fs/btrfs/sysfs.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2007 Oracle.  All rights reserved.
   4  */
   5
   6 #include <linux/sched.h>
   7 #include <linux/sched/mm.h>
   8 #include <linux/slab.h>
   9 #include <linux/spinlock.h>
  10 #include <linux/completion.h>
  11 #include <linux/bug.h>
  12 #include <linux/list.h>
  13 #include <crypto/hash.h>
  14 #include "messages.h"
  15 #include "ctree.h"
  16 #include "discard.h"
  17 #include "disk-io.h"
  18 #include "send.h"
  19 #include "transaction.h"
  20 #include "sysfs.h"
  21 #include "volumes.h"
  22 #include "space-info.h"
  23 #include "block-group.h"
  24 #include "qgroup.h"
  25 #include "misc.h"
  26 #include "fs.h"
  27 #include "accessors.h"
  28
  29 /*
  30  * Structure name                       Path
  31  * --------------------------------------------------------------------------
  32  * btrfs_supported_static_feature_attrs /sys/fs/btrfs/features
  33  * btrfs_supported_feature_attrs        /sys/fs/btrfs/features and
  34  *                                      /sys/fs/btrfs/<uuid>/features
  35  * btrfs_attrs                          /sys/fs/btrfs/<uuid>
  36  * devid_attrs                          /sys/fs/btrfs/<uuid>/devinfo/<devid>
  37  * allocation_attrs                     /sys/fs/btrfs/<uuid>/allocation
  38  * qgroup_attrs                         /sys/fs/btrfs/<uuid>/qgroups/<level>_<qgroupid>
  39  * space_info_attrs                     /sys/fs/btrfs/<uuid>/allocation/<bg-type>
  40  * raid_attrs                           /sys/fs/btrfs/<uuid>/allocation/<bg-type>/<bg-profile>
  41  * discard_attrs                        /sys/fs/btrfs/<uuid>/discard
  42  *
  43  * When built with BTRFS_CONFIG_DEBUG:
  44  *
  45  * btrfs_debug_feature_attrs            /sys/fs/btrfs/debug
  46  * btrfs_debug_mount_attrs              /sys/fs/btrfs/<uuid>/debug
  47  */
  48
  49 struct btrfs_feature_attr {
  50         struct kobj_attribute kobj_attr;
  51         enum btrfs_feature_set feature_set;
  52         u64 feature_bit;
  53 };
  54
  55 /* For raid type sysfs entries */
  56 struct raid_kobject {
  57         u64 flags;
  58         struct kobject kobj;
  59 };
  60
  61 #define __INIT_KOBJ_ATTR(_name, _mode, _show, _store)                   \
  62 {                                                                       \
  63         .attr   = { .name = __stringify(_name), .mode = _mode },        \
  64         .show   = _show,                                                \
  65         .store  = _store,                                               \
  66 }
  67
  68 #define BTRFS_ATTR_W(_prefix, _name, _store)                            \
  69         static struct kobj_attribute btrfs_attr_##_prefix##_##_name =   \
  70                         __INIT_KOBJ_ATTR(_name, 0200, NULL, _store)
  71
  72 #define BTRFS_ATTR_RW(_prefix, _name, _show, _store)                    \
  73         static struct kobj_attribute btrfs_attr_##_prefix##_##_name =   \
  74                         __INIT_KOBJ_ATTR(_name, 0644, _show, _store)
  75
  76 #define BTRFS_ATTR(_prefix, _name, _show)                               \
  77         static struct kobj_attribute btrfs_attr_##_prefix##_##_name =   \
  78                         __INIT_KOBJ_ATTR(_name, 0444, _show, NULL)
  79
  80 #define BTRFS_ATTR_PTR(_prefix, _name)                                  \
  81         (&btrfs_attr_##_prefix##_##_name.attr)
  82
  83 #define BTRFS_FEAT_ATTR(_name, _feature_set, _feature_prefix, _feature_bit)  \
  84 static struct btrfs_feature_attr btrfs_attr_features_##_name = {             \
  85         .kobj_attr = __INIT_KOBJ_ATTR(_name, S_IRUGO,                        \
  86                                       btrfs_feature_attr_show,               \
  87                                       btrfs_feature_attr_store),             \
  88         .feature_set    = _feature_set,                                      \
  89         .feature_bit    = _feature_prefix ##_## _feature_bit,                \
  90 }
  91 #define BTRFS_FEAT_ATTR_PTR(_name)                                           \
  92         (&btrfs_attr_features_##_name.kobj_attr.attr)
  93
  94 #define BTRFS_FEAT_ATTR_COMPAT(name, feature) \
  95         BTRFS_FEAT_ATTR(name, FEAT_COMPAT, BTRFS_FEATURE_COMPAT, feature)
  96 #define BTRFS_FEAT_ATTR_COMPAT_RO(name, feature) \
  97         BTRFS_FEAT_ATTR(name, FEAT_COMPAT_RO, BTRFS_FEATURE_COMPAT_RO, feature)
  98 #define BTRFS_FEAT_ATTR_INCOMPAT(name, feature) \
  99         BTRFS_FEAT_ATTR(name, FEAT_INCOMPAT, BTRFS_FEATURE_INCOMPAT, feature)
 100
 101 static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj);
 102 static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj);
 103 static struct kobject *get_btrfs_kobj(struct kobject *kobj);
 104
 105 static struct btrfs_feature_attr *to_btrfs_feature_attr(struct kobj_attribute *a)
 106 {
 107         return container_of(a, struct btrfs_feature_attr, kobj_attr);
 108 }
 109
 110 static struct kobj_attribute *attr_to_btrfs_attr(struct attribute *attr)
 111 {
 112         return container_of(attr, struct kobj_attribute, attr);
 113 }
 114
 115 static struct btrfs_feature_attr *attr_to_btrfs_feature_attr(
 116                 struct attribute *attr)
 117 {
 118         return to_btrfs_feature_attr(attr_to_btrfs_attr(attr));
 119 }
 120
 121 static u64 get_features(struct btrfs_fs_info *fs_info,
 122                         enum btrfs_feature_set set)
 123 {
 124         struct btrfs_super_block *disk_super = fs_info->super_copy;
 125         if (set == FEAT_COMPAT)
 126                 return btrfs_super_compat_flags(disk_super);
 127         else if (set == FEAT_COMPAT_RO)
 128                 return btrfs_super_compat_ro_flags(disk_super);
 129         else
 130                 return btrfs_super_incompat_flags(disk_super);
 131 }
 132
 133 static void set_features(struct btrfs_fs_info *fs_info,
 134                          enum btrfs_feature_set set, u64 features)
 135 {
 136         struct btrfs_super_block *disk_super = fs_info->super_copy;
 137         if (set == FEAT_COMPAT)
 138                 btrfs_set_super_compat_flags(disk_super, features);
 139         else if (set == FEAT_COMPAT_RO)
 140                 btrfs_set_super_compat_ro_flags(disk_super, features);
 141         else
 142                 btrfs_set_super_incompat_flags(disk_super, features);
 143 }
 144
 145 static int can_modify_feature(struct btrfs_feature_attr *fa)
 146 {
 147         int val = 0;
 148         u64 set, clear;
 149         switch (fa->feature_set) {
 150         case FEAT_COMPAT:
 151                 set = BTRFS_FEATURE_COMPAT_SAFE_SET;
 152                 clear = BTRFS_FEATURE_COMPAT_SAFE_CLEAR;
 153                 break;
 154         case FEAT_COMPAT_RO:
 155                 set = BTRFS_FEATURE_COMPAT_RO_SAFE_SET;
 156                 clear = BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR;
 157                 break;
 158         case FEAT_INCOMPAT:
 159                 set = BTRFS_FEATURE_INCOMPAT_SAFE_SET;
 160                 clear = BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR;
 161                 break;
 162         default:
 163                 pr_warn("btrfs: sysfs: unknown feature set %d\n",
 164                                 fa->feature_set);
 165                 return 0;
 166         }
 167
 168         if (set & fa->feature_bit)
 169                 val |= 1;
 170         if (clear & fa->feature_bit)
 171                 val |= 2;
 172
 173         return val;
 174 }
 175
 176 static ssize_t btrfs_feature_attr_show(struct kobject *kobj,
 177                                        struct kobj_attribute *a, char *buf)
 178 {
 179         int val = 0;
 180         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 181         struct btrfs_feature_attr *fa = to_btrfs_feature_attr(a);
 182         if (fs_info) {
 183                 u64 features = get_features(fs_info, fa->feature_set);
 184                 if (features & fa->feature_bit)
 185                         val = 1;
 186         } else
 187                 val = can_modify_feature(fa);
 188
 189         return sysfs_emit(buf, "%d\n", val);
 190 }
 191
 192 static ssize_t btrfs_feature_attr_store(struct kobject *kobj,
 193                                         struct kobj_attribute *a,
 194                                         const char *buf, size_t count)
 195 {
 196         struct btrfs_fs_info *fs_info;
 197         struct btrfs_feature_attr *fa = to_btrfs_feature_attr(a);
 198         u64 features, set, clear;
 199         unsigned long val;
 200         int ret;
 201
 202         fs_info = to_fs_info(kobj);
 203         if (!fs_info)
 204                 return -EPERM;
 205
 206         if (sb_rdonly(fs_info->sb))
 207                 return -EROFS;
 208
 209         ret = kstrtoul(skip_spaces(buf), 0, &val);
 210         if (ret)
 211                 return ret;
 212
 213         if (fa->feature_set == FEAT_COMPAT) {
 214                 set = BTRFS_FEATURE_COMPAT_SAFE_SET;
 215                 clear = BTRFS_FEATURE_COMPAT_SAFE_CLEAR;
 216         } else if (fa->feature_set == FEAT_COMPAT_RO) {
 217                 set = BTRFS_FEATURE_COMPAT_RO_SAFE_SET;
 218                 clear = BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR;
 219         } else {
 220                 set = BTRFS_FEATURE_INCOMPAT_SAFE_SET;
 221                 clear = BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR;
 222         }
 223
 224         features = get_features(fs_info, fa->feature_set);
 225
 226         /* Nothing to do */
 227         if ((val && (features & fa->feature_bit)) ||
 228             (!val && !(features & fa->feature_bit)))
 229                 return count;
 230
 231         if ((val && !(set & fa->feature_bit)) ||
 232             (!val && !(clear & fa->feature_bit))) {
 233                 btrfs_info(fs_info,
 234                         "%sabling feature %s on mounted fs is not supported.",
 235                         val ? "En" : "Dis", fa->kobj_attr.attr.name);
 236                 return -EPERM;
 237         }
 238
 239         btrfs_info(fs_info, "%s %s feature flag",
 240                    val ? "Setting" : "Clearing", fa->kobj_attr.attr.name);
 241
 242         spin_lock(&fs_info->super_lock);
 243         features = get_features(fs_info, fa->feature_set);
 244         if (val)
 245                 features |= fa->feature_bit;
 246         else
 247                 features &= ~fa->feature_bit;
 248         set_features(fs_info, fa->feature_set, features);
 249         spin_unlock(&fs_info->super_lock);
 250
 251         /*
 252          * We don't want to do full transaction commit from inside sysfs
 253          */
 254         set_bit(BTRFS_FS_NEED_TRANS_COMMIT, &fs_info->flags);
 255         wake_up_process(fs_info->transaction_kthread);
 256
 257         return count;
 258 }
 259
 260 static umode_t btrfs_feature_visible(struct kobject *kobj,
 261                                      struct attribute *attr, int unused)
 262 {
 263         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 264         umode_t mode = attr->mode;
 265
 266         if (fs_info) {
 267                 struct btrfs_feature_attr *fa;
 268                 u64 features;
 269
 270                 fa = attr_to_btrfs_feature_attr(attr);
 271                 features = get_features(fs_info, fa->feature_set);
 272
 273                 if (can_modify_feature(fa))
 274                         mode |= S_IWUSR;
 275                 else if (!(features & fa->feature_bit))
 276                         mode = 0;
 277         }
 278
 279         return mode;
 280 }
 281
 282 BTRFS_FEAT_ATTR_INCOMPAT(default_subvol, DEFAULT_SUBVOL);
 283 BTRFS_FEAT_ATTR_INCOMPAT(mixed_groups, MIXED_GROUPS);
 284 BTRFS_FEAT_ATTR_INCOMPAT(compress_lzo, COMPRESS_LZO);
 285 BTRFS_FEAT_ATTR_INCOMPAT(compress_zstd, COMPRESS_ZSTD);
 286 BTRFS_FEAT_ATTR_INCOMPAT(extended_iref, EXTENDED_IREF);
 287 BTRFS_FEAT_ATTR_INCOMPAT(raid56, RAID56);
 288 BTRFS_FEAT_ATTR_INCOMPAT(skinny_metadata, SKINNY_METADATA);
 289 BTRFS_FEAT_ATTR_INCOMPAT(no_holes, NO_HOLES);
 290 BTRFS_FEAT_ATTR_INCOMPAT(metadata_uuid, METADATA_UUID);
 291 BTRFS_FEAT_ATTR_COMPAT_RO(free_space_tree, FREE_SPACE_TREE);
 292 BTRFS_FEAT_ATTR_COMPAT_RO(block_group_tree, BLOCK_GROUP_TREE);
 293 BTRFS_FEAT_ATTR_INCOMPAT(raid1c34, RAID1C34);
 294 BTRFS_FEAT_ATTR_INCOMPAT(simple_quota, SIMPLE_QUOTA);
 295 #ifdef CONFIG_BLK_DEV_ZONED
 296 BTRFS_FEAT_ATTR_INCOMPAT(zoned, ZONED);
 297 #endif
 298 #ifdef CONFIG_BTRFS_DEBUG
 299 /* Remove once support for extent tree v2 is feature complete */
 300 BTRFS_FEAT_ATTR_INCOMPAT(extent_tree_v2, EXTENT_TREE_V2);
 301 /* Remove once support for raid stripe tree is feature complete. */
 302 BTRFS_FEAT_ATTR_INCOMPAT(raid_stripe_tree, RAID_STRIPE_TREE);
 303 #endif
 304 #ifdef CONFIG_FS_VERITY
 305 BTRFS_FEAT_ATTR_COMPAT_RO(verity, VERITY);
 306 #endif
 307
 308 /*
 309  * Features which depend on feature bits and may differ between each fs.
 310  *
 311  * /sys/fs/btrfs/features      - all available features implemented by this version
 312  * /sys/fs/btrfs/UUID/features - features of the fs which are enabled or
 313  *                               can be changed on a mounted filesystem.
 314  */
 315 static struct attribute *btrfs_supported_feature_attrs[] = {
 316         BTRFS_FEAT_ATTR_PTR(default_subvol),
 317         BTRFS_FEAT_ATTR_PTR(mixed_groups),
 318         BTRFS_FEAT_ATTR_PTR(compress_lzo),
 319         BTRFS_FEAT_ATTR_PTR(compress_zstd),
 320         BTRFS_FEAT_ATTR_PTR(extended_iref),
 321         BTRFS_FEAT_ATTR_PTR(raid56),
 322         BTRFS_FEAT_ATTR_PTR(skinny_metadata),
 323         BTRFS_FEAT_ATTR_PTR(no_holes),
 324         BTRFS_FEAT_ATTR_PTR(metadata_uuid),
 325         BTRFS_FEAT_ATTR_PTR(free_space_tree),
 326         BTRFS_FEAT_ATTR_PTR(raid1c34),
 327         BTRFS_FEAT_ATTR_PTR(block_group_tree),
 328         BTRFS_FEAT_ATTR_PTR(simple_quota),
 329 #ifdef CONFIG_BLK_DEV_ZONED
 330         BTRFS_FEAT_ATTR_PTR(zoned),
 331 #endif
 332 #ifdef CONFIG_BTRFS_DEBUG
 333         BTRFS_FEAT_ATTR_PTR(extent_tree_v2),
 334         BTRFS_FEAT_ATTR_PTR(raid_stripe_tree),
 335 #endif
 336 #ifdef CONFIG_FS_VERITY
 337         BTRFS_FEAT_ATTR_PTR(verity),
 338 #endif
 339         NULL
 340 };
 341
 342 static const struct attribute_group btrfs_feature_attr_group = {
 343         .name = "features",
 344         .is_visible = btrfs_feature_visible,
 345         .attrs = btrfs_supported_feature_attrs,
 346 };
 347
 348 static ssize_t rmdir_subvol_show(struct kobject *kobj,
 349                                  struct kobj_attribute *ka, char *buf)
 350 {
 351         return sysfs_emit(buf, "0\n");
 352 }
 353 BTRFS_ATTR(static_feature, rmdir_subvol, rmdir_subvol_show);
 354
 355 static ssize_t supported_checksums_show(struct kobject *kobj,
 356                                         struct kobj_attribute *a, char *buf)
 357 {
 358         ssize_t ret = 0;
 359         int i;
 360
 361         for (i = 0; i < btrfs_get_num_csums(); i++) {
 362                 /*
 363                  * This "trick" only works as long as 'enum btrfs_csum_type' has
 364                  * no holes in it
 365                  */
 366                 ret += sysfs_emit_at(buf, ret, "%s%s", (i == 0 ? "" : " "),
 367                                      btrfs_super_csum_name(i));
 368
 369         }
 370
 371         ret += sysfs_emit_at(buf, ret, "\n");
 372         return ret;
 373 }
 374 BTRFS_ATTR(static_feature, supported_checksums, supported_checksums_show);
 375
 376 static ssize_t send_stream_version_show(struct kobject *kobj,
 377                                         struct kobj_attribute *ka, char *buf)
 378 {
 379         return sysfs_emit(buf, "%d\n", BTRFS_SEND_STREAM_VERSION);
 380 }
 381 BTRFS_ATTR(static_feature, send_stream_version, send_stream_version_show);
 382
 383 static const char *rescue_opts[] = {
 384         "usebackuproot",
 385         "nologreplay",
 386         "ignorebadroots",
 387         "ignoredatacsums",
 388         "ignoremetacsums",
 389         "ignoresuperflags",
 390         "all",
 391 };
 392
 393 static ssize_t supported_rescue_options_show(struct kobject *kobj,
 394                                              struct kobj_attribute *a,
 395                                              char *buf)
 396 {
 397         ssize_t ret = 0;
 398         int i;
 399
 400         for (i = 0; i < ARRAY_SIZE(rescue_opts); i++)
 401                 ret += sysfs_emit_at(buf, ret, "%s%s", (i ? " " : ""), rescue_opts[i]);
 402         ret += sysfs_emit_at(buf, ret, "\n");
 403         return ret;
 404 }
 405 BTRFS_ATTR(static_feature, supported_rescue_options,
 406            supported_rescue_options_show);
 407
 408 static ssize_t supported_sectorsizes_show(struct kobject *kobj,
 409                                           struct kobj_attribute *a,
 410                                           char *buf)
 411 {
 412         ssize_t ret = 0;
 413
 414         /* An artificial limit to only support 4K and PAGE_SIZE */
 415         if (PAGE_SIZE > SZ_4K)
 416                 ret += sysfs_emit_at(buf, ret, "%u ", SZ_4K);
 417         ret += sysfs_emit_at(buf, ret, "%lu\n", PAGE_SIZE);
 418
 419         return ret;
 420 }
 421 BTRFS_ATTR(static_feature, supported_sectorsizes,
 422            supported_sectorsizes_show);
 423
 424 static ssize_t acl_show(struct kobject *kobj, struct kobj_attribute *a, char *buf)
 425 {
 426         return sysfs_emit(buf, "%d\n", IS_ENABLED(CONFIG_BTRFS_FS_POSIX_ACL));
 427 }
 428 BTRFS_ATTR(static_feature, acl, acl_show);
 429
 430 static ssize_t temp_fsid_supported_show(struct kobject *kobj,
 431                                         struct kobj_attribute *a, char *buf)
 432 {
 433         return sysfs_emit(buf, "0\n");
 434 }
 435 BTRFS_ATTR(static_feature, temp_fsid, temp_fsid_supported_show);
 436
 437 /*
 438  * Features which only depend on kernel version.
 439  *
 440  * These are listed in /sys/fs/btrfs/features along with
 441  * btrfs_supported_feature_attrs.
 442  */
 443 static struct attribute *btrfs_supported_static_feature_attrs[] = {
 444         BTRFS_ATTR_PTR(static_feature, acl),
 445         BTRFS_ATTR_PTR(static_feature, rmdir_subvol),
 446         BTRFS_ATTR_PTR(static_feature, supported_checksums),
 447         BTRFS_ATTR_PTR(static_feature, send_stream_version),
 448         BTRFS_ATTR_PTR(static_feature, supported_rescue_options),
 449         BTRFS_ATTR_PTR(static_feature, supported_sectorsizes),
 450         BTRFS_ATTR_PTR(static_feature, temp_fsid),
 451         NULL
 452 };
 453
 454 static const struct attribute_group btrfs_static_feature_attr_group = {
 455         .name = "features",
 456         .attrs = btrfs_supported_static_feature_attrs,
 457 };
 458
 459 /*
 460  * Discard statistics and tunables
 461  */
 462 #define discard_to_fs_info(_kobj)       to_fs_info(get_btrfs_kobj(_kobj))
 463
 464 static ssize_t btrfs_discardable_bytes_show(struct kobject *kobj,
 465                                             struct kobj_attribute *a,
 466                                             char *buf)
 467 {
 468         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 469
 470         return sysfs_emit(buf, "%lld\n",
 471                         atomic64_read(&fs_info->discard_ctl.discardable_bytes));
 472 }
 473 BTRFS_ATTR(discard, discardable_bytes, btrfs_discardable_bytes_show);
 474
 475 static ssize_t btrfs_discardable_extents_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 sysfs_emit(buf, "%d\n",
 482                         atomic_read(&fs_info->discard_ctl.discardable_extents));
 483 }
 484 BTRFS_ATTR(discard, discardable_extents, btrfs_discardable_extents_show);
 485
 486 static ssize_t btrfs_discard_bitmap_bytes_show(struct kobject *kobj,
 487                                                struct kobj_attribute *a,
 488                                                char *buf)
 489 {
 490         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 491
 492         return sysfs_emit(buf, "%llu\n",
 493                           fs_info->discard_ctl.discard_bitmap_bytes);
 494 }
 495 BTRFS_ATTR(discard, discard_bitmap_bytes, btrfs_discard_bitmap_bytes_show);
 496
 497 static ssize_t btrfs_discard_bytes_saved_show(struct kobject *kobj,
 498                                               struct kobj_attribute *a,
 499                                               char *buf)
 500 {
 501         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 502
 503         return sysfs_emit(buf, "%lld\n",
 504                 atomic64_read(&fs_info->discard_ctl.discard_bytes_saved));
 505 }
 506 BTRFS_ATTR(discard, discard_bytes_saved, btrfs_discard_bytes_saved_show);
 507
 508 static ssize_t btrfs_discard_extent_bytes_show(struct kobject *kobj,
 509                                                struct kobj_attribute *a,
 510                                                char *buf)
 511 {
 512         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 513
 514         return sysfs_emit(buf, "%llu\n",
 515                           fs_info->discard_ctl.discard_extent_bytes);
 516 }
 517 BTRFS_ATTR(discard, discard_extent_bytes, btrfs_discard_extent_bytes_show);
 518
 519 static ssize_t btrfs_discard_iops_limit_show(struct kobject *kobj,
 520                                              struct kobj_attribute *a,
 521                                              char *buf)
 522 {
 523         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 524
 525         return sysfs_emit(buf, "%u\n",
 526                           READ_ONCE(fs_info->discard_ctl.iops_limit));
 527 }
 528
 529 static ssize_t btrfs_discard_iops_limit_store(struct kobject *kobj,
 530                                               struct kobj_attribute *a,
 531                                               const char *buf, size_t len)
 532 {
 533         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 534         struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
 535         u32 iops_limit;
 536         int ret;
 537
 538         ret = kstrtou32(buf, 10, &iops_limit);
 539         if (ret)
 540                 return -EINVAL;
 541
 542         WRITE_ONCE(discard_ctl->iops_limit, iops_limit);
 543         btrfs_discard_calc_delay(discard_ctl);
 544         btrfs_discard_schedule_work(discard_ctl, true);
 545         return len;
 546 }
 547 BTRFS_ATTR_RW(discard, iops_limit, btrfs_discard_iops_limit_show,
 548               btrfs_discard_iops_limit_store);
 549
 550 static ssize_t btrfs_discard_kbps_limit_show(struct kobject *kobj,
 551                                              struct kobj_attribute *a,
 552                                              char *buf)
 553 {
 554         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 555
 556         return sysfs_emit(buf, "%u\n",
 557                           READ_ONCE(fs_info->discard_ctl.kbps_limit));
 558 }
 559
 560 static ssize_t btrfs_discard_kbps_limit_store(struct kobject *kobj,
 561                                               struct kobj_attribute *a,
 562                                               const char *buf, size_t len)
 563 {
 564         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 565         struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
 566         u32 kbps_limit;
 567         int ret;
 568
 569         ret = kstrtou32(buf, 10, &kbps_limit);
 570         if (ret)
 571                 return -EINVAL;
 572
 573         WRITE_ONCE(discard_ctl->kbps_limit, kbps_limit);
 574         btrfs_discard_schedule_work(discard_ctl, true);
 575         return len;
 576 }
 577 BTRFS_ATTR_RW(discard, kbps_limit, btrfs_discard_kbps_limit_show,
 578               btrfs_discard_kbps_limit_store);
 579
 580 static ssize_t btrfs_discard_max_discard_size_show(struct kobject *kobj,
 581                                                    struct kobj_attribute *a,
 582                                                    char *buf)
 583 {
 584         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 585
 586         return sysfs_emit(buf, "%llu\n",
 587                           READ_ONCE(fs_info->discard_ctl.max_discard_size));
 588 }
 589
 590 static ssize_t btrfs_discard_max_discard_size_store(struct kobject *kobj,
 591                                                     struct kobj_attribute *a,
 592                                                     const char *buf, size_t len)
 593 {
 594         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 595         struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
 596         u64 max_discard_size;
 597         int ret;
 598
 599         ret = kstrtou64(buf, 10, &max_discard_size);
 600         if (ret)
 601                 return -EINVAL;
 602
 603         WRITE_ONCE(discard_ctl->max_discard_size, max_discard_size);
 604
 605         return len;
 606 }
 607 BTRFS_ATTR_RW(discard, max_discard_size, btrfs_discard_max_discard_size_show,
 608               btrfs_discard_max_discard_size_store);
 609
 610 /*
 611  * Per-filesystem stats for discard (when mounted with discard=async).
 612  *
 613  * Path: /sys/fs/btrfs/<uuid>/discard/
 614  */
 615 static const struct attribute *discard_attrs[] = {
 616         BTRFS_ATTR_PTR(discard, discardable_bytes),
 617         BTRFS_ATTR_PTR(discard, discardable_extents),
 618         BTRFS_ATTR_PTR(discard, discard_bitmap_bytes),
 619         BTRFS_ATTR_PTR(discard, discard_bytes_saved),
 620         BTRFS_ATTR_PTR(discard, discard_extent_bytes),
 621         BTRFS_ATTR_PTR(discard, iops_limit),
 622         BTRFS_ATTR_PTR(discard, kbps_limit),
 623         BTRFS_ATTR_PTR(discard, max_discard_size),
 624         NULL,
 625 };
 626
 627 #ifdef CONFIG_BTRFS_DEBUG
 628
 629 /*
 630  * Per-filesystem runtime debugging exported via sysfs.
 631  *
 632  * Path: /sys/fs/btrfs/UUID/debug/
 633  */
 634 static const struct attribute *btrfs_debug_mount_attrs[] = {
 635         NULL,
 636 };
 637
 638 /*
 639  * Runtime debugging exported via sysfs, applies to all mounted filesystems.
 640  *
 641  * Path: /sys/fs/btrfs/debug
 642  */
 643 static struct attribute *btrfs_debug_feature_attrs[] = {
 644         NULL
 645 };
 646
 647 static const struct attribute_group btrfs_debug_feature_attr_group = {
 648         .name = "debug",
 649         .attrs = btrfs_debug_feature_attrs,
 650 };
 651
 652 #endif
 653
 654 static ssize_t btrfs_show_u64(u64 *value_ptr, spinlock_t *lock, char *buf)
 655 {
 656         u64 val;
 657         if (lock)
 658                 spin_lock(lock);
 659         val = *value_ptr;
 660         if (lock)
 661                 spin_unlock(lock);
 662         return sysfs_emit(buf, "%llu\n", val);
 663 }
 664
 665 static ssize_t global_rsv_size_show(struct kobject *kobj,
 666                                     struct kobj_attribute *ka, char *buf)
 667 {
 668         struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent);
 669         struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
 670         return btrfs_show_u64(&block_rsv->size, &block_rsv->lock, buf);
 671 }
 672 BTRFS_ATTR(allocation, global_rsv_size, global_rsv_size_show);
 673
 674 static ssize_t global_rsv_reserved_show(struct kobject *kobj,
 675                                         struct kobj_attribute *a, char *buf)
 676 {
 677         struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent);
 678         struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
 679         return btrfs_show_u64(&block_rsv->reserved, &block_rsv->lock, buf);
 680 }
 681 BTRFS_ATTR(allocation, global_rsv_reserved, global_rsv_reserved_show);
 682
 683 #define to_space_info(_kobj) container_of(_kobj, struct btrfs_space_info, kobj)
 684 #define to_raid_kobj(_kobj) container_of(_kobj, struct raid_kobject, kobj)
 685
 686 static ssize_t raid_bytes_show(struct kobject *kobj,
 687                                struct kobj_attribute *attr, char *buf);
 688 BTRFS_ATTR(raid, total_bytes, raid_bytes_show);
 689 BTRFS_ATTR(raid, used_bytes, raid_bytes_show);
 690
 691 static ssize_t raid_bytes_show(struct kobject *kobj,
 692                                struct kobj_attribute *attr, char *buf)
 693
 694 {
 695         struct btrfs_space_info *sinfo = to_space_info(kobj->parent);
 696         struct btrfs_block_group *block_group;
 697         int index = btrfs_bg_flags_to_raid_index(to_raid_kobj(kobj)->flags);
 698         u64 val = 0;
 699
 700         down_read(&sinfo->groups_sem);
 701         list_for_each_entry(block_group, &sinfo->block_groups[index], list) {
 702                 if (&attr->attr == BTRFS_ATTR_PTR(raid, total_bytes))
 703                         val += block_group->length;
 704                 else
 705                         val += block_group->used;
 706         }
 707         up_read(&sinfo->groups_sem);
 708         return sysfs_emit(buf, "%llu\n", val);
 709 }
 710
 711 /*
 712  * Allocation information about block group profiles.
 713  *
 714  * Path: /sys/fs/btrfs/<uuid>/allocation/<bg-type>/<bg-profile>/
 715  */
 716 static struct attribute *raid_attrs[] = {
 717         BTRFS_ATTR_PTR(raid, total_bytes),
 718         BTRFS_ATTR_PTR(raid, used_bytes),
 719         NULL
 720 };
 721 ATTRIBUTE_GROUPS(raid);
 722
 723 static void release_raid_kobj(struct kobject *kobj)
 724 {
 725         kfree(to_raid_kobj(kobj));
 726 }
 727
 728 static const struct kobj_type btrfs_raid_ktype = {
 729         .sysfs_ops = &kobj_sysfs_ops,
 730         .release = release_raid_kobj,
 731         .default_groups = raid_groups,
 732 };
 733
 734 #define SPACE_INFO_ATTR(field)                                          \
 735 static ssize_t btrfs_space_info_show_##field(struct kobject *kobj,      \
 736                                              struct kobj_attribute *a,  \
 737                                              char *buf)                 \
 738 {                                                                       \
 739         struct btrfs_space_info *sinfo = to_space_info(kobj);           \
 740         return btrfs_show_u64(&sinfo->field, &sinfo->lock, buf);        \
 741 }                                                                       \
 742 BTRFS_ATTR(space_info, field, btrfs_space_info_show_##field)
 743
 744 static ssize_t btrfs_chunk_size_show(struct kobject *kobj,
 745                                      struct kobj_attribute *a, char *buf)
 746 {
 747         struct btrfs_space_info *sinfo = to_space_info(kobj);
 748
 749         return sysfs_emit(buf, "%llu\n", READ_ONCE(sinfo->chunk_size));
 750 }
 751
 752 /*
 753  * Store new chunk size in space info. Can be called on a read-only filesystem.
 754  *
 755  * If the new chunk size value is larger than 10% of free space it is reduced
 756  * to match that limit. Alignment must be to 256M and the system chunk size
 757  * cannot be set.
 758  */
 759 static ssize_t btrfs_chunk_size_store(struct kobject *kobj,
 760                                       struct kobj_attribute *a,
 761                                       const char *buf, size_t len)
 762 {
 763         struct btrfs_space_info *space_info = to_space_info(kobj);
 764         struct btrfs_fs_info *fs_info = to_fs_info(get_btrfs_kobj(kobj));
 765         char *retptr;
 766         u64 val;
 767
 768         if (!capable(CAP_SYS_ADMIN))
 769                 return -EPERM;
 770
 771         if (!fs_info->fs_devices)
 772                 return -EINVAL;
 773
 774         if (btrfs_is_zoned(fs_info))
 775                 return -EINVAL;
 776
 777         /* System block type must not be changed. */
 778         if (space_info->flags & BTRFS_BLOCK_GROUP_SYSTEM)
 779                 return -EPERM;
 780
 781         val = memparse(buf, &retptr);
 782         /* There could be trailing '\n', also catch any typos after the value */
 783         retptr = skip_spaces(retptr);
 784         if (*retptr != 0 || val == 0)
 785                 return -EINVAL;
 786
 787         val = min(val, BTRFS_MAX_DATA_CHUNK_SIZE);
 788
 789         /* Limit stripe size to 10% of available space. */
 790         val = min(mult_perc(fs_info->fs_devices->total_rw_bytes, 10), val);
 791
 792         /* Must be multiple of 256M. */
 793         val &= ~((u64)SZ_256M - 1);
 794
 795         /* Must be at least 256M. */
 796         if (val < SZ_256M)
 797                 return -EINVAL;
 798
 799         btrfs_update_space_info_chunk_size(space_info, val);
 800
 801         return len;
 802 }
 803
 804 static ssize_t btrfs_size_classes_show(struct kobject *kobj,
 805                                        struct kobj_attribute *a, char *buf)
 806 {
 807         struct btrfs_space_info *sinfo = to_space_info(kobj);
 808         struct btrfs_block_group *bg;
 809         u32 none = 0;
 810         u32 small = 0;
 811         u32 medium = 0;
 812         u32 large = 0;
 813
 814         for (int i = 0; i < BTRFS_NR_RAID_TYPES; ++i) {
 815                 down_read(&sinfo->groups_sem);
 816                 list_for_each_entry(bg, &sinfo->block_groups[i], list) {
 817                         if (!btrfs_block_group_should_use_size_class(bg))
 818                                 continue;
 819                         switch (bg->size_class) {
 820                         case BTRFS_BG_SZ_NONE:
 821                                 none++;
 822                                 break;
 823                         case BTRFS_BG_SZ_SMALL:
 824                                 small++;
 825                                 break;
 826                         case BTRFS_BG_SZ_MEDIUM:
 827                                 medium++;
 828                                 break;
 829                         case BTRFS_BG_SZ_LARGE:
 830                                 large++;
 831                                 break;
 832                         }
 833                 }
 834                 up_read(&sinfo->groups_sem);
 835         }
 836         return sysfs_emit(buf, "none %u\n"
 837                                "small %u\n"
 838                                "medium %u\n"
 839                                "large %u\n",
 840                                none, small, medium, large);
 841 }
 842
 843 #ifdef CONFIG_BTRFS_DEBUG
 844 /*
 845  * Request chunk allocation with current chunk size.
 846  */
 847 static ssize_t btrfs_force_chunk_alloc_store(struct kobject *kobj,
 848                                              struct kobj_attribute *a,
 849                                              const char *buf, size_t len)
 850 {
 851         struct btrfs_space_info *space_info = to_space_info(kobj);
 852         struct btrfs_fs_info *fs_info = to_fs_info(get_btrfs_kobj(kobj));
 853         struct btrfs_trans_handle *trans;
 854         bool val;
 855         int ret;
 856
 857         if (!capable(CAP_SYS_ADMIN))
 858                 return -EPERM;
 859
 860         if (sb_rdonly(fs_info->sb))
 861                 return -EROFS;
 862
 863         ret = kstrtobool(buf, &val);
 864         if (ret)
 865                 return ret;
 866
 867         if (!val)
 868                 return -EINVAL;
 869
 870         /*
 871          * This is unsafe to be called from sysfs context and may cause
 872          * unexpected problems.
 873          */
 874         trans = btrfs_start_transaction(fs_info->tree_root, 0);
 875         if (IS_ERR(trans))
 876                 return PTR_ERR(trans);
 877         ret = btrfs_force_chunk_alloc(trans, space_info->flags);
 878         btrfs_end_transaction(trans);
 879
 880         if (ret == 1)
 881                 return len;
 882
 883         return -ENOSPC;
 884 }
 885 BTRFS_ATTR_W(space_info, force_chunk_alloc, btrfs_force_chunk_alloc_store);
 886
 887 #endif
 888
 889 SPACE_INFO_ATTR(flags);
 890 SPACE_INFO_ATTR(total_bytes);
 891 SPACE_INFO_ATTR(bytes_used);
 892 SPACE_INFO_ATTR(bytes_pinned);
 893 SPACE_INFO_ATTR(bytes_reserved);
 894 SPACE_INFO_ATTR(bytes_may_use);
 895 SPACE_INFO_ATTR(bytes_readonly);
 896 SPACE_INFO_ATTR(bytes_zone_unusable);
 897 SPACE_INFO_ATTR(disk_used);
 898 SPACE_INFO_ATTR(disk_total);
 899 SPACE_INFO_ATTR(reclaim_count);
 900 SPACE_INFO_ATTR(reclaim_bytes);
 901 SPACE_INFO_ATTR(reclaim_errors);
 902 BTRFS_ATTR_RW(space_info, chunk_size, btrfs_chunk_size_show, btrfs_chunk_size_store);
 903 BTRFS_ATTR(space_info, size_classes, btrfs_size_classes_show);
 904
 905 static ssize_t btrfs_sinfo_bg_reclaim_threshold_show(struct kobject *kobj,
 906                                                      struct kobj_attribute *a,
 907                                                      char *buf)
 908 {
 909         struct btrfs_space_info *space_info = to_space_info(kobj);
 910         ssize_t ret;
 911
 912         spin_lock(&space_info->lock);
 913         ret = sysfs_emit(buf, "%d\n", btrfs_calc_reclaim_threshold(space_info));
 914         spin_unlock(&space_info->lock);
 915         return ret;
 916 }
 917
 918 static ssize_t btrfs_sinfo_bg_reclaim_threshold_store(struct kobject *kobj,
 919                                                       struct kobj_attribute *a,
 920                                                       const char *buf, size_t len)
 921 {
 922         struct btrfs_space_info *space_info = to_space_info(kobj);
 923         int thresh;
 924         int ret;
 925
 926         if (READ_ONCE(space_info->dynamic_reclaim))
 927                 return -EINVAL;
 928
 929         ret = kstrtoint(buf, 10, &thresh);
 930         if (ret)
 931                 return ret;
 932
 933         if (thresh < 0 || thresh > 100)
 934                 return -EINVAL;
 935
 936         WRITE_ONCE(space_info->bg_reclaim_threshold, thresh);
 937
 938         return len;
 939 }
 940
 941 BTRFS_ATTR_RW(space_info, bg_reclaim_threshold,
 942               btrfs_sinfo_bg_reclaim_threshold_show,
 943               btrfs_sinfo_bg_reclaim_threshold_store);
 944
 945 static ssize_t btrfs_sinfo_dynamic_reclaim_show(struct kobject *kobj,
 946                                                 struct kobj_attribute *a,
 947                                                 char *buf)
 948 {
 949         struct btrfs_space_info *space_info = to_space_info(kobj);
 950
 951         return sysfs_emit(buf, "%d\n", READ_ONCE(space_info->dynamic_reclaim));
 952 }
 953
 954 static ssize_t btrfs_sinfo_dynamic_reclaim_store(struct kobject *kobj,
 955                                                  struct kobj_attribute *a,
 956                                                  const char *buf, size_t len)
 957 {
 958         struct btrfs_space_info *space_info = to_space_info(kobj);
 959         int dynamic_reclaim;
 960         int ret;
 961
 962         ret = kstrtoint(buf, 10, &dynamic_reclaim);
 963         if (ret)
 964                 return ret;
 965
 966         if (dynamic_reclaim < 0)
 967                 return -EINVAL;
 968
 969         WRITE_ONCE(space_info->dynamic_reclaim, dynamic_reclaim != 0);
 970
 971         return len;
 972 }
 973
 974 BTRFS_ATTR_RW(space_info, dynamic_reclaim,
 975               btrfs_sinfo_dynamic_reclaim_show,
 976               btrfs_sinfo_dynamic_reclaim_store);
 977
 978 static ssize_t btrfs_sinfo_periodic_reclaim_show(struct kobject *kobj,
 979                                                 struct kobj_attribute *a,
 980                                                 char *buf)
 981 {
 982         struct btrfs_space_info *space_info = to_space_info(kobj);
 983
 984         return sysfs_emit(buf, "%d\n", READ_ONCE(space_info->periodic_reclaim));
 985 }
 986
 987 static ssize_t btrfs_sinfo_periodic_reclaim_store(struct kobject *kobj,
 988                                                  struct kobj_attribute *a,
 989                                                  const char *buf, size_t len)
 990 {
 991         struct btrfs_space_info *space_info = to_space_info(kobj);
 992         int periodic_reclaim;
 993         int ret;
 994
 995         ret = kstrtoint(buf, 10, &periodic_reclaim);
 996         if (ret)
 997                 return ret;
 998
 999         if (periodic_reclaim < 0)
1000                 return -EINVAL;
1001
1002         WRITE_ONCE(space_info->periodic_reclaim, periodic_reclaim != 0);
1003
1004         return len;
1005 }
1006
1007 BTRFS_ATTR_RW(space_info, periodic_reclaim,
1008               btrfs_sinfo_periodic_reclaim_show,
1009               btrfs_sinfo_periodic_reclaim_store);
1010
1011 /*
1012  * Allocation information about block group types.
1013  *
1014  * Path: /sys/fs/btrfs/<uuid>/allocation/<bg-type>/
1015  */
1016 static struct attribute *space_info_attrs[] = {
1017         BTRFS_ATTR_PTR(space_info, flags),
1018         BTRFS_ATTR_PTR(space_info, total_bytes),
1019         BTRFS_ATTR_PTR(space_info, bytes_used),
1020         BTRFS_ATTR_PTR(space_info, bytes_pinned),
1021         BTRFS_ATTR_PTR(space_info, bytes_reserved),
1022         BTRFS_ATTR_PTR(space_info, bytes_may_use),
1023         BTRFS_ATTR_PTR(space_info, bytes_readonly),
1024         BTRFS_ATTR_PTR(space_info, bytes_zone_unusable),
1025         BTRFS_ATTR_PTR(space_info, disk_used),
1026         BTRFS_ATTR_PTR(space_info, disk_total),
1027         BTRFS_ATTR_PTR(space_info, bg_reclaim_threshold),
1028         BTRFS_ATTR_PTR(space_info, dynamic_reclaim),
1029         BTRFS_ATTR_PTR(space_info, chunk_size),
1030         BTRFS_ATTR_PTR(space_info, size_classes),
1031         BTRFS_ATTR_PTR(space_info, reclaim_count),
1032         BTRFS_ATTR_PTR(space_info, reclaim_bytes),
1033         BTRFS_ATTR_PTR(space_info, reclaim_errors),
1034         BTRFS_ATTR_PTR(space_info, periodic_reclaim),
1035 #ifdef CONFIG_BTRFS_DEBUG
1036         BTRFS_ATTR_PTR(space_info, force_chunk_alloc),
1037 #endif
1038         NULL,
1039 };
1040 ATTRIBUTE_GROUPS(space_info);
1041
1042 static void space_info_release(struct kobject *kobj)
1043 {
1044         struct btrfs_space_info *sinfo = to_space_info(kobj);
1045         kfree(sinfo);
1046 }
1047
1048 static const struct kobj_type space_info_ktype = {
1049         .sysfs_ops = &kobj_sysfs_ops,
1050         .release = space_info_release,
1051         .default_groups = space_info_groups,
1052 };
1053
1054 /*
1055  * Allocation information about block groups.
1056  *
1057  * Path: /sys/fs/btrfs/<uuid>/allocation/
1058  */
1059 static const struct attribute *allocation_attrs[] = {
1060         BTRFS_ATTR_PTR(allocation, global_rsv_reserved),
1061         BTRFS_ATTR_PTR(allocation, global_rsv_size),
1062         NULL,
1063 };
1064
1065 static ssize_t btrfs_label_show(struct kobject *kobj,
1066                                 struct kobj_attribute *a, char *buf)
1067 {
1068         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1069         char *label = fs_info->super_copy->label;
1070         ssize_t ret;
1071
1072         spin_lock(&fs_info->super_lock);
1073         ret = sysfs_emit(buf, label[0] ? "%s\n" : "%s", label);
1074         spin_unlock(&fs_info->super_lock);
1075
1076         return ret;
1077 }
1078
1079 static ssize_t btrfs_label_store(struct kobject *kobj,
1080                                  struct kobj_attribute *a,
1081                                  const char *buf, size_t len)
1082 {
1083         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1084         size_t p_len;
1085
1086         if (!fs_info)
1087                 return -EPERM;
1088
1089         if (sb_rdonly(fs_info->sb))
1090                 return -EROFS;
1091
1092         /*
1093          * p_len is the len until the first occurrence of either
1094          * '\n' or '\0'
1095          */
1096         p_len = strcspn(buf, "\n");
1097
1098         if (p_len >= BTRFS_LABEL_SIZE)
1099                 return -EINVAL;
1100
1101         spin_lock(&fs_info->super_lock);
1102         memset(fs_info->super_copy->label, 0, BTRFS_LABEL_SIZE);
1103         memcpy(fs_info->super_copy->label, buf, p_len);
1104         spin_unlock(&fs_info->super_lock);
1105
1106         /*
1107          * We don't want to do full transaction commit from inside sysfs
1108          */
1109         set_bit(BTRFS_FS_NEED_TRANS_COMMIT, &fs_info->flags);
1110         wake_up_process(fs_info->transaction_kthread);
1111
1112         return len;
1113 }
1114 BTRFS_ATTR_RW(, label, btrfs_label_show, btrfs_label_store);
1115
1116 static ssize_t btrfs_nodesize_show(struct kobject *kobj,
1117                                 struct kobj_attribute *a, char *buf)
1118 {
1119         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1120
1121         return sysfs_emit(buf, "%u\n", fs_info->super_copy->nodesize);
1122 }
1123
1124 BTRFS_ATTR(, nodesize, btrfs_nodesize_show);
1125
1126 static ssize_t btrfs_sectorsize_show(struct kobject *kobj,
1127                                 struct kobj_attribute *a, char *buf)
1128 {
1129         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1130
1131         return sysfs_emit(buf, "%u\n", fs_info->super_copy->sectorsize);
1132 }
1133
1134 BTRFS_ATTR(, sectorsize, btrfs_sectorsize_show);
1135
1136 static ssize_t btrfs_commit_stats_show(struct kobject *kobj,
1137                                        struct kobj_attribute *a, char *buf)
1138 {
1139         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1140
1141         return sysfs_emit(buf,
1142                 "commits %llu\n"
1143                 "last_commit_ms %llu\n"
1144                 "max_commit_ms %llu\n"
1145                 "total_commit_ms %llu\n",
1146                 fs_info->commit_stats.commit_count,
1147                 div_u64(fs_info->commit_stats.last_commit_dur, NSEC_PER_MSEC),
1148                 div_u64(fs_info->commit_stats.max_commit_dur, NSEC_PER_MSEC),
1149                 div_u64(fs_info->commit_stats.total_commit_dur, NSEC_PER_MSEC));
1150 }
1151
1152 static ssize_t btrfs_commit_stats_store(struct kobject *kobj,
1153                                         struct kobj_attribute *a,
1154                                         const char *buf, size_t len)
1155 {
1156         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1157         unsigned long val;
1158         int ret;
1159
1160         if (!fs_info)
1161                 return -EPERM;
1162
1163         if (!capable(CAP_SYS_RESOURCE))
1164                 return -EPERM;
1165
1166         ret = kstrtoul(buf, 10, &val);
1167         if (ret)
1168                 return ret;
1169         if (val)
1170                 return -EINVAL;
1171
1172         WRITE_ONCE(fs_info->commit_stats.max_commit_dur, 0);
1173
1174         return len;
1175 }
1176 BTRFS_ATTR_RW(, commit_stats, btrfs_commit_stats_show, btrfs_commit_stats_store);
1177
1178 static ssize_t btrfs_clone_alignment_show(struct kobject *kobj,
1179                                 struct kobj_attribute *a, char *buf)
1180 {
1181         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1182
1183         return sysfs_emit(buf, "%u\n", fs_info->super_copy->sectorsize);
1184 }
1185
1186 BTRFS_ATTR(, clone_alignment, btrfs_clone_alignment_show);
1187
1188 static ssize_t quota_override_show(struct kobject *kobj,
1189                                    struct kobj_attribute *a, char *buf)
1190 {
1191         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1192         int quota_override;
1193
1194         quota_override = test_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
1195         return sysfs_emit(buf, "%d\n", quota_override);
1196 }
1197
1198 static ssize_t quota_override_store(struct kobject *kobj,
1199                                     struct kobj_attribute *a,
1200                                     const char *buf, size_t len)
1201 {
1202         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1203         unsigned long knob;
1204         int err;
1205
1206         if (!fs_info)
1207                 return -EPERM;
1208
1209         if (!capable(CAP_SYS_RESOURCE))
1210                 return -EPERM;
1211
1212         err = kstrtoul(buf, 10, &knob);
1213         if (err)
1214                 return err;
1215         if (knob > 1)
1216                 return -EINVAL;
1217
1218         if (knob)
1219                 set_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
1220         else
1221                 clear_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
1222
1223         return len;
1224 }
1225
1226 BTRFS_ATTR_RW(, quota_override, quota_override_show, quota_override_store);
1227
1228 static ssize_t btrfs_metadata_uuid_show(struct kobject *kobj,
1229                                 struct kobj_attribute *a, char *buf)
1230 {
1231         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1232
1233         return sysfs_emit(buf, "%pU\n", fs_info->fs_devices->metadata_uuid);
1234 }
1235
1236 BTRFS_ATTR(, metadata_uuid, btrfs_metadata_uuid_show);
1237
1238 static ssize_t btrfs_checksum_show(struct kobject *kobj,
1239                                    struct kobj_attribute *a, char *buf)
1240 {
1241         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1242         u16 csum_type = btrfs_super_csum_type(fs_info->super_copy);
1243
1244         return sysfs_emit(buf, "%s (%s)\n",
1245                           btrfs_super_csum_name(csum_type),
1246                           crypto_shash_driver_name(fs_info->csum_shash));
1247 }
1248
1249 BTRFS_ATTR(, checksum, btrfs_checksum_show);
1250
1251 static ssize_t btrfs_exclusive_operation_show(struct kobject *kobj,
1252                 struct kobj_attribute *a, char *buf)
1253 {
1254         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1255         const char *str;
1256
1257         switch (READ_ONCE(fs_info->exclusive_operation)) {
1258                 case  BTRFS_EXCLOP_NONE:
1259                         str = "none\n";
1260                         break;
1261                 case BTRFS_EXCLOP_BALANCE:
1262                         str = "balance\n";
1263                         break;
1264                 case BTRFS_EXCLOP_BALANCE_PAUSED:
1265                         str = "balance paused\n";
1266                         break;
1267                 case BTRFS_EXCLOP_DEV_ADD:
1268                         str = "device add\n";
1269                         break;
1270                 case BTRFS_EXCLOP_DEV_REMOVE:
1271                         str = "device remove\n";
1272                         break;
1273                 case BTRFS_EXCLOP_DEV_REPLACE:
1274                         str = "device replace\n";
1275                         break;
1276                 case BTRFS_EXCLOP_RESIZE:
1277                         str = "resize\n";
1278                         break;
1279                 case BTRFS_EXCLOP_SWAP_ACTIVATE:
1280                         str = "swap activate\n";
1281                         break;
1282                 default:
1283                         str = "UNKNOWN\n";
1284                         break;
1285         }
1286         return sysfs_emit(buf, "%s", str);
1287 }
1288 BTRFS_ATTR(, exclusive_operation, btrfs_exclusive_operation_show);
1289
1290 static ssize_t btrfs_generation_show(struct kobject *kobj,
1291                                      struct kobj_attribute *a, char *buf)
1292 {
1293         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1294
1295         return sysfs_emit(buf, "%llu\n", btrfs_get_fs_generation(fs_info));
1296 }
1297 BTRFS_ATTR(, generation, btrfs_generation_show);
1298
1299 static ssize_t btrfs_temp_fsid_show(struct kobject *kobj,
1300                                     struct kobj_attribute *a, char *buf)
1301 {
1302         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1303
1304         return sysfs_emit(buf, "%d\n", fs_info->fs_devices->temp_fsid);
1305 }
1306 BTRFS_ATTR(, temp_fsid, btrfs_temp_fsid_show);
1307
1308 static const char * const btrfs_read_policy_name[] = { "pid" };
1309
1310 static ssize_t btrfs_read_policy_show(struct kobject *kobj,
1311                                       struct kobj_attribute *a, char *buf)
1312 {
1313         struct btrfs_fs_devices *fs_devices = to_fs_devs(kobj);
1314         const enum btrfs_read_policy policy = READ_ONCE(fs_devices->read_policy);
1315         ssize_t ret = 0;
1316         int i;
1317
1318         for (i = 0; i < BTRFS_NR_READ_POLICY; i++) {
1319                 if (policy == i)
1320                         ret += sysfs_emit_at(buf, ret, "%s[%s]",
1321                                          (ret == 0 ? "" : " "),
1322                                          btrfs_read_policy_name[i]);
1323                 else
1324                         ret += sysfs_emit_at(buf, ret, "%s%s",
1325                                          (ret == 0 ? "" : " "),
1326                                          btrfs_read_policy_name[i]);
1327         }
1328
1329         ret += sysfs_emit_at(buf, ret, "\n");
1330
1331         return ret;
1332 }
1333
1334 static ssize_t btrfs_read_policy_store(struct kobject *kobj,
1335                                        struct kobj_attribute *a,
1336                                        const char *buf, size_t len)
1337 {
1338         struct btrfs_fs_devices *fs_devices = to_fs_devs(kobj);
1339         int i;
1340
1341         for (i = 0; i < BTRFS_NR_READ_POLICY; i++) {
1342                 if (sysfs_streq(buf, btrfs_read_policy_name[i])) {
1343                         if (i != READ_ONCE(fs_devices->read_policy)) {
1344                                 WRITE_ONCE(fs_devices->read_policy, i);
1345                                 btrfs_info(fs_devices->fs_info,
1346                                            "read policy set to '%s'",
1347                                            btrfs_read_policy_name[i]);
1348                         }
1349                         return len;
1350                 }
1351         }
1352
1353         return -EINVAL;
1354 }
1355 BTRFS_ATTR_RW(, read_policy, btrfs_read_policy_show, btrfs_read_policy_store);
1356
1357 static ssize_t btrfs_bg_reclaim_threshold_show(struct kobject *kobj,
1358                                                struct kobj_attribute *a,
1359                                                char *buf)
1360 {
1361         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1362
1363         return sysfs_emit(buf, "%d\n", READ_ONCE(fs_info->bg_reclaim_threshold));
1364 }
1365
1366 static ssize_t btrfs_bg_reclaim_threshold_store(struct kobject *kobj,
1367                                                 struct kobj_attribute *a,
1368                                                 const char *buf, size_t len)
1369 {
1370         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1371         int thresh;
1372         int ret;
1373
1374         ret = kstrtoint(buf, 10, &thresh);
1375         if (ret)
1376                 return ret;
1377
1378 #ifdef CONFIG_BTRFS_DEBUG
1379         if (thresh != 0 && (thresh > 100))
1380                 return -EINVAL;
1381 #else
1382         if (thresh != 0 && (thresh <= 50 || thresh > 100))
1383                 return -EINVAL;
1384 #endif
1385
1386         WRITE_ONCE(fs_info->bg_reclaim_threshold, thresh);
1387
1388         return len;
1389 }
1390 BTRFS_ATTR_RW(, bg_reclaim_threshold, btrfs_bg_reclaim_threshold_show,
1391               btrfs_bg_reclaim_threshold_store);
1392
1393 #ifdef CONFIG_BTRFS_DEBUG
1394 static ssize_t btrfs_offload_csum_show(struct kobject *kobj,
1395                                        struct kobj_attribute *a, char *buf)
1396 {
1397         struct btrfs_fs_devices *fs_devices = to_fs_devs(kobj);
1398
1399         switch (READ_ONCE(fs_devices->offload_csum_mode)) {
1400         case BTRFS_OFFLOAD_CSUM_AUTO:
1401                 return sysfs_emit(buf, "auto\n");
1402         case BTRFS_OFFLOAD_CSUM_FORCE_ON:
1403                 return sysfs_emit(buf, "1\n");
1404         case BTRFS_OFFLOAD_CSUM_FORCE_OFF:
1405                 return sysfs_emit(buf, "0\n");
1406         default:
1407                 WARN_ON(1);
1408                 return -EINVAL;
1409         }
1410 }
1411
1412 static ssize_t btrfs_offload_csum_store(struct kobject *kobj,
1413                                         struct kobj_attribute *a, const char *buf,
1414                                         size_t len)
1415 {
1416         struct btrfs_fs_devices *fs_devices = to_fs_devs(kobj);
1417         int ret;
1418         bool val;
1419
1420         ret = kstrtobool(buf, &val);
1421         if (ret == 0)
1422                 WRITE_ONCE(fs_devices->offload_csum_mode,
1423                            val ? BTRFS_OFFLOAD_CSUM_FORCE_ON : BTRFS_OFFLOAD_CSUM_FORCE_OFF);
1424         else if (ret == -EINVAL && sysfs_streq(buf, "auto"))
1425                 WRITE_ONCE(fs_devices->offload_csum_mode, BTRFS_OFFLOAD_CSUM_AUTO);
1426         else
1427                 return -EINVAL;
1428
1429         return len;
1430 }
1431 BTRFS_ATTR_RW(, offload_csum, btrfs_offload_csum_show, btrfs_offload_csum_store);
1432 #endif
1433
1434 /*
1435  * Per-filesystem information and stats.
1436  *
1437  * Path: /sys/fs/btrfs/<uuid>/
1438  */
1439 static const struct attribute *btrfs_attrs[] = {
1440         BTRFS_ATTR_PTR(, label),
1441         BTRFS_ATTR_PTR(, nodesize),
1442         BTRFS_ATTR_PTR(, sectorsize),
1443         BTRFS_ATTR_PTR(, clone_alignment),
1444         BTRFS_ATTR_PTR(, quota_override),
1445         BTRFS_ATTR_PTR(, metadata_uuid),
1446         BTRFS_ATTR_PTR(, checksum),
1447         BTRFS_ATTR_PTR(, exclusive_operation),
1448         BTRFS_ATTR_PTR(, generation),
1449         BTRFS_ATTR_PTR(, read_policy),
1450         BTRFS_ATTR_PTR(, bg_reclaim_threshold),
1451         BTRFS_ATTR_PTR(, commit_stats),
1452         BTRFS_ATTR_PTR(, temp_fsid),
1453 #ifdef CONFIG_BTRFS_DEBUG
1454         BTRFS_ATTR_PTR(, offload_csum),
1455 #endif
1456         NULL,
1457 };
1458
1459 static void btrfs_release_fsid_kobj(struct kobject *kobj)
1460 {
1461         struct btrfs_fs_devices *fs_devs = to_fs_devs(kobj);
1462
1463         memset(&fs_devs->fsid_kobj, 0, sizeof(struct kobject));
1464         complete(&fs_devs->kobj_unregister);
1465 }
1466
1467 static const struct kobj_type btrfs_ktype = {
1468         .sysfs_ops      = &kobj_sysfs_ops,
1469         .release        = btrfs_release_fsid_kobj,
1470 };
1471
1472 static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj)
1473 {
1474         if (kobj->ktype != &btrfs_ktype)
1475                 return NULL;
1476         return container_of(kobj, struct btrfs_fs_devices, fsid_kobj);
1477 }
1478
1479 static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj)
1480 {
1481         if (kobj->ktype != &btrfs_ktype)
1482                 return NULL;
1483         return to_fs_devs(kobj)->fs_info;
1484 }
1485
1486 static struct kobject *get_btrfs_kobj(struct kobject *kobj)
1487 {
1488         while (kobj) {
1489                 if (kobj->ktype == &btrfs_ktype)
1490                         return kobj;
1491                 kobj = kobj->parent;
1492         }
1493         return NULL;
1494 }
1495
1496 #define NUM_FEATURE_BITS 64
1497 #define BTRFS_FEATURE_NAME_MAX 13
1498 static char btrfs_unknown_feature_names[FEAT_MAX][NUM_FEATURE_BITS][BTRFS_FEATURE_NAME_MAX];
1499 static struct btrfs_feature_attr btrfs_feature_attrs[FEAT_MAX][NUM_FEATURE_BITS];
1500
1501 static_assert(ARRAY_SIZE(btrfs_unknown_feature_names) ==
1502               ARRAY_SIZE(btrfs_feature_attrs));
1503 static_assert(ARRAY_SIZE(btrfs_unknown_feature_names[0]) ==
1504               ARRAY_SIZE(btrfs_feature_attrs[0]));
1505
1506 static const u64 supported_feature_masks[FEAT_MAX] = {
1507         [FEAT_COMPAT]    = BTRFS_FEATURE_COMPAT_SUPP,
1508         [FEAT_COMPAT_RO] = BTRFS_FEATURE_COMPAT_RO_SUPP,
1509         [FEAT_INCOMPAT]  = BTRFS_FEATURE_INCOMPAT_SUPP,
1510 };
1511
1512 static int addrm_unknown_feature_attrs(struct btrfs_fs_info *fs_info, bool add)
1513 {
1514         int set;
1515
1516         for (set = 0; set < FEAT_MAX; set++) {
1517                 int i;
1518                 struct attribute *attrs[2];
1519                 struct attribute_group agroup = {
1520                         .name = "features",
1521                         .attrs = attrs,
1522                 };
1523                 u64 features = get_features(fs_info, set);
1524                 features &= ~supported_feature_masks[set];
1525
1526                 if (!features)
1527                         continue;
1528
1529                 attrs[1] = NULL;
1530                 for (i = 0; i < NUM_FEATURE_BITS; i++) {
1531                         struct btrfs_feature_attr *fa;
1532
1533                         if (!(features & (1ULL << i)))
1534                                 continue;
1535
1536                         fa = &btrfs_feature_attrs[set][i];
1537                         attrs[0] = &fa->kobj_attr.attr;
1538                         if (add) {
1539                                 int ret;
1540                                 ret = sysfs_merge_group(&fs_info->fs_devices->fsid_kobj,
1541                                                         &agroup);
1542                                 if (ret)
1543                                         return ret;
1544                         } else
1545                                 sysfs_unmerge_group(&fs_info->fs_devices->fsid_kobj,
1546                                                     &agroup);
1547                 }
1548
1549         }
1550         return 0;
1551 }
1552
1553 static void __btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs)
1554 {
1555         if (fs_devs->devinfo_kobj) {
1556                 kobject_del(fs_devs->devinfo_kobj);
1557                 kobject_put(fs_devs->devinfo_kobj);
1558                 fs_devs->devinfo_kobj = NULL;
1559         }
1560
1561         if (fs_devs->devices_kobj) {
1562                 kobject_del(fs_devs->devices_kobj);
1563                 kobject_put(fs_devs->devices_kobj);
1564                 fs_devs->devices_kobj = NULL;
1565         }
1566
1567         if (fs_devs->fsid_kobj.state_initialized) {
1568                 kobject_del(&fs_devs->fsid_kobj);
1569                 kobject_put(&fs_devs->fsid_kobj);
1570                 wait_for_completion(&fs_devs->kobj_unregister);
1571         }
1572 }
1573
1574 /* when fs_devs is NULL it will remove all fsid kobject */
1575 void btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs)
1576 {
1577         struct list_head *fs_uuids = btrfs_get_fs_uuids();
1578
1579         if (fs_devs) {
1580                 __btrfs_sysfs_remove_fsid(fs_devs);
1581                 return;
1582         }
1583
1584         list_for_each_entry(fs_devs, fs_uuids, fs_list) {
1585                 __btrfs_sysfs_remove_fsid(fs_devs);
1586         }
1587 }
1588
1589 static void btrfs_sysfs_remove_fs_devices(struct btrfs_fs_devices *fs_devices)
1590 {
1591         struct btrfs_device *device;
1592         struct btrfs_fs_devices *seed;
1593
1594         list_for_each_entry(device, &fs_devices->devices, dev_list)
1595                 btrfs_sysfs_remove_device(device);
1596
1597         list_for_each_entry(seed, &fs_devices->seed_list, seed_list) {
1598                 list_for_each_entry(device, &seed->devices, dev_list)
1599                         btrfs_sysfs_remove_device(device);
1600         }
1601 }
1602
1603 void btrfs_sysfs_remove_mounted(struct btrfs_fs_info *fs_info)
1604 {
1605         struct kobject *fsid_kobj = &fs_info->fs_devices->fsid_kobj;
1606
1607         sysfs_remove_link(fsid_kobj, "bdi");
1608
1609         if (fs_info->space_info_kobj) {
1610                 sysfs_remove_files(fs_info->space_info_kobj, allocation_attrs);
1611                 kobject_del(fs_info->space_info_kobj);
1612                 kobject_put(fs_info->space_info_kobj);
1613         }
1614         if (fs_info->discard_kobj) {
1615                 sysfs_remove_files(fs_info->discard_kobj, discard_attrs);
1616                 kobject_del(fs_info->discard_kobj);
1617                 kobject_put(fs_info->discard_kobj);
1618         }
1619 #ifdef CONFIG_BTRFS_DEBUG
1620         if (fs_info->debug_kobj) {
1621                 sysfs_remove_files(fs_info->debug_kobj, btrfs_debug_mount_attrs);
1622                 kobject_del(fs_info->debug_kobj);
1623                 kobject_put(fs_info->debug_kobj);
1624         }
1625 #endif
1626         addrm_unknown_feature_attrs(fs_info, false);
1627         sysfs_remove_group(fsid_kobj, &btrfs_feature_attr_group);
1628         sysfs_remove_files(fsid_kobj, btrfs_attrs);
1629         btrfs_sysfs_remove_fs_devices(fs_info->fs_devices);
1630 }
1631
1632 static const char * const btrfs_feature_set_names[FEAT_MAX] = {
1633         [FEAT_COMPAT]    = "compat",
1634         [FEAT_COMPAT_RO] = "compat_ro",
1635         [FEAT_INCOMPAT]  = "incompat",
1636 };
1637
1638 const char *btrfs_feature_set_name(enum btrfs_feature_set set)
1639 {
1640         return btrfs_feature_set_names[set];
1641 }
1642
1643 char *btrfs_printable_features(enum btrfs_feature_set set, u64 flags)
1644 {
1645         size_t bufsize = 4096; /* safe max, 64 names * 64 bytes */
1646         int len = 0;
1647         int i;
1648         char *str;
1649
1650         str = kmalloc(bufsize, GFP_KERNEL);
1651         if (!str)
1652                 return str;
1653
1654         for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
1655                 const char *name;
1656
1657                 if (!(flags & (1ULL << i)))
1658                         continue;
1659
1660                 name = btrfs_feature_attrs[set][i].kobj_attr.attr.name;
1661                 len += scnprintf(str + len, bufsize - len, "%s%s",
1662                                 len ? "," : "", name);
1663         }
1664
1665         return str;
1666 }
1667
1668 static void init_feature_attrs(void)
1669 {
1670         struct btrfs_feature_attr *fa;
1671         int set, i;
1672
1673         memset(btrfs_feature_attrs, 0, sizeof(btrfs_feature_attrs));
1674         memset(btrfs_unknown_feature_names, 0,
1675                sizeof(btrfs_unknown_feature_names));
1676
1677         for (i = 0; btrfs_supported_feature_attrs[i]; i++) {
1678                 struct btrfs_feature_attr *sfa;
1679                 struct attribute *a = btrfs_supported_feature_attrs[i];
1680                 int bit;
1681                 sfa = attr_to_btrfs_feature_attr(a);
1682                 bit = ilog2(sfa->feature_bit);
1683                 fa = &btrfs_feature_attrs[sfa->feature_set][bit];
1684
1685                 fa->kobj_attr.attr.name = sfa->kobj_attr.attr.name;
1686         }
1687
1688         for (set = 0; set < FEAT_MAX; set++) {
1689                 for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
1690                         char *name = btrfs_unknown_feature_names[set][i];
1691                         fa = &btrfs_feature_attrs[set][i];
1692
1693                         if (fa->kobj_attr.attr.name)
1694                                 continue;
1695
1696                         snprintf(name, BTRFS_FEATURE_NAME_MAX, "%s:%u",
1697                                  btrfs_feature_set_names[set], i);
1698
1699                         fa->kobj_attr.attr.name = name;
1700                         fa->kobj_attr.attr.mode = S_IRUGO;
1701                         fa->feature_set = set;
1702                         fa->feature_bit = 1ULL << i;
1703                 }
1704         }
1705 }
1706
1707 /*
1708  * Create a sysfs entry for a given block group type at path
1709  * /sys/fs/btrfs/UUID/allocation/data/TYPE
1710  */
1711 void btrfs_sysfs_add_block_group_type(struct btrfs_block_group *cache)
1712 {
1713         struct btrfs_fs_info *fs_info = cache->fs_info;
1714         struct btrfs_space_info *space_info = cache->space_info;
1715         struct raid_kobject *rkobj;
1716         const int index = btrfs_bg_flags_to_raid_index(cache->flags);
1717         unsigned int nofs_flag;
1718         int ret;
1719
1720         /*
1721          * Setup a NOFS context because kobject_add(), deep in its call chain,
1722          * does GFP_KERNEL allocations, and we are often called in a context
1723          * where if reclaim is triggered we can deadlock (we are either holding
1724          * a transaction handle or some lock required for a transaction
1725          * commit).
1726          */
1727         nofs_flag = memalloc_nofs_save();
1728
1729         rkobj = kzalloc(sizeof(*rkobj), GFP_NOFS);
1730         if (!rkobj) {
1731                 memalloc_nofs_restore(nofs_flag);
1732                 btrfs_warn(cache->fs_info,
1733                                 "couldn't alloc memory for raid level kobject");
1734                 return;
1735         }
1736
1737         rkobj->flags = cache->flags;
1738         kobject_init(&rkobj->kobj, &btrfs_raid_ktype);
1739
1740         /*
1741          * We call this either on mount, or if we've created a block group for a
1742          * new index type while running (i.e. when restriping).  The running
1743          * case is tricky because we could race with other threads, so we need
1744          * to have this check to make sure we didn't already init the kobject.
1745          *
1746          * We don't have to protect on the free side because it only happens on
1747          * unmount.
1748          */
1749         spin_lock(&space_info->lock);
1750         if (space_info->block_group_kobjs[index]) {
1751                 spin_unlock(&space_info->lock);
1752                 kobject_put(&rkobj->kobj);
1753                 return;
1754         } else {
1755                 space_info->block_group_kobjs[index] = &rkobj->kobj;
1756         }
1757         spin_unlock(&space_info->lock);
1758
1759         ret = kobject_add(&rkobj->kobj, &space_info->kobj, "%s",
1760                           btrfs_bg_type_to_raid_name(rkobj->flags));
1761         memalloc_nofs_restore(nofs_flag);
1762         if (ret) {
1763                 spin_lock(&space_info->lock);
1764                 space_info->block_group_kobjs[index] = NULL;
1765                 spin_unlock(&space_info->lock);
1766                 kobject_put(&rkobj->kobj);
1767                 btrfs_warn(fs_info,
1768                         "failed to add kobject for block cache, ignoring");
1769                 return;
1770         }
1771 }
1772
1773 /*
1774  * Remove sysfs directories for all block group types of a given space info and
1775  * the space info as well
1776  */
1777 void btrfs_sysfs_remove_space_info(struct btrfs_space_info *space_info)
1778 {
1779         int i;
1780
1781         for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) {
1782                 struct kobject *kobj;
1783
1784                 kobj = space_info->block_group_kobjs[i];
1785                 space_info->block_group_kobjs[i] = NULL;
1786                 if (kobj) {
1787                         kobject_del(kobj);
1788                         kobject_put(kobj);
1789                 }
1790         }
1791         kobject_del(&space_info->kobj);
1792         kobject_put(&space_info->kobj);
1793 }
1794
1795 static const char *alloc_name(u64 flags)
1796 {
1797         switch (flags) {
1798         case BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA:
1799                 return "mixed";
1800         case BTRFS_BLOCK_GROUP_METADATA:
1801                 return "metadata";
1802         case BTRFS_BLOCK_GROUP_DATA:
1803                 return "data";
1804         case BTRFS_BLOCK_GROUP_SYSTEM:
1805                 return "system";
1806         default:
1807                 WARN_ON(1);
1808                 return "invalid-combination";
1809         }
1810 }
1811
1812 /*
1813  * Create a sysfs entry for a space info type at path
1814  * /sys/fs/btrfs/UUID/allocation/TYPE
1815  */
1816 int btrfs_sysfs_add_space_info_type(struct btrfs_fs_info *fs_info,
1817                                     struct btrfs_space_info *space_info)
1818 {
1819         int ret;
1820
1821         ret = kobject_init_and_add(&space_info->kobj, &space_info_ktype,
1822                                    fs_info->space_info_kobj, "%s",
1823                                    alloc_name(space_info->flags));
1824         if (ret) {
1825                 kobject_put(&space_info->kobj);
1826                 return ret;
1827         }
1828
1829         return 0;
1830 }
1831
1832 void btrfs_sysfs_remove_device(struct btrfs_device *device)
1833 {
1834         struct kobject *devices_kobj;
1835
1836         /*
1837          * Seed fs_devices devices_kobj aren't used, fetch kobject from the
1838          * fs_info::fs_devices.
1839          */
1840         devices_kobj = device->fs_info->fs_devices->devices_kobj;
1841         ASSERT(devices_kobj);
1842
1843         if (device->bdev)
1844                 sysfs_remove_link(devices_kobj, bdev_kobj(device->bdev)->name);
1845
1846         if (device->devid_kobj.state_initialized) {
1847                 kobject_del(&device->devid_kobj);
1848                 kobject_put(&device->devid_kobj);
1849                 wait_for_completion(&device->kobj_unregister);
1850         }
1851 }
1852
1853 static ssize_t btrfs_devinfo_in_fs_metadata_show(struct kobject *kobj,
1854                                                  struct kobj_attribute *a,
1855                                                  char *buf)
1856 {
1857         int val;
1858         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1859                                                    devid_kobj);
1860
1861         val = !!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state);
1862
1863         return sysfs_emit(buf, "%d\n", val);
1864 }
1865 BTRFS_ATTR(devid, in_fs_metadata, btrfs_devinfo_in_fs_metadata_show);
1866
1867 static ssize_t btrfs_devinfo_missing_show(struct kobject *kobj,
1868                                         struct kobj_attribute *a, char *buf)
1869 {
1870         int val;
1871         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1872                                                    devid_kobj);
1873
1874         val = !!test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state);
1875
1876         return sysfs_emit(buf, "%d\n", val);
1877 }
1878 BTRFS_ATTR(devid, missing, btrfs_devinfo_missing_show);
1879
1880 static ssize_t btrfs_devinfo_replace_target_show(struct kobject *kobj,
1881                                                  struct kobj_attribute *a,
1882                                                  char *buf)
1883 {
1884         int val;
1885         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1886                                                    devid_kobj);
1887
1888         val = !!test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state);
1889
1890         return sysfs_emit(buf, "%d\n", val);
1891 }
1892 BTRFS_ATTR(devid, replace_target, btrfs_devinfo_replace_target_show);
1893
1894 static ssize_t btrfs_devinfo_scrub_speed_max_show(struct kobject *kobj,
1895                                              struct kobj_attribute *a,
1896                                              char *buf)
1897 {
1898         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1899                                                    devid_kobj);
1900
1901         return sysfs_emit(buf, "%llu\n", READ_ONCE(device->scrub_speed_max));
1902 }
1903
1904 static ssize_t btrfs_devinfo_scrub_speed_max_store(struct kobject *kobj,
1905                                               struct kobj_attribute *a,
1906                                               const char *buf, size_t len)
1907 {
1908         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1909                                                    devid_kobj);
1910         char *endptr;
1911         unsigned long long limit;
1912
1913         limit = memparse(buf, &endptr);
1914         /* There could be trailing '\n', also catch any typos after the value. */
1915         endptr = skip_spaces(endptr);
1916         if (*endptr != 0)
1917                 return -EINVAL;
1918         WRITE_ONCE(device->scrub_speed_max, limit);
1919         return len;
1920 }
1921 BTRFS_ATTR_RW(devid, scrub_speed_max, btrfs_devinfo_scrub_speed_max_show,
1922               btrfs_devinfo_scrub_speed_max_store);
1923
1924 static ssize_t btrfs_devinfo_writeable_show(struct kobject *kobj,
1925                                             struct kobj_attribute *a, char *buf)
1926 {
1927         int val;
1928         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1929                                                    devid_kobj);
1930
1931         val = !!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state);
1932
1933         return sysfs_emit(buf, "%d\n", val);
1934 }
1935 BTRFS_ATTR(devid, writeable, btrfs_devinfo_writeable_show);
1936
1937 static ssize_t btrfs_devinfo_fsid_show(struct kobject *kobj,
1938                                        struct kobj_attribute *a, char *buf)
1939 {
1940         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1941                                                    devid_kobj);
1942
1943         return sysfs_emit(buf, "%pU\n", device->fs_devices->fsid);
1944 }
1945 BTRFS_ATTR(devid, fsid, btrfs_devinfo_fsid_show);
1946
1947 static ssize_t btrfs_devinfo_error_stats_show(struct kobject *kobj,
1948                 struct kobj_attribute *a, char *buf)
1949 {
1950         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1951                                                    devid_kobj);
1952
1953         if (!device->dev_stats_valid)
1954                 return sysfs_emit(buf, "invalid\n");
1955
1956         /*
1957          * Print all at once so we get a snapshot of all values from the same
1958          * time. Keep them in sync and in order of definition of
1959          * btrfs_dev_stat_values.
1960          */
1961         return sysfs_emit(buf,
1962                 "write_errs %d\n"
1963                 "read_errs %d\n"
1964                 "flush_errs %d\n"
1965                 "corruption_errs %d\n"
1966                 "generation_errs %d\n",
1967                 btrfs_dev_stat_read(device, BTRFS_DEV_STAT_WRITE_ERRS),
1968                 btrfs_dev_stat_read(device, BTRFS_DEV_STAT_READ_ERRS),
1969                 btrfs_dev_stat_read(device, BTRFS_DEV_STAT_FLUSH_ERRS),
1970                 btrfs_dev_stat_read(device, BTRFS_DEV_STAT_CORRUPTION_ERRS),
1971                 btrfs_dev_stat_read(device, BTRFS_DEV_STAT_GENERATION_ERRS));
1972 }
1973 BTRFS_ATTR(devid, error_stats, btrfs_devinfo_error_stats_show);
1974
1975 /*
1976  * Information about one device.
1977  *
1978  * Path: /sys/fs/btrfs/<uuid>/devinfo/<devid>/
1979  */
1980 static struct attribute *devid_attrs[] = {
1981         BTRFS_ATTR_PTR(devid, error_stats),
1982         BTRFS_ATTR_PTR(devid, fsid),
1983         BTRFS_ATTR_PTR(devid, in_fs_metadata),
1984         BTRFS_ATTR_PTR(devid, missing),
1985         BTRFS_ATTR_PTR(devid, replace_target),
1986         BTRFS_ATTR_PTR(devid, scrub_speed_max),
1987         BTRFS_ATTR_PTR(devid, writeable),
1988         NULL
1989 };
1990 ATTRIBUTE_GROUPS(devid);
1991
1992 static void btrfs_release_devid_kobj(struct kobject *kobj)
1993 {
1994         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1995                                                    devid_kobj);
1996
1997         memset(&device->devid_kobj, 0, sizeof(struct kobject));
1998         complete(&device->kobj_unregister);
1999 }
2000
2001 static const struct kobj_type devid_ktype = {
2002         .sysfs_ops      = &kobj_sysfs_ops,
2003         .default_groups = devid_groups,
2004         .release        = btrfs_release_devid_kobj,
2005 };
2006
2007 int btrfs_sysfs_add_device(struct btrfs_device *device)
2008 {
2009         int ret;
2010         unsigned int nofs_flag;
2011         struct kobject *devices_kobj;
2012         struct kobject *devinfo_kobj;
2013
2014         /*
2015          * Make sure we use the fs_info::fs_devices to fetch the kobjects even
2016          * for the seed fs_devices
2017          */
2018         devices_kobj = device->fs_info->fs_devices->devices_kobj;
2019         devinfo_kobj = device->fs_info->fs_devices->devinfo_kobj;
2020         ASSERT(devices_kobj);
2021         ASSERT(devinfo_kobj);
2022
2023         nofs_flag = memalloc_nofs_save();
2024
2025         if (device->bdev) {
2026                 struct kobject *disk_kobj = bdev_kobj(device->bdev);
2027
2028                 ret = sysfs_create_link(devices_kobj, disk_kobj, disk_kobj->name);
2029                 if (ret) {
2030                         btrfs_warn(device->fs_info,
2031                                 "creating sysfs device link for devid %llu failed: %d",
2032                                 device->devid, ret);
2033                         goto out;
2034                 }
2035         }
2036
2037         init_completion(&device->kobj_unregister);
2038         ret = kobject_init_and_add(&device->devid_kobj, &devid_ktype,
2039                                    devinfo_kobj, "%llu", device->devid);
2040         if (ret) {
2041                 kobject_put(&device->devid_kobj);
2042                 btrfs_warn(device->fs_info,
2043                            "devinfo init for devid %llu failed: %d",
2044                            device->devid, ret);
2045         }
2046
2047 out:
2048         memalloc_nofs_restore(nofs_flag);
2049         return ret;
2050 }
2051
2052 static int btrfs_sysfs_add_fs_devices(struct btrfs_fs_devices *fs_devices)
2053 {
2054         int ret;
2055         struct btrfs_device *device;
2056         struct btrfs_fs_devices *seed;
2057
2058         list_for_each_entry(device, &fs_devices->devices, dev_list) {
2059                 ret = btrfs_sysfs_add_device(device);
2060                 if (ret)
2061                         goto fail;
2062         }
2063
2064         list_for_each_entry(seed, &fs_devices->seed_list, seed_list) {
2065                 list_for_each_entry(device, &seed->devices, dev_list) {
2066                         ret = btrfs_sysfs_add_device(device);
2067                         if (ret)
2068                                 goto fail;
2069                 }
2070         }
2071
2072         return 0;
2073
2074 fail:
2075         btrfs_sysfs_remove_fs_devices(fs_devices);
2076         return ret;
2077 }
2078
2079 void btrfs_kobject_uevent(struct block_device *bdev, enum kobject_action action)
2080 {
2081         int ret;
2082
2083         ret = kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, action);
2084         if (ret)
2085                 pr_warn("BTRFS: Sending event '%d' to kobject: '%s' (%p): failed\n",
2086                         action, kobject_name(&disk_to_dev(bdev->bd_disk)->kobj),
2087                         &disk_to_dev(bdev->bd_disk)->kobj);
2088 }
2089
2090 void btrfs_sysfs_update_sprout_fsid(struct btrfs_fs_devices *fs_devices)
2091
2092 {
2093         char fsid_buf[BTRFS_UUID_UNPARSED_SIZE];
2094
2095         /*
2096          * Sprouting changes fsid of the mounted filesystem, rename the fsid
2097          * directory
2098          */
2099         snprintf(fsid_buf, BTRFS_UUID_UNPARSED_SIZE, "%pU", fs_devices->fsid);
2100         if (kobject_rename(&fs_devices->fsid_kobj, fsid_buf))
2101                 btrfs_warn(fs_devices->fs_info,
2102                                 "sysfs: failed to create fsid for sprout");
2103 }
2104
2105 void btrfs_sysfs_update_devid(struct btrfs_device *device)
2106 {
2107         char tmp[24];
2108
2109         snprintf(tmp, sizeof(tmp), "%llu", device->devid);
2110
2111         if (kobject_rename(&device->devid_kobj, tmp))
2112                 btrfs_warn(device->fs_devices->fs_info,
2113                            "sysfs: failed to update devid for %llu",
2114                            device->devid);
2115 }
2116
2117 /* /sys/fs/btrfs/ entry */
2118 static struct kset *btrfs_kset;
2119
2120 /*
2121  * Creates:
2122  *              /sys/fs/btrfs/UUID
2123  *
2124  * Can be called by the device discovery thread.
2125  */
2126 int btrfs_sysfs_add_fsid(struct btrfs_fs_devices *fs_devs)
2127 {
2128         int error;
2129
2130         init_completion(&fs_devs->kobj_unregister);
2131         fs_devs->fsid_kobj.kset = btrfs_kset;
2132         error = kobject_init_and_add(&fs_devs->fsid_kobj, &btrfs_ktype, NULL,
2133                                      "%pU", fs_devs->fsid);
2134         if (error) {
2135                 kobject_put(&fs_devs->fsid_kobj);
2136                 return error;
2137         }
2138
2139         fs_devs->devices_kobj = kobject_create_and_add("devices",
2140                                                        &fs_devs->fsid_kobj);
2141         if (!fs_devs->devices_kobj) {
2142                 btrfs_err(fs_devs->fs_info,
2143                           "failed to init sysfs device interface");
2144                 btrfs_sysfs_remove_fsid(fs_devs);
2145                 return -ENOMEM;
2146         }
2147
2148         fs_devs->devinfo_kobj = kobject_create_and_add("devinfo",
2149                                                        &fs_devs->fsid_kobj);
2150         if (!fs_devs->devinfo_kobj) {
2151                 btrfs_err(fs_devs->fs_info,
2152                           "failed to init sysfs devinfo kobject");
2153                 btrfs_sysfs_remove_fsid(fs_devs);
2154                 return -ENOMEM;
2155         }
2156
2157         return 0;
2158 }
2159
2160 int btrfs_sysfs_add_mounted(struct btrfs_fs_info *fs_info)
2161 {
2162         int error;
2163         struct btrfs_fs_devices *fs_devs = fs_info->fs_devices;
2164         struct kobject *fsid_kobj = &fs_devs->fsid_kobj;
2165
2166         error = btrfs_sysfs_add_fs_devices(fs_devs);
2167         if (error)
2168                 return error;
2169
2170         error = sysfs_create_files(fsid_kobj, btrfs_attrs);
2171         if (error) {
2172                 btrfs_sysfs_remove_fs_devices(fs_devs);
2173                 return error;
2174         }
2175
2176         error = sysfs_create_group(fsid_kobj,
2177                                    &btrfs_feature_attr_group);
2178         if (error)
2179                 goto failure;
2180
2181 #ifdef CONFIG_BTRFS_DEBUG
2182         fs_info->debug_kobj = kobject_create_and_add("debug", fsid_kobj);
2183         if (!fs_info->debug_kobj) {
2184                 error = -ENOMEM;
2185                 goto failure;
2186         }
2187
2188         error = sysfs_create_files(fs_info->debug_kobj, btrfs_debug_mount_attrs);
2189         if (error)
2190                 goto failure;
2191 #endif
2192
2193         /* Discard directory */
2194         fs_info->discard_kobj = kobject_create_and_add("discard", fsid_kobj);
2195         if (!fs_info->discard_kobj) {
2196                 error = -ENOMEM;
2197                 goto failure;
2198         }
2199
2200         error = sysfs_create_files(fs_info->discard_kobj, discard_attrs);
2201         if (error)
2202                 goto failure;
2203
2204         error = addrm_unknown_feature_attrs(fs_info, true);
2205         if (error)
2206                 goto failure;
2207
2208         error = sysfs_create_link(fsid_kobj, &fs_info->sb->s_bdi->dev->kobj, "bdi");
2209         if (error)
2210                 goto failure;
2211
2212         fs_info->space_info_kobj = kobject_create_and_add("allocation",
2213                                                   fsid_kobj);
2214         if (!fs_info->space_info_kobj) {
2215                 error = -ENOMEM;
2216                 goto failure;
2217         }
2218
2219         error = sysfs_create_files(fs_info->space_info_kobj, allocation_attrs);
2220         if (error)
2221                 goto failure;
2222
2223         return 0;
2224 failure:
2225         btrfs_sysfs_remove_mounted(fs_info);
2226         return error;
2227 }
2228
2229 static ssize_t qgroup_enabled_show(struct kobject *qgroups_kobj,
2230                                    struct kobj_attribute *a,
2231                                    char *buf)
2232 {
2233         struct btrfs_fs_info *fs_info = to_fs_info(qgroups_kobj->parent);
2234         bool enabled;
2235
2236         spin_lock(&fs_info->qgroup_lock);
2237         enabled = fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_ON;
2238         spin_unlock(&fs_info->qgroup_lock);
2239
2240         return sysfs_emit(buf, "%d\n", enabled);
2241 }
2242 BTRFS_ATTR(qgroups, enabled, qgroup_enabled_show);
2243
2244 static ssize_t qgroup_mode_show(struct kobject *qgroups_kobj,
2245                                 struct kobj_attribute *a,
2246                                 char *buf)
2247 {
2248         struct btrfs_fs_info *fs_info = to_fs_info(qgroups_kobj->parent);
2249         ssize_t ret = 0;
2250
2251         spin_lock(&fs_info->qgroup_lock);
2252         ASSERT(btrfs_qgroup_enabled(fs_info));
2253         switch (btrfs_qgroup_mode(fs_info)) {
2254         case BTRFS_QGROUP_MODE_FULL:
2255                 ret = sysfs_emit(buf, "qgroup\n");
2256                 break;
2257         case BTRFS_QGROUP_MODE_SIMPLE:
2258                 ret = sysfs_emit(buf, "squota\n");
2259                 break;
2260         default:
2261                 btrfs_warn(fs_info, "unexpected qgroup mode %d\n",
2262                            btrfs_qgroup_mode(fs_info));
2263                 break;
2264         }
2265         spin_unlock(&fs_info->qgroup_lock);
2266
2267         return ret;
2268 }
2269 BTRFS_ATTR(qgroups, mode, qgroup_mode_show);
2270
2271 static ssize_t qgroup_inconsistent_show(struct kobject *qgroups_kobj,
2272                                         struct kobj_attribute *a,
2273                                         char *buf)
2274 {
2275         struct btrfs_fs_info *fs_info = to_fs_info(qgroups_kobj->parent);
2276         bool inconsistent;
2277
2278         spin_lock(&fs_info->qgroup_lock);
2279         inconsistent = (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT);
2280         spin_unlock(&fs_info->qgroup_lock);
2281
2282         return sysfs_emit(buf, "%d\n", inconsistent);
2283 }
2284 BTRFS_ATTR(qgroups, inconsistent, qgroup_inconsistent_show);
2285
2286 static ssize_t qgroup_drop_subtree_thres_show(struct kobject *qgroups_kobj,
2287                                               struct kobj_attribute *a,
2288                                               char *buf)
2289 {
2290         struct btrfs_fs_info *fs_info = to_fs_info(qgroups_kobj->parent);
2291         u8 result;
2292
2293         spin_lock(&fs_info->qgroup_lock);
2294         result = fs_info->qgroup_drop_subtree_thres;
2295         spin_unlock(&fs_info->qgroup_lock);
2296
2297         return sysfs_emit(buf, "%d\n", result);
2298 }
2299
2300 static ssize_t qgroup_drop_subtree_thres_store(struct kobject *qgroups_kobj,
2301                                                struct kobj_attribute *a,
2302                                                const char *buf, size_t len)
2303 {
2304         struct btrfs_fs_info *fs_info = to_fs_info(qgroups_kobj->parent);
2305         u8 new_thres;
2306         int ret;
2307
2308         ret = kstrtou8(buf, 10, &new_thres);
2309         if (ret)
2310                 return -EINVAL;
2311
2312         if (new_thres > BTRFS_MAX_LEVEL)
2313                 return -EINVAL;
2314
2315         spin_lock(&fs_info->qgroup_lock);
2316         fs_info->qgroup_drop_subtree_thres = new_thres;
2317         spin_unlock(&fs_info->qgroup_lock);
2318
2319         return len;
2320 }
2321 BTRFS_ATTR_RW(qgroups, drop_subtree_threshold, qgroup_drop_subtree_thres_show,
2322               qgroup_drop_subtree_thres_store);
2323
2324 /*
2325  * Qgroups global info
2326  *
2327  * Path: /sys/fs/btrfs/<uuid>/qgroups/
2328  */
2329 static struct attribute *qgroups_attrs[] = {
2330         BTRFS_ATTR_PTR(qgroups, enabled),
2331         BTRFS_ATTR_PTR(qgroups, inconsistent),
2332         BTRFS_ATTR_PTR(qgroups, drop_subtree_threshold),
2333         BTRFS_ATTR_PTR(qgroups, mode),
2334         NULL
2335 };
2336 ATTRIBUTE_GROUPS(qgroups);
2337
2338 static void qgroups_release(struct kobject *kobj)
2339 {
2340         kfree(kobj);
2341 }
2342
2343 static const struct kobj_type qgroups_ktype = {
2344         .sysfs_ops = &kobj_sysfs_ops,
2345         .default_groups = qgroups_groups,
2346         .release = qgroups_release,
2347 };
2348
2349 static inline struct btrfs_fs_info *qgroup_kobj_to_fs_info(struct kobject *kobj)
2350 {
2351         return to_fs_info(kobj->parent->parent);
2352 }
2353
2354 #define QGROUP_ATTR(_member, _show_name)                                        \
2355 static ssize_t btrfs_qgroup_show_##_member(struct kobject *qgroup_kobj,         \
2356                                            struct kobj_attribute *a,            \
2357                                            char *buf)                           \
2358 {                                                                               \
2359         struct btrfs_fs_info *fs_info = qgroup_kobj_to_fs_info(qgroup_kobj);    \
2360         struct btrfs_qgroup *qgroup = container_of(qgroup_kobj,                 \
2361                         struct btrfs_qgroup, kobj);                             \
2362         return btrfs_show_u64(&qgroup->_member, &fs_info->qgroup_lock, buf);    \
2363 }                                                                               \
2364 BTRFS_ATTR(qgroup, _show_name, btrfs_qgroup_show_##_member)
2365
2366 #define QGROUP_RSV_ATTR(_name, _type)                                           \
2367 static ssize_t btrfs_qgroup_rsv_show_##_name(struct kobject *qgroup_kobj,       \
2368                                              struct kobj_attribute *a,          \
2369                                              char *buf)                         \
2370 {                                                                               \
2371         struct btrfs_fs_info *fs_info = qgroup_kobj_to_fs_info(qgroup_kobj);    \
2372         struct btrfs_qgroup *qgroup = container_of(qgroup_kobj,                 \
2373                         struct btrfs_qgroup, kobj);                             \
2374         return btrfs_show_u64(&qgroup->rsv.values[_type],                       \
2375                         &fs_info->qgroup_lock, buf);                            \
2376 }                                                                               \
2377 BTRFS_ATTR(qgroup, rsv_##_name, btrfs_qgroup_rsv_show_##_name)
2378
2379 QGROUP_ATTR(rfer, referenced);
2380 QGROUP_ATTR(excl, exclusive);
2381 QGROUP_ATTR(max_rfer, max_referenced);
2382 QGROUP_ATTR(max_excl, max_exclusive);
2383 QGROUP_ATTR(lim_flags, limit_flags);
2384 QGROUP_RSV_ATTR(data, BTRFS_QGROUP_RSV_DATA);
2385 QGROUP_RSV_ATTR(meta_pertrans, BTRFS_QGROUP_RSV_META_PERTRANS);
2386 QGROUP_RSV_ATTR(meta_prealloc, BTRFS_QGROUP_RSV_META_PREALLOC);
2387
2388 /*
2389  * Qgroup information.
2390  *
2391  * Path: /sys/fs/btrfs/<uuid>/qgroups/<level>_<qgroupid>/
2392  */
2393 static struct attribute *qgroup_attrs[] = {
2394         BTRFS_ATTR_PTR(qgroup, referenced),
2395         BTRFS_ATTR_PTR(qgroup, exclusive),
2396         BTRFS_ATTR_PTR(qgroup, max_referenced),
2397         BTRFS_ATTR_PTR(qgroup, max_exclusive),
2398         BTRFS_ATTR_PTR(qgroup, limit_flags),
2399         BTRFS_ATTR_PTR(qgroup, rsv_data),
2400         BTRFS_ATTR_PTR(qgroup, rsv_meta_pertrans),
2401         BTRFS_ATTR_PTR(qgroup, rsv_meta_prealloc),
2402         NULL
2403 };
2404 ATTRIBUTE_GROUPS(qgroup);
2405
2406 static void qgroup_release(struct kobject *kobj)
2407 {
2408         struct btrfs_qgroup *qgroup = container_of(kobj, struct btrfs_qgroup, kobj);
2409
2410         memset(&qgroup->kobj, 0, sizeof(*kobj));
2411 }
2412
2413 static const struct kobj_type qgroup_ktype = {
2414         .sysfs_ops = &kobj_sysfs_ops,
2415         .release = qgroup_release,
2416         .default_groups = qgroup_groups,
2417 };
2418
2419 int btrfs_sysfs_add_one_qgroup(struct btrfs_fs_info *fs_info,
2420                                 struct btrfs_qgroup *qgroup)
2421 {
2422         struct kobject *qgroups_kobj = fs_info->qgroups_kobj;
2423         int ret;
2424
2425         if (btrfs_is_testing(fs_info))
2426                 return 0;
2427         if (qgroup->kobj.state_initialized)
2428                 return 0;
2429         if (!qgroups_kobj)
2430                 return -EINVAL;
2431
2432         ret = kobject_init_and_add(&qgroup->kobj, &qgroup_ktype, qgroups_kobj,
2433                         "%hu_%llu", btrfs_qgroup_level(qgroup->qgroupid),
2434                         btrfs_qgroup_subvolid(qgroup->qgroupid));
2435         if (ret < 0)
2436                 kobject_put(&qgroup->kobj);
2437
2438         return ret;
2439 }
2440
2441 void btrfs_sysfs_del_qgroups(struct btrfs_fs_info *fs_info)
2442 {
2443         struct btrfs_qgroup *qgroup;
2444         struct btrfs_qgroup *next;
2445
2446         if (btrfs_is_testing(fs_info))
2447                 return;
2448
2449         rbtree_postorder_for_each_entry_safe(qgroup, next,
2450                                              &fs_info->qgroup_tree, node)
2451                 btrfs_sysfs_del_one_qgroup(fs_info, qgroup);
2452         if (fs_info->qgroups_kobj) {
2453                 kobject_del(fs_info->qgroups_kobj);
2454                 kobject_put(fs_info->qgroups_kobj);
2455                 fs_info->qgroups_kobj = NULL;
2456         }
2457 }
2458
2459 /* Called when qgroups get initialized, thus there is no need for locking */
2460 int btrfs_sysfs_add_qgroups(struct btrfs_fs_info *fs_info)
2461 {
2462         struct kobject *fsid_kobj = &fs_info->fs_devices->fsid_kobj;
2463         struct btrfs_qgroup *qgroup;
2464         struct btrfs_qgroup *next;
2465         int ret = 0;
2466
2467         if (btrfs_is_testing(fs_info))
2468                 return 0;
2469
2470         ASSERT(fsid_kobj);
2471         if (fs_info->qgroups_kobj)
2472                 return 0;
2473
2474         fs_info->qgroups_kobj = kzalloc(sizeof(struct kobject), GFP_KERNEL);
2475         if (!fs_info->qgroups_kobj)
2476                 return -ENOMEM;
2477
2478         ret = kobject_init_and_add(fs_info->qgroups_kobj, &qgroups_ktype,
2479                                    fsid_kobj, "qgroups");
2480         if (ret < 0)
2481                 goto out;
2482
2483         rbtree_postorder_for_each_entry_safe(qgroup, next,
2484                                              &fs_info->qgroup_tree, node) {
2485                 ret = btrfs_sysfs_add_one_qgroup(fs_info, qgroup);
2486                 if (ret < 0)
2487                         goto out;
2488         }
2489
2490 out:
2491         if (ret < 0)
2492                 btrfs_sysfs_del_qgroups(fs_info);
2493         return ret;
2494 }
2495
2496 void btrfs_sysfs_del_one_qgroup(struct btrfs_fs_info *fs_info,
2497                                 struct btrfs_qgroup *qgroup)
2498 {
2499         if (btrfs_is_testing(fs_info))
2500                 return;
2501
2502         if (qgroup->kobj.state_initialized) {
2503                 kobject_del(&qgroup->kobj);
2504                 kobject_put(&qgroup->kobj);
2505         }
2506 }
2507
2508 /*
2509  * Change per-fs features in /sys/fs/btrfs/UUID/features to match current
2510  * values in superblock. Call after any changes to incompat/compat_ro flags
2511  */
2512 void btrfs_sysfs_feature_update(struct btrfs_fs_info *fs_info)
2513 {
2514         struct kobject *fsid_kobj;
2515         int ret;
2516
2517         if (!fs_info)
2518                 return;
2519
2520         fsid_kobj = &fs_info->fs_devices->fsid_kobj;
2521         if (!fsid_kobj->state_initialized)
2522                 return;
2523
2524         ret = sysfs_update_group(fsid_kobj, &btrfs_feature_attr_group);
2525         if (ret < 0)
2526                 btrfs_warn(fs_info,
2527                            "failed to update /sys/fs/btrfs/%pU/features: %d",
2528                            fs_info->fs_devices->fsid, ret);
2529 }
2530
2531 int __init btrfs_init_sysfs(void)
2532 {
2533         int ret;
2534
2535         btrfs_kset = kset_create_and_add("btrfs", NULL, fs_kobj);
2536         if (!btrfs_kset)
2537                 return -ENOMEM;
2538
2539         init_feature_attrs();
2540         ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
2541         if (ret)
2542                 goto out2;
2543         ret = sysfs_merge_group(&btrfs_kset->kobj,
2544                                 &btrfs_static_feature_attr_group);
2545         if (ret)
2546                 goto out_remove_group;
2547
2548 #ifdef CONFIG_BTRFS_DEBUG
2549         ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_debug_feature_attr_group);
2550         if (ret) {
2551                 sysfs_unmerge_group(&btrfs_kset->kobj,
2552                                     &btrfs_static_feature_attr_group);
2553                 goto out_remove_group;
2554         }
2555 #endif
2556
2557         return 0;
2558
2559 out_remove_group:
2560         sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
2561 out2:
2562         kset_unregister(btrfs_kset);
2563
2564         return ret;
2565 }
2566
2567 void __cold btrfs_exit_sysfs(void)
2568 {
2569         sysfs_unmerge_group(&btrfs_kset->kobj,
2570                             &btrfs_static_feature_attr_group);
2571         sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
2572 #ifdef CONFIG_BTRFS_DEBUG
2573         sysfs_remove_group(&btrfs_kset->kobj, &btrfs_debug_feature_attr_group);
2574 #endif
2575         kset_unregister(btrfs_kset);
2576 }