {
1680                 kobject_put(&fs_devs->fsid_kobj);
1681                 return error;
1682         }
1683
1684         fs_devs->devices_kobj = kobject_create_and_add("devices",
1685                                                        &fs_devs->fsid_kobj);
1686         if (!fs_devs->devices_kobj) {
1687                 btrfs_err(fs_devs->fs_info,
1688                           "failed to init sysfs device interface");
1689                 btrfs_sysfs_remove_fsid(fs_devs);
1690                 return -ENOMEM;
1691         }
1692
1693         fs_devs->devinfo_kobj = kobject_create_and_add("devinfo",
1694                                                        &fs_devs->fsid_kobj);
1695         if (!fs_devs->devinfo_kobj) {
1696                 btrfs_err(fs_devs->fs_info,
1697                           "failed to init sysfs devinfo kobject");
1698                 btrfs_sysfs_remove_fsid(fs_devs);
1699                 return -ENOMEM;
1700         }
1701
1702         return 0;
1703 }
1704
1705 int btrfs_sysfs_add_mounted(struct btrfs_fs_info *fs_info)
1706 {
1707         int error;
1708         struct btrfs_fs_devices *fs_devs = fs_info->fs_devices;
1709         struct kobject *fsid_kobj = &fs_devs->fsid_kobj;
1710
1711         error = btrfs_sysfs_add_fs_devices(fs_devs);
1712         if (error)
1713                 return error;
1714
1715         error = sysfs_create_files(fsid_kobj, btrfs_attrs);
1716         if (error) {
1717                 btrfs_sysfs_remove_fs_devices(fs_devs);
1718                 return error;
1719         }
1720
1721         error = sysfs_create_group(fsid_kobj,
1722                                    &btrfs_feature_attr_group);
1723         if (error)
1724                 goto failure;
1725
1726 #ifdef CONFIG_BTRFS_DEBUG
1727         fs_info->debug_kobj = kobject_create_and_add("debug", fsid_kobj);
1728         if (!fs_info->debug_kobj) {
1729                 error = -ENOMEM;
1730                 goto failure;
1731         }
1732
1733         error = sysfs_create_files(fs_info->debug_kobj, btrfs_debug_mount_attrs);
1734         if (error)
1735                 goto failure;
1736
1737         /* Discard directory */
1738         fs_info->discard_debug_kobj = kobject_create_and_add("discard",
1739                                                      fs_info->debug_kobj);
1740         if (!fs_info->discard_debug_kobj) {
1741                 error = -ENOMEM;
1742                 goto failure;
1743         }
1744
1745         error = sysfs_create_files(fs_info->discard_debug_kobj,
1746                                    discard_debug_attrs);
1747         if (error)
1748                 goto failure;
1749 #endif
1750
1751         error = addrm_unknown_feature_attrs(fs_info, true);
1752         if (error)
1753                 goto failure;
1754
1755         error = sysfs_create_link(fsid_kobj, &fs_info->sb->s_bdi->dev->kobj, "bdi");
1756         if (error)
1757                 goto failure;
1758
1759         fs_info->space_info_kobj = kobject_create_and_add("allocation",
1760                                                   fsid_kobj);
1761         if (!fs_info->space_info_kobj) {
1762                 error = -ENOMEM;
1763                 goto failure;
1764         }
1765
1766         error = sysfs_create_files(fs_info->space_info_kobj, allocation_attrs);
1767         if (error)
1768                 goto failure;
1769
1770         return 0;
1771 failure:
1772         btrfs_sysfs_remove_mounted(fs_info);
1773         return error;
1774 }
1775
1776 static inline struct btrfs_fs_info *qgroup_kobj_to_fs_info(struct kobject *kobj)
1777 {
1778         return to_fs_info(kobj->parent->parent);
1779 }
1780
1781 #define QGROUP_ATTR(_member, _show_name)                                        \
1782 static ssize_t btrfs_qgroup_show_##_member(struct kobject *qgroup_kobj,         \
1783                                            struct kobj_attribute *a,            \
1784                                            char *buf)                           \
1785 {                                                                               \
1786         struct btrfs_fs_info *fs_info = qgroup_kobj_to_fs_info(qgroup_kobj);    \
1787         struct btrfs_qgroup *qgroup = container_of(qgroup_kobj,                 \
1788                         struct btrfs_qgroup, kobj);                             \
1789         return btrfs_show_u64(&qgroup->_member, &fs_info->qgroup_lock, buf);    \
1790 }                                                                               \
1791 BTRFS_ATTR(qgroup, _show_name, btrfs_qgroup_show_##_member)
1792
1793 #define QGROUP_RSV_ATTR(_name, _type)                                           \
1794 static ssize_t btrfs_qgroup_rsv_show_##_name(struct kobject *qgroup_kobj,       \
1795                                              struct kobj_attribute *a,          \
1796                                              char *buf)                         \
1797 {                                                                               \
1798         struct btrfs_fs_info *fs_info = qgroup_kobj_to_fs_info(qgroup_kobj);    \
1799         struct btrfs_qgroup *qgroup = container_of(qgroup_kobj,                 \
1800                         struct btrfs_qgroup, kobj);                             \
1801         return btrfs_show_u64(&qgroup->rsv.values[_type],                       \
1802                         &fs_info->qgroup_lock, buf);                            \
1803 }                                                                               \
1804 BTRFS_ATTR(qgroup, rsv_##_name, btrfs_qgroup_rsv_show_##_name)
1805
1806 QGROUP_ATTR(rfer, referenced);
1807 QGROUP_ATTR(excl, exclusive);
1808 QGROUP_ATTR(max_rfer, max_referenced);
1809 QGROUP_ATTR(max_excl, max_exclusive);
1810 QGROUP_ATTR(lim_flags, limit_flags);
1811 QGROUP_RSV_ATTR(data, BTRFS_QGROUP_RSV_DATA);
1812 QGROUP_RSV_ATTR(meta_pertrans, BTRFS_QGROUP_RSV_META_PERTRANS);
1813 QGROUP_RSV_ATTR(meta_prealloc, BTRFS_QGROUP_RSV_META_PREALLOC);
1814
1815 static struct attribute *qgroup_attrs[] = {
1816         BTRFS_ATTR_PTR(qgroup, referenced),
1817         BTRFS_ATTR_PTR(qgroup, exclusive),
1818         BTRFS_ATTR_PTR(qgroup, max_referenced),
1819         BTRFS_ATTR_PTR(qgroup, max_exclusive),
1820         BTRFS_ATTR_PTR(qgroup, limit_flags),
1821         BTRFS_ATTR_PTR(qgroup, rsv_data),
1822         BTRFS_ATTR_PTR(qgroup, rsv_meta_pertrans),
1823         BTRFS_ATTR_PTR(qgroup, rsv_meta_prealloc),
1824         NULL
1825 };
1826 ATTRIBUTE_GROUPS(qgroup);
1827
1828 static void qgroup_release(struct kobject *kobj)
1829 {
1830         struct btrfs_qgroup *qgroup = container_of(kobj, struct btrfs_qgroup, kobj);
1831
1832         memset(&qgroup->kobj, 0, sizeof(*kobj));
1833 }
1834
1835 static struct kobj_type qgroup_ktype = {
1836         .sysfs_ops = &kobj_sysfs_ops,
1837         .release = qgroup_release,
1838         .default_groups = qgroup_groups,
1839 };
1840
1841 int btrfs_sysfs_add_one_qgroup(struct btrfs_fs_info *fs_info,
1842                                 struct btrfs_qgroup *qgroup)
1843 {
1844         struct kobject *qgroups_kobj = fs_info->qgroups_kobj;
1845         int ret;
1846
1847         if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
1848                 return 0;
1849         if (qgroup->kobj.state_initialized)
1850                 return 0;
1851         if (!qgroups_kobj)
1852                 return -EINVAL;
1853
1854         ret = kobject_init_and_add(&qgroup->kobj, &qgroup_ktype, qgroups_kobj,
1855                         "%hu_%llu", btrfs_qgroup_level(qgroup->qgroupid),
1856                         btrfs_qgroup_subvolid(qgroup->qgroupid));
1857         if (ret < 0)
1858                 kobject_put(&qgroup->kobj);
1859
1860         return ret;
1861 }
1862
1863 void btrfs_sysfs_del_qgroups(struct btrfs_fs_info *fs_info)
1864 {
1865         struct btrfs_qgroup *qgroup;
1866         struct btrfs_qgroup *next;
1867
1868         if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
1869                 return;
1870
1871         rbtree_postorder_for_each_entry_safe(qgroup, next,
1872                                              &fs_info->qgroup_tree, node)
1873                 btrfs_sysfs_del_one_qgroup(fs_info, qgroup);
1874         if (fs_info->qgroups_kobj) {
1875                 kobject_del(fs_info->qgroups_kobj);
1876                 kobject_put(fs_info->qgroups_kobj);
1877                 fs_info->qgroups_kobj = NULL;
1878         }
1879 }
1880
1881 /* Called when qgroups get initialized, thus there is no need for locking */
1882 int btrfs_sysfs_add_qgroups(struct btrfs_fs_info *fs_info)
1883 {
1884         struct kobject *fsid_kobj = &fs_info->fs_devices->fsid_kobj;
1885         struct btrfs_qgroup *qgroup;
1886         struct btrfs_qgroup *next;
1887         int ret = 0;
1888
1889         if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
1890                 return 0;
1891
1892         ASSERT(fsid_kobj);
1893         if (fs_info->qgroups_kobj)
1894                 return 0;
1895
1896         fs_info->qgroups_kobj = kobject_create_and_add("qgroups", fsid_kobj);
1897         if (!fs_info->qgroups_kobj) {
1898                 ret = -ENOMEM;
1899                 goto out;
1900         }
1901         rbtree_postorder_for_each_entry_safe(qgroup, next,
1902                                              &fs_info->qgroup_tree, node) {
1903                 ret = btrfs_sysfs_add_one_qgroup(fs_info, qgroup);
1904                 if (ret < 0)
1905                         goto out;
1906         }
1907
1908 out:
1909         if (ret < 0)
1910                 btrfs_sysfs_del_qgroups(fs_info);
1911         return ret;
1912 }
1913
1914 void btrfs_sysfs_del_one_qgroup(struct btrfs_fs_info *fs_info,
1915                                 struct btrfs_qgroup *qgroup)
1916 {
1917         if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
1918                 return;
1919
1920         if (qgroup->kobj.state_initialized) {
1921                 kobject_del(&qgroup->kobj);
1922                 kobject_put(&qgroup->kobj);
1923         }
1924 }
1925
1926 /*
1927  * Change per-fs features in /sys/fs/btrfs/UUID/features to match current
1928  * values in superblock. Call after any changes to incompat/compat_ro flags
1929  */
1930 void btrfs_sysfs_feature_update(struct btrfs_fs_info *fs_info,
1931                 u64 bit, enum btrfs_feature_set set)
1932 {
1933         struct btrfs_fs_devices *fs_devs;
1934         struct kobject *fsid_kobj;
1935         u64 __maybe_unused features;
1936         int __maybe_unused ret;
1937
1938         if (!fs_info)
1939                 return;
1940
1941         /*
1942          * See 14e46e04958df74 and e410e34fad913dd, feature bit updates are not
1943          * safe when called from some contexts (eg. balance)
1944          */
1945         features = get_features(fs_info, set);
1946         ASSERT(bit & supported_feature_masks[set]);
1947
1948         fs_devs = fs_info->fs_devices;
1949         fsid_kobj = &fs_devs->fsid_kobj;
1950
1951         if (!fsid_kobj->state_initialized)
1952                 return;
1953
1954         /*
1955          * FIXME: this is too heavy to update just one value, ideally we'd like
1956          * to use sysfs_update_group but some refactoring is needed first.
1957          */
1958         sysfs_remove_group(fsid_kobj, &btrfs_feature_attr_group);
1959         ret = sysfs_create_group(fsid_kobj, &btrfs_feature_attr_group);
1960 }
1961
1962 int __init btrfs_init_sysfs(void)
1963 {
1964         int ret;
1965
1966         btrfs_kset = kset_create_and_add("btrfs", NULL, fs_kobj);
1967         if (!btrfs_kset)
1968                 return -ENOMEM;
1969
1970         init_feature_attrs();
1971         ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
1972         if (ret)
1973                 goto out2;
1974         ret = sysfs_merge_group(&btrfs_kset->kobj,
1975                                 &btrfs_static_feature_attr_group);
1976         if (ret)
1977                 goto out_remove_group;
1978
1979 #ifdef CONFIG_BTRFS_DEBUG
1980         ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_debug_feature_attr_group);
1981         if (ret)
1982                 goto out2;
1983 #endif
1984
1985         return 0;
1986
1987 out_remove_group:
1988         sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
1989 out2:
1990         kset_unregister(btrfs_kset);
1991
1992         return ret;
1993 }
1994
1995 void __cold btrfs_exit_sysfs(void)
1996 {
1997         sysfs_unmerge_group(&btrfs_kset->kobj,
1998                             &btrfs_static_feature_attr_group);
1999         sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
2000 #ifdef CONFIG_BTRFS_DEBUG
2001         sysfs_remove_group(&btrfs_kset->kobj, &btrfs_debug_feature_attr_group);
2002 #endif
2003         kset_unregister(btrfs_kset);
2004 }
2005