fs/btrfs/sysfs.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2007 Oracle.  All rights reserved.
   4  */
   5
   6 #include <linux/sched.h>
   7 #include <linux/sched/mm.h>
   8 #include <linux/slab.h>
   9 #include <linux/spinlock.h>
  10 #include <linux/completion.h>
  11 #include <linux/bug.h>
  12 #include <crypto/hash.h>
  13
  14 #include "ctree.h"
  15 #include "discard.h"
  16 #include "disk-io.h"
  17 #include "send.h"
  18 #include "transaction.h"
  19 #include "sysfs.h"
  20 #include "volumes.h"
  21 #include "space-info.h"
  22 #include "block-group.h"
  23 #include "qgroup.h"
  24
  25 /*
  26  * Structure name                       Path
  27  * --------------------------------------------------------------------------
  28  * btrfs_supported_static_feature_attrs /sys/fs/btrfs/features
  29  * btrfs_supported_feature_attrs        /sys/fs/btrfs/features and
  30  *                                      /sys/fs/btrfs/<uuid>/features
  31  * btrfs_attrs                          /sys/fs/btrfs/<uuid>
  32  * devid_attrs                          /sys/fs/btrfs/<uuid>/devinfo/<devid>
  33  * allocation_attrs                     /sys/fs/btrfs/<uuid>/allocation
  34  * qgroup_attrs                         /sys/fs/btrfs/<uuid>/qgroups/<level>_<qgroupid>
  35  * space_info_attrs                     /sys/fs/btrfs/<uuid>/allocation/<bg-type>
  36  * raid_attrs                           /sys/fs/btrfs/<uuid>/allocation/<bg-type>/<bg-profile>
  37  *
  38  * When built with BTRFS_CONFIG_DEBUG:
  39  *
  40  * btrfs_debug_feature_attrs            /sys/fs/btrfs/debug
  41  * btrfs_debug_mount_attrs              /sys/fs/btrfs/<uuid>/debug
  42  * discard_debug_attrs                  /sys/fs/btrfs/<uuid>/debug/discard
  43  */
  44
  45 struct btrfs_feature_attr {
  46         struct kobj_attribute kobj_attr;
  47         enum btrfs_feature_set feature_set;
  48         u64 feature_bit;
  49 };
  50
  51 /* For raid type sysfs entries */
  52 struct raid_kobject {
  53         u64 flags;
  54         struct kobject kobj;
  55 };
  56
  57 #define __INIT_KOBJ_ATTR(_name, _mode, _show, _store)                   \
  58 {                                                                       \
  59         .attr   = { .name = __stringify(_name), .mode = _mode },        \
  60         .show   = _show,                                                \
  61         .store  = _store,                                               \
  62 }
  63
  64 #define BTRFS_ATTR_RW(_prefix, _name, _show, _store)                    \
  65         static struct kobj_attribute btrfs_attr_##_prefix##_##_name =   \
  66                         __INIT_KOBJ_ATTR(_name, 0644, _show, _store)
  67
  68 #define BTRFS_ATTR(_prefix, _name, _show)                               \
  69         static struct kobj_attribute btrfs_attr_##_prefix##_##_name =   \
  70                         __INIT_KOBJ_ATTR(_name, 0444, _show, NULL)
  71
  72 #define BTRFS_ATTR_PTR(_prefix, _name)                                  \
  73         (&btrfs_attr_##_prefix##_##_name.attr)
  74
  75 #define BTRFS_FEAT_ATTR(_name, _feature_set, _feature_prefix, _feature_bit)  \
  76 static struct btrfs_feature_attr btrfs_attr_features_##_name = {             \
  77         .kobj_attr = __INIT_KOBJ_ATTR(_name, S_IRUGO,                        \
  78                                       btrfs_feature_attr_show,               \
  79                                       btrfs_feature_attr_store),             \
  80         .feature_set    = _feature_set,                                      \
  81         .feature_bit    = _feature_prefix ##_## _feature_bit,                \
  82 }
  83 #define BTRFS_FEAT_ATTR_PTR(_name)                                           \
  84         (&btrfs_attr_features_##_name.kobj_attr.attr)
  85
  86 #define BTRFS_FEAT_ATTR_COMPAT(name, feature) \
  87         BTRFS_FEAT_ATTR(name, FEAT_COMPAT, BTRFS_FEATURE_COMPAT, feature)
  88 #define BTRFS_FEAT_ATTR_COMPAT_RO(name, feature) \
  89         BTRFS_FEAT_ATTR(name, FEAT_COMPAT_RO, BTRFS_FEATURE_COMPAT_RO, feature)
  90 #define BTRFS_FEAT_ATTR_INCOMPAT(name, feature) \
  91         BTRFS_FEAT_ATTR(name, FEAT_INCOMPAT, BTRFS_FEATURE_INCOMPAT, feature)
  92
  93 static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj);
  94 static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj);
  95
  96 static struct btrfs_feature_attr *to_btrfs_feature_attr(struct kobj_attribute *a)
  97 {
  98         return container_of(a, struct btrfs_feature_attr, kobj_attr);
  99 }
 100
 101 static struct kobj_attribute *attr_to_btrfs_attr(struct attribute *attr)
 102 {
 103         return container_of(attr, struct kobj_attribute, attr);
 104 }
 105
 106 static struct btrfs_feature_attr *attr_to_btrfs_feature_attr(
 107                 struct attribute *attr)
 108 {
 109         return to_btrfs_feature_attr(attr_to_btrfs_attr(attr));
 110 }
 111
 112 static u64 get_features(struct btrfs_fs_info *fs_info,
 113                         enum btrfs_feature_set set)
 114 {
 115         struct btrfs_super_block *disk_super = fs_info->super_copy;
 116         if (set == FEAT_COMPAT)
 117                 return btrfs_super_compat_flags(disk_super);
 118         else if (set == FEAT_COMPAT_RO)
 119                 return btrfs_super_compat_ro_flags(disk_super);
 120         else
 121                 return btrfs_super_incompat_flags(disk_super);
 122 }
 123
 124 static void set_features(struct btrfs_fs_info *fs_info,
 125                          enum btrfs_feature_set set, u64 features)
 126 {
 127         struct btrfs_super_block *disk_super = fs_info->super_copy;
 128         if (set == FEAT_COMPAT)
 129                 btrfs_set_super_compat_flags(disk_super, features);
 130         else if (set == FEAT_COMPAT_RO)
 131                 btrfs_set_super_compat_ro_flags(disk_super, features);
 132         else
 133                 btrfs_set_super_incompat_flags(disk_super, features);
 134 }
 135
 136 static int can_modify_feature(struct btrfs_feature_attr *fa)
 137 {
 138         int val = 0;
 139         u64 set, clear;
 140         switch (fa->feature_set) {
 141         case FEAT_COMPAT:
 142                 set = BTRFS_FEATURE_COMPAT_SAFE_SET;
 143                 clear = BTRFS_FEATURE_COMPAT_SAFE_CLEAR;
 144                 break;
 145         case FEAT_COMPAT_RO:
 146                 set = BTRFS_FEATURE_COMPAT_RO_SAFE_SET;
 147                 clear = BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR;
 148                 break;
 149         case FEAT_INCOMPAT:
 150                 set = BTRFS_FEATURE_INCOMPAT_SAFE_SET;
 151                 clear = BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR;
 152                 break;
 153         default:
 154                 pr_warn("btrfs: sysfs: unknown feature set %d\n",
 155                                 fa->feature_set);
 156                 return 0;
 157         }
 158
 159         if (set & fa->feature_bit)
 160                 val |= 1;
 161         if (clear & fa->feature_bit)
 162                 val |= 2;
 163
 164         return val;
 165 }
 166
 167 static ssize_t btrfs_feature_attr_show(struct kobject *kobj,
 168                                        struct kobj_attribute *a, char *buf)
 169 {
 170         int val = 0;
 171         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 172         struct btrfs_feature_attr *fa = to_btrfs_feature_attr(a);
 173         if (fs_info) {
 174                 u64 features = get_features(fs_info, fa->feature_set);
 175                 if (features & fa->feature_bit)
 176                         val = 1;
 177         } else
 178                 val = can_modify_feature(fa);
 179
 180         return sysfs_emit(buf, "%d\n", val);
 181 }
 182
 183 static ssize_t btrfs_feature_attr_store(struct kobject *kobj,
 184                                         struct kobj_attribute *a,
 185                                         const char *buf, size_t count)
 186 {
 187         struct btrfs_fs_info *fs_info;
 188         struct btrfs_feature_attr *fa = to_btrfs_feature_attr(a);
 189         u64 features, set, clear;
 190         unsigned long val;
 191         int ret;
 192
 193         fs_info = to_fs_info(kobj);
 194         if (!fs_info)
 195                 return -EPERM;
 196
 197         if (sb_rdonly(fs_info->sb))
 198                 return -EROFS;
 199
 200         ret = kstrtoul(skip_spaces(buf), 0, &val);
 201         if (ret)
 202                 return ret;
 203
 204         if (fa->feature_set == FEAT_COMPAT) {
 205                 set = BTRFS_FEATURE_COMPAT_SAFE_SET;
 206                 clear = BTRFS_FEATURE_COMPAT_SAFE_CLEAR;
 207         } else if (fa->feature_set == FEAT_COMPAT_RO) {
 208                 set = BTRFS_FEATURE_COMPAT_RO_SAFE_SET;
 209                 clear = BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR;
 210         } else {
 211                 set = BTRFS_FEATURE_INCOMPAT_SAFE_SET;
 212                 clear = BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR;
 213         }
 214
 215         features = get_features(fs_info, fa->feature_set);
 216
 217         /* Nothing to do */
 218         if ((val && (features & fa->feature_bit)) ||
 219             (!val && !(features & fa->feature_bit)))
 220                 return count;
 221
 222         if ((val && !(set & fa->feature_bit)) ||
 223             (!val && !(clear & fa->feature_bit))) {
 224                 btrfs_info(fs_info,
 225                         "%sabling feature %s on mounted fs is not supported.",
 226                         val ? "En" : "Dis", fa->kobj_attr.attr.name);
 227                 return -EPERM;
 228         }
 229
 230         btrfs_info(fs_info, "%s %s feature flag",
 231                    val ? "Setting" : "Clearing", fa->kobj_attr.attr.name);
 232
 233         spin_lock(&fs_info->super_lock);
 234         features = get_features(fs_info, fa->feature_set);
 235         if (val)
 236                 features |= fa->feature_bit;
 237         else
 238                 features &= ~fa->feature_bit;
 239         set_features(fs_info, fa->feature_set, features);
 240         spin_unlock(&fs_info->super_lock);
 241
 242         /*
 243          * We don't want to do full transaction commit from inside sysfs
 244          */
 245         btrfs_set_pending(fs_info, COMMIT);
 246         wake_up_process(fs_info->transaction_kthread);
 247
 248         return count;
 249 }
 250
 251 static umode_t btrfs_feature_visible(struct kobject *kobj,
 252                                      struct attribute *attr, int unused)
 253 {
 254         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 255         umode_t mode = attr->mode;
 256
 257         if (fs_info) {
 258                 struct btrfs_feature_attr *fa;
 259                 u64 features;
 260
 261                 fa = attr_to_btrfs_feature_attr(attr);
 262                 features = get_features(fs_info, fa->feature_set);
 263
 264                 if (can_modify_feature(fa))
 265                         mode |= S_IWUSR;
 266                 else if (!(features & fa->feature_bit))
 267                         mode = 0;
 268         }
 269
 270         return mode;
 271 }
 272
 273 BTRFS_FEAT_ATTR_INCOMPAT(mixed_backref, MIXED_BACKREF);
 274 BTRFS_FEAT_ATTR_INCOMPAT(default_subvol, DEFAULT_SUBVOL);
 275 BTRFS_FEAT_ATTR_INCOMPAT(mixed_groups, MIXED_GROUPS);
 276 BTRFS_FEAT_ATTR_INCOMPAT(compress_lzo, COMPRESS_LZO);
 277 BTRFS_FEAT_ATTR_INCOMPAT(compress_zstd, COMPRESS_ZSTD);
 278 BTRFS_FEAT_ATTR_INCOMPAT(big_metadata, BIG_METADATA);
 279 BTRFS_FEAT_ATTR_INCOMPAT(extended_iref, EXTENDED_IREF);
 280 BTRFS_FEAT_ATTR_INCOMPAT(raid56, RAID56);
 281 BTRFS_FEAT_ATTR_INCOMPAT(skinny_metadata, SKINNY_METADATA);
 282 BTRFS_FEAT_ATTR_INCOMPAT(no_holes, NO_HOLES);
 283 BTRFS_FEAT_ATTR_INCOMPAT(metadata_uuid, METADATA_UUID);
 284 BTRFS_FEAT_ATTR_COMPAT_RO(free_space_tree, FREE_SPACE_TREE);
 285 BTRFS_FEAT_ATTR_INCOMPAT(raid1c34, RAID1C34);
 286 /* Remove once support for zoned allocation is feature complete */
 287 #ifdef CONFIG_BTRFS_DEBUG
 288 BTRFS_FEAT_ATTR_INCOMPAT(zoned, ZONED);
 289 #endif
 290 #ifdef CONFIG_FS_VERITY
 291 BTRFS_FEAT_ATTR_COMPAT_RO(verity, VERITY);
 292 #endif
 293
 294 /*
 295  * Features which depend on feature bits and may differ between each fs.
 296  *
 297  * /sys/fs/btrfs/features      - all available features implemeted by this version
 298  * /sys/fs/btrfs/UUID/features - features of the fs which are enabled or
 299  *                               can be changed on a mounted filesystem.
 300  */
 301 static struct attribute *btrfs_supported_feature_attrs[] = {
 302         BTRFS_FEAT_ATTR_PTR(mixed_backref),
 303         BTRFS_FEAT_ATTR_PTR(default_subvol),
 304         BTRFS_FEAT_ATTR_PTR(mixed_groups),
 305         BTRFS_FEAT_ATTR_PTR(compress_lzo),
 306         BTRFS_FEAT_ATTR_PTR(compress_zstd),
 307         BTRFS_FEAT_ATTR_PTR(big_metadata),
 308         BTRFS_FEAT_ATTR_PTR(extended_iref),
 309         BTRFS_FEAT_ATTR_PTR(raid56),
 310         BTRFS_FEAT_ATTR_PTR(skinny_metadata),
 311         BTRFS_FEAT_ATTR_PTR(no_holes),
 312         BTRFS_FEAT_ATTR_PTR(metadata_uuid),
 313         BTRFS_FEAT_ATTR_PTR(free_space_tree),
 314         BTRFS_FEAT_ATTR_PTR(raid1c34),
 315 #ifdef CONFIG_BTRFS_DEBUG
 316         BTRFS_FEAT_ATTR_PTR(zoned),
 317 #endif
 318 #ifdef CONFIG_FS_VERITY
 319         BTRFS_FEAT_ATTR_PTR(verity),
 320 #endif
 321         NULL
 322 };
 323
 324 static const struct attribute_group btrfs_feature_attr_group = {
 325         .name = "features",
 326         .is_visible = btrfs_feature_visible,
 327         .attrs = btrfs_supported_feature_attrs,
 328 };
 329
 330 static ssize_t rmdir_subvol_show(struct kobject *kobj,
 331                                  struct kobj_attribute *ka, char *buf)
 332 {
 333         return sysfs_emit(buf, "0\n");
 334 }
 335 BTRFS_ATTR(static_feature, rmdir_subvol, rmdir_subvol_show);
 336
 337 static ssize_t supported_checksums_show(struct kobject *kobj,
 338                                         struct kobj_attribute *a, char *buf)
 339 {
 340         ssize_t ret = 0;
 341         int i;
 342
 343         for (i = 0; i < btrfs_get_num_csums(); i++) {
 344                 /*
 345                  * This "trick" only works as long as 'enum btrfs_csum_type' has
 346                  * no holes in it
 347                  */
 348                 ret += sysfs_emit_at(buf, ret, "%s%s", (i == 0 ? "" : " "),
 349                                      btrfs_super_csum_name(i));
 350
 351         }
 352
 353         ret += sysfs_emit_at(buf, ret, "\n");
 354         return ret;
 355 }
 356 BTRFS_ATTR(static_feature, supported_checksums, supported_checksums_show);
 357
 358 static ssize_t send_stream_version_show(struct kobject *kobj,
 359                                         struct kobj_attribute *ka, char *buf)
 360 {
 361         return sysfs_emit(buf, "%d\n", BTRFS_SEND_STREAM_VERSION);
 362 }
 363 BTRFS_ATTR(static_feature, send_stream_version, send_stream_version_show);
 364
 365 static const char *rescue_opts[] = {
 366         "usebackuproot",
 367         "nologreplay",
 368         "ignorebadroots",
 369         "ignoredatacsums",
 370         "all",
 371 };
 372
 373 static ssize_t supported_rescue_options_show(struct kobject *kobj,
 374                                              struct kobj_attribute *a,
 375                                              char *buf)
 376 {
 377         ssize_t ret = 0;
 378         int i;
 379
 380         for (i = 0; i < ARRAY_SIZE(rescue_opts); i++)
 381                 ret += sysfs_emit_at(buf, ret, "%s%s", (i ? " " : ""), rescue_opts[i]);
 382         ret += sysfs_emit_at(buf, ret, "\n");
 383         return ret;
 384 }
 385 BTRFS_ATTR(static_feature, supported_rescue_options,
 386            supported_rescue_options_show);
 387
 388 static ssize_t supported_sectorsizes_show(struct kobject *kobj,
 389                                           struct kobj_attribute *a,
 390                                           char *buf)
 391 {
 392         ssize_t ret = 0;
 393
 394         /* 4K sector size is also supported with 64K page size */
 395         if (PAGE_SIZE == SZ_64K)
 396                 ret += sysfs_emit_at(buf, ret, "%u ", SZ_4K);
 397
 398         /* Only sectorsize == PAGE_SIZE is now supported */
 399         ret += sysfs_emit_at(buf, ret, "%lu\n", PAGE_SIZE);
 400
 401         return ret;
 402 }
 403 BTRFS_ATTR(static_feature, supported_sectorsizes,
 404            supported_sectorsizes_show);
 405
 406 /*
 407  * Features which only depend on kernel version.
 408  *
 409  * These are listed in /sys/fs/btrfs/features along with
 410  * btrfs_supported_feature_attrs.
 411  */
 412 static struct attribute *btrfs_supported_static_feature_attrs[] = {
 413         BTRFS_ATTR_PTR(static_feature, rmdir_subvol),
 414         BTRFS_ATTR_PTR(static_feature, supported_checksums),
 415         BTRFS_ATTR_PTR(static_feature, send_stream_version),
 416         BTRFS_ATTR_PTR(static_feature, supported_rescue_options),
 417         BTRFS_ATTR_PTR(static_feature, supported_sectorsizes),
 418         NULL
 419 };
 420
 421 static const struct attribute_group btrfs_static_feature_attr_group = {
 422         .name = "features",
 423         .attrs = btrfs_supported_static_feature_attrs,
 424 };
 425
 426 #ifdef CONFIG_BTRFS_DEBUG
 427
 428 /*
 429  * Discard statistics and tunables
 430  */
 431 #define discard_to_fs_info(_kobj)       to_fs_info((_kobj)->parent->parent)
 432
 433 static ssize_t btrfs_discardable_bytes_show(struct kobject *kobj,
 434                                             struct kobj_attribute *a,
 435                                             char *buf)
 436 {
 437         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 438
 439         return sysfs_emit(buf, "%lld\n",
 440                         atomic64_read(&fs_info->discard_ctl.discardable_bytes));
 441 }
 442 BTRFS_ATTR(discard, discardable_bytes, btrfs_discardable_bytes_show);
 443
 444 static ssize_t btrfs_discardable_extents_show(struct kobject *kobj,
 445                                               struct kobj_attribute *a,
 446                                               char *buf)
 447 {
 448         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 449
 450         return sysfs_emit(buf, "%d\n",
 451                         atomic_read(&fs_info->discard_ctl.discardable_extents));
 452 }
 453 BTRFS_ATTR(discard, discardable_extents, btrfs_discardable_extents_show);
 454
 455 static ssize_t btrfs_discard_bitmap_bytes_show(struct kobject *kobj,
 456                                                struct kobj_attribute *a,
 457                                                char *buf)
 458 {
 459         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 460
 461         return sysfs_emit(buf, "%llu\n",
 462                           fs_info->discard_ctl.discard_bitmap_bytes);
 463 }
 464 BTRFS_ATTR(discard, discard_bitmap_bytes, btrfs_discard_bitmap_bytes_show);
 465
 466 static ssize_t btrfs_discard_bytes_saved_show(struct kobject *kobj,
 467                                               struct kobj_attribute *a,
 468                                               char *buf)
 469 {
 470         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 471
 472         return sysfs_emit(buf, "%lld\n",
 473                 atomic64_read(&fs_info->discard_ctl.discard_bytes_saved));
 474 }
 475 BTRFS_ATTR(discard, discard_bytes_saved, btrfs_discard_bytes_saved_show);
 476
 477 static ssize_t btrfs_discard_extent_bytes_show(struct kobject *kobj,
 478                                                struct kobj_attribute *a,
 479                                                char *buf)
 480 {
 481         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 482
 483         return sysfs_emit(buf, "%llu\n",
 484                           fs_info->discard_ctl.discard_extent_bytes);
 485 }
 486 BTRFS_ATTR(discard, discard_extent_bytes, btrfs_discard_extent_bytes_show);
 487
 488 static ssize_t btrfs_discard_iops_limit_show(struct kobject *kobj,
 489                                              struct kobj_attribute *a,
 490                                              char *buf)
 491 {
 492         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 493
 494         return sysfs_emit(buf, "%u\n",
 495                           READ_ONCE(fs_info->discard_ctl.iops_limit));
 496 }
 497
 498 static ssize_t btrfs_discard_iops_limit_store(struct kobject *kobj,
 499                                               struct kobj_attribute *a,
 500                                               const char *buf, size_t len)
 501 {
 502         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 503         struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
 504         u32 iops_limit;
 505         int ret;
 506
 507         ret = kstrtou32(buf, 10, &iops_limit);
 508         if (ret)
 509                 return -EINVAL;
 510
 511         WRITE_ONCE(discard_ctl->iops_limit, iops_limit);
 512         btrfs_discard_calc_delay(discard_ctl);
 513         btrfs_discard_schedule_work(discard_ctl, true);
 514         return len;
 515 }
 516 BTRFS_ATTR_RW(discard, iops_limit, btrfs_discard_iops_limit_show,
 517               btrfs_discard_iops_limit_store);
 518
 519 static ssize_t btrfs_discard_kbps_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.kbps_limit));
 527 }
 528
 529 static ssize_t btrfs_discard_kbps_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 kbps_limit;
 536         int ret;
 537
 538         ret = kstrtou32(buf, 10, &kbps_limit);
 539         if (ret)
 540                 return -EINVAL;
 541
 542         WRITE_ONCE(discard_ctl->kbps_limit, kbps_limit);
 543         btrfs_discard_schedule_work(discard_ctl, true);
 544         return len;
 545 }
 546 BTRFS_ATTR_RW(discard, kbps_limit, btrfs_discard_kbps_limit_show,
 547               btrfs_discard_kbps_limit_store);
 548
 549 static ssize_t btrfs_discard_max_discard_size_show(struct kobject *kobj,
 550                                                    struct kobj_attribute *a,
 551                                                    char *buf)
 552 {
 553         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 554
 555         return sysfs_emit(buf, "%llu\n",
 556                           READ_ONCE(fs_info->discard_ctl.max_discard_size));
 557 }
 558
 559 static ssize_t btrfs_discard_max_discard_size_store(struct kobject *kobj,
 560                                                     struct kobj_attribute *a,
 561                                                     const char *buf, size_t len)
 562 {
 563         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 564         struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
 565         u64 max_discard_size;
 566         int ret;
 567
 568         ret = kstrtou64(buf, 10, &max_discard_size);
 569         if (ret)
 570                 return -EINVAL;
 571
 572         WRITE_ONCE(discard_ctl->max_discard_size, max_discard_size);
 573
 574         return len;
 575 }
 576 BTRFS_ATTR_RW(discard, max_discard_size, btrfs_discard_max_discard_size_show,
 577               btrfs_discard_max_discard_size_store);
 578
 579 /*
 580  * Per-filesystem debugging of discard (when mounted with discard=async).
 581  *
 582  * Path: /sys/fs/btrfs/<uuid>/debug/discard/
 583  */
 584 static const struct attribute *discard_debug_attrs[] = {
 585         BTRFS_ATTR_PTR(discard, discardable_bytes),
 586         BTRFS_ATTR_PTR(discard, discardable_extents),
 587         BTRFS_ATTR_PTR(discard, discard_bitmap_bytes),
 588         BTRFS_ATTR_PTR(discard, discard_bytes_saved),
 589         BTRFS_ATTR_PTR(discard, discard_extent_bytes),
 590         BTRFS_ATTR_PTR(discard, iops_limit),
 591         BTRFS_ATTR_PTR(discard, kbps_limit),
 592         BTRFS_ATTR_PTR(discard, max_discard_size),
 593         NULL,
 594 };
 595
 596 /*
 597  * Per-filesystem runtime debugging exported via sysfs.
 598  *
 599  * Path: /sys/fs/btrfs/UUID/debug/
 600  */
 601 static const struct attribute *btrfs_debug_mount_attrs[] = {
 602         NULL,
 603 };
 604
 605 /*
 606  * Runtime debugging exported via sysfs, applies to all mounted filesystems.
 607  *
 608  * Path: /sys/fs/btrfs/debug
 609  */
 610 static struct attribute *btrfs_debug_feature_attrs[] = {
 611         NULL
 612 };
 613
 614 static const struct attribute_group btrfs_debug_feature_attr_group = {
 615         .name = "debug",
 616         .attrs = btrfs_debug_feature_attrs,
 617 };
 618
 619 #endif
 620
 621 static ssize_t btrfs_show_u64(u64 *value_ptr, spinlock_t *lock, char *buf)
 622 {
 623         u64 val;
 624         if (lock)
 625                 spin_lock(lock);
 626         val = *value_ptr;
 627         if (lock)
 628                 spin_unlock(lock);
 629         return sysfs_emit(buf, "%llu\n", val);
 630 }
 631
 632 static ssize_t global_rsv_size_show(struct kobject *kobj,
 633                                     struct kobj_attribute *ka, char *buf)
 634 {
 635         struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent);
 636         struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
 637         return btrfs_show_u64(&block_rsv->size, &block_rsv->lock, buf);
 638 }
 639 BTRFS_ATTR(allocation, global_rsv_size, global_rsv_size_show);
 640
 641 static ssize_t global_rsv_reserved_show(struct kobject *kobj,
 642                                         struct kobj_attribute *a, char *buf)
 643 {
 644         struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent);
 645         struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
 646         return btrfs_show_u64(&block_rsv->reserved, &block_rsv->lock, buf);
 647 }
 648 BTRFS_ATTR(allocation, global_rsv_reserved, global_rsv_reserved_show);
 649
 650 #define to_space_info(_kobj) container_of(_kobj, struct btrfs_space_info, kobj)
 651 #define to_raid_kobj(_kobj) container_of(_kobj, struct raid_kobject, kobj)
 652
 653 static ssize_t raid_bytes_show(struct kobject *kobj,
 654                                struct kobj_attribute *attr, char *buf);
 655 BTRFS_ATTR(raid, total_bytes, raid_bytes_show);
 656 BTRFS_ATTR(raid, used_bytes, raid_bytes_show);
 657
 658 static ssize_t raid_bytes_show(struct kobject *kobj,
 659                                struct kobj_attribute *attr, char *buf)
 660
 661 {
 662         struct btrfs_space_info *sinfo = to_space_info(kobj->parent);
 663         struct btrfs_block_group *block_group;
 664         int index = btrfs_bg_flags_to_raid_index(to_raid_kobj(kobj)->flags);
 665         u64 val = 0;
 666
 667         down_read(&sinfo->groups_sem);
 668         list_for_each_entry(block_group, &sinfo->block_groups[index], list) {
 669                 if (&attr->attr == BTRFS_ATTR_PTR(raid, total_bytes))
 670                         val += block_group->length;
 671                 else
 672                         val += block_group->used;
 673         }
 674         up_read(&sinfo->groups_sem);
 675         return sysfs_emit(buf, "%llu\n", val);
 676 }
 677
 678 /*
 679  * Allocation information about block group profiles.
 680  *
 681  * Path: /sys/fs/btrfs/<uuid>/allocation/<bg-type>/<bg-profile>/
 682  */
 683 static struct attribute *raid_attrs[] = {
 684         BTRFS_ATTR_PTR(raid, total_bytes),
 685         BTRFS_ATTR_PTR(raid, used_bytes),
 686         NULL
 687 };
 688 ATTRIBUTE_GROUPS(raid);
 689
 690 static void release_raid_kobj(struct kobject *kobj)
 691 {
 692         kfree(to_raid_kobj(kobj));
 693 }
 694
 695 static struct kobj_type btrfs_raid_ktype = {
 696         .sysfs_ops = &kobj_sysfs_ops,
 697         .release = release_raid_kobj,
 698         .default_groups = raid_groups,
 699 };
 700
 701 #define SPACE_INFO_ATTR(field)                                          \
 702 static ssize_t btrfs_space_info_show_##field(struct kobject *kobj,      \
 703                                              struct kobj_attribute *a,  \
 704                                              char *buf)                 \
 705 {                                                                       \
 706         struct btrfs_space_info *sinfo = to_space_info(kobj);           \
 707         return btrfs_show_u64(&sinfo->field, &sinfo->lock, buf);        \
 708 }                                                                       \
 709 BTRFS_ATTR(space_info, field, btrfs_space_info_show_##field)
 710
 711 SPACE_INFO_ATTR(flags);
 712 SPACE_INFO_ATTR(total_bytes);
 713 SPACE_INFO_ATTR(bytes_used);
 714 SPACE_INFO_ATTR(bytes_pinned);
 715 SPACE_INFO_ATTR(bytes_reserved);
 716 SPACE_INFO_ATTR(bytes_may_use);
 717 SPACE_INFO_ATTR(bytes_readonly);
 718 SPACE_INFO_ATTR(bytes_zone_unusable);
 719 SPACE_INFO_ATTR(disk_used);
 720 SPACE_INFO_ATTR(disk_total);
 721
 722 /*
 723  * Allocation information about block group types.
 724  *
 725  * Path: /sys/fs/btrfs/<uuid>/allocation/<bg-type>/
 726  */
 727 static struct attribute *space_info_attrs[] = {
 728         BTRFS_ATTR_PTR(space_info, flags),
 729         BTRFS_ATTR_PTR(space_info, total_bytes),
 730         BTRFS_ATTR_PTR(space_info, bytes_used),
 731         BTRFS_ATTR_PTR(space_info, bytes_pinned),
 732         BTRFS_ATTR_PTR(space_info, bytes_reserved),
 733         BTRFS_ATTR_PTR(space_info, bytes_may_use),
 734         BTRFS_ATTR_PTR(space_info, bytes_readonly),
 735         BTRFS_ATTR_PTR(space_info, bytes_zone_unusable),
 736         BTRFS_ATTR_PTR(space_info, disk_used),
 737         BTRFS_ATTR_PTR(space_info, disk_total),
 738         NULL,
 739 };
 740 ATTRIBUTE_GROUPS(space_info);
 741
 742 static void space_info_release(struct kobject *kobj)
 743 {
 744         struct btrfs_space_info *sinfo = to_space_info(kobj);
 745         kfree(sinfo);
 746 }
 747
 748 static struct kobj_type space_info_ktype = {
 749         .sysfs_ops = &kobj_sysfs_ops,
 750         .release = space_info_release,
 751         .default_groups = space_info_groups,
 752 };
 753
 754 /*
 755  * Allocation information about block groups.
 756  *
 757  * Path: /sys/fs/btrfs/<uuid>/allocation/
 758  */
 759 static const struct attribute *allocation_attrs[] = {
 760         BTRFS_ATTR_PTR(allocation, global_rsv_reserved),
 761         BTRFS_ATTR_PTR(allocation, global_rsv_size),
 762         NULL,
 763 };
 764
 765 static ssize_t btrfs_label_show(struct kobject *kobj,
 766                                 struct kobj_attribute *a, char *buf)
 767 {
 768         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 769         char *label = fs_info->super_copy->label;
 770         ssize_t ret;
 771
 772         spin_lock(&fs_info->super_lock);
 773         ret = sysfs_emit(buf, label[0] ? "%s\n" : "%s", label);
 774         spin_unlock(&fs_info->super_lock);
 775
 776         return ret;
 777 }
 778
 779 static ssize_t btrfs_label_store(struct kobject *kobj,
 780                                  struct kobj_attribute *a,
 781                                  const char *buf, size_t len)
 782 {
 783         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 784         size_t p_len;
 785
 786         if (!fs_info)
 787                 return -EPERM;
 788
 789         if (sb_rdonly(fs_info->sb))
 790                 return -EROFS;
 791
 792         /*
 793          * p_len is the len until the first occurrence of either
 794          * '\n' or '\0'
 795          */
 796         p_len = strcspn(buf, "\n");
 797
 798         if (p_len >= BTRFS_LABEL_SIZE)
 799                 return -EINVAL;
 800
 801         spin_lock(&fs_info->super_lock);
 802         memset(fs_info->super_copy->label, 0, BTRFS_LABEL_SIZE);
 803         memcpy(fs_info->super_copy->label, buf, p_len);
 804         spin_unlock(&fs_info->super_lock);
 805
 806         /*
 807          * We don't want to do full transaction commit from inside sysfs
 808          */
 809         btrfs_set_pending(fs_info, COMMIT);
 810         wake_up_process(fs_info->transaction_kthread);
 811
 812         return len;
 813 }
 814 BTRFS_ATTR_RW(, label, btrfs_label_show, btrfs_label_store);
 815
 816 static ssize_t btrfs_nodesize_show(struct kobject *kobj,
 817                                 struct kobj_attribute *a, char *buf)
 818 {
 819         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 820
 821         return sysfs_emit(buf, "%u\n", fs_info->super_copy->nodesize);
 822 }
 823
 824 BTRFS_ATTR(, nodesize, btrfs_nodesize_show);
 825
 826 static ssize_t btrfs_sectorsize_show(struct kobject *kobj,
 827                                 struct kobj_attribute *a, char *buf)
 828 {
 829         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 830
 831         return sysfs_emit(buf, "%u\n", fs_info->super_copy->sectorsize);
 832 }
 833
 834 BTRFS_ATTR(, sectorsize, btrfs_sectorsize_show);
 835
 836 static ssize_t btrfs_clone_alignment_show(struct kobject *kobj,
 837                                 struct kobj_attribute *a, char *buf)
 838 {
 839         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 840
 841         return sysfs_emit(buf, "%u\n", fs_info->super_copy->sectorsize);
 842 }
 843
 844 BTRFS_ATTR(, clone_alignment, btrfs_clone_alignment_show);
 845
 846 static ssize_t quota_override_show(struct kobject *kobj,
 847                                    struct kobj_attribute *a, char *buf)
 848 {
 849         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 850         int quota_override;
 851
 852         quota_override = test_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
 853         return sysfs_emit(buf, "%d\n", quota_override);
 854 }
 855
 856 static ssize_t quota_override_store(struct kobject *kobj,
 857                                     struct kobj_attribute *a,
 858                                     const char *buf, size_t len)
 859 {
 860         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 861         unsigned long knob;
 862         int err;
 863
 864         if (!fs_info)
 865                 return -EPERM;
 866
 867         if (!capable(CAP_SYS_RESOURCE))
 868                 return -EPERM;
 869
 870         err = kstrtoul(buf, 10, &knob);
 871         if (err)
 872                 return err;
 873         if (knob > 1)
 874                 return -EINVAL;
 875
 876         if (knob)
 877                 set_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
 878         else
 879                 clear_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
 880
 881         return len;
 882 }
 883
 884 BTRFS_ATTR_RW(, quota_override, quota_override_show, quota_override_store);
 885
 886 static ssize_t btrfs_metadata_uuid_show(struct kobject *kobj,
 887                                 struct kobj_attribute *a, char *buf)
 888 {
 889         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 890
 891         return sysfs_emit(buf, "%pU\n", fs_info->fs_devices->metadata_uuid);
 892 }
 893
 894 BTRFS_ATTR(, metadata_uuid, btrfs_metadata_uuid_show);
 895
 896 static ssize_t btrfs_checksum_show(struct kobject *kobj,
 897                                    struct kobj_attribute *a, char *buf)
 898 {
 899         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 900         u16 csum_type = btrfs_super_csum_type(fs_info->super_copy);
 901
 902         return sysfs_emit(buf, "%s (%s)\n",
 903                           btrfs_super_csum_name(csum_type),
 904                           crypto_shash_driver_name(fs_info->csum_shash));
 905 }
 906
 907 BTRFS_ATTR(, checksum, btrfs_checksum_show);
 908
 909 static ssize_t btrfs_exclusive_operation_show(struct kobject *kobj,
 910                 struct kobj_attribute *a, char *buf)
 911 {
 912         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 913         const char *str;
 914
 915         switch (READ_ONCE(fs_info->exclusive_operation)) {
 916                 case  BTRFS_EXCLOP_NONE:
 917                         str = "none\n";
 918                         break;
 919                 case BTRFS_EXCLOP_BALANCE:
 920                         str = "balance\n";
 921                         break;
 922                 case BTRFS_EXCLOP_DEV_ADD:
 923                         str = "device add\n";
 924                         break;
 925                 case BTRFS_EXCLOP_DEV_REMOVE:
 926                         str = "device remove\n";
 927                         break;
 928                 case BTRFS_EXCLOP_DEV_REPLACE:
 929                         str = "device replace\n";
 930                         break;
 931                 case BTRFS_EXCLOP_RESIZE:
 932                         str = "resize\n";
 933                         break;
 934                 case BTRFS_EXCLOP_SWAP_ACTIVATE:
 935                         str = "swap activate\n";
 936                         break;
 937                 default:
 938                         str = "UNKNOWN\n";
 939                         break;
 940         }
 941         return sysfs_emit(buf, "%s", str);
 942 }
 943 BTRFS_ATTR(, exclusive_operation, btrfs_exclusive_operation_show);
 944
 945 static ssize_t btrfs_generation_show(struct kobject *kobj,
 946                                      struct kobj_attribute *a, char *buf)
 947 {
 948         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 949
 950         return sysfs_emit(buf, "%llu\n", fs_info->generation);
 951 }
 952 BTRFS_ATTR(, generation, btrfs_generation_show);
 953
 954 /*
 955  * Look for an exact string @string in @buffer with possible leading or
 956  * trailing whitespace
 957  */
 958 static bool strmatch(const char *buffer, const char *string)
 959 {
 960         const size_t len = strlen(string);
 961
 962         /* Skip leading whitespace */
 963         buffer = skip_spaces(buffer);
 964
 965         /* Match entire string, check if the rest is whitespace or empty */
 966         if (strncmp(string, buffer, len) == 0 &&
 967             strlen(skip_spaces(buffer + len)) == 0)
 968                 return true;
 969
 970         return false;
 971 }
 972
 973 static const char * const btrfs_read_policy_name[] = { "pid" };
 974
 975 static ssize_t btrfs_read_policy_show(struct kobject *kobj,
 976                                       struct kobj_attribute *a, char *buf)
 977 {
 978         struct btrfs_fs_devices *fs_devices = to_fs_devs(kobj);
 979         ssize_t ret = 0;
 980         int i;
 981
 982         for (i = 0; i < BTRFS_NR_READ_POLICY; i++) {
 983                 if (fs_devices->read_policy == i)
 984                         ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s[%s]",
 985                                          (ret == 0 ? "" : " "),
 986                                          btrfs_read_policy_name[i]);
 987                 else
 988                         ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%s",
 989                                          (ret == 0 ? "" : " "),
 990                                          btrfs_read_policy_name[i]);
 991         }
 992
 993         ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
 994
 995         return ret;
 996 }
 997
 998 static ssize_t btrfs_read_policy_store(struct kobject *kobj,
 999                                        struct kobj_attribute *a,
1000                                        const char *buf, size_t len)
1001 {
1002         struct btrfs_fs_devices *fs_devices = to_fs_devs(kobj);
1003         int i;
1004
1005         for (i = 0; i < BTRFS_NR_READ_POLICY; i++) {
1006                 if (strmatch(buf, btrfs_read_policy_name[i])) {
1007                         if (i != fs_devices->read_policy) {
1008                                 fs_devices->read_policy = i;
1009                                 btrfs_info(fs_devices->fs_info,
1010                                            "read policy set to '%s'",
1011                                            btrfs_read_policy_name[i]);
1012                         }
1013                         return len;
1014                 }
1015         }
1016
1017         return -EINVAL;
1018 }
1019 BTRFS_ATTR_RW(, read_policy, btrfs_read_policy_show, btrfs_read_policy_store);
1020
1021 static ssize_t btrfs_bg_reclaim_threshold_show(struct kobject *kobj,
1022                                                struct kobj_attribute *a,
1023                                                char *buf)
1024 {
1025         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1026         ssize_t ret;
1027
1028         ret = sysfs_emit(buf, "%d\n", READ_ONCE(fs_info->bg_reclaim_threshold));
1029
1030         return ret;
1031 }
1032
1033 static ssize_t btrfs_bg_reclaim_threshold_store(struct kobject *kobj,
1034                                                 struct kobj_attribute *a,
1035                                                 const char *buf, size_t len)
1036 {
1037         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1038         int thresh;
1039         int ret;
1040
1041         ret = kstrtoint(buf, 10, &thresh);
1042         if (ret)
1043                 return ret;
1044
1045         if (thresh != 0 && (thresh <= 50 || thresh > 100))
1046                 return -EINVAL;
1047
1048         WRITE_ONCE(fs_info->bg_reclaim_threshold, thresh);
1049
1050         return len;
1051 }
1052 BTRFS_ATTR_RW(, bg_reclaim_threshold, btrfs_bg_reclaim_threshold_show,
1053               btrfs_bg_reclaim_threshold_store);
1054
1055 /*
1056  * Per-filesystem information and stats.
1057  *
1058  * Path: /sys/fs/btrfs/<uuid>/
1059  */
1060 static const struct attribute *btrfs_attrs[] = {
1061         BTRFS_ATTR_PTR(, label),
1062         BTRFS_ATTR_PTR(, nodesize),
1063         BTRFS_ATTR_PTR(, sectorsize),
1064         BTRFS_ATTR_PTR(, clone_alignment),
1065         BTRFS_ATTR_PTR(, quota_override),
1066         BTRFS_ATTR_PTR(, metadata_uuid),
1067         BTRFS_ATTR_PTR(, checksum),
1068         BTRFS_ATTR_PTR(, exclusive_operation),
1069         BTRFS_ATTR_PTR(, generation),
1070         BTRFS_ATTR_PTR(, read_policy),
1071         BTRFS_ATTR_PTR(, bg_reclaim_threshold),
1072         NULL,
1073 };
1074
1075 static void btrfs_release_fsid_kobj(struct kobject *kobj)
1076 {
1077         struct btrfs_fs_devices *fs_devs = to_fs_devs(kobj);
1078
1079         memset(&fs_devs->fsid_kobj, 0, sizeof(struct kobject));
1080         complete(&fs_devs->kobj_unregister);
1081 }
1082
1083 static struct kobj_type btrfs_ktype = {
1084         .sysfs_ops      = &kobj_sysfs_ops,
1085         .release        = btrfs_release_fsid_kobj,
1086 };
1087
1088 static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj)
1089 {
1090         if (kobj->ktype != &btrfs_ktype)
1091                 return NULL;
1092         return container_of(kobj, struct btrfs_fs_devices, fsid_kobj);
1093 }
1094
1095 static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj)
1096 {
1097         if (kobj->ktype != &btrfs_ktype)
1098                 return NULL;
1099         return to_fs_devs(kobj)->fs_info;
1100 }
1101
1102 #define NUM_FEATURE_BITS 64
1103 #define BTRFS_FEATURE_NAME_MAX 13
1104 static char btrfs_unknown_feature_names[FEAT_MAX][NUM_FEATURE_BITS][BTRFS_FEATURE_NAME_MAX];
1105 static struct btrfs_feature_attr btrfs_feature_attrs[FEAT_MAX][NUM_FEATURE_BITS];
1106
1107 static const u64 supported_feature_masks[FEAT_MAX] = {
1108         [FEAT_COMPAT]    = BTRFS_FEATURE_COMPAT_SUPP,
1109         [FEAT_COMPAT_RO] = BTRFS_FEATURE_COMPAT_RO_SUPP,
1110         [FEAT_INCOMPAT]  = BTRFS_FEATURE_INCOMPAT_SUPP,
1111 };
1112
1113 static int addrm_unknown_feature_attrs(struct btrfs_fs_info *fs_info, bool add)
1114 {
1115         int set;
1116
1117         for (set = 0; set < FEAT_MAX; set++) {
1118                 int i;
1119                 struct attribute *attrs[2];
1120                 struct attribute_group agroup = {
1121                         .name = "features",
1122                         .attrs = attrs,
1123                 };
1124                 u64 features = get_features(fs_info, set);
1125                 features &= ~supported_feature_masks[set];
1126
1127                 if (!features)
1128                         continue;
1129
1130                 attrs[1] = NULL;
1131                 for (i = 0; i < NUM_FEATURE_BITS; i++) {
1132                         struct btrfs_feature_attr *fa;
1133
1134                         if (!(features & (1ULL << i)))
1135                                 continue;
1136
1137                         fa = &btrfs_feature_attrs[set][i];
1138                         attrs[0] = &fa->kobj_attr.attr;
1139                         if (add) {
1140                                 int ret;
1141                                 ret = sysfs_merge_group(&fs_info->fs_devices->fsid_kobj,
1142                                                         &agroup);
1143                                 if (ret)
1144                                         return ret;
1145                         } else
1146                                 sysfs_unmerge_group(&fs_info->fs_devices->fsid_kobj,
1147                                                     &agroup);
1148                 }
1149
1150         }
1151         return 0;
1152 }
1153
1154 static void __btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs)
1155 {
1156         if (fs_devs->devinfo_kobj) {
1157                 kobject_del(fs_devs->devinfo_kobj);
1158                 kobject_put(fs_devs->devinfo_kobj);
1159                 fs_devs->devinfo_kobj = NULL;
1160         }
1161
1162         if (fs_devs->devices_kobj) {
1163                 kobject_del(fs_devs->devices_kobj);
1164                 kobject_put(fs_devs->devices_kobj);
1165                 fs_devs->devices_kobj = NULL;
1166         }
1167
1168         if (fs_devs->fsid_kobj.state_initialized) {
1169                 kobject_del(&fs_devs->fsid_kobj);
1170                 kobject_put(&fs_devs->fsid_kobj);
1171                 wait_for_completion(&fs_devs->kobj_unregister);
1172         }
1173 }
1174
1175 /* when fs_devs is NULL it will remove all fsid kobject */
1176 void btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs)
1177 {
1178         struct list_head *fs_uuids = btrfs_get_fs_uuids();
1179
1180         if (fs_devs) {
1181                 __btrfs_sysfs_remove_fsid(fs_devs);
1182                 return;
1183         }
1184
1185         list_for_each_entry(fs_devs, fs_uuids, fs_list) {
1186                 __btrfs_sysfs_remove_fsid(fs_devs);
1187         }
1188 }
1189
1190 static void btrfs_sysfs_remove_fs_devices(struct btrfs_fs_devices *fs_devices)
1191 {
1192         struct btrfs_device *device;
1193         struct btrfs_fs_devices *seed;
1194
1195         list_for_each_entry(device, &fs_devices->devices, dev_list)
1196                 btrfs_sysfs_remove_device(device);
1197
1198         list_for_each_entry(seed, &fs_devices->seed_list, seed_list) {
1199                 list_for_each_entry(device, &seed->devices, dev_list)
1200                         btrfs_sysfs_remove_device(device);
1201         }
1202 }
1203
1204 void btrfs_sysfs_remove_mounted(struct btrfs_fs_info *fs_info)
1205 {
1206         struct kobject *fsid_kobj = &fs_info->fs_devices->fsid_kobj;
1207
1208         sysfs_remove_link(fsid_kobj, "bdi");
1209
1210         if (fs_info->space_info_kobj) {
1211                 sysfs_remove_files(fs_info->space_info_kobj, allocation_attrs);
1212                 kobject_del(fs_info->space_info_kobj);
1213                 kobject_put(fs_info->space_info_kobj);
1214         }
1215 #ifdef CONFIG_BTRFS_DEBUG
1216         if (fs_info->discard_debug_kobj) {
1217                 sysfs_remove_files(fs_info->discard_debug_kobj,
1218                                    discard_debug_attrs);
1219                 kobject_del(fs_info->discard_debug_kobj);
1220                 kobject_put(fs_info->discard_debug_kobj);
1221         }
1222         if (fs_info->debug_kobj) {
1223                 sysfs_remove_files(fs_info->debug_kobj, btrfs_debug_mount_attrs);
1224                 kobject_del(fs_info->debug_kobj);
1225                 kobject_put(fs_info->debug_kobj);
1226         }
1227 #endif
1228         addrm_unknown_feature_attrs(fs_info, false);
1229         sysfs_remove_group(fsid_kobj, &btrfs_feature_attr_group);
1230         sysfs_remove_files(fsid_kobj, btrfs_attrs);
1231         btrfs_sysfs_remove_fs_devices(fs_info->fs_devices);
1232 }
1233
1234 static const char * const btrfs_feature_set_names[FEAT_MAX] = {
1235         [FEAT_COMPAT]    = "compat",
1236         [FEAT_COMPAT_RO] = "compat_ro",
1237         [FEAT_INCOMPAT]  = "incompat",
1238 };
1239
1240 const char *btrfs_feature_set_name(enum btrfs_feature_set set)
1241 {
1242         return btrfs_feature_set_names[set];
1243 }
1244
1245 char *btrfs_printable_features(enum btrfs_feature_set set, u64 flags)
1246 {
1247         size_t bufsize = 4096; /* safe max, 64 names * 64 bytes */
1248         int len = 0;
1249         int i;
1250         char *str;
1251
1252         str = kmalloc(bufsize, GFP_KERNEL);
1253         if (!str)
1254                 return str;
1255
1256         for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
1257                 const char *name;
1258
1259                 if (!(flags & (1ULL << i)))
1260                         continue;
1261
1262                 name = btrfs_feature_attrs[set][i].kobj_attr.attr.name;
1263                 len += scnprintf(str + len, bufsize - len, "%s%s",
1264                                 len ? "," : "", name);
1265         }
1266
1267         return str;
1268 }
1269
1270 static void init_feature_attrs(void)
1271 {
1272         struct btrfs_feature_attr *fa;
1273         int set, i;
1274
1275         BUILD_BUG_ON(ARRAY_SIZE(btrfs_unknown_feature_names) !=
1276                      ARRAY_SIZE(btrfs_feature_attrs));
1277         BUILD_BUG_ON(ARRAY_SIZE(btrfs_unknown_feature_names[0]) !=
1278                      ARRAY_SIZE(btrfs_feature_attrs[0]));
1279
1280         memset(btrfs_feature_attrs, 0, sizeof(btrfs_feature_attrs));
1281         memset(btrfs_unknown_feature_names, 0,
1282                sizeof(btrfs_unknown_feature_names));
1283
1284         for (i = 0; btrfs_supported_feature_attrs[i]; i++) {
1285                 struct btrfs_feature_attr *sfa;
1286                 struct attribute *a = btrfs_supported_feature_attrs[i];
1287                 int bit;
1288                 sfa = attr_to_btrfs_feature_attr(a);
1289                 bit = ilog2(sfa->feature_bit);
1290                 fa = &btrfs_feature_attrs[sfa->feature_set][bit];
1291
1292                 fa->kobj_attr.attr.name = sfa->kobj_attr.attr.name;
1293         }
1294
1295         for (set = 0; set < FEAT_MAX; set++) {
1296                 for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
1297                         char *name = btrfs_unknown_feature_names[set][i];
1298                         fa = &btrfs_feature_attrs[set][i];
1299
1300                         if (fa->kobj_attr.attr.name)
1301                                 continue;
1302
1303                         snprintf(name, BTRFS_FEATURE_NAME_MAX, "%s:%u",
1304                                  btrfs_feature_set_names[set], i);
1305
1306                         fa->kobj_attr.attr.name = name;
1307                         fa->kobj_attr.attr.mode = S_IRUGO;
1308                         fa->feature_set = set;
1309                         fa->feature_bit = 1ULL << i;
1310                 }
1311         }
1312 }
1313
1314 /*
1315  * Create a sysfs entry for a given block group type at path
1316  * /sys/fs/btrfs/UUID/allocation/data/TYPE
1317  */
1318 void btrfs_sysfs_add_block_group_type(struct btrfs_block_group *cache)
1319 {
1320         struct btrfs_fs_info *fs_info = cache->fs_info;
1321         struct btrfs_space_info *space_info = cache->space_info;
1322         struct raid_kobject *rkobj;
1323         const int index = btrfs_bg_flags_to_raid_index(cache->flags);
1324         unsigned int nofs_flag;
1325         int ret;
1326
1327         /*
1328          * Setup a NOFS context because kobject_add(), deep in its call chain,
1329          * does GFP_KERNEL allocations, and we are often called in a context
1330          * where if reclaim is triggered we can deadlock (we are either holding
1331          * a transaction handle or some lock required for a transaction
1332          * commit).
1333          */
1334         nofs_flag = memalloc_nofs_save();
1335
1336         rkobj = kzalloc(sizeof(*rkobj), GFP_NOFS);
1337         if (!rkobj) {
1338                 memalloc_nofs_restore(nofs_flag);
1339                 btrfs_warn(cache->fs_info,
1340                                 "couldn't alloc memory for raid level kobject");
1341                 return;
1342         }
1343
1344         rkobj->flags = cache->flags;
1345         kobject_init(&rkobj->kobj, &btrfs_raid_ktype);
1346
1347         /*
1348          * We call this either on mount, or if we've created a block group for a
1349          * new index type while running (i.e. when restriping).  The running
1350          * case is tricky because we could race with other threads, so we need
1351          * to have this check to make sure we didn't already init the kobject.
1352          *
1353          * We don't have to protect on the free side because it only happens on
1354          * unmount.
1355          */
1356         spin_lock(&space_info->lock);
1357         if (space_info->block_group_kobjs[index]) {
1358                 spin_unlock(&space_info->lock);
1359                 kobject_put(&rkobj->kobj);
1360                 return;
1361         } else {
1362                 space_info->block_group_kobjs[index] = &rkobj->kobj;
1363         }
1364         spin_unlock(&space_info->lock);
1365
1366         ret = kobject_add(&rkobj->kobj, &space_info->kobj, "%s",
1367                           btrfs_bg_type_to_raid_name(rkobj->flags));
1368         memalloc_nofs_restore(nofs_flag);
1369         if (ret) {
1370                 spin_lock(&space_info->lock);
1371                 space_info->block_group_kobjs[index] = NULL;
1372                 spin_unlock(&space_info->lock);
1373                 kobject_put(&rkobj->kobj);
1374                 btrfs_warn(fs_info,
1375                         "failed to add kobject for block cache, ignoring");
1376                 return;
1377         }
1378 }
1379
1380 /*
1381  * Remove sysfs directories for all block group types of a given space info and
1382  * the space info as well
1383  */
1384 void btrfs_sysfs_remove_space_info(struct btrfs_space_info *space_info)
1385 {
1386         int i;
1387
1388         for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) {
1389                 struct kobject *kobj;
1390
1391                 kobj = space_info->block_group_kobjs[i];
1392                 space_info->block_group_kobjs[i] = NULL;
1393                 if (kobj) {
1394                         kobject_del(kobj);
1395                         kobject_put(kobj);
1396                 }
1397         }
1398         kobject_del(&space_info->kobj);
1399         kobject_put(&space_info->kobj);
1400 }
1401
1402 static const char *alloc_name(u64 flags)
1403 {
1404         switch (flags) {
1405         case BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA:
1406                 return "mixed";
1407         case BTRFS_BLOCK_GROUP_METADATA:
1408                 return "metadata";
1409         case BTRFS_BLOCK_GROUP_DATA:
1410                 return "data";
1411         case BTRFS_BLOCK_GROUP_SYSTEM:
1412                 return "system";
1413         default:
1414                 WARN_ON(1);
1415                 return "invalid-combination";
1416         }
1417 }
1418
1419 /*
1420  * Create a sysfs entry for a space info type at path
1421  * /sys/fs/btrfs/UUID/allocation/TYPE
1422  */
1423 int btrfs_sysfs_add_space_info_type(struct btrfs_fs_info *fs_info,
1424                                     struct btrfs_space_info *space_info)
1425 {
1426         int ret;
1427
1428         ret = kobject_init_and_add(&space_info->kobj, &space_info_ktype,
1429                                    fs_info->space_info_kobj, "%s",
1430                                    alloc_name(space_info->flags));
1431         if (ret) {
1432                 kobject_put(&space_info->kobj);
1433                 return ret;
1434         }
1435
1436         return 0;
1437 }
1438
1439 void btrfs_sysfs_remove_device(struct btrfs_device *device)
1440 {
1441         struct kobject *devices_kobj;
1442
1443         /*
1444          * Seed fs_devices devices_kobj aren't used, fetch kobject from the
1445          * fs_info::fs_devices.
1446          */
1447         devices_kobj = device->fs_info->fs_devices->devices_kobj;
1448         ASSERT(devices_kobj);
1449
1450         if (device->bdev)
1451                 sysfs_remove_link(devices_kobj, bdev_kobj(device->bdev)->name);
1452
1453         if (device->devid_kobj.state_initialized) {
1454                 kobject_del(&device->devid_kobj);
1455                 kobject_put(&device->devid_kobj);
1456                 wait_for_completion(&device->kobj_unregister);
1457         }
1458 }
1459
1460 static ssize_t btrfs_devinfo_in_fs_metadata_show(struct kobject *kobj,
1461                                                  struct kobj_attribute *a,
1462                                                  char *buf)
1463 {
1464         int val;
1465         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1466                                                    devid_kobj);
1467
1468         val = !!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state);
1469
1470         return sysfs_emit(buf, "%d\n", val);
1471 }
1472 BTRFS_ATTR(devid, in_fs_metadata, btrfs_devinfo_in_fs_metadata_show);
1473
1474 static ssize_t btrfs_devinfo_missing_show(struct kobject *kobj,
1475                                         struct kobj_attribute *a, char *buf)
1476 {
1477         int val;
1478         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1479                                                    devid_kobj);
1480
1481         val = !!test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state);
1482
1483         return sysfs_emit(buf, "%d\n", val);
1484 }
1485 BTRFS_ATTR(devid, missing, btrfs_devinfo_missing_show);
1486
1487 static ssize_t btrfs_devinfo_replace_target_show(struct kobject *kobj,
1488                                                  struct kobj_attribute *a,
1489                                                  char *buf)
1490 {
1491         int val;
1492         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1493                                                    devid_kobj);
1494
1495         val = !!test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state);
1496
1497         return sysfs_emit(buf, "%d\n", val);
1498 }
1499 BTRFS_ATTR(devid, replace_target, btrfs_devinfo_replace_target_show);
1500
1501 static ssize_t btrfs_devinfo_scrub_speed_max_show(struct kobject *kobj,
1502                                              struct kobj_attribute *a,
1503                                              char *buf)
1504 {
1505         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1506                                                    devid_kobj);
1507
1508         return sysfs_emit(buf, "%llu\n", READ_ONCE(device->scrub_speed_max));
1509 }
1510
1511 static ssize_t btrfs_devinfo_scrub_speed_max_store(struct kobject *kobj,
1512                                               struct kobj_attribute *a,
1513                                               const char *buf, size_t len)
1514 {
1515         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1516                                                    devid_kobj);
1517         char *endptr;
1518         unsigned long long limit;
1519
1520         limit = memparse(buf, &endptr);
1521         WRITE_ONCE(device->scrub_speed_max, limit);
1522         return len;
1523 }
1524 BTRFS_ATTR_RW(devid, scrub_speed_max, btrfs_devinfo_scrub_speed_max_show,
1525               btrfs_devinfo_scrub_speed_max_store);
1526
1527 static ssize_t btrfs_devinfo_writeable_show(struct kobject *kobj,
1528                                             struct kobj_attribute *a, char *buf)
1529 {
1530         int val;
1531         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1532                                                    devid_kobj);
1533
1534         val = !!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state);
1535
1536         return sysfs_emit(buf, "%d\n", val);
1537 }
1538 BTRFS_ATTR(devid, writeable, btrfs_devinfo_writeable_show);
1539
1540 static ssize_t btrfs_devinfo_fsid_show(struct kobject *kobj,
1541                                        struct kobj_attribute *a, char *buf)
1542 {
1543         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1544                                                    devid_kobj);
1545
1546         return sysfs_emit(buf, "%pU\n", device->fs_devices->fsid);
1547 }
1548 BTRFS_ATTR(devid, fsid, btrfs_devinfo_fsid_show);
1549
1550 static ssize_t btrfs_devinfo_error_stats_show(struct kobject *kobj,
1551                 struct kobj_attribute *a, char *buf)
1552 {
1553         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1554                                                    devid_kobj);
1555
1556         if (!device->dev_stats_valid)
1557                 return sysfs_emit(buf, "invalid\n");
1558
1559         /*
1560          * Print all at once so we get a snapshot of all values from the same
1561          * time. Keep them in sync and in order of definition of
1562          * btrfs_dev_stat_values.
1563          */
1564         return sysfs_emit(buf,
1565                 "write_errs %d\n"
1566                 "read_errs %d\n"
1567                 "flush_errs %d\n"
1568                 "corruption_errs %d\n"
1569                 "generation_errs %d\n",
1570                 btrfs_dev_stat_read(device, BTRFS_DEV_STAT_WRITE_ERRS),
1571                 btrfs_dev_stat_read(device, BTRFS_DEV_STAT_READ_ERRS),
1572                 btrfs_dev_stat_read(device, BTRFS_DEV_STAT_FLUSH_ERRS),
1573                 btrfs_dev_stat_read(device, BTRFS_DEV_STAT_CORRUPTION_ERRS),
1574                 btrfs_dev_stat_read(device, BTRFS_DEV_STAT_GENERATION_ERRS));
1575 }
1576 BTRFS_ATTR(devid, error_stats, btrfs_devinfo_error_stats_show);
1577
1578 /*
1579  * Information about one device.
1580  *
1581  * Path: /sys/fs/btrfs/<uuid>/devinfo/<devid>/
1582  */
1583 static struct attribute *devid_attrs[] = {
1584         BTRFS_ATTR_PTR(devid, error_stats),
1585         BTRFS_ATTR_PTR(devid, fsid),
1586         BTRFS_ATTR_PTR(devid, in_fs_metadata),
1587         BTRFS_ATTR_PTR(devid, missing),
1588         BTRFS_ATTR_PTR(devid, replace_target),
1589         BTRFS_ATTR_PTR(devid, scrub_speed_max),
1590         BTRFS_ATTR_PTR(devid, writeable),
1591         NULL
1592 };
1593 ATTRIBUTE_GROUPS(devid);
1594
1595 static void btrfs_release_devid_kobj(struct kobject *kobj)
1596 {
1597         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1598                                                    devid_kobj);
1599
1600         memset(&device->devid_kobj, 0, sizeof(struct kobject));
1601         complete(&device->kobj_unregister);
1602 }
1603
1604 static struct kobj_type devid_ktype = {
1605         .sysfs_ops      = &kobj_sysfs_ops,
1606         .default_groups = devid_groups,
1607         .release        = btrfs_release_devid_kobj,
1608 };
1609
1610 int btrfs_sysfs_add_device(struct btrfs_device *device)
1611 {
1612         int ret;
1613         unsigned int nofs_flag;
1614         struct kobject *devices_kobj;
1615         struct kobject *devinfo_kobj;
1616
1617         /*
1618          * Make sure we use the fs_info::fs_devices to fetch the kobjects even
1619          * for the seed fs_devices
1620          */
1621         devices_kobj = device->fs_info->fs_devices->devices_kobj;
1622         devinfo_kobj = device->fs_info->fs_devices->devinfo_kobj;
1623         ASSERT(devices_kobj);
1624         ASSERT(devinfo_kobj);
1625
1626         nofs_flag = memalloc_nofs_save();
1627
1628         if (device->bdev) {
1629                 struct kobject *disk_kobj = bdev_kobj(device->bdev);
1630
1631                 ret = sysfs_create_link(devices_kobj, disk_kobj, disk_kobj->name);
1632                 if (ret) {
1633                         btrfs_warn(device->fs_info,
1634                                 "creating sysfs device link for devid %llu failed: %d",
1635                                 device->devid, ret);
1636                         goto out;
1637                 }
1638         }
1639
1640         init_completion(&device->kobj_unregister);
1641         ret = kobject_init_and_add(&device->devid_kobj, &devid_ktype,
1642                                    devinfo_kobj, "%llu", device->devid);
1643         if (ret) {
1644                 kobject_put(&device->devid_kobj);
1645                 btrfs_warn(device->fs_info,
1646                            "devinfo init for devid %llu failed: %d",
1647                            device->devid, ret);
1648         }
1649
1650 out:
1651         memalloc_nofs_restore(nofs_flag);
1652         return ret;
1653 }
1654
1655 static int btrfs_sysfs_add_fs_devices(struct btrfs_fs_devices *fs_devices)
1656 {
1657         int ret;
1658         struct btrfs_device *device;
1659         struct btrfs_fs_devices *seed;
1660
1661         list_for_each_entry(device, &fs_devices->devices, dev_list) {
1662                 ret = btrfs_sysfs_add_device(device);
1663                 if (ret)
1664                         goto fail;
1665         }
1666
1667         list_for_each_entry(seed, &fs_devices->seed_list, seed_list) {
1668                 list_for_each_entry(device, &seed->devices, dev_list) {
1669                         ret = btrfs_sysfs_add_device(device);
1670                         if (ret)
1671                                 goto fail;
1672                 }
1673         }
1674
1675         return 0;
1676
1677 fail:
1678         btrfs_sysfs_remove_fs_devices(fs_devices);
1679         return ret;
1680 }
1681
1682 void btrfs_kobject_uevent(struct block_device *bdev, enum kobject_action action)
1683 {
1684         int ret;
1685
1686         ret = kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, action);
1687         if (ret)
1688                 pr_warn("BTRFS: Sending event '%d' to kobject: '%s' (%p): failed\n",
1689                         action, kobject_name(&disk_to_dev(bdev->bd_disk)->kobj),
1690                         &disk_to_dev(bdev->bd_disk)->kobj);
1691 }
1692
1693 void btrfs_sysfs_update_sprout_fsid(struct btrfs_fs_devices *fs_devices)
1694
1695 {
1696         char fsid_buf[BTRFS_UUID_UNPARSED_SIZE];
1697
1698         /*
1699          * Sprouting changes fsid of the mounted filesystem, rename the fsid
1700          * directory
1701          */
1702         snprintf(fsid_buf, BTRFS_UUID_UNPARSED_SIZE, "%pU", fs_devices->fsid);
1703         if (kobject_rename(&fs_devices->fsid_kobj, fsid_buf))
1704                 btrfs_warn(fs_devices->fs_info,
1705                                 "sysfs: failed to create fsid for sprout");
1706 }
1707
1708 void btrfs_sysfs_update_devid(struct btrfs_device *device)
1709 {
1710         char tmp[24];
1711
1712         snprintf(tmp, sizeof(tmp), "%llu", device->devid);
1713
1714         if (kobject_rename(&device->devid_kobj, tmp))
1715                 btrfs_warn(device->fs_devices->fs_info,
1716                            "sysfs: failed to update devid for %llu",
1717                            device->devid);
1718 }
1719
1720 /* /sys/fs/btrfs/ entry */
1721 static struct kset *btrfs_kset;
1722
1723 /*
1724  * Creates:
1725  *              /sys/fs/btrfs/UUID
1726  *
1727  * Can be called by the device discovery thread.
1728  */
1729 int btrfs_sysfs_add_fsid(struct btrfs_fs_devices *fs_devs)
1730 {
1731         int error;
1732
1733         init_completion(&fs_devs->kobj_unregister);
1734         fs_devs->fsid_kobj.kset = btrfs_kset;
1735         error = kobject_init_and_add(&fs_devs->fsid_kobj, &btrfs_ktype, NULL,
1736                                      "%pU", fs_devs->fsid);
1737         if (error) {
1738                 kobject_put(&fs_devs->fsid_kobj);
1739                 return error;
1740         }
1741
1742         fs_devs->devices_kobj = kobject_create_and_add("devices",
1743                                                        &fs_devs->fsid_kobj);
1744         if (!fs_devs->devices_kobj) {
1745                 btrfs_err(fs_devs->fs_info,
1746                           "failed to init sysfs device interface");
1747                 btrfs_sysfs_remove_fsid(fs_devs);
1748                 return -ENOMEM;
1749         }
1750
1751         fs_devs->devinfo_kobj = kobject_create_and_add("devinfo",
1752                                                        &fs_devs->fsid_kobj);
1753         if (!fs_devs->devinfo_kobj) {
1754                 btrfs_err(fs_devs->fs_info,
1755                           "failed to init sysfs devinfo kobject");
1756                 btrfs_sysfs_remove_fsid(fs_devs);
1757                 return -ENOMEM;
1758         }
1759
1760         return 0;
1761 }
1762
1763 int btrfs_sysfs_add_mounted(struct btrfs_fs_info *fs_info)
1764 {
1765         int error;
1766         struct btrfs_fs_devices *fs_devs = fs_info->fs_devices;
1767         struct kobject *fsid_kobj = &fs_devs->fsid_kobj;
1768
1769         error = btrfs_sysfs_add_fs_devices(fs_devs);
1770         if (error)
1771                 return error;
1772
1773         error = sysfs_create_files(fsid_kobj, btrfs_attrs);
1774         if (error) {
1775                 btrfs_sysfs_remove_fs_devices(fs_devs);
1776                 return error;
1777         }
1778
1779         error = sysfs_create_group(fsid_kobj,
1780                                    &btrfs_feature_attr_group);
1781         if (error)
1782                 goto failure;
1783
1784 #ifdef CONFIG_BTRFS_DEBUG
1785         fs_info->debug_kobj = kobject_create_and_add("debug", fsid_kobj);
1786         if (!fs_info->debug_kobj) {
1787                 error = -ENOMEM;
1788                 goto failure;
1789         }
1790
1791         error = sysfs_create_files(fs_info->debug_kobj, btrfs_debug_mount_attrs);
1792         if (error)
1793                 goto failure;
1794
1795         /* Discard directory */
1796         fs_info->discard_debug_kobj = kobject_create_and_add("discard",
1797                                                      fs_info->debug_kobj);
1798         if (!fs_info->discard_debug_kobj) {
1799                 error = -ENOMEM;
1800                 goto failure;
1801         }
1802
1803         error = sysfs_create_files(fs_info->discard_debug_kobj,
1804                                    discard_debug_attrs);
1805         if (error)
1806                 goto failure;
1807 #endif
1808
1809         error = addrm_unknown_feature_attrs(fs_info, true);
1810         if (error)
1811                 goto failure;
1812
1813         error = sysfs_create_link(fsid_kobj, &fs_info->sb->s_bdi->dev->kobj, "bdi");
1814         if (error)
1815                 goto failure;
1816
1817         fs_info->space_info_kobj = kobject_create_and_add("allocation",
1818                                                   fsid_kobj);
1819         if (!fs_info->space_info_kobj) {
1820                 error = -ENOMEM;
1821                 goto failure;
1822         }
1823
1824         error = sysfs_create_files(fs_info->space_info_kobj, allocation_attrs);
1825         if (error)
1826                 goto failure;
1827
1828         return 0;
1829 failure:
1830         btrfs_sysfs_remove_mounted(fs_info);
1831         return error;
1832 }
1833
1834 static inline struct btrfs_fs_info *qgroup_kobj_to_fs_info(struct kobject *kobj)
1835 {
1836         return to_fs_info(kobj->parent->parent);
1837 }
1838
1839 #define QGROUP_ATTR(_member, _show_name)                                        \
1840 static ssize_t btrfs_qgroup_show_##_member(struct kobject *qgroup_kobj,         \
1841                                            struct kobj_attribute *a,            \
1842                                            char *buf)                           \
1843 {                                                                               \
1844         struct btrfs_fs_info *fs_info = qgroup_kobj_to_fs_info(qgroup_kobj);    \
1845         struct btrfs_qgroup *qgroup = container_of(qgroup_kobj,                 \
1846                         struct btrfs_qgroup, kobj);                             \
1847         return btrfs_show_u64(&qgroup->_member, &fs_info->qgroup_lock, buf);    \
1848 }                                                                               \
1849 BTRFS_ATTR(qgroup, _show_name, btrfs_qgroup_show_##_member)
1850
1851 #define QGROUP_RSV_ATTR(_name, _type)                                           \
1852 static ssize_t btrfs_qgroup_rsv_show_##_name(struct kobject *qgroup_kobj,       \
1853                                              struct kobj_attribute *a,          \
1854                                              char *buf)                         \
1855 {                                                                               \
1856         struct btrfs_fs_info *fs_info = qgroup_kobj_to_fs_info(qgroup_kobj);    \
1857         struct btrfs_qgroup *qgroup = container_of(qgroup_kobj,                 \
1858                         struct btrfs_qgroup, kobj);                             \
1859         return btrfs_show_u64(&qgroup->rsv.values[_type],                       \
1860                         &fs_info->qgroup_lock, buf);                            \
1861 }                                                                               \
1862 BTRFS_ATTR(qgroup, rsv_##_name, btrfs_qgroup_rsv_show_##_name)
1863
1864 QGROUP_ATTR(rfer, referenced);
1865 QGROUP_ATTR(excl, exclusive);
1866 QGROUP_ATTR(max_rfer, max_referenced);
1867 QGROUP_ATTR(max_excl, max_exclusive);
1868 QGROUP_ATTR(lim_flags, limit_flags);
1869 QGROUP_RSV_ATTR(data, BTRFS_QGROUP_RSV_DATA);
1870 QGROUP_RSV_ATTR(meta_pertrans, BTRFS_QGROUP_RSV_META_PERTRANS);
1871 QGROUP_RSV_ATTR(meta_prealloc, BTRFS_QGROUP_RSV_META_PREALLOC);
1872
1873 /*
1874  * Qgroup information.
1875  *
1876  * Path: /sys/fs/btrfs/<uuid>/qgroups/<level>_<qgroupid>/
1877  */
1878 static struct attribute *qgroup_attrs[] = {
1879         BTRFS_ATTR_PTR(qgroup, referenced),
1880         BTRFS_ATTR_PTR(qgroup, exclusive),
1881         BTRFS_ATTR_PTR(qgroup, max_referenced),
1882         BTRFS_ATTR_PTR(qgroup, max_exclusive),
1883         BTRFS_ATTR_PTR(qgroup, limit_flags),
1884         BTRFS_ATTR_PTR(qgroup, rsv_data),
1885         BTRFS_ATTR_PTR(qgroup, rsv_meta_pertrans),
1886         BTRFS_ATTR_PTR(qgroup, rsv_meta_prealloc),
1887         NULL
1888 };
1889 ATTRIBUTE_GROUPS(qgroup);
1890
1891 static void qgroup_release(struct kobject *kobj)
1892 {
1893         struct btrfs_qgroup *qgroup = container_of(kobj, struct btrfs_qgroup, kobj);
1894
1895         memset(&qgroup->kobj, 0, sizeof(*kobj));
1896 }
1897
1898 static struct kobj_type qgroup_ktype = {
1899         .sysfs_ops = &kobj_sysfs_ops,
1900         .release = qgroup_release,
1901         .default_groups = qgroup_groups,
1902 };
1903
1904 int btrfs_sysfs_add_one_qgroup(struct btrfs_fs_info *fs_info,
1905                                 struct btrfs_qgroup *qgroup)
1906 {
1907         struct kobject *qgroups_kobj = fs_info->qgroups_kobj;
1908         int ret;
1909
1910         if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
1911                 return 0;
1912         if (qgroup->kobj.state_initialized)
1913                 return 0;
1914         if (!qgroups_kobj)
1915                 return -EINVAL;
1916
1917         ret = kobject_init_and_add(&qgroup->kobj, &qgroup_ktype, qgroups_kobj,
1918                         "%hu_%llu", btrfs_qgroup_level(qgroup->qgroupid),
1919                         btrfs_qgroup_subvolid(qgroup->qgroupid));
1920         if (ret < 0)
1921                 kobject_put(&qgroup->kobj);
1922
1923         return ret;
1924 }
1925
1926 void btrfs_sysfs_del_qgroups(struct btrfs_fs_info *fs_info)
1927 {
1928         struct btrfs_qgroup *qgroup;
1929         struct btrfs_qgroup *next;
1930
1931         if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
1932                 return;
1933
1934         rbtree_postorder_for_each_entry_safe(qgroup, next,
1935                                              &fs_info->qgroup_tree, node)
1936                 btrfs_sysfs_del_one_qgroup(fs_info, qgroup);
1937         if (fs_info->qgroups_kobj) {
1938                 kobject_del(fs_info->qgroups_kobj);
1939                 kobject_put(fs_info->qgroups_kobj);
1940                 fs_info->qgroups_kobj = NULL;
1941         }
1942 }
1943
1944 /* Called when qgroups get initialized, thus there is no need for locking */
1945 int btrfs_sysfs_add_qgroups(struct btrfs_fs_info *fs_info)
1946 {
1947         struct kobject *fsid_kobj = &fs_info->fs_devices->fsid_kobj;
1948         struct btrfs_qgroup *qgroup;
1949         struct btrfs_qgroup *next;
1950         int ret = 0;
1951
1952         if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
1953                 return 0;
1954
1955         ASSERT(fsid_kobj);
1956         if (fs_info->qgroups_kobj)
1957                 return 0;
1958
1959         fs_info->qgroups_kobj = kobject_create_and_add("qgroups", fsid_kobj);
1960         if (!fs_info->qgroups_kobj) {
1961                 ret = -ENOMEM;
1962                 goto out;
1963         }
1964         rbtree_postorder_for_each_entry_safe(qgroup, next,
1965                                              &fs_info->qgroup_tree, node) {
1966                 ret = btrfs_sysfs_add_one_qgroup(fs_info, qgroup);
1967                 if (ret < 0)
1968                         goto out;
1969         }
1970
1971 out:
1972         if (ret < 0)
1973                 btrfs_sysfs_del_qgroups(fs_info);
1974         return ret;
1975 }
1976
1977 void btrfs_sysfs_del_one_qgroup(struct btrfs_fs_info *fs_info,
1978                                 struct btrfs_qgroup *qgroup)
1979 {
1980         if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
1981                 return;
1982
1983         if (qgroup->kobj.state_initialized) {
1984                 kobject_del(&qgroup->kobj);
1985                 kobject_put(&qgroup->kobj);
1986         }
1987 }
1988
1989 /*
1990  * Change per-fs features in /sys/fs/btrfs/UUID/features to match current
1991  * values in superblock. Call after any changes to incompat/compat_ro flags
1992  */
1993 void btrfs_sysfs_feature_update(struct btrfs_fs_info *fs_info,
1994                 u64 bit, enum btrfs_feature_set set)
1995 {
1996         struct btrfs_fs_devices *fs_devs;
1997         struct kobject *fsid_kobj;
1998         u64 __maybe_unused features;
1999         int __maybe_unused ret;
2000
2001         if (!fs_info)
2002                 return;
2003
2004         /*
2005          * See 14e46e04958df74 and e410e34fad913dd, feature bit updates are not
2006          * safe when called from some contexts (eg. balance)
2007          */
2008         features = get_features(fs_info, set);
2009         ASSERT(bit & supported_feature_masks[set]);
2010
2011         fs_devs = fs_info->fs_devices;
2012         fsid_kobj = &fs_devs->fsid_kobj;
2013
2014         if (!fsid_kobj->state_initialized)
2015                 return;
2016
2017         /*
2018          * FIXME: this is too heavy to update just one value, ideally we'd like
2019          * to use sysfs_update_group but some refactoring is needed first.
2020          */
2021         sysfs_remove_group(fsid_kobj, &btrfs_feature_attr_group);
2022         ret = sysfs_create_group(fsid_kobj, &btrfs_feature_attr_group);
2023 }
2024
2025 int __init btrfs_init_sysfs(void)
2026 {
2027         int ret;
2028
2029         btrfs_kset = kset_create_and_add("btrfs", NULL, fs_kobj);
2030         if (!btrfs_kset)
2031                 return -ENOMEM;
2032
2033         init_feature_attrs();
2034         ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
2035         if (ret)
2036                 goto out2;
2037         ret = sysfs_merge_group(&btrfs_kset->kobj,
2038                                 &btrfs_static_feature_attr_group);
2039         if (ret)
2040                 goto out_remove_group;
2041
2042 #ifdef CONFIG_BTRFS_DEBUG
2043         ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_debug_feature_attr_group);
2044         if (ret)
2045                 goto out2;
2046 #endif
2047
2048         return 0;
2049
2050 out_remove_group:
2051         sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
2052 out2:
2053         kset_unregister(btrfs_kset);
2054
2055         return ret;
2056 }
2057
2058 void __cold btrfs_exit_sysfs(void)
2059 {
2060         sysfs_unmerge_group(&btrfs_kset->kobj,
2061                             &btrfs_static_feature_attr_group);
2062         sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
2063 #ifdef CONFIG_BTRFS_DEBUG
2064         sysfs_remove_group(&btrfs_kset->kobj, &btrfs_debug_feature_attr_group);
2065 #endif
2066         kset_unregister(btrfs_kset);
2067 }
2068