linux/fs/btrfs/sysfs.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Copyright (C) 2007 Oracle.  All rights reserved.
   4 */
   5
   6#include <linux/sched.h>
   7#include <linux/sched/mm.h>
   8#include <linux/slab.h>
   9#include <linux/spinlock.h>
  10#include <linux/completion.h>
  11#include <linux/bug.h>
  12#include <crypto/hash.h>
  13
  14#include "ctree.h"
  15#include "discard.h"
  16#include "disk-io.h"
  17#include "transaction.h"
  18#include "sysfs.h"
  19#include "volumes.h"
  20#include "space-info.h"
  21#include "block-group.h"
  22
  23struct btrfs_feature_attr {
  24        struct kobj_attribute kobj_attr;
  25        enum btrfs_feature_set feature_set;
  26        u64 feature_bit;
  27};
  28
  29/* For raid type sysfs entries */
  30struct raid_kobject {
  31        u64 flags;
  32        struct kobject kobj;
  33};
  34
  35#define __INIT_KOBJ_ATTR(_name, _mode, _show, _store)                   \
  36{                                                                       \
  37        .attr   = { .name = __stringify(_name), .mode = _mode },        \
  38        .show   = _show,                                                \
  39        .store  = _store,                                               \
  40}
  41
  42#define BTRFS_ATTR_RW(_prefix, _name, _show, _store)                    \
  43        static struct kobj_attribute btrfs_attr_##_prefix##_##_name =   \
  44                        __INIT_KOBJ_ATTR(_name, 0644, _show, _store)
  45
  46#define BTRFS_ATTR(_prefix, _name, _show)                               \
  47        static struct kobj_attribute btrfs_attr_##_prefix##_##_name =   \
  48                        __INIT_KOBJ_ATTR(_name, 0444, _show, NULL)
  49
  50#define BTRFS_ATTR_PTR(_prefix, _name)                                  \
  51        (&btrfs_attr_##_prefix##_##_name.attr)
  52
  53#define BTRFS_FEAT_ATTR(_name, _feature_set, _feature_prefix, _feature_bit)  \
  54static struct btrfs_feature_attr btrfs_attr_features_##_name = {             \
  55        .kobj_attr = __INIT_KOBJ_ATTR(_name, S_IRUGO,                        \
  56                                      btrfs_feature_attr_show,               \
  57                                      btrfs_feature_attr_store),             \
  58        .feature_set    = _feature_set,                                      \
  59        .feature_bit    = _feature_prefix ##_## _feature_bit,                \
  60}
  61#define BTRFS_FEAT_ATTR_PTR(_name)                                           \
  62        (&btrfs_attr_features_##_name.kobj_attr.attr)
  63
  64#define BTRFS_FEAT_ATTR_COMPAT(name, feature) \
  65        BTRFS_FEAT_ATTR(name, FEAT_COMPAT, BTRFS_FEATURE_COMPAT, feature)
  66#define BTRFS_FEAT_ATTR_COMPAT_RO(name, feature) \
  67        BTRFS_FEAT_ATTR(name, FEAT_COMPAT_RO, BTRFS_FEATURE_COMPAT_RO, feature)
  68#define BTRFS_FEAT_ATTR_INCOMPAT(name, feature) \
  69        BTRFS_FEAT_ATTR(name, FEAT_INCOMPAT, BTRFS_FEATURE_INCOMPAT, feature)
  70
  71static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj);
  72static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj);
  73
  74static struct btrfs_feature_attr *to_btrfs_feature_attr(struct kobj_attribute *a)
  75{
  76        return container_of(a, struct btrfs_feature_attr, kobj_attr);
  77}
  78
  79static struct kobj_attribute *attr_to_btrfs_attr(struct attribute *attr)
  80{
  81        return container_of(attr, struct kobj_attribute, attr);
  82}
  83
  84static struct btrfs_feature_attr *attr_to_btrfs_feature_attr(
  85                struct attribute *attr)
  86{
  87        return to_btrfs_feature_attr(attr_to_btrfs_attr(attr));
  88}
  89
  90static u64 get_features(struct btrfs_fs_info *fs_info,
  91                        enum btrfs_feature_set set)
  92{
  93        struct btrfs_super_block *disk_super = fs_info->super_copy;
  94        if (set == FEAT_COMPAT)
  95                return btrfs_super_compat_flags(disk_super);
  96        else if (set == FEAT_COMPAT_RO)
  97                return btrfs_super_compat_ro_flags(disk_super);
  98        else
  99                return btrfs_super_incompat_flags(disk_super);
 100}
 101
 102static void set_features(struct btrfs_fs_info *fs_info,
 103                         enum btrfs_feature_set set, u64 features)
 104{
 105        struct btrfs_super_block *disk_super = fs_info->super_copy;
 106        if (set == FEAT_COMPAT)
 107                btrfs_set_super_compat_flags(disk_super, features);
 108        else if (set == FEAT_COMPAT_RO)
 109                btrfs_set_super_compat_ro_flags(disk_super, features);
 110        else
 111                btrfs_set_super_incompat_flags(disk_super, features);
 112}
 113
 114static int can_modify_feature(struct btrfs_feature_attr *fa)
 115{
 116        int val = 0;
 117        u64 set, clear;
 118        switch (fa->feature_set) {
 119        case FEAT_COMPAT:
 120                set = BTRFS_FEATURE_COMPAT_SAFE_SET;
 121                clear = BTRFS_FEATURE_COMPAT_SAFE_CLEAR;
 122                break;
 123        case FEAT_COMPAT_RO:
 124                set = BTRFS_FEATURE_COMPAT_RO_SAFE_SET;
 125                clear = BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR;
 126                break;
 127        case FEAT_INCOMPAT:
 128                set = BTRFS_FEATURE_INCOMPAT_SAFE_SET;
 129                clear = BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR;
 130                break;
 131        default:
 132                pr_warn("btrfs: sysfs: unknown feature set %d\n",
 133                                fa->feature_set);
 134                return 0;
 135        }
 136
 137        if (set & fa->feature_bit)
 138                val |= 1;
 139        if (clear & fa->feature_bit)
 140                val |= 2;
 141
 142        return val;
 143}
 144
 145static ssize_t btrfs_feature_attr_show(struct kobject *kobj,
 146                                       struct kobj_attribute *a, char *buf)
 147{
 148        int val = 0;
 149        struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 150        struct btrfs_feature_attr *fa = to_btrfs_feature_attr(a);
 151        if (fs_info) {
 152                u64 features = get_features(fs_info, fa->feature_set);
 153                if (features & fa->feature_bit)
 154                        val = 1;
 155        } else
 156                val = can_modify_feature(fa);
 157
 158        return scnprintf(buf, PAGE_SIZE, "%d\n", val);
 159}
 160
 161static ssize_t btrfs_feature_attr_store(struct kobject *kobj,
 162                                        struct kobj_attribute *a,
 163                                        const char *buf, size_t count)
 164{
 165        struct btrfs_fs_info *fs_info;
 166        struct btrfs_feature_attr *fa = to_btrfs_feature_attr(a);
 167        u64 features, set, clear;
 168        unsigned long val;
 169        int ret;
 170
 171        fs_info = to_fs_info(kobj);
 172        if (!fs_info)
 173                return -EPERM;
 174
 175        if (sb_rdonly(fs_info->sb))
 176                return -EROFS;
 177
 178        ret = kstrtoul(skip_spaces(buf), 0, &val);
 179        if (ret)
 180                return ret;
 181
 182        if (fa->feature_set == FEAT_COMPAT) {
 183                set = BTRFS_FEATURE_COMPAT_SAFE_SET;
 184                clear = BTRFS_FEATURE_COMPAT_SAFE_CLEAR;
 185        } else if (fa->feature_set == FEAT_COMPAT_RO) {
 186                set = BTRFS_FEATURE_COMPAT_RO_SAFE_SET;
 187                clear = BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR;
 188        } else {
 189                set = BTRFS_FEATURE_INCOMPAT_SAFE_SET;
 190                clear = BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR;
 191        }
 192
 193        features = get_features(fs_info, fa->feature_set);
 194
 195        /* Nothing to do */
 196        if ((val && (features & fa->feature_bit)) ||
 197            (!val && !(features & fa->feature_bit)))
 198                return count;
 199
 200        if ((val && !(set & fa->feature_bit)) ||
 201            (!val && !(clear & fa->feature_bit))) {
 202                btrfs_info(fs_info,
 203                        "%sabling feature %s on mounted fs is not supported.",
 204                        val ? "En" : "Dis", fa->kobj_attr.attr.name);
 205                return -EPERM;
 206        }
 207
 208        btrfs_info(fs_info, "%s %s feature flag",
 209                   val ? "Setting" : "Clearing", fa->kobj_attr.attr.name);
 210
 211        spin_lock(&fs_info->super_lock);
 212        features = get_features(fs_info, fa->feature_set);
 213        if (val)
 214                features |= fa->feature_bit;
 215        else
 216                features &= ~fa->feature_bit;
 217        set_features(fs_info, fa->feature_set, features);
 218        spin_unlock(&fs_info->super_lock);
 219
 220        /*
 221         * We don't want to do full transaction commit from inside sysfs
 222         */
 223        btrfs_set_pending(fs_info, COMMIT);
 224        wake_up_process(fs_info->transaction_kthread);
 225
 226        return count;
 227}
 228
 229static umode_t btrfs_feature_visible(struct kobject *kobj,
 230                                     struct attribute *attr, int unused)
 231{
 232        struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 233        umode_t mode = attr->mode;
 234
 235        if (fs_info) {
 236                struct btrfs_feature_attr *fa;
 237                u64 features;
 238
 239                fa = attr_to_btrfs_feature_attr(attr);
 240                features = get_features(fs_info, fa->feature_set);
 241
 242                if (can_modify_feature(fa))
 243                        mode |= S_IWUSR;
 244                else if (!(features & fa->feature_bit))
 245                        mode = 0;
 246        }
 247
 248        return mode;
 249}
 250
 251BTRFS_FEAT_ATTR_INCOMPAT(mixed_backref, MIXED_BACKREF);
 252BTRFS_FEAT_ATTR_INCOMPAT(default_subvol, DEFAULT_SUBVOL);
 253BTRFS_FEAT_ATTR_INCOMPAT(mixed_groups, MIXED_GROUPS);
 254BTRFS_FEAT_ATTR_INCOMPAT(compress_lzo, COMPRESS_LZO);
 255BTRFS_FEAT_ATTR_INCOMPAT(compress_zstd, COMPRESS_ZSTD);
 256BTRFS_FEAT_ATTR_INCOMPAT(big_metadata, BIG_METADATA);
 257BTRFS_FEAT_ATTR_INCOMPAT(extended_iref, EXTENDED_IREF);
 258BTRFS_FEAT_ATTR_INCOMPAT(raid56, RAID56);
 259BTRFS_FEAT_ATTR_INCOMPAT(skinny_metadata, SKINNY_METADATA);
 260BTRFS_FEAT_ATTR_INCOMPAT(no_holes, NO_HOLES);
 261BTRFS_FEAT_ATTR_INCOMPAT(metadata_uuid, METADATA_UUID);
 262BTRFS_FEAT_ATTR_COMPAT_RO(free_space_tree, FREE_SPACE_TREE);
 263BTRFS_FEAT_ATTR_INCOMPAT(raid1c34, RAID1C34);
 264
 265static struct attribute *btrfs_supported_feature_attrs[] = {
 266        BTRFS_FEAT_ATTR_PTR(mixed_backref),
 267        BTRFS_FEAT_ATTR_PTR(default_subvol),
 268        BTRFS_FEAT_ATTR_PTR(mixed_groups),
 269        BTRFS_FEAT_ATTR_PTR(compress_lzo),
 270        BTRFS_FEAT_ATTR_PTR(compress_zstd),
 271        BTRFS_FEAT_ATTR_PTR(big_metadata),
 272        BTRFS_FEAT_ATTR_PTR(extended_iref),
 273        BTRFS_FEAT_ATTR_PTR(raid56),
 274        BTRFS_FEAT_ATTR_PTR(skinny_metadata),
 275        BTRFS_FEAT_ATTR_PTR(no_holes),
 276        BTRFS_FEAT_ATTR_PTR(metadata_uuid),
 277        BTRFS_FEAT_ATTR_PTR(free_space_tree),
 278        BTRFS_FEAT_ATTR_PTR(raid1c34),
 279        NULL
 280};
 281
 282/*
 283 * Features which depend on feature bits and may differ between each fs.
 284 *
 285 * /sys/fs/btrfs/features lists all available features of this kernel while
 286 * /sys/fs/btrfs/UUID/features shows features of the fs which are enabled or
 287 * can be changed online.
 288 */
 289static const struct attribute_group btrfs_feature_attr_group = {
 290        .name = "features",
 291        .is_visible = btrfs_feature_visible,
 292        .attrs = btrfs_supported_feature_attrs,
 293};
 294
 295static ssize_t rmdir_subvol_show(struct kobject *kobj,
 296                                 struct kobj_attribute *ka, char *buf)
 297{
 298        return scnprintf(buf, PAGE_SIZE, "0\n");
 299}
 300BTRFS_ATTR(static_feature, rmdir_subvol, rmdir_subvol_show);
 301
 302static ssize_t supported_checksums_show(struct kobject *kobj,
 303                                        struct kobj_attribute *a, char *buf)
 304{
 305        ssize_t ret = 0;
 306        int i;
 307
 308        for (i = 0; i < btrfs_get_num_csums(); i++) {
 309                /*
 310                 * This "trick" only works as long as 'enum btrfs_csum_type' has
 311                 * no holes in it
 312                 */
 313                ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%s",
 314                                (i == 0 ? "" : " "), btrfs_super_csum_name(i));
 315
 316        }
 317
 318        ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
 319        return ret;
 320}
 321BTRFS_ATTR(static_feature, supported_checksums, supported_checksums_show);
 322
 323static struct attribute *btrfs_supported_static_feature_attrs[] = {
 324        BTRFS_ATTR_PTR(static_feature, rmdir_subvol),
 325        BTRFS_ATTR_PTR(static_feature, supported_checksums),
 326        NULL
 327};
 328
 329/*
 330 * Features which only depend on kernel version.
 331 *
 332 * These are listed in /sys/fs/btrfs/features along with
 333 * btrfs_feature_attr_group
 334 */
 335static const struct attribute_group btrfs_static_feature_attr_group = {
 336        .name = "features",
 337        .attrs = btrfs_supported_static_feature_attrs,
 338};
 339
 340#ifdef CONFIG_BTRFS_DEBUG
 341
 342/*
 343 * Discard statistics and tunables
 344 */
 345#define discard_to_fs_info(_kobj)       to_fs_info((_kobj)->parent->parent)
 346
 347static ssize_t btrfs_discardable_bytes_show(struct kobject *kobj,
 348                                            struct kobj_attribute *a,
 349                                            char *buf)
 350{
 351        struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 352
 353        return scnprintf(buf, PAGE_SIZE, "%lld\n",
 354                        atomic64_read(&fs_info->discard_ctl.discardable_bytes));
 355}
 356BTRFS_ATTR(discard, discardable_bytes, btrfs_discardable_bytes_show);
 357
 358static ssize_t btrfs_discardable_extents_show(struct kobject *kobj,
 359                                              struct kobj_attribute *a,
 360                                              char *buf)
 361{
 362        struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 363
 364        return scnprintf(buf, PAGE_SIZE, "%d\n",
 365                        atomic_read(&fs_info->discard_ctl.discardable_extents));
 366}
 367BTRFS_ATTR(discard, discardable_extents, btrfs_discardable_extents_show);
 368
 369static ssize_t btrfs_discard_bitmap_bytes_show(struct kobject *kobj,
 370                                               struct kobj_attribute *a,
 371                                               char *buf)
 372{
 373        struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 374
 375        return scnprintf(buf, PAGE_SIZE, "%lld\n",
 376                        fs_info->discard_ctl.discard_bitmap_bytes);
 377}
 378BTRFS_ATTR(discard, discard_bitmap_bytes, btrfs_discard_bitmap_bytes_show);
 379
 380static ssize_t btrfs_discard_bytes_saved_show(struct kobject *kobj,
 381                                              struct kobj_attribute *a,
 382                                              char *buf)
 383{
 384        struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 385
 386        return scnprintf(buf, PAGE_SIZE, "%lld\n",
 387                atomic64_read(&fs_info->discard_ctl.discard_bytes_saved));
 388}
 389BTRFS_ATTR(discard, discard_bytes_saved, btrfs_discard_bytes_saved_show);
 390
 391static ssize_t btrfs_discard_extent_bytes_show(struct kobject *kobj,
 392                                               struct kobj_attribute *a,
 393                                               char *buf)
 394{
 395        struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 396
 397        return scnprintf(buf, PAGE_SIZE, "%lld\n",
 398                        fs_info->discard_ctl.discard_extent_bytes);
 399}
 400BTRFS_ATTR(discard, discard_extent_bytes, btrfs_discard_extent_bytes_show);
 401
 402static ssize_t btrfs_discard_iops_limit_show(struct kobject *kobj,
 403                                             struct kobj_attribute *a,
 404                                             char *buf)
 405{
 406        struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 407
 408        return scnprintf(buf, PAGE_SIZE, "%u\n",
 409                        READ_ONCE(fs_info->discard_ctl.iops_limit));
 410}
 411
 412static ssize_t btrfs_discard_iops_limit_store(struct kobject *kobj,
 413                                              struct kobj_attribute *a,
 414                                              const char *buf, size_t len)
 415{
 416        struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 417        struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
 418        u32 iops_limit;
 419        int ret;
 420
 421        ret = kstrtou32(buf, 10, &iops_limit);
 422        if (ret)
 423                return -EINVAL;
 424
 425        WRITE_ONCE(discard_ctl->iops_limit, iops_limit);
 426
 427        return len;
 428}
 429BTRFS_ATTR_RW(discard, iops_limit, btrfs_discard_iops_limit_show,
 430              btrfs_discard_iops_limit_store);
 431
 432static ssize_t btrfs_discard_kbps_limit_show(struct kobject *kobj,
 433                                             struct kobj_attribute *a,
 434                                             char *buf)
 435{
 436        struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 437
 438        return scnprintf(buf, PAGE_SIZE, "%u\n",
 439                        READ_ONCE(fs_info->discard_ctl.kbps_limit));
 440}
 441
 442static ssize_t btrfs_discard_kbps_limit_store(struct kobject *kobj,
 443                                              struct kobj_attribute *a,
 444                                              const char *buf, size_t len)
 445{
 446        struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 447        struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
 448        u32 kbps_limit;
 449        int ret;
 450
 451        ret = kstrtou32(buf, 10, &kbps_limit);
 452        if (ret)
 453                return -EINVAL;
 454
 455        WRITE_ONCE(discard_ctl->kbps_limit, kbps_limit);
 456
 457        return len;
 458}
 459BTRFS_ATTR_RW(discard, kbps_limit, btrfs_discard_kbps_limit_show,
 460              btrfs_discard_kbps_limit_store);
 461
 462static ssize_t btrfs_discard_max_discard_size_show(struct kobject *kobj,
 463                                                   struct kobj_attribute *a,
 464                                                   char *buf)
 465{
 466        struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 467
 468        return scnprintf(buf, PAGE_SIZE, "%llu\n",
 469                        READ_ONCE(fs_info->discard_ctl.max_discard_size));
 470}
 471
 472static ssize_t btrfs_discard_max_discard_size_store(struct kobject *kobj,
 473                                                    struct kobj_attribute *a,
 474                                                    const char *buf, size_t len)
 475{
 476        struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 477        struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
 478        u64 max_discard_size;
 479        int ret;
 480
 481        ret = kstrtou64(buf, 10, &max_discard_size);
 482        if (ret)
 483                return -EINVAL;
 484
 485        WRITE_ONCE(discard_ctl->max_discard_size, max_discard_size);
 486
 487        return len;
 488}
 489BTRFS_ATTR_RW(discard, max_discard_size, btrfs_discard_max_discard_size_show,
 490              btrfs_discard_max_discard_size_store);
 491
 492static const struct attribute *discard_debug_attrs[] = {
 493        BTRFS_ATTR_PTR(discard, discardable_bytes),
 494        BTRFS_ATTR_PTR(discard, discardable_extents),
 495        BTRFS_ATTR_PTR(discard, discard_bitmap_bytes),
 496        BTRFS_ATTR_PTR(discard, discard_bytes_saved),
 497        BTRFS_ATTR_PTR(discard, discard_extent_bytes),
 498        BTRFS_ATTR_PTR(discard, iops_limit),
 499        BTRFS_ATTR_PTR(discard, kbps_limit),
 500        BTRFS_ATTR_PTR(discard, max_discard_size),
 501        NULL,
 502};
 503
 504/*
 505 * Runtime debugging exported via sysfs
 506 *
 507 * /sys/fs/btrfs/debug - applies to module or all filesystems
 508 * /sys/fs/btrfs/UUID  - applies only to the given filesystem
 509 */
 510static const struct attribute *btrfs_debug_mount_attrs[] = {
 511        NULL,
 512};
 513
 514static struct attribute *btrfs_debug_feature_attrs[] = {
 515        NULL
 516};
 517
 518static const struct attribute_group btrfs_debug_feature_attr_group = {
 519        .name = "debug",
 520        .attrs = btrfs_debug_feature_attrs,
 521};
 522
 523#endif
 524
 525static ssize_t btrfs_show_u64(u64 *value_ptr, spinlock_t *lock, char *buf)
 526{
 527        u64 val;
 528        if (lock)
 529                spin_lock(lock);
 530        val = *value_ptr;
 531        if (lock)
 532                spin_unlock(lock);
 533        return scnprintf(buf, PAGE_SIZE, "%llu\n", val);
 534}
 535
 536static ssize_t global_rsv_size_show(struct kobject *kobj,
 537                                    struct kobj_attribute *ka, char *buf)
 538{
 539        struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent);
 540        struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
 541        return btrfs_show_u64(&block_rsv->size, &block_rsv->lock, buf);
 542}
 543BTRFS_ATTR(allocation, global_rsv_size, global_rsv_size_show);
 544
 545static ssize_t global_rsv_reserved_show(struct kobject *kobj,
 546                                        struct kobj_attribute *a, char *buf)
 547{
 548        struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent);
 549        struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
 550        return btrfs_show_u64(&block_rsv->reserved, &block_rsv->lock, buf);
 551}
 552BTRFS_ATTR(allocation, global_rsv_reserved, global_rsv_reserved_show);
 553
 554#define to_space_info(_kobj) container_of(_kobj, struct btrfs_space_info, kobj)
 555#define to_raid_kobj(_kobj) container_of(_kobj, struct raid_kobject, kobj)
 556
 557static ssize_t raid_bytes_show(struct kobject *kobj,
 558                               struct kobj_attribute *attr, char *buf);
 559BTRFS_ATTR(raid, total_bytes, raid_bytes_show);
 560BTRFS_ATTR(raid, used_bytes, raid_bytes_show);
 561
 562static ssize_t raid_bytes_show(struct kobject *kobj,
 563                               struct kobj_attribute *attr, char *buf)
 564
 565{
 566        struct btrfs_space_info *sinfo = to_space_info(kobj->parent);
 567        struct btrfs_block_group *block_group;
 568        int index = btrfs_bg_flags_to_raid_index(to_raid_kobj(kobj)->flags);
 569        u64 val = 0;
 570
 571        down_read(&sinfo->groups_sem);
 572        list_for_each_entry(block_group, &sinfo->block_groups[index], list) {
 573                if (&attr->attr == BTRFS_ATTR_PTR(raid, total_bytes))
 574                        val += block_group->length;
 575                else
 576                        val += block_group->used;
 577        }
 578        up_read(&sinfo->groups_sem);
 579        return scnprintf(buf, PAGE_SIZE, "%llu\n", val);
 580}
 581
 582static struct attribute *raid_attrs[] = {
 583        BTRFS_ATTR_PTR(raid, total_bytes),
 584        BTRFS_ATTR_PTR(raid, used_bytes),
 585        NULL
 586};
 587ATTRIBUTE_GROUPS(raid);
 588
 589static void release_raid_kobj(struct kobject *kobj)
 590{
 591        kfree(to_raid_kobj(kobj));
 592}
 593
 594static struct kobj_type btrfs_raid_ktype = {
 595        .sysfs_ops = &kobj_sysfs_ops,
 596        .release = release_raid_kobj,
 597        .default_groups = raid_groups,
 598};
 599
 600#define SPACE_INFO_ATTR(field)                                          \
 601static ssize_t btrfs_space_info_show_##field(struct kobject *kobj,      \
 602                                             struct kobj_attribute *a,  \
 603                                             char *buf)                 \
 604{                                                                       \
 605        struct btrfs_space_info *sinfo = to_space_info(kobj);           \
 606        return btrfs_show_u64(&sinfo->field, &sinfo->lock, buf);        \
 607}                                                                       \
 608BTRFS_ATTR(space_info, field, btrfs_space_info_show_##field)
 609
 610static ssize_t btrfs_space_info_show_total_bytes_pinned(struct kobject *kobj,
 611                                                       struct kobj_attribute *a,
 612                                                       char *buf)
 613{
 614        struct btrfs_space_info *sinfo = to_space_info(kobj);
 615        s64 val = percpu_counter_sum(&sinfo->total_bytes_pinned);
 616        return scnprintf(buf, PAGE_SIZE, "%lld\n", val);
 617}
 618
 619SPACE_INFO_ATTR(flags);
 620SPACE_INFO_ATTR(total_bytes);
 621SPACE_INFO_ATTR(bytes_used);
 622SPACE_INFO_ATTR(bytes_pinned);
 623SPACE_INFO_ATTR(bytes_reserved);
 624SPACE_INFO_ATTR(bytes_may_use);
 625SPACE_INFO_ATTR(bytes_readonly);
 626SPACE_INFO_ATTR(disk_used);
 627SPACE_INFO_ATTR(disk_total);
 628BTRFS_ATTR(space_info, total_bytes_pinned,
 629           btrfs_space_info_show_total_bytes_pinned);
 630
 631static struct attribute *space_info_attrs[] = {
 632        BTRFS_ATTR_PTR(space_info, flags),
 633        BTRFS_ATTR_PTR(space_info, total_bytes),
 634        BTRFS_ATTR_PTR(space_info, bytes_used),
 635        BTRFS_ATTR_PTR(space_info, bytes_pinned),
 636        BTRFS_ATTR_PTR(space_info, bytes_reserved),
 637        BTRFS_ATTR_PTR(space_info, bytes_may_use),
 638        BTRFS_ATTR_PTR(space_info, bytes_readonly),
 639        BTRFS_ATTR_PTR(space_info, disk_used),
 640        BTRFS_ATTR_PTR(space_info, disk_total),
 641        BTRFS_ATTR_PTR(space_info, total_bytes_pinned),
 642        NULL,
 643};
 644ATTRIBUTE_GROUPS(space_info);
 645
 646static void space_info_release(struct kobject *kobj)
 647{
 648        struct btrfs_space_info *sinfo = to_space_info(kobj);
 649        percpu_counter_destroy(&sinfo->total_bytes_pinned);
 650        kfree(sinfo);
 651}
 652
 653static struct kobj_type space_info_ktype = {
 654        .sysfs_ops = &kobj_sysfs_ops,
 655        .release = space_info_release,
 656        .default_groups = space_info_groups,
 657};
 658
 659static const struct attribute *allocation_attrs[] = {
 660        BTRFS_ATTR_PTR(allocation, global_rsv_reserved),
 661        BTRFS_ATTR_PTR(allocation, global_rsv_size),
 662        NULL,
 663};
 664
 665static ssize_t btrfs_label_show(struct kobject *kobj,
 666                                struct kobj_attribute *a, char *buf)
 667{
 668        struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 669        char *label = fs_info->super_copy->label;
 670        ssize_t ret;
 671
 672        spin_lock(&fs_info->super_lock);
 673        ret = scnprintf(buf, PAGE_SIZE, label[0] ? "%s\n" : "%s", label);
 674        spin_unlock(&fs_info->super_lock);
 675
 676        return ret;
 677}
 678
 679static ssize_t btrfs_label_store(struct kobject *kobj,
 680                                 struct kobj_attribute *a,
 681                                 const char *buf, size_t len)
 682{
 683        struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 684        size_t p_len;
 685
 686        if (!fs_info)
 687                return -EPERM;
 688
 689        if (sb_rdonly(fs_info->sb))
 690                return -EROFS;
 691
 692        /*
 693         * p_len is the len until the first occurrence of either
 694         * '\n' or '\0'
 695         */
 696        p_len = strcspn(buf, "\n");
 697
 698        if (p_len >= BTRFS_LABEL_SIZE)
 699                return -EINVAL;
 700
 701        spin_lock(&fs_info->super_lock);
 702        memset(fs_info->super_copy->label, 0, BTRFS_LABEL_SIZE);
 703        memcpy(fs_info->super_copy->label, buf, p_len);
 704        spin_unlock(&fs_info->super_lock);
 705
 706        /*
 707         * We don't want to do full transaction commit from inside sysfs
 708         */
 709        btrfs_set_pending(fs_info, COMMIT);
 710        wake_up_process(fs_info->transaction_kthread);
 711
 712        return len;
 713}
 714BTRFS_ATTR_RW(, label, btrfs_label_show, btrfs_label_store);
 715
 716static ssize_t btrfs_nodesize_show(struct kobject *kobj,
 717                                struct kobj_attribute *a, char *buf)
 718{
 719        struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 720
 721        return scnprintf(buf, PAGE_SIZE, "%u\n", fs_info->super_copy->nodesize);
 722}
 723
 724BTRFS_ATTR(, nodesize, btrfs_nodesize_show);
 725
 726static ssize_t btrfs_sectorsize_show(struct kobject *kobj,
 727                                struct kobj_attribute *a, char *buf)
 728{
 729        struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 730
 731        return scnprintf(buf, PAGE_SIZE, "%u\n",
 732                         fs_info->super_copy->sectorsize);
 733}
 734
 735BTRFS_ATTR(, sectorsize, btrfs_sectorsize_show);
 736
 737static ssize_t btrfs_clone_alignment_show(struct kobject *kobj,
 738                                struct kobj_attribute *a, char *buf)
 739{
 740        struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 741
 742        return scnprintf(buf, PAGE_SIZE, "%u\n", fs_info->super_copy->sectorsize);
 743}
 744
 745BTRFS_ATTR(, clone_alignment, btrfs_clone_alignment_show);
 746
 747static ssize_t quota_override_show(struct kobject *kobj,
 748                                   struct kobj_attribute *a, char *buf)
 749{
 750        struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 751        int quota_override;
 752
 753        quota_override = test_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
 754        return scnprintf(buf, PAGE_SIZE, "%d\n", quota_override);
 755}
 756
 757static ssize_t quota_override_store(struct kobject *kobj,
 758                                    struct kobj_attribute *a,
 759                                    const char *buf, size_t len)
 760{
 761        struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 762        unsigned long knob;
 763        int err;
 764
 765        if (!fs_info)
 766                return -EPERM;
 767
 768        if (!capable(CAP_SYS_RESOURCE))
 769                return -EPERM;
 770
 771        err = kstrtoul(buf, 10, &knob);
 772        if (err)
 773                return err;
 774        if (knob > 1)
 775                return -EINVAL;
 776
 777        if (knob)
 778                set_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
 779        else
 780                clear_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
 781
 782        return len;
 783}
 784
 785BTRFS_ATTR_RW(, quota_override, quota_override_show, quota_override_store);
 786
 787static ssize_t btrfs_metadata_uuid_show(struct kobject *kobj,
 788                                struct kobj_attribute *a, char *buf)
 789{
 790        struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 791
 792        return scnprintf(buf, PAGE_SIZE, "%pU\n",
 793                        fs_info->fs_devices->metadata_uuid);
 794}
 795
 796BTRFS_ATTR(, metadata_uuid, btrfs_metadata_uuid_show);
 797
 798static ssize_t btrfs_checksum_show(struct kobject *kobj,
 799                                   struct kobj_attribute *a, char *buf)
 800{
 801        struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 802        u16 csum_type = btrfs_super_csum_type(fs_info->super_copy);
 803
 804        return scnprintf(buf, PAGE_SIZE, "%s (%s)\n",
 805                        btrfs_super_csum_name(csum_type),
 806                        crypto_shash_driver_name(fs_info->csum_shash));
 807}
 808
 809BTRFS_ATTR(, checksum, btrfs_checksum_show);
 810
 811static const struct attribute *btrfs_attrs[] = {
 812        BTRFS_ATTR_PTR(, label),
 813        BTRFS_ATTR_PTR(, nodesize),
 814        BTRFS_ATTR_PTR(, sectorsize),
 815        BTRFS_ATTR_PTR(, clone_alignment),
 816        BTRFS_ATTR_PTR(, quota_override),
 817        BTRFS_ATTR_PTR(, metadata_uuid),
 818        BTRFS_ATTR_PTR(, checksum),
 819        NULL,
 820};
 821
 822static void btrfs_release_fsid_kobj(struct kobject *kobj)
 823{
 824        struct btrfs_fs_devices *fs_devs = to_fs_devs(kobj);
 825
 826        memset(&fs_devs->fsid_kobj, 0, sizeof(struct kobject));
 827        complete(&fs_devs->kobj_unregister);
 828}
 829
 830static struct kobj_type btrfs_ktype = {
 831        .sysfs_ops      = &kobj_sysfs_ops,
 832        .release        = btrfs_release_fsid_kobj,
 833};
 834
 835static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj)
 836{
 837        if (kobj->ktype != &btrfs_ktype)
 838                return NULL;
 839        return container_of(kobj, struct btrfs_fs_devices, fsid_kobj);
 840}
 841
 842static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj)
 843{
 844        if (kobj->ktype != &btrfs_ktype)
 845                return NULL;
 846        return to_fs_devs(kobj)->fs_info;
 847}
 848
 849#define NUM_FEATURE_BITS 64
 850#define BTRFS_FEATURE_NAME_MAX 13
 851static char btrfs_unknown_feature_names[FEAT_MAX][NUM_FEATURE_BITS][BTRFS_FEATURE_NAME_MAX];
 852static struct btrfs_feature_attr btrfs_feature_attrs[FEAT_MAX][NUM_FEATURE_BITS];
 853
 854static const u64 supported_feature_masks[FEAT_MAX] = {
 855        [FEAT_COMPAT]    = BTRFS_FEATURE_COMPAT_SUPP,
 856        [FEAT_COMPAT_RO] = BTRFS_FEATURE_COMPAT_RO_SUPP,
 857        [FEAT_INCOMPAT]  = BTRFS_FEATURE_INCOMPAT_SUPP,
 858};
 859
 860static int addrm_unknown_feature_attrs(struct btrfs_fs_info *fs_info, bool add)
 861{
 862        int set;
 863
 864        for (set = 0; set < FEAT_MAX; set++) {
 865                int i;
 866                struct attribute *attrs[2];
 867                struct attribute_group agroup = {
 868                        .name = "features",
 869                        .attrs = attrs,
 870                };
 871                u64 features = get_features(fs_info, set);
 872                features &= ~supported_feature_masks[set];
 873
 874                if (!features)
 875                        continue;
 876
 877                attrs[1] = NULL;
 878                for (i = 0; i < NUM_FEATURE_BITS; i++) {
 879                        struct btrfs_feature_attr *fa;
 880
 881                        if (!(features & (1ULL << i)))
 882                                continue;
 883
 884                        fa = &btrfs_feature_attrs[set][i];
 885                        attrs[0] = &fa->kobj_attr.attr;
 886                        if (add) {
 887                                int ret;
 888                                ret = sysfs_merge_group(&fs_info->fs_devices->fsid_kobj,
 889                                                        &agroup);
 890                                if (ret)
 891                                        return ret;
 892                        } else
 893                                sysfs_unmerge_group(&fs_info->fs_devices->fsid_kobj,
 894                                                    &agroup);
 895                }
 896
 897        }
 898        return 0;
 899}
 900
 901static void __btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs)
 902{
 903        if (fs_devs->devinfo_kobj) {
 904                kobject_del(fs_devs->devinfo_kobj);
 905                kobject_put(fs_devs->devinfo_kobj);
 906                fs_devs->devinfo_kobj = NULL;
 907        }
 908
 909        if (fs_devs->devices_kobj) {
 910                kobject_del(fs_devs->devices_kobj);
 911                kobject_put(fs_devs->devices_kobj);
 912                fs_devs->devices_kobj = NULL;
 913        }
 914
 915        if (fs_devs->fsid_kobj.state_initialized) {
 916                kobject_del(&fs_devs->fsid_kobj);
 917                kobject_put(&fs_devs->fsid_kobj);
 918                wait_for_completion(&fs_devs->kobj_unregister);
 919        }
 920}
 921
 922/* when fs_devs is NULL it will remove all fsid kobject */
 923void btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs)
 924{
 925        struct list_head *fs_uuids = btrfs_get_fs_uuids();
 926
 927        if (fs_devs) {
 928                __btrfs_sysfs_remove_fsid(fs_devs);
 929                return;
 930        }
 931
 932        list_for_each_entry(fs_devs, fs_uuids, fs_list) {
 933                __btrfs_sysfs_remove_fsid(fs_devs);
 934        }
 935}
 936
 937void btrfs_sysfs_remove_mounted(struct btrfs_fs_info *fs_info)
 938{
 939        btrfs_reset_fs_info_ptr(fs_info);
 940
 941        if (fs_info->space_info_kobj) {
 942                sysfs_remove_files(fs_info->space_info_kobj, allocation_attrs);
 943                kobject_del(fs_info->space_info_kobj);
 944                kobject_put(fs_info->space_info_kobj);
 945        }
 946#ifdef CONFIG_BTRFS_DEBUG
 947        if (fs_info->discard_debug_kobj) {
 948                sysfs_remove_files(fs_info->discard_debug_kobj,
 949                                   discard_debug_attrs);
 950                kobject_del(fs_info->discard_debug_kobj);
 951                kobject_put(fs_info->discard_debug_kobj);
 952        }
 953        if (fs_info->debug_kobj) {
 954                sysfs_remove_files(fs_info->debug_kobj, btrfs_debug_mount_attrs);
 955                kobject_del(fs_info->debug_kobj);
 956                kobject_put(fs_info->debug_kobj);
 957        }
 958#endif
 959        addrm_unknown_feature_attrs(fs_info, false);
 960        sysfs_remove_group(&fs_info->fs_devices->fsid_kobj, &btrfs_feature_attr_group);
 961        sysfs_remove_files(&fs_info->fs_devices->fsid_kobj, btrfs_attrs);
 962        btrfs_sysfs_remove_devices_dir(fs_info->fs_devices, NULL);
 963}
 964
 965static const char * const btrfs_feature_set_names[FEAT_MAX] = {
 966        [FEAT_COMPAT]    = "compat",
 967        [FEAT_COMPAT_RO] = "compat_ro",
 968        [FEAT_INCOMPAT]  = "incompat",
 969};
 970
 971const char * const btrfs_feature_set_name(enum btrfs_feature_set set)
 972{
 973        return btrfs_feature_set_names[set];
 974}
 975
 976char *btrfs_printable_features(enum btrfs_feature_set set, u64 flags)
 977{
 978        size_t bufsize = 4096; /* safe max, 64 names * 64 bytes */
 979        int len = 0;
 980        int i;
 981        char *str;
 982
 983        str = kmalloc(bufsize, GFP_KERNEL);
 984        if (!str)
 985                return str;
 986
 987        for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
 988                const char *name;
 989
 990                if (!(flags & (1ULL << i)))
 991                        continue;
 992
 993                name = btrfs_feature_attrs[set][i].kobj_attr.attr.name;
 994                len += scnprintf(str + len, bufsize - len, "%s%s",
 995                                len ? "," : "", name);
 996        }
 997
 998        return str;
 999}
1000
1001static void init_feature_attrs(void)
1002{
1003        struct btrfs_feature_attr *fa;
1004        int set, i;
1005
1006        BUILD_BUG_ON(ARRAY_SIZE(btrfs_unknown_feature_names) !=
1007                     ARRAY_SIZE(btrfs_feature_attrs));
1008        BUILD_BUG_ON(ARRAY_SIZE(btrfs_unknown_feature_names[0]) !=
1009                     ARRAY_SIZE(btrfs_feature_attrs[0]));
1010
1011        memset(btrfs_feature_attrs, 0, sizeof(btrfs_feature_attrs));
1012        memset(btrfs_unknown_feature_names, 0,
1013               sizeof(btrfs_unknown_feature_names));
1014
1015        for (i = 0; btrfs_supported_feature_attrs[i]; i++) {
1016                struct btrfs_feature_attr *sfa;
1017                struct attribute *a = btrfs_supported_feature_attrs[i];
1018                int bit;
1019                sfa = attr_to_btrfs_feature_attr(a);
1020                bit = ilog2(sfa->feature_bit);
1021                fa = &btrfs_feature_attrs[sfa->feature_set][bit];
1022
1023                fa->kobj_attr.attr.name = sfa->kobj_attr.attr.name;
1024        }
1025
1026        for (set = 0; set < FEAT_MAX; set++) {
1027                for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
1028                        char *name = btrfs_unknown_feature_names[set][i];
1029                        fa = &btrfs_feature_attrs[set][i];
1030
1031                        if (fa->kobj_attr.attr.name)
1032                                continue;
1033
1034                        snprintf(name, BTRFS_FEATURE_NAME_MAX, "%s:%u",
1035                                 btrfs_feature_set_names[set], i);
1036
1037                        fa->kobj_attr.attr.name = name;
1038                        fa->kobj_attr.attr.mode = S_IRUGO;
1039                        fa->feature_set = set;
1040                        fa->feature_bit = 1ULL << i;
1041                }
1042        }
1043}
1044
1045/*
1046 * Create a sysfs entry for a given block group type at path
1047 * /sys/fs/btrfs/UUID/allocation/data/TYPE
1048 */
1049void btrfs_sysfs_add_block_group_type(struct btrfs_block_group *cache)
1050{
1051        struct btrfs_fs_info *fs_info = cache->fs_info;
1052        struct btrfs_space_info *space_info = cache->space_info;
1053        struct raid_kobject *rkobj;
1054        const int index = btrfs_bg_flags_to_raid_index(cache->flags);
1055        unsigned int nofs_flag;
1056        int ret;
1057
1058        /*
1059         * Setup a NOFS context because kobject_add(), deep in its call chain,
1060         * does GFP_KERNEL allocations, and we are often called in a context
1061         * where if reclaim is triggered we can deadlock (we are either holding
1062         * a transaction handle or some lock required for a transaction
1063         * commit).
1064         */
1065        nofs_flag = memalloc_nofs_save();
1066
1067        rkobj = kzalloc(sizeof(*rkobj), GFP_NOFS);
1068        if (!rkobj) {
1069                memalloc_nofs_restore(nofs_flag);
1070                btrfs_warn(cache->fs_info,
1071                                "couldn't alloc memory for raid level kobject");
1072                return;
1073        }
1074
1075        rkobj->flags = cache->flags;
1076        kobject_init(&rkobj->kobj, &btrfs_raid_ktype);
1077        ret = kobject_add(&rkobj->kobj, &space_info->kobj, "%s",
1078                          btrfs_bg_type_to_raid_name(rkobj->flags));
1079        memalloc_nofs_restore(nofs_flag);
1080        if (ret) {
1081                kobject_put(&rkobj->kobj);
1082                btrfs_warn(fs_info,
1083                        "failed to add kobject for block cache, ignoring");
1084                return;
1085        }
1086
1087        space_info->block_group_kobjs[index] = &rkobj->kobj;
1088}
1089
1090/*
1091 * Remove sysfs directories for all block group types of a given space info and
1092 * the space info as well
1093 */
1094void btrfs_sysfs_remove_space_info(struct btrfs_space_info *space_info)
1095{
1096        int i;
1097
1098        for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) {
1099                struct kobject *kobj;
1100
1101                kobj = space_info->block_group_kobjs[i];
1102                space_info->block_group_kobjs[i] = NULL;
1103                if (kobj) {
1104                        kobject_del(kobj);
1105                        kobject_put(kobj);
1106                }
1107        }
1108        kobject_del(&space_info->kobj);
1109        kobject_put(&space_info->kobj);
1110}
1111
1112static const char *alloc_name(u64 flags)
1113{
1114        switch (flags) {
1115        case BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA:
1116                return "mixed";
1117        case BTRFS_BLOCK_GROUP_METADATA:
1118                return "metadata";
1119        case BTRFS_BLOCK_GROUP_DATA:
1120                return "data";
1121        case BTRFS_BLOCK_GROUP_SYSTEM:
1122                return "system";
1123        default:
1124                WARN_ON(1);
1125                return "invalid-combination";
1126        };
1127}
1128
1129/*
1130 * Create a sysfs entry for a space info type at path
1131 * /sys/fs/btrfs/UUID/allocation/TYPE
1132 */
1133int btrfs_sysfs_add_space_info_type(struct btrfs_fs_info *fs_info,
1134                                    struct btrfs_space_info *space_info)
1135{
1136        int ret;
1137
1138        ret = kobject_init_and_add(&space_info->kobj, &space_info_ktype,
1139                                   fs_info->space_info_kobj, "%s",
1140                                   alloc_name(space_info->flags));
1141        if (ret) {
1142                kobject_put(&space_info->kobj);
1143                return ret;
1144        }
1145
1146        return 0;
1147}
1148
1149/* when one_device is NULL, it removes all device links */
1150
1151int btrfs_sysfs_remove_devices_dir(struct btrfs_fs_devices *fs_devices,
1152                struct btrfs_device *one_device)
1153{
1154        struct hd_struct *disk;
1155        struct kobject *disk_kobj;
1156
1157        if (!fs_devices->devices_kobj)
1158                return -EINVAL;
1159
1160        if (one_device) {
1161                if (one_device->bdev) {
1162                        disk = one_device->bdev->bd_part;
1163                        disk_kobj = &part_to_dev(disk)->kobj;
1164                        sysfs_remove_link(fs_devices->devices_kobj,
1165                                          disk_kobj->name);
1166                }
1167
1168                kobject_del(&one_device->devid_kobj);
1169                kobject_put(&one_device->devid_kobj);
1170
1171                wait_for_completion(&one_device->kobj_unregister);
1172
1173                return 0;
1174        }
1175
1176        list_for_each_entry(one_device, &fs_devices->devices, dev_list) {
1177
1178                if (one_device->bdev) {
1179                        disk = one_device->bdev->bd_part;
1180                        disk_kobj = &part_to_dev(disk)->kobj;
1181                        sysfs_remove_link(fs_devices->devices_kobj,
1182                                          disk_kobj->name);
1183                }
1184                kobject_del(&one_device->devid_kobj);
1185                kobject_put(&one_device->devid_kobj);
1186
1187                wait_for_completion(&one_device->kobj_unregister);
1188        }
1189
1190        return 0;
1191}
1192
1193static ssize_t btrfs_devinfo_in_fs_metadata_show(struct kobject *kobj,
1194                                                 struct kobj_attribute *a,
1195                                                 char *buf)
1196{
1197        int val;
1198        struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1199                                                   devid_kobj);
1200
1201        val = !!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state);
1202
1203        return scnprintf(buf, PAGE_SIZE, "%d\n", val);
1204}
1205BTRFS_ATTR(devid, in_fs_metadata, btrfs_devinfo_in_fs_metadata_show);
1206
1207static ssize_t btrfs_devinfo_missing_show(struct kobject *kobj,
1208                                        struct kobj_attribute *a, char *buf)
1209{
1210        int val;
1211        struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1212                                                   devid_kobj);
1213
1214        val = !!test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state);
1215
1216        return scnprintf(buf, PAGE_SIZE, "%d\n", val);
1217}
1218BTRFS_ATTR(devid, missing, btrfs_devinfo_missing_show);
1219
1220static ssize_t btrfs_devinfo_replace_target_show(struct kobject *kobj,
1221                                                 struct kobj_attribute *a,
1222                                                 char *buf)
1223{
1224        int val;
1225        struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1226                                                   devid_kobj);
1227
1228        val = !!test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state);
1229
1230        return scnprintf(buf, PAGE_SIZE, "%d\n", val);
1231}
1232BTRFS_ATTR(devid, replace_target, btrfs_devinfo_replace_target_show);
1233
1234static ssize_t btrfs_devinfo_writeable_show(struct kobject *kobj,
1235                                            struct kobj_attribute *a, char *buf)
1236{
1237        int val;
1238        struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1239                                                   devid_kobj);
1240
1241        val = !!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state);
1242
1243        return scnprintf(buf, PAGE_SIZE, "%d\n", val);
1244}
1245BTRFS_ATTR(devid, writeable, btrfs_devinfo_writeable_show);
1246
1247static struct attribute *devid_attrs[] = {
1248        BTRFS_ATTR_PTR(devid, in_fs_metadata),
1249        BTRFS_ATTR_PTR(devid, missing),
1250        BTRFS_ATTR_PTR(devid, replace_target),
1251        BTRFS_ATTR_PTR(devid, writeable),
1252        NULL
1253};
1254ATTRIBUTE_GROUPS(devid);
1255
1256static void btrfs_release_devid_kobj(struct kobject *kobj)
1257{
1258        struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1259                                                   devid_kobj);
1260
1261        memset(&device->devid_kobj, 0, sizeof(struct kobject));
1262        complete(&device->kobj_unregister);
1263}
1264
1265static struct kobj_type devid_ktype = {
1266        .sysfs_ops      = &kobj_sysfs_ops,
1267        .default_groups = devid_groups,
1268        .release        = btrfs_release_devid_kobj,
1269};
1270
1271int btrfs_sysfs_add_devices_dir(struct btrfs_fs_devices *fs_devices,
1272                                struct btrfs_device *one_device)
1273{
1274        int error = 0;
1275        struct btrfs_device *dev;
1276
1277        list_for_each_entry(dev, &fs_devices->devices, dev_list) {
1278
1279                if (one_device && one_device != dev)
1280                        continue;
1281
1282                if (dev->bdev) {
1283                        struct hd_struct *disk;
1284                        struct kobject *disk_kobj;
1285
1286                        disk = dev->bdev->bd_part;
1287                        disk_kobj = &part_to_dev(disk)->kobj;
1288
1289                        error = sysfs_create_link(fs_devices->devices_kobj,
1290                                                  disk_kobj, disk_kobj->name);
1291                        if (error)
1292                                break;
1293                }
1294
1295                init_completion(&dev->kobj_unregister);
1296                error = kobject_init_and_add(&dev->devid_kobj, &devid_ktype,
1297                                             fs_devices->devinfo_kobj, "%llu",
1298                                             dev->devid);
1299                if (error) {
1300                        kobject_put(&dev->devid_kobj);
1301                        break;
1302                }
1303        }
1304
1305        return error;
1306}
1307
1308void btrfs_kobject_uevent(struct block_device *bdev, enum kobject_action action)
1309{
1310        int ret;
1311
1312        ret = kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, action);
1313        if (ret)
1314                pr_warn("BTRFS: Sending event '%d' to kobject: '%s' (%p): failed\n",
1315                        action, kobject_name(&disk_to_dev(bdev->bd_disk)->kobj),
1316                        &disk_to_dev(bdev->bd_disk)->kobj);
1317}
1318
1319void btrfs_sysfs_update_sprout_fsid(struct btrfs_fs_devices *fs_devices,
1320                                    const u8 *fsid)
1321{
1322        char fsid_buf[BTRFS_UUID_UNPARSED_SIZE];
1323
1324        /*
1325         * Sprouting changes fsid of the mounted filesystem, rename the fsid
1326         * directory
1327         */
1328        snprintf(fsid_buf, BTRFS_UUID_UNPARSED_SIZE, "%pU", fsid);
1329        if (kobject_rename(&fs_devices->fsid_kobj, fsid_buf))
1330                btrfs_warn(fs_devices->fs_info,
1331                                "sysfs: failed to create fsid for sprout");
1332}
1333
1334void btrfs_sysfs_update_devid(struct btrfs_device *device)
1335{
1336        char tmp[24];
1337
1338        snprintf(tmp, sizeof(tmp), "%llu", device->devid);
1339
1340        if (kobject_rename(&device->devid_kobj, tmp))
1341                btrfs_warn(device->fs_devices->fs_info,
1342                           "sysfs: failed to update devid for %llu",
1343                           device->devid);
1344}
1345
1346/* /sys/fs/btrfs/ entry */
1347static struct kset *btrfs_kset;
1348
1349/*
1350 * Creates:
1351 *              /sys/fs/btrfs/UUID
1352 *
1353 * Can be called by the device discovery thread.
1354 */
1355int btrfs_sysfs_add_fsid(struct btrfs_fs_devices *fs_devs)
1356{
1357        int error;
1358
1359        init_completion(&fs_devs->kobj_unregister);
1360        fs_devs->fsid_kobj.kset = btrfs_kset;
1361        error = kobject_init_and_add(&fs_devs->fsid_kobj, &btrfs_ktype, NULL,
1362                                     "%pU", fs_devs->fsid);
1363        if (error) {
1364                kobject_put(&fs_devs->fsid_kobj);
1365                return error;
1366        }
1367
1368        fs_devs->devices_kobj = kobject_create_and_add("devices",
1369                                                       &fs_devs->fsid_kobj);
1370        if (!fs_devs->devices_kobj) {
1371                btrfs_err(fs_devs->fs_info,
1372                          "failed to init sysfs device interface");
1373                btrfs_sysfs_remove_fsid(fs_devs);
1374                return -ENOMEM;
1375        }
1376
1377        fs_devs->devinfo_kobj = kobject_create_and_add("devinfo",
1378                                                       &fs_devs->fsid_kobj);
1379        if (!fs_devs->devinfo_kobj) {
1380                btrfs_err(fs_devs->fs_info,
1381                          "failed to init sysfs devinfo kobject");
1382                btrfs_sysfs_remove_fsid(fs_devs);
1383                return -ENOMEM;
1384        }
1385
1386        return 0;
1387}
1388
1389int btrfs_sysfs_add_mounted(struct btrfs_fs_info *fs_info)
1390{
1391        int error;
1392        struct btrfs_fs_devices *fs_devs = fs_info->fs_devices;
1393        struct kobject *fsid_kobj = &fs_devs->fsid_kobj;
1394
1395        btrfs_set_fs_info_ptr(fs_info);
1396
1397        error = btrfs_sysfs_add_devices_dir(fs_devs, NULL);
1398        if (error)
1399                return error;
1400
1401        error = sysfs_create_files(fsid_kobj, btrfs_attrs);
1402        if (error) {
1403                btrfs_sysfs_remove_devices_dir(fs_devs, NULL);
1404                return error;
1405        }
1406
1407        error = sysfs_create_group(fsid_kobj,
1408                                   &btrfs_feature_attr_group);
1409        if (error)
1410                goto failure;
1411
1412#ifdef CONFIG_BTRFS_DEBUG
1413        fs_info->debug_kobj = kobject_create_and_add("debug", fsid_kobj);
1414        if (!fs_info->debug_kobj) {
1415                error = -ENOMEM;
1416                goto failure;
1417        }
1418
1419        error = sysfs_create_files(fs_info->debug_kobj, btrfs_debug_mount_attrs);
1420        if (error)
1421                goto failure;
1422
1423        /* Discard directory */
1424        fs_info->discard_debug_kobj = kobject_create_and_add("discard",
1425                                                     fs_info->debug_kobj);
1426        if (!fs_info->discard_debug_kobj) {
1427                error = -ENOMEM;
1428                goto failure;
1429        }
1430
1431        error = sysfs_create_files(fs_info->discard_debug_kobj,
1432                                   discard_debug_attrs);
1433        if (error)
1434                goto failure;
1435#endif
1436
1437        error = addrm_unknown_feature_attrs(fs_info, true);
1438        if (error)
1439                goto failure;
1440
1441        fs_info->space_info_kobj = kobject_create_and_add("allocation",
1442                                                  fsid_kobj);
1443        if (!fs_info->space_info_kobj) {
1444                error = -ENOMEM;
1445                goto failure;
1446        }
1447
1448        error = sysfs_create_files(fs_info->space_info_kobj, allocation_attrs);
1449        if (error)
1450                goto failure;
1451
1452        return 0;
1453failure:
1454        btrfs_sysfs_remove_mounted(fs_info);
1455        return error;
1456}
1457
1458
1459/*
1460 * Change per-fs features in /sys/fs/btrfs/UUID/features to match current
1461 * values in superblock. Call after any changes to incompat/compat_ro flags
1462 */
1463void btrfs_sysfs_feature_update(struct btrfs_fs_info *fs_info,
1464                u64 bit, enum btrfs_feature_set set)
1465{
1466        struct btrfs_fs_devices *fs_devs;
1467        struct kobject *fsid_kobj;
1468        u64 features;
1469        int ret;
1470
1471        if (!fs_info)
1472                return;
1473
1474        features = get_features(fs_info, set);
1475        ASSERT(bit & supported_feature_masks[set]);
1476
1477        fs_devs = fs_info->fs_devices;
1478        fsid_kobj = &fs_devs->fsid_kobj;
1479
1480        if (!fsid_kobj->state_initialized)
1481                return;
1482
1483        /*
1484         * FIXME: this is too heavy to update just one value, ideally we'd like
1485         * to use sysfs_update_group but some refactoring is needed first.
1486         */
1487        sysfs_remove_group(fsid_kobj, &btrfs_feature_attr_group);
1488        ret = sysfs_create_group(fsid_kobj, &btrfs_feature_attr_group);
1489}
1490
1491int __init btrfs_init_sysfs(void)
1492{
1493        int ret;
1494
1495        btrfs_kset = kset_create_and_add("btrfs", NULL, fs_kobj);
1496        if (!btrfs_kset)
1497                return -ENOMEM;
1498
1499        init_feature_attrs();
1500        ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
1501        if (ret)
1502                goto out2;
1503        ret = sysfs_merge_group(&btrfs_kset->kobj,
1504                                &btrfs_static_feature_attr_group);
1505        if (ret)
1506                goto out_remove_group;
1507
1508#ifdef CONFIG_BTRFS_DEBUG
1509        ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_debug_feature_attr_group);
1510        if (ret)
1511                goto out2;
1512#endif
1513
1514        return 0;
1515
1516out_remove_group:
1517        sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
1518out2:
1519        kset_unregister(btrfs_kset);
1520
1521        return ret;
1522}
1523
1524void __cold btrfs_exit_sysfs(void)
1525{
1526        sysfs_unmerge_group(&btrfs_kset->kobj,
1527                            &btrfs_static_feature_attr_group);
1528        sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
1529#ifdef CONFIG_BTRFS_DEBUG
1530        sysfs_remove_group(&btrfs_kset->kobj, &btrfs_debug_feature_attr_group);
1531#endif
1532        kset_unregister(btrfs_kset);
1533}
1534
1535