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 scnprintf(buf, PAGE_SIZE, "%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 scnprintf(buf, PAGE_SIZE, "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 += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%s",
 349                                 (i == 0 ? "" : " "), btrfs_super_csum_name(i));
 350
 351         }
 352
 353         ret += scnprintf(buf + ret, PAGE_SIZE - 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 snprintf(buf, PAGE_SIZE, "%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 += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%s",
 382                                  (i ? " " : ""), rescue_opts[i]);
 383         ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
 384         return ret;
 385 }
 386 BTRFS_ATTR(static_feature, supported_rescue_options,
 387            supported_rescue_options_show);
 388
 389 static ssize_t supported_sectorsizes_show(struct kobject *kobj,
 390                                           struct kobj_attribute *a,
 391                                           char *buf)
 392 {
 393         ssize_t ret = 0;
 394
 395         /* 4K sector size is also supported with 64K page size */
 396         if (PAGE_SIZE == SZ_64K)
 397                 ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%u ", SZ_4K);
 398
 399         /* Only sectorsize == PAGE_SIZE is now supported */
 400         ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%lu\n", PAGE_SIZE);
 401
 402         return ret;
 403 }
 404 BTRFS_ATTR(static_feature, supported_sectorsizes,
 405            supported_sectorsizes_show);
 406
 407 /*
 408  * Features which only depend on kernel version.
 409  *
 410  * These are listed in /sys/fs/btrfs/features along with
 411  * btrfs_supported_feature_attrs.
 412  */
 413 static struct attribute *btrfs_supported_static_feature_attrs[] = {
 414         BTRFS_ATTR_PTR(static_feature, rmdir_subvol),
 415         BTRFS_ATTR_PTR(static_feature, supported_checksums),
 416         BTRFS_ATTR_PTR(static_feature, send_stream_version),
 417         BTRFS_ATTR_PTR(static_feature, supported_rescue_options),
 418         BTRFS_ATTR_PTR(static_feature, supported_sectorsizes),
 419         NULL
 420 };
 421
 422 static const struct attribute_group btrfs_static_feature_attr_group = {
 423         .name = "features",
 424         .attrs = btrfs_supported_static_feature_attrs,
 425 };
 426
 427 #ifdef CONFIG_BTRFS_DEBUG
 428
 429 /*
 430  * Discard statistics and tunables
 431  */
 432 #define discard_to_fs_info(_kobj)       to_fs_info((_kobj)->parent->parent)
 433
 434 static ssize_t btrfs_discardable_bytes_show(struct kobject *kobj,
 435                                             struct kobj_attribute *a,
 436                                             char *buf)
 437 {
 438         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 439
 440         return scnprintf(buf, PAGE_SIZE, "%lld\n",
 441                         atomic64_read(&fs_info->discard_ctl.discardable_bytes));
 442 }
 443 BTRFS_ATTR(discard, discardable_bytes, btrfs_discardable_bytes_show);
 444
 445 static ssize_t btrfs_discardable_extents_show(struct kobject *kobj,
 446                                               struct kobj_attribute *a,
 447                                               char *buf)
 448 {
 449         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 450
 451         return scnprintf(buf, PAGE_SIZE, "%d\n",
 452                         atomic_read(&fs_info->discard_ctl.discardable_extents));
 453 }
 454 BTRFS_ATTR(discard, discardable_extents, btrfs_discardable_extents_show);
 455
 456 static ssize_t btrfs_discard_bitmap_bytes_show(struct kobject *kobj,
 457                                                struct kobj_attribute *a,
 458                                                char *buf)
 459 {
 460         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 461
 462         return scnprintf(buf, PAGE_SIZE, "%llu\n",
 463                         fs_info->discard_ctl.discard_bitmap_bytes);
 464 }
 465 BTRFS_ATTR(discard, discard_bitmap_bytes, btrfs_discard_bitmap_bytes_show);
 466
 467 static ssize_t btrfs_discard_bytes_saved_show(struct kobject *kobj,
 468                                               struct kobj_attribute *a,
 469                                               char *buf)
 470 {
 471         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 472
 473         return scnprintf(buf, PAGE_SIZE, "%lld\n",
 474                 atomic64_read(&fs_info->discard_ctl.discard_bytes_saved));
 475 }
 476 BTRFS_ATTR(discard, discard_bytes_saved, btrfs_discard_bytes_saved_show);
 477
 478 static ssize_t btrfs_discard_extent_bytes_show(struct kobject *kobj,
 479                                                struct kobj_attribute *a,
 480                                                char *buf)
 481 {
 482         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 483
 484         return scnprintf(buf, PAGE_SIZE, "%llu\n",
 485                         fs_info->discard_ctl.discard_extent_bytes);
 486 }
 487 BTRFS_ATTR(discard, discard_extent_bytes, btrfs_discard_extent_bytes_show);
 488
 489 static ssize_t btrfs_discard_iops_limit_show(struct kobject *kobj,
 490                                              struct kobj_attribute *a,
 491                                              char *buf)
 492 {
 493         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 494
 495         return scnprintf(buf, PAGE_SIZE, "%u\n",
 496                         READ_ONCE(fs_info->discard_ctl.iops_limit));
 497 }
 498
 499 static ssize_t btrfs_discard_iops_limit_store(struct kobject *kobj,
 500                                               struct kobj_attribute *a,
 501                                               const char *buf, size_t len)
 502 {
 503         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 504         struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
 505         u32 iops_limit;
 506         int ret;
 507
 508         ret = kstrtou32(buf, 10, &iops_limit);
 509         if (ret)
 510                 return -EINVAL;
 511
 512         WRITE_ONCE(discard_ctl->iops_limit, iops_limit);
 513         btrfs_discard_calc_delay(discard_ctl);
 514         btrfs_discard_schedule_work(discard_ctl, true);
 515         return len;
 516 }
 517 BTRFS_ATTR_RW(discard, iops_limit, btrfs_discard_iops_limit_show,
 518               btrfs_discard_iops_limit_store);
 519
 520 static ssize_t btrfs_discard_kbps_limit_show(struct kobject *kobj,
 521                                              struct kobj_attribute *a,
 522                                              char *buf)
 523 {
 524         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 525
 526         return scnprintf(buf, PAGE_SIZE, "%u\n",
 527                         READ_ONCE(fs_info->discard_ctl.kbps_limit));
 528 }
 529
 530 static ssize_t btrfs_discard_kbps_limit_store(struct kobject *kobj,
 531                                               struct kobj_attribute *a,
 532                                               const char *buf, size_t len)
 533 {
 534         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 535         struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
 536         u32 kbps_limit;
 537         int ret;
 538
 539         ret = kstrtou32(buf, 10, &kbps_limit);
 540         if (ret)
 541                 return -EINVAL;
 542
 543         WRITE_ONCE(discard_ctl->kbps_limit, kbps_limit);
 544         btrfs_discard_schedule_work(discard_ctl, true);
 545         return len;
 546 }
 547 BTRFS_ATTR_RW(discard, kbps_limit, btrfs_discard_kbps_limit_show,
 548               btrfs_discard_kbps_limit_store);
 549
 550 static ssize_t btrfs_discard_max_discard_size_show(struct kobject *kobj,
 551                                                    struct kobj_attribute *a,
 552                                                    char *buf)
 553 {
 554         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 555
 556         return scnprintf(buf, PAGE_SIZE, "%llu\n",
 557                         READ_ONCE(fs_info->discard_ctl.max_discard_size));
 558 }
 559
 560 static ssize_t btrfs_discard_max_discard_size_store(struct kobject *kobj,
 561                                                     struct kobj_attribute *a,
 562                                                     const char *buf, size_t len)
 563 {
 564         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 565         struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
 566         u64 max_discard_size;
 567         int ret;
 568
 569         ret = kstrtou64(buf, 10, &max_discard_size);
 570         if (ret)
 571                 return -EINVAL;
 572
 573         WRITE_ONCE(discard_ctl->max_discard_size, max_discard_size);
 574
 575         return len;
 576 }
 577 BTRFS_ATTR_RW(discard, max_discard_size, btrfs_discard_max_discard_size_show,
 578               btrfs_discard_max_discard_size_store);
 579
 580 /*
 581  * Per-filesystem debugging of discard (when mounted with discard=async).
 582  *
 583  * Path: /sys/fs/btrfs/<uuid>/debug/discard/
 584  */
 585 static const struct attribute *discard_debug_attrs[] = {
 586         BTRFS_ATTR_PTR(discard, discardable_bytes),
 587         BTRFS_ATTR_PTR(discard, discardable_extents),
 588         BTRFS_ATTR_PTR(discard, discard_bitmap_bytes),
 589         BTRFS_ATTR_PTR(discard, discard_bytes_saved),
 590         BTRFS_ATTR_PTR(discard, discard_extent_bytes),
 591         BTRFS_ATTR_PTR(discard, iops_limit),
 592         BTRFS_ATTR_PTR(discard, kbps_limit),
 593         BTRFS_ATTR_PTR(discard, max_discard_size),
 594         NULL,
 595 };
 596
 597 /*
 598  * Per-filesystem runtime debugging exported via sysfs.
 599  *
 600  * Path: /sys/fs/btrfs/UUID/debug/
 601  */
 602 static const struct attribute *btrfs_debug_mount_attrs[] = {
 603         NULL,
 604 };
 605
 606 /*
 607  * Runtime debugging exported via sysfs, applies to all mounted filesystems.
 608  *
 609  * Path: /sys/fs/btrfs/debug
 610  */
 611 static struct attribute *btrfs_debug_feature_attrs[] = {
 612         NULL
 613 };
 614
 615 static const struct attribute_group btrfs_debug_feature_attr_group = {
 616         .name = "debug",
 617         .attrs = btrfs_debug_feature_attrs,
 618 };
 619
 620 #endif
 621
 622 static ssize_t btrfs_show_u64(u64 *value_ptr, spinlock_t *lock, char *buf)
 623 {
 624         u64 val;
 625         if (lock)
 626                 spin_lock(lock);
 627         val = *value_ptr;
 628         if (lock)
 629                 spin_unlock(lock);
 630         return scnprintf(buf, PAGE_SIZE, "%llu\n", val);
 631 }
 632
 633 static ssize_t global_rsv_size_show(struct kobject *kobj,
 634                                     struct kobj_attribute *ka, char *buf)
 635 {
 636         struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent);
 637         struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
 638         return btrfs_show_u64(&block_rsv->size, &block_rsv->lock, buf);
 639 }
 640 BTRFS_ATTR(allocation, global_rsv_size, global_rsv_size_show);
 641
 642 static ssize_t global_rsv_reserved_show(struct kobject *kobj,
 643                                         struct kobj_attribute *a, char *buf)
 644 {
 645         struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent);
 646         struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
 647         return btrfs_show_u64(&block_rsv->reserved, &block_rsv->lock, buf);
 648 }
 649 BTRFS_ATTR(allocation, global_rsv_reserved, global_rsv_reserved_show);
 650
 651 #define to_space_info(_kobj) container_of(_kobj, struct btrfs_space_info, kobj)
 652 #define to_raid_kobj(_kobj) container_of(_kobj, struct raid_kobject, kobj)
 653
 654 static ssize_t raid_bytes_show(struct kobject *kobj,
 655                                struct kobj_attribute *attr, char *buf);
 656 BTRFS_ATTR(raid, total_bytes, raid_bytes_show);
 657 BTRFS_ATTR(raid, used_bytes, raid_bytes_show);
 658
 659 static ssize_t raid_bytes_show(struct kobject *kobj,
 660                                struct kobj_attribute *attr, char *buf)
 661
 662 {
 663         struct btrfs_space_info *sinfo = to_space_info(kobj->parent);
 664         struct btrfs_block_group *block_group;
 665         int index = btrfs_bg_flags_to_raid_index(to_raid_kobj(kobj)->flags);
 666         u64 val = 0;
 667
 668         down_read(&sinfo->groups_sem);
 669         list_for_each_entry(block_group, &sinfo->block_groups[index], list) {
 670                 if (&attr->attr == BTRFS_ATTR_PTR(raid, total_bytes))
 671                         val += block_group->length;
 672                 else
 673                         val += block_group->used;
 674         }
 675         up_read(&sinfo->groups_sem);
 676         return scnprintf(buf, PAGE_SIZE, "%llu\n", val);
 677 }
 678
 679 /*
 680  * Allocation information about block group profiles.
 681  *
 682  * Path: /sys/fs/btrfs/<uuid>/allocation/<bg-type>/<bg-profile>/
 683  */
 684 static struct attribute *raid_attrs[] = {
 685         BTRFS_ATTR_PTR(raid, total_bytes),
 686         BTRFS_ATTR_PTR(raid, used_bytes),
 687         NULL
 688 };
 689 ATTRIBUTE_GROUPS(raid);
 690
 691 static void release_raid_kobj(struct kobject *kobj)
 692 {
 693         kfree(to_raid_kobj(kobj));
 694 }
 695
 696 static struct kobj_type btrfs_raid_ktype = {
 697         .sysfs_ops = &kobj_sysfs_ops,
 698         .release = release_raid_kobj,
 699         .default_groups = raid_groups,
 700 };
 701
 702 #define SPACE_INFO_ATTR(field)                                          \
 703 static ssize_t btrfs_space_info_show_##field(struct kobject *kobj,      \
 704                                              struct kobj_attribute *a,  \
 705                                              char *buf)                 \
 706 {                                                                       \
 707         struct btrfs_space_info *sinfo = to_space_info(kobj);           \
 708         return btrfs_show_u64(&sinfo->field, &sinfo->lock, buf);        \
 709 }                                                                       \
 710 BTRFS_ATTR(space_info, field, btrfs_space_info_show_##field)
 711
 712 SPACE_INFO_ATTR(flags);
 713 SPACE_INFO_ATTR(total_bytes);
 714 SPACE_INFO_ATTR(bytes_used);
 715 SPACE_INFO_ATTR(bytes_pinned);
 716 SPACE_INFO_ATTR(bytes_reserved);
 717 SPACE_INFO_ATTR(bytes_may_use);
 718 SPACE_INFO_ATTR(bytes_readonly);
 719 SPACE_INFO_ATTR(bytes_zone_unusable);
 720 SPACE_INFO_ATTR(disk_used);
 721 SPACE_INFO_ATTR(disk_total);
 722
 723 /*
 724  * Allocation information about block group types.
 725  *
 726  * Path: /sys/fs/btrfs/<uuid>/allocation/<bg-type>/
 727  */
 728 static struct attribute *space_info_attrs[] = {
 729         BTRFS_ATTR_PTR(space_info, flags),
 730         BTRFS_ATTR_PTR(space_info, total_bytes),
 731         BTRFS_ATTR_PTR(space_info, bytes_used),
 732         BTRFS_ATTR_PTR(space_info, bytes_pinned),
 733         BTRFS_ATTR_PTR(space_info, bytes_reserved),
 734         BTRFS_ATTR_PTR(space_info, bytes_may_use),
 735         BTRFS_ATTR_PTR(space_info, bytes_readonly),
 736         BTRFS_ATTR_PTR(space_info, bytes_zone_unusable),
 737         BTRFS_ATTR_PTR(space_info, disk_used),
 738         BTRFS_ATTR_PTR(space_info, disk_total),
 739         NULL,
 740 };
 741 ATTRIBUTE_GROUPS(space_info);
 742
 743 static void space_info_release(struct kobject *kobj)
 744 {
 745         struct btrfs_space_info *sinfo = to_space_info(kobj);
 746         kfree(sinfo);
 747 }
 748
 749 static struct kobj_type space_info_ktype = {
 750         .sysfs_ops = &kobj_sysfs_ops,
 751         .release = space_info_release,
 752         .default_groups = space_info_groups,
 753 };
 754
 755 /*
 756  * Allocation information about block groups.
 757  *
 758  * Path: /sys/fs/btrfs/<uuid>/allocation/
 759  */
 760 static const struct attribute *allocation_attrs[] = {
 761         BTRFS_ATTR_PTR(allocation, global_rsv_reserved),
 762         BTRFS_ATTR_PTR(allocation, global_rsv_size),
 763         NULL,
 764 };
 765
 766 static ssize_t btrfs_label_show(struct kobject *kobj,
 767                                 struct kobj_attribute *a, char *buf)
 768 {
 769         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 770         char *label = fs_info->super_copy->label;
 771         ssize_t ret;
 772
 773         spin_lock(&fs_info->super_lock);
 774         ret = scnprintf(buf, PAGE_SIZE, label[0] ? "%s\n" : "%s", label);
 775         spin_unlock(&fs_info->super_lock);
 776
 777         return ret;
 778 }
 779
 780 static ssize_t btrfs_label_store(struct kobject *kobj,
 781                                  struct kobj_attribute *a,
 782                                  const char *buf, size_t len)
 783 {
 784         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 785         size_t p_len;
 786
 787         if (!fs_info)
 788                 return -EPERM;
 789
 790         if (sb_rdonly(fs_info->sb))
 791                 return -EROFS;
 792
 793         /*
 794          * p_len is the len until the first occurrence of either
 795          * '\n' or '\0'
 796          */
 797         p_len = strcspn(buf, "\n");
 798
 799         if (p_len >= BTRFS_LABEL_SIZE)
 800                 return -EINVAL;
 801
 802         spin_lock(&fs_info->super_lock);
 803         memset(fs_info->super_copy->label, 0, BTRFS_LABEL_SIZE);
 804         memcpy(fs_info->super_copy->label, buf, p_len);
 805         spin_unlock(&fs_info->super_lock);
 806
 807         /*
 808          * We don't want to do full transaction commit from inside sysfs
 809          */
 810         btrfs_set_pending(fs_info, COMMIT);
 811         wake_up_process(fs_info->transaction_kthread);
 812
 813         return len;
 814 }
 815 BTRFS_ATTR_RW(, label, btrfs_label_show, btrfs_label_store);
 816
 817 static ssize_t btrfs_nodesize_show(struct kobject *kobj,
 818                                 struct kobj_attribute *a, char *buf)
 819 {
 820         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 821
 822         return scnprintf(buf, PAGE_SIZE, "%u\n", fs_info->super_copy->nodesize);
 823 }
 824
 825 BTRFS_ATTR(, nodesize, btrfs_nodesize_show);
 826
 827 static ssize_t btrfs_sectorsize_show(struct kobject *kobj,
 828                                 struct kobj_attribute *a, char *buf)
 829 {
 830         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 831
 832         return scnprintf(buf, PAGE_SIZE, "%u\n",
 833                          fs_info->super_copy->sectorsize);
 834 }
 835
 836 BTRFS_ATTR(, sectorsize, btrfs_sectorsize_show);
 837
 838 static ssize_t btrfs_clone_alignment_show(struct kobject *kobj,
 839                                 struct kobj_attribute *a, char *buf)
 840 {
 841         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 842
 843         return scnprintf(buf, PAGE_SIZE, "%u\n", fs_info->super_copy->sectorsize);
 844 }
 845
 846 BTRFS_ATTR(, clone_alignment, btrfs_clone_alignment_show);
 847
 848 static ssize_t quota_override_show(struct kobject *kobj,
 849                                    struct kobj_attribute *a, char *buf)
 850 {
 851         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 852         int quota_override;
 853
 854         quota_override = test_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
 855         return scnprintf(buf, PAGE_SIZE, "%d\n", quota_override);
 856 }
 857
 858 static ssize_t quota_override_store(struct kobject *kobj,
 859                                     struct kobj_attribute *a,
 860                                     const char *buf, size_t len)
 861 {
 862         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 863         unsigned long knob;
 864         int err;
 865
 866         if (!fs_info)
 867                 return -EPERM;
 868
 869         if (!capable(CAP_SYS_RESOURCE))
 870                 return -EPERM;
 871
 872         err = kstrtoul(buf, 10, &knob);
 873         if (err)
 874                 return err;
 875         if (knob > 1)
 876                 return -EINVAL;
 877
 878         if (knob)
 879                 set_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
 880         else
 881                 clear_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
 882
 883         return len;
 884 }
 885
 886 BTRFS_ATTR_RW(, quota_override, quota_override_show, quota_override_store);
 887
 888 static ssize_t btrfs_metadata_uuid_show(struct kobject *kobj,
 889                                 struct kobj_attribute *a, char *buf)
 890 {
 891         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 892
 893         return scnprintf(buf, PAGE_SIZE, "%pU\n",
 894                         fs_info->fs_devices->metadata_uuid);
 895 }
 896
 897 BTRFS_ATTR(, metadata_uuid, btrfs_metadata_uuid_show);
 898
 899 static ssize_t btrfs_checksum_show(struct kobject *kobj,
 900                                    struct kobj_attribute *a, char *buf)
 901 {
 902         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 903         u16 csum_type = btrfs_super_csum_type(fs_info->super_copy);
 904
 905         return scnprintf(buf, PAGE_SIZE, "%s (%s)\n",
 906                         btrfs_super_csum_name(csum_type),
 907                         crypto_shash_driver_name(fs_info->csum_shash));
 908 }
 909
 910 BTRFS_ATTR(, checksum, btrfs_checksum_show);
 911
 912 static ssize_t btrfs_exclusive_operation_show(struct kobject *kobj,
 913                 struct kobj_attribute *a, char *buf)
 914 {
 915         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 916         const char *str;
 917
 918         switch (READ_ONCE(fs_info->exclusive_operation)) {
 919                 case  BTRFS_EXCLOP_NONE:
 920                         str = "none\n";
 921                         break;
 922                 case BTRFS_EXCLOP_BALANCE:
 923                         str = "balance\n";
 924                         break;
 925                 case BTRFS_EXCLOP_DEV_ADD:
 926                         str = "device add\n";
 927                         break;
 928                 case BTRFS_EXCLOP_DEV_REMOVE:
 929                         str = "device remove\n";
 930                         break;
 931                 case BTRFS_EXCLOP_DEV_REPLACE:
 932                         str = "device replace\n";
 933                         break;
 934                 case BTRFS_EXCLOP_RESIZE:
 935                         str = "resize\n";
 936                         break;
 937                 case BTRFS_EXCLOP_SWAP_ACTIVATE:
 938                         str = "swap activate\n";
 939                         break;
 940                 default:
 941                         str = "UNKNOWN\n";
 942                         break;
 943         }
 944         return scnprintf(buf, PAGE_SIZE, "%s", str);
 945 }
 946 BTRFS_ATTR(, exclusive_operation, btrfs_exclusive_operation_show);
 947
 948 static ssize_t btrfs_generation_show(struct kobject *kobj,
 949                                      struct kobj_attribute *a, char *buf)
 950 {
 951         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 952
 953         return scnprintf(buf, PAGE_SIZE, "%llu\n", fs_info->generation);
 954 }
 955 BTRFS_ATTR(, generation, btrfs_generation_show);
 956
 957 /*
 958  * Look for an exact string @string in @buffer with possible leading or
 959  * trailing whitespace
 960  */
 961 static bool strmatch(const char *buffer, const char *string)
 962 {
 963         const size_t len = strlen(string);
 964
 965         /* Skip leading whitespace */
 966         buffer = skip_spaces(buffer);
 967
 968         /* Match entire string, check if the rest is whitespace or empty */
 969         if (strncmp(string, buffer, len) == 0 &&
 970             strlen(skip_spaces(buffer + len)) == 0)
 971                 return true;
 972
 973         return false;
 974 }
 975
 976 static const char * const btrfs_read_policy_name[] = { "pid" };
 977
 978 static ssize_t btrfs_read_policy_show(struct kobject *kobj,
 979                                       struct kobj_attribute *a, char *buf)
 980 {
 981         struct btrfs_fs_devices *fs_devices = to_fs_devs(kobj);
 982         ssize_t ret = 0;
 983         int i;
 984
 985         for (i = 0; i < BTRFS_NR_READ_POLICY; i++) {
 986                 if (fs_devices->read_policy == i)
 987                         ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s[%s]",
 988                                          (ret == 0 ? "" : " "),
 989                                          btrfs_read_policy_name[i]);
 990                 else
 991                         ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%s",
 992                                          (ret == 0 ? "" : " "),
 993                                          btrfs_read_policy_name[i]);
 994         }
 995
 996         ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
 997
 998         return ret;
 999 }
1000
1001 static ssize_t btrfs_read_policy_store(struct kobject *kobj,
1002                                        struct kobj_attribute *a,
1003                                        const char *buf, size_t len)
1004 {
1005         struct btrfs_fs_devices *fs_devices = to_fs_devs(kobj);
1006         int i;
1007
1008         for (i = 0; i < BTRFS_NR_READ_POLICY; i++) {
1009                 if (strmatch(buf, btrfs_read_policy_name[i])) {
1010                         if (i != fs_devices->read_policy) {
1011                                 fs_devices->read_policy = i;
1012                                 btrfs_info(fs_devices->fs_info,
1013                                            "read policy set to '%s'",
1014                                            btrfs_read_policy_name[i]);
1015                         }
1016                         return len;
1017                 }
1018         }
1019
1020         return -EINVAL;
1021 }
1022 BTRFS_ATTR_RW(, read_policy, btrfs_read_policy_show, btrfs_read_policy_store);
1023
1024 static ssize_t btrfs_bg_reclaim_threshold_show(struct kobject *kobj,
1025                                                struct kobj_attribute *a,
1026                                                char *buf)
1027 {
1028         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1029         ssize_t ret;
1030
1031         ret = scnprintf(buf, PAGE_SIZE, "%d\n",
1032                         READ_ONCE(fs_info->bg_reclaim_threshold));
1033
1034         return ret;
1035 }
1036
1037 static ssize_t btrfs_bg_reclaim_threshold_store(struct kobject *kobj,
1038                                                 struct kobj_attribute *a,
1039                                                 const char *buf, size_t len)
1040 {
1041         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1042         int thresh;
1043         int ret;
1044
1045         ret = kstrtoint(buf, 10, &thresh);
1046         if (ret)
1047                 return ret;
1048
1049         if (thresh != 0 && (thresh <= 50 || thresh > 100))
1050                 return -EINVAL;
1051
1052         WRITE_ONCE(fs_info->bg_reclaim_threshold, thresh);
1053
1054         return len;
1055 }
1056 BTRFS_ATTR_RW(, bg_reclaim_threshold, btrfs_bg_reclaim_threshold_show,
1057               btrfs_bg_reclaim_threshold_store);
1058
1059 /*
1060  * Per-filesystem information and stats.
1061  *
1062  * Path: /sys/fs/btrfs/<uuid>/
1063  */
1064 static const struct attribute *btrfs_attrs[] = {
1065         BTRFS_ATTR_PTR(, label),
1066         BTRFS_ATTR_PTR(, nodesize),
1067         BTRFS_ATTR_PTR(, sectorsize),
1068         BTRFS_ATTR_PTR(, clone_alignment),
1069         BTRFS_ATTR_PTR(, quota_override),
1070         BTRFS_ATTR_PTR(, metadata_uuid),
1071         BTRFS_ATTR_PTR(, checksum),
1072         BTRFS_ATTR_PTR(, exclusive_operation),
1073         BTRFS_ATTR_PTR(, generation),
1074         BTRFS_ATTR_PTR(, read_policy),
1075         BTRFS_ATTR_PTR(, bg_reclaim_threshold),
1076         NULL,
1077 };
1078
1079 static void btrfs_release_fsid_kobj(struct kobject *kobj)
1080 {
1081         struct btrfs_fs_devices *fs_devs = to_fs_devs(kobj);
1082
1083         memset(&fs_devs->fsid_kobj, 0, sizeof(struct kobject));
1084         complete(&fs_devs->kobj_unregister);
1085 }
1086
1087 static struct kobj_type btrfs_ktype = {
1088         .sysfs_ops      = &kobj_sysfs_ops,
1089         .release        = btrfs_release_fsid_kobj,
1090 };
1091
1092 static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj)
1093 {
1094         if (kobj->ktype != &btrfs_ktype)
1095                 return NULL;
1096         return container_of(kobj, struct btrfs_fs_devices, fsid_kobj);
1097 }
1098
1099 static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj)
1100 {
1101         if (kobj->ktype != &btrfs_ktype)
1102                 return NULL;
1103         return to_fs_devs(kobj)->fs_info;
1104 }
1105
1106 #define NUM_FEATURE_BITS 64
1107 #define BTRFS_FEATURE_NAME_MAX 13
1108 static char btrfs_unknown_feature_names[FEAT_MAX][NUM_FEATURE_BITS][BTRFS_FEATURE_NAME_MAX];
1109 static struct btrfs_feature_attr btrfs_feature_attrs[FEAT_MAX][NUM_FEATURE_BITS];
1110
1111 static const u64 supported_feature_masks[FEAT_MAX] = {
1112         [FEAT_COMPAT]    = BTRFS_FEATURE_COMPAT_SUPP,
1113         [FEAT_COMPAT_RO] = BTRFS_FEATURE_COMPAT_RO_SUPP,
1114         [FEAT_INCOMPAT]  = BTRFS_FEATURE_INCOMPAT_SUPP,
1115 };
1116
1117 static int addrm_unknown_feature_attrs(struct btrfs_fs_info *fs_info, bool add)
1118 {
1119         int set;
1120
1121         for (set = 0; set < FEAT_MAX; set++) {
1122                 int i;
1123                 struct attribute *attrs[2];
1124                 struct attribute_group agroup = {
1125                         .name = "features",
1126                         .attrs = attrs,
1127                 };
1128                 u64 features = get_features(fs_info, set);
1129                 features &= ~supported_feature_masks[set];
1130
1131                 if (!features)
1132                         continue;
1133
1134                 attrs[1] = NULL;
1135                 for (i = 0; i < NUM_FEATURE_BITS; i++) {
1136                         struct btrfs_feature_attr *fa;
1137
1138                         if (!(features & (1ULL << i)))
1139                                 continue;
1140
1141                         fa = &btrfs_feature_attrs[set][i];
1142                         attrs[0] = &fa->kobj_attr.attr;
1143                         if (add) {
1144                                 int ret;
1145                                 ret = sysfs_merge_group(&fs_info->fs_devices->fsid_kobj,
1146                                                         &agroup);
1147                                 if (ret)
1148                                         return ret;
1149                         } else
1150                                 sysfs_unmerge_group(&fs_info->fs_devices->fsid_kobj,
1151                                                     &agroup);
1152                 }
1153
1154         }
1155         return 0;
1156 }
1157
1158 static void __btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs)
1159 {
1160         if (fs_devs->devinfo_kobj) {
1161                 kobject_del(fs_devs->devinfo_kobj);
1162                 kobject_put(fs_devs->devinfo_kobj);
1163                 fs_devs->devinfo_kobj = NULL;
1164         }
1165
1166         if (fs_devs->devices_kobj) {
1167                 kobject_del(fs_devs->devices_kobj);
1168                 kobject_put(fs_devs->devices_kobj);
1169                 fs_devs->devices_kobj = NULL;
1170         }
1171
1172         if (fs_devs->fsid_kobj.state_initialized) {
1173                 kobject_del(&fs_devs->fsid_kobj);
1174                 kobject_put(&fs_devs->fsid_kobj);
1175                 wait_for_completion(&fs_devs->kobj_unregister);
1176         }
1177 }
1178
1179 /* when fs_devs is NULL it will remove all fsid kobject */
1180 void btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs)
1181 {
1182         struct list_head *fs_uuids = btrfs_get_fs_uuids();
1183
1184         if (fs_devs) {
1185                 __btrfs_sysfs_remove_fsid(fs_devs);
1186                 return;
1187         }
1188
1189         list_for_each_entry(fs_devs, fs_uuids, fs_list) {
1190                 __btrfs_sysfs_remove_fsid(fs_devs);
1191         }
1192 }
1193
1194 static void btrfs_sysfs_remove_fs_devices(struct btrfs_fs_devices *fs_devices)
1195 {
1196         struct btrfs_device *device;
1197         struct btrfs_fs_devices *seed;
1198
1199         list_for_each_entry(device, &fs_devices->devices, dev_list)
1200                 btrfs_sysfs_remove_device(device);
1201
1202         list_for_each_entry(seed, &fs_devices->seed_list, seed_list) {
1203                 list_for_each_entry(device, &seed->devices, dev_list)
1204                         btrfs_sysfs_remove_device(device);
1205         }
1206 }
1207
1208 void btrfs_sysfs_remove_mounted(struct btrfs_fs_info *fs_info)
1209 {
1210         struct kobject *fsid_kobj = &fs_info->fs_devices->fsid_kobj;
1211
1212         sysfs_remove_link(fsid_kobj, "bdi");
1213
1214         if (fs_info->space_info_kobj) {
1215                 sysfs_remove_files(fs_info->space_info_kobj, allocation_attrs);
1216                 kobject_del(fs_info->space_info_kobj);
1217                 kobject_put(fs_info->space_info_kobj);
1218         }
1219 #ifdef CONFIG_BTRFS_DEBUG
1220         if (fs_info->discard_debug_kobj) {
1221                 sysfs_remove_files(fs_info->discard_debug_kobj,
1222                                    discard_debug_attrs);
1223                 kobject_del(fs_info->discard_debug_kobj);
1224                 kobject_put(fs_info->discard_debug_kobj);
1225         }
1226         if (fs_info->debug_kobj) {
1227                 sysfs_remove_files(fs_info->debug_kobj, btrfs_debug_mount_attrs);
1228                 kobject_del(fs_info->debug_kobj);
1229                 kobject_put(fs_info->debug_kobj);
1230         }
1231 #endif
1232         addrm_unknown_feature_attrs(fs_info, false);
1233         sysfs_remove_group(fsid_kobj, &btrfs_feature_attr_group);
1234         sysfs_remove_files(fsid_kobj, btrfs_attrs);
1235         btrfs_sysfs_remove_fs_devices(fs_info->fs_devices);
1236 }
1237
1238 static const char * const btrfs_feature_set_names[FEAT_MAX] = {
1239         [FEAT_COMPAT]    = "compat",
1240         [FEAT_COMPAT_RO] = "compat_ro",
1241         [FEAT_INCOMPAT]  = "incompat",
1242 };
1243
1244 const char *btrfs_feature_set_name(enum btrfs_feature_set set)
1245 {
1246         return btrfs_feature_set_names[set];
1247 }
1248
1249 char *btrfs_printable_features(enum btrfs_feature_set set, u64 flags)
1250 {
1251         size_t bufsize = 4096; /* safe max, 64 names * 64 bytes */
1252         int len = 0;
1253         int i;
1254         char *str;
1255
1256         str = kmalloc(bufsize, GFP_KERNEL);
1257         if (!str)
1258                 return str;
1259
1260         for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
1261                 const char *name;
1262
1263                 if (!(flags & (1ULL << i)))
1264                         continue;
1265
1266                 name = btrfs_feature_attrs[set][i].kobj_attr.attr.name;
1267                 len += scnprintf(str + len, bufsize - len, "%s%s",
1268                                 len ? "," : "", name);
1269         }
1270
1271         return str;
1272 }
1273
1274 static void init_feature_attrs(void)
1275 {
1276         struct btrfs_feature_attr *fa;
1277         int set, i;
1278
1279         BUILD_BUG_ON(ARRAY_SIZE(btrfs_unknown_feature_names) !=
1280                      ARRAY_SIZE(btrfs_feature_attrs));
1281         BUILD_BUG_ON(ARRAY_SIZE(btrfs_unknown_feature_names[0]) !=
1282                      ARRAY_SIZE(btrfs_feature_attrs[0]));
1283
1284         memset(btrfs_feature_attrs, 0, sizeof(btrfs_feature_attrs));
1285         memset(btrfs_unknown_feature_names, 0,
1286                sizeof(btrfs_unknown_feature_names));
1287
1288         for (i = 0; btrfs_supported_feature_attrs[i]; i++) {
1289                 struct btrfs_feature_attr *sfa;
1290                 struct attribute *a = btrfs_supported_feature_attrs[i];
1291                 int bit;
1292                 sfa = attr_to_btrfs_feature_attr(a);
1293                 bit = ilog2(sfa->feature_bit);
1294                 fa = &btrfs_feature_attrs[sfa->feature_set][bit];
1295
1296                 fa->kobj_attr.attr.name = sfa->kobj_attr.attr.name;
1297         }
1298
1299         for (set = 0; set < FEAT_MAX; set++) {
1300                 for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
1301                         char *name = btrfs_unknown_feature_names[set][i];
1302                         fa = &btrfs_feature_attrs[set][i];
1303
1304                         if (fa->kobj_attr.attr.name)
1305                                 continue;
1306
1307                         snprintf(name, BTRFS_FEATURE_NAME_MAX, "%s:%u",
1308                                  btrfs_feature_set_names[set], i);
1309
1310                         fa->kobj_attr.attr.name = name;
1311                         fa->kobj_attr.attr.mode = S_IRUGO;
1312                         fa->feature_set = set;
1313                         fa->feature_bit = 1ULL << i;
1314                 }
1315         }
1316 }
1317
1318 /*
1319  * Create a sysfs entry for a given block group type at path
1320  * /sys/fs/btrfs/UUID/allocation/data/TYPE
1321  */
1322 void btrfs_sysfs_add_block_group_type(struct btrfs_block_group *cache)
1323 {
1324         struct btrfs_fs_info *fs_info = cache->fs_info;
1325         struct btrfs_space_info *space_info = cache->space_info;
1326         struct raid_kobject *rkobj;
1327         const int index = btrfs_bg_flags_to_raid_index(cache->flags);
1328         unsigned int nofs_flag;
1329         int ret;
1330
1331         /*
1332          * Setup a NOFS context because kobject_add(), deep in its call chain,
1333          * does GFP_KERNEL allocations, and we are often called in a context
1334          * where if reclaim is triggered we can deadlock (we are either holding
1335          * a transaction handle or some lock required for a transaction
1336          * commit).
1337          */
1338         nofs_flag = memalloc_nofs_save();
1339
1340         rkobj = kzalloc(sizeof(*rkobj), GFP_NOFS);
1341         if (!rkobj) {
1342                 memalloc_nofs_restore(nofs_flag);
1343                 btrfs_warn(cache->fs_info,
1344                                 "couldn't alloc memory for raid level kobject");
1345                 return;
1346         }
1347
1348         rkobj->flags = cache->flags;
1349         kobject_init(&rkobj->kobj, &btrfs_raid_ktype);
1350
1351         /*
1352          * We call this either on mount, or if we've created a block group for a
1353          * new index type while running (i.e. when restriping).  The running
1354          * case is tricky because we could race with other threads, so we need
1355          * to have this check to make sure we didn't already init the kobject.
1356          *
1357          * We don't have to protect on the free side because it only happens on
1358          * unmount.
1359          */
1360         spin_lock(&space_info->lock);
1361         if (space_info->block_group_kobjs[index]) {
1362                 spin_unlock(&space_info->lock);
1363                 kobject_put(&rkobj->kobj);
1364                 return;
1365         } else {
1366                 space_info->block_group_kobjs[index] = &rkobj->kobj;
1367         }
1368         spin_unlock(&space_info->lock);
1369
1370         ret = kobject_add(&rkobj->kobj, &space_info->kobj, "%s",
1371                           btrfs_bg_type_to_raid_name(rkobj->flags));
1372         memalloc_nofs_restore(nofs_flag);
1373         if (ret) {
1374                 spin_lock(&space_info->lock);
1375                 space_info->block_group_kobjs[index] = NULL;
1376                 spin_unlock(&space_info->lock);
1377                 kobject_put(&rkobj->kobj);
1378                 btrfs_warn(fs_info,
1379                         "failed to add kobject for block cache, ignoring");
1380                 return;
1381         }
1382 }
1383
1384 /*
1385  * Remove sysfs directories for all block group types of a given space info and
1386  * the space info as well
1387  */
1388 void btrfs_sysfs_remove_space_info(struct btrfs_space_info *space_info)
1389 {
1390         int i;
1391
1392         for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) {
1393                 struct kobject *kobj;
1394
1395                 kobj = space_info->block_group_kobjs[i];
1396                 space_info->block_group_kobjs[i] = NULL;
1397                 if (kobj) {
1398                         kobject_del(kobj);
1399                         kobject_put(kobj);
1400                 }
1401         }
1402         kobject_del(&space_info->kobj);
1403         kobject_put(&space_info->kobj);
1404 }
1405
1406 static const char *alloc_name(u64 flags)
1407 {
1408         switch (flags) {
1409         case BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA:
1410                 return "mixed";
1411         case BTRFS_BLOCK_GROUP_METADATA:
1412                 return "metadata";
1413         case BTRFS_BLOCK_GROUP_DATA:
1414                 return "data";
1415         case BTRFS_BLOCK_GROUP_SYSTEM:
1416                 return "system";
1417         default:
1418                 WARN_ON(1);
1419                 return "invalid-combination";
1420         }
1421 }
1422
1423 /*
1424  * Create a sysfs entry for a space info type at path
1425  * /sys/fs/btrfs/UUID/allocation/TYPE
1426  */
1427 int btrfs_sysfs_add_space_info_type(struct btrfs_fs_info *fs_info,
1428                                     struct btrfs_space_info *space_info)
1429 {
1430         int ret;
1431
1432         ret = kobject_init_and_add(&space_info->kobj, &space_info_ktype,
1433                                    fs_info->space_info_kobj, "%s",
1434                                    alloc_name(space_info->flags));
1435         if (ret) {
1436                 kobject_put(&space_info->kobj);
1437                 return ret;
1438         }
1439
1440         return 0;
1441 }
1442
1443 void btrfs_sysfs_remove_device(struct btrfs_device *device)
1444 {
1445         struct kobject *devices_kobj;
1446
1447         /*
1448          * Seed fs_devices devices_kobj aren't used, fetch kobject from the
1449          * fs_info::fs_devices.
1450          */
1451         devices_kobj = device->fs_info->fs_devices->devices_kobj;
1452         ASSERT(devices_kobj);
1453
1454         if (device->bdev)
1455                 sysfs_remove_link(devices_kobj, bdev_kobj(device->bdev)->name);
1456
1457         if (device->devid_kobj.state_initialized) {
1458                 kobject_del(&device->devid_kobj);
1459                 kobject_put(&device->devid_kobj);
1460                 wait_for_completion(&device->kobj_unregister);
1461         }
1462 }
1463
1464 static ssize_t btrfs_devinfo_in_fs_metadata_show(struct kobject *kobj,
1465                                                  struct kobj_attribute *a,
1466                                                  char *buf)
1467 {
1468         int val;
1469         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1470                                                    devid_kobj);
1471
1472         val = !!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state);
1473
1474         return scnprintf(buf, PAGE_SIZE, "%d\n", val);
1475 }
1476 BTRFS_ATTR(devid, in_fs_metadata, btrfs_devinfo_in_fs_metadata_show);
1477
1478 static ssize_t btrfs_devinfo_missing_show(struct kobject *kobj,
1479                                         struct kobj_attribute *a, char *buf)
1480 {
1481         int val;
1482         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1483                                                    devid_kobj);
1484
1485         val = !!test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state);
1486
1487         return scnprintf(buf, PAGE_SIZE, "%d\n", val);
1488 }
1489 BTRFS_ATTR(devid, missing, btrfs_devinfo_missing_show);
1490
1491 static ssize_t btrfs_devinfo_replace_target_show(struct kobject *kobj,
1492                                                  struct kobj_attribute *a,
1493                                                  char *buf)
1494 {
1495         int val;
1496         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1497                                                    devid_kobj);
1498
1499         val = !!test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state);
1500
1501         return scnprintf(buf, PAGE_SIZE, "%d\n", val);
1502 }
1503 BTRFS_ATTR(devid, replace_target, btrfs_devinfo_replace_target_show);
1504
1505 static ssize_t btrfs_devinfo_scrub_speed_max_show(struct kobject *kobj,
1506                                              struct kobj_attribute *a,
1507                                              char *buf)
1508 {
1509         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1510                                                    devid_kobj);
1511
1512         return scnprintf(buf, PAGE_SIZE, "%llu\n",
1513                          READ_ONCE(device->scrub_speed_max));
1514 }
1515
1516 static ssize_t btrfs_devinfo_scrub_speed_max_store(struct kobject *kobj,
1517                                               struct kobj_attribute *a,
1518                                               const char *buf, size_t len)
1519 {
1520         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1521                                                    devid_kobj);
1522         char *endptr;
1523         unsigned long long limit;
1524
1525         limit = memparse(buf, &endptr);
1526         WRITE_ONCE(device->scrub_speed_max, limit);
1527         return len;
1528 }
1529 BTRFS_ATTR_RW(devid, scrub_speed_max, btrfs_devinfo_scrub_speed_max_show,
1530               btrfs_devinfo_scrub_speed_max_store);
1531
1532 static ssize_t btrfs_devinfo_writeable_show(struct kobject *kobj,
1533                                             struct kobj_attribute *a, char *buf)
1534 {
1535         int val;
1536         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1537                                                    devid_kobj);
1538
1539         val = !!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state);
1540
1541         return scnprintf(buf, PAGE_SIZE, "%d\n", val);
1542 }
1543 BTRFS_ATTR(devid, writeable, btrfs_devinfo_writeable_show);
1544
1545 static ssize_t btrfs_devinfo_error_stats_show(struct kobject *kobj,
1546                 struct kobj_attribute *a, char *buf)
1547 {
1548         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1549                                                    devid_kobj);
1550
1551         if (!device->dev_stats_valid)
1552                 return scnprintf(buf, PAGE_SIZE, "invalid\n");
1553
1554         /*
1555          * Print all at once so we get a snapshot of all values from the same
1556          * time. Keep them in sync and in order of definition of
1557          * btrfs_dev_stat_values.
1558          */
1559         return scnprintf(buf, PAGE_SIZE,
1560                 "write_errs %d\n"
1561                 "read_errs %d\n"
1562                 "flush_errs %d\n"
1563                 "corruption_errs %d\n"
1564                 "generation_errs %d\n",
1565                 btrfs_dev_stat_read(device, BTRFS_DEV_STAT_WRITE_ERRS),
1566                 btrfs_dev_stat_read(device, BTRFS_DEV_STAT_READ_ERRS),
1567                 btrfs_dev_stat_read(device, BTRFS_DEV_STAT_FLUSH_ERRS),
1568                 btrfs_dev_stat_read(device, BTRFS_DEV_STAT_CORRUPTION_ERRS),
1569                 btrfs_dev_stat_read(device, BTRFS_DEV_STAT_GENERATION_ERRS));
1570 }
1571 BTRFS_ATTR(devid, error_stats, btrfs_devinfo_error_stats_show);
1572
1573 /*
1574  * Information about one device.
1575  *
1576  * Path: /sys/fs/btrfs/<uuid>/devinfo/<devid>/
1577  */
1578 static struct attribute *devid_attrs[] = {
1579         BTRFS_ATTR_PTR(devid, error_stats),
1580         BTRFS_ATTR_PTR(devid, in_fs_metadata),
1581         BTRFS_ATTR_PTR(devid, missing),
1582         BTRFS_ATTR_PTR(devid, replace_target),
1583         BTRFS_ATTR_PTR(devid, scrub_speed_max),
1584         BTRFS_ATTR_PTR(devid, writeable),
1585         NULL
1586 };
1587 ATTRIBUTE_GROUPS(devid);
1588
1589 static void btrfs_release_devid_kobj(struct kobject *kobj)
1590 {
1591         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1592                                                    devid_kobj);
1593
1594         memset(&device->devid_kobj, 0, sizeof(struct kobject));
1595         complete(&device->kobj_unregister);
1596 }
1597
1598 static struct kobj_type devid_ktype = {
1599         .sysfs_ops      = &kobj_sysfs_ops,
1600         .default_groups = devid_groups,
1601         .release        = btrfs_release_devid_kobj,
1602 };
1603
1604 int btrfs_sysfs_add_device(struct btrfs_device *device)
1605 {
1606         int ret;
1607         unsigned int nofs_flag;
1608         struct kobject *devices_kobj;
1609         struct kobject *devinfo_kobj;
1610
1611         /*
1612          * Make sure we use the fs_info::fs_devices to fetch the kobjects even
1613          * for the seed fs_devices
1614          */
1615         devices_kobj = device->fs_info->fs_devices->devices_kobj;
1616         devinfo_kobj = device->fs_info->fs_devices->devinfo_kobj;
1617         ASSERT(devices_kobj);
1618         ASSERT(devinfo_kobj);
1619
1620         nofs_flag = memalloc_nofs_save();
1621
1622         if (device->bdev) {
1623                 struct kobject *disk_kobj = bdev_kobj(device->bdev);
1624
1625                 ret = sysfs_create_link(devices_kobj, disk_kobj, disk_kobj->name);
1626                 if (ret) {
1627                         btrfs_warn(device->fs_info,
1628                                 "creating sysfs device link for devid %llu failed: %d",
1629                                 device->devid, ret);
1630                         goto out;
1631                 }
1632         }
1633
1634         init_completion(&device->kobj_unregister);
1635         ret = kobject_init_and_add(&device->devid_kobj, &devid_ktype,
1636                                    devinfo_kobj, "%llu", device->devid);
1637         if (ret) {
1638                 kobject_put(&device->devid_kobj);
1639                 btrfs_warn(device->fs_info,
1640                            "devinfo init for devid %llu failed: %d",
1641                            device->devid, ret);
1642         }
1643
1644 out:
1645         memalloc_nofs_restore(nofs_flag);
1646         return ret;
1647 }
1648
1649 static int btrfs_sysfs_add_fs_devices(struct btrfs_fs_devices *fs_devices)
1650 {
1651         int ret;
1652         struct btrfs_device *device;
1653         struct btrfs_fs_devices *seed;
1654
1655         list_for_each_entry(device, &fs_devices->devices, dev_list) {
1656                 ret = btrfs_sysfs_add_device(device);
1657                 if (ret)
1658                         goto fail;
1659         }
1660
1661         list_for_each_entry(seed, &fs_devices->seed_list, seed_list) {
1662                 list_for_each_entry(device, &seed->devices, dev_list) {
1663                         ret = btrfs_sysfs_add_device(device);
1664                         if (ret)
1665                                 goto fail;
1666                 }
1667         }
1668
1669         return 0;
1670
1671 fail:
1672         btrfs_sysfs_remove_fs_devices(fs_devices);
1673         return ret;
1674 }
1675
1676 void btrfs_kobject_uevent(struct block_device *bdev, enum kobject_action action)
1677 {
1678         int ret;
1679
1680         ret = kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, action);
1681         if (ret)
1682                 pr_warn("BTRFS: Sending event '%d' to kobject: '%s' (%p): failed\n",
1683                         action, kobject_name(&disk_to_dev(bdev->bd_disk)->kobj),
1684                         &disk_to_dev(bdev->bd_disk)->kobj);
1685 }
1686
1687 void btrfs_sysfs_update_sprout_fsid(struct btrfs_fs_devices *fs_devices)
1688
1689 {
1690         char fsid_buf[BTRFS_UUID_UNPARSED_SIZE];
1691
1692         /*
1693          * Sprouting changes fsid of the mounted filesystem, rename the fsid
1694          * directory
1695          */
1696         snprintf(fsid_buf, BTRFS_UUID_UNPARSED_SIZE, "%pU", fs_devices->fsid);
1697         if (kobject_rename(&fs_devices->fsid_kobj, fsid_buf))
1698                 btrfs_warn(fs_devices->fs_info,
1699                                 "sysfs: failed to create fsid for sprout");
1700 }
1701
1702 void btrfs_sysfs_update_devid(struct btrfs_device *device)
1703 {
1704         char tmp[24];
1705
1706         snprintf(tmp, sizeof(tmp), "%llu", device->devid);
1707
1708         if (kobject_rename(&device->devid_kobj, tmp))
1709                 btrfs_warn(device->fs_devices->fs_info,
1710                            "sysfs: failed to update devid for %llu",
1711                            device->devid);
1712 }
1713
1714 /* /sys/fs/btrfs/ entry */
1715 static struct kset *btrfs_kset;
1716
1717 /*
1718  * Creates:
1719  *              /sys/fs/btrfs/UUID
1720  *
1721  * Can be called by the device discovery thread.
1722  */
1723 int btrfs_sysfs_add_fsid(struct btrfs_fs_devices *fs_devs)
1724 {
1725         int error;
1726
1727         init_completion(&fs_devs->kobj_unregister);
1728         fs_devs->fsid_kobj.kset = btrfs_kset;
1729         error = kobject_init_and_add(&fs_devs->fsid_kobj, &btrfs_ktype, NULL,
1730                                      "%pU", fs_devs->fsid);
1731         if (error) {
1732                 kobject_put(&fs_devs->fsid_kobj);
1733                 return error;
1734         }
1735
1736         fs_devs->devices_kobj = kobject_create_and_add("devices",
1737                                                        &fs_devs->fsid_kobj);
1738         if (!fs_devs->devices_kobj) {
1739                 btrfs_err(fs_devs->fs_info,
1740                           "failed to init sysfs device interface");
1741                 btrfs_sysfs_remove_fsid(fs_devs);
1742                 return -ENOMEM;
1743         }
1744
1745         fs_devs->devinfo_kobj = kobject_create_and_add("devinfo",
1746                                                        &fs_devs->fsid_kobj);
1747         if (!fs_devs->devinfo_kobj) {
1748                 btrfs_err(fs_devs->fs_info,
1749                           "failed to init sysfs devinfo kobject");
1750                 btrfs_sysfs_remove_fsid(fs_devs);
1751                 return -ENOMEM;
1752         }
1753
1754         return 0;
1755 }
1756
1757 int btrfs_sysfs_add_mounted(struct btrfs_fs_info *fs_info)
1758 {
1759         int error;
1760         struct btrfs_fs_devices *fs_devs = fs_info->fs_devices;
1761         struct kobject *fsid_kobj = &fs_devs->fsid_kobj;
1762
1763         error = btrfs_sysfs_add_fs_devices(fs_devs);
1764         if (error)
1765                 return error;
1766
1767         error = sysfs_create_files(fsid_kobj, btrfs_attrs);
1768         if (error) {
1769                 btrfs_sysfs_remove_fs_devices(fs_devs);
1770                 return error;
1771         }
1772
1773         error = sysfs_create_group(fsid_kobj,
1774                                    &btrfs_feature_attr_group);
1775         if (error)
1776                 goto failure;
1777
1778 #ifdef CONFIG_BTRFS_DEBUG
1779         fs_info->debug_kobj = kobject_create_and_add("debug", fsid_kobj);
1780         if (!fs_info->debug_kobj) {
1781                 error = -ENOMEM;
1782                 goto failure;
1783         }
1784
1785         error = sysfs_create_files(fs_info->debug_kobj, btrfs_debug_mount_attrs);
1786         if (error)
1787                 goto failure;
1788
1789         /* Discard directory */
1790         fs_info->discard_debug_kobj = kobject_create_and_add("discard",
1791                                                      fs_info->debug_kobj);
1792         if (!fs_info->discard_debug_kobj) {
1793                 error = -ENOMEM;
1794                 goto failure;
1795         }
1796
1797         error = sysfs_create_files(fs_info->discard_debug_kobj,
1798                                    discard_debug_attrs);
1799         if (error)
1800                 goto failure;
1801 #endif
1802
1803         error = addrm_unknown_feature_attrs(fs_info, true);
1804         if (error)
1805                 goto failure;
1806
1807         error = sysfs_create_link(fsid_kobj, &fs_info->sb->s_bdi->dev->kobj, "bdi");
1808         if (error)
1809                 goto failure;
1810
1811         fs_info->space_info_kobj = kobject_create_and_add("allocation",
1812                                                   fsid_kobj);
1813         if (!fs_info->space_info_kobj) {
1814                 error = -ENOMEM;
1815                 goto failure;
1816         }
1817
1818         error = sysfs_create_files(fs_info->space_info_kobj, allocation_attrs);
1819         if (error)
1820                 goto failure;
1821
1822         return 0;
1823 failure:
1824         btrfs_sysfs_remove_mounted(fs_info);
1825         return error;
1826 }
1827
1828 static inline struct btrfs_fs_info *qgroup_kobj_to_fs_info(struct kobject *kobj)
1829 {
1830         return to_fs_info(kobj->parent->parent);
1831 }
1832
1833 #define QGROUP_ATTR(_member, _show_name)                                        \
1834 static ssize_t btrfs_qgroup_show_##_member(struct kobject *qgroup_kobj,         \
1835                                            struct kobj_attribute *a,            \
1836                                            char *buf)                           \
1837 {                                                                               \
1838         struct btrfs_fs_info *fs_info = qgroup_kobj_to_fs_info(qgroup_kobj);    \
1839         struct btrfs_qgroup *qgroup = container_of(qgroup_kobj,                 \
1840                         struct btrfs_qgroup, kobj);                             \
1841         return btrfs_show_u64(&qgroup->_member, &fs_info->qgroup_lock, buf);    \
1842 }                                                                               \
1843 BTRFS_ATTR(qgroup, _show_name, btrfs_qgroup_show_##_member)
1844
1845 #define QGROUP_RSV_ATTR(_name, _type)                                           \
1846 static ssize_t btrfs_qgroup_rsv_show_##_name(struct kobject *qgroup_kobj,       \
1847                                              struct kobj_attribute *a,          \
1848                                              char *buf)                         \
1849 {                                                                               \
1850         struct btrfs_fs_info *fs_info = qgroup_kobj_to_fs_info(qgroup_kobj);    \
1851         struct btrfs_qgroup *qgroup = container_of(qgroup_kobj,                 \
1852                         struct btrfs_qgroup, kobj);                             \
1853         return btrfs_show_u64(&qgroup->rsv.values[_type],                       \
1854                         &fs_info->qgroup_lock, buf);                            \
1855 }                                                                               \
1856 BTRFS_ATTR(qgroup, rsv_##_name, btrfs_qgroup_rsv_show_##_name)
1857
1858 QGROUP_ATTR(rfer, referenced);
1859 QGROUP_ATTR(excl, exclusive);
1860 QGROUP_ATTR(max_rfer, max_referenced);
1861 QGROUP_ATTR(max_excl, max_exclusive);
1862 QGROUP_ATTR(lim_flags, limit_flags);
1863 QGROUP_RSV_ATTR(data, BTRFS_QGROUP_RSV_DATA);
1864 QGROUP_RSV_ATTR(meta_pertrans, BTRFS_QGROUP_RSV_META_PERTRANS);
1865 QGROUP_RSV_ATTR(meta_prealloc, BTRFS_QGROUP_RSV_META_PREALLOC);
1866
1867 /*
1868  * Qgroup information.
1869  *
1870  * Path: /sys/fs/btrfs/<uuid>/qgroups/<level>_<qgroupid>/
1871  */
1872 static struct attribute *qgroup_attrs[] = {
1873         BTRFS_ATTR_PTR(qgroup, referenced),
1874         BTRFS_ATTR_PTR(qgroup, exclusive),
1875         BTRFS_ATTR_PTR(qgroup, max_referenced),
1876         BTRFS_ATTR_PTR(qgroup, max_exclusive),
1877         BTRFS_ATTR_PTR(qgroup, limit_flags),
1878         BTRFS_ATTR_PTR(qgroup, rsv_data),
1879         BTRFS_ATTR_PTR(qgroup, rsv_meta_pertrans),
1880         BTRFS_ATTR_PTR(qgroup, rsv_meta_prealloc),
1881         NULL
1882 };
1883 ATTRIBUTE_GROUPS(qgroup);
1884
1885 static void qgroup_release(struct kobject *kobj)
1886 {
1887         struct btrfs_qgroup *qgroup = container_of(kobj, struct btrfs_qgroup, kobj);
1888
1889         memset(&qgroup->kobj, 0, sizeof(*kobj));
1890 }
1891
1892 static struct kobj_type qgroup_ktype = {
1893         .sysfs_ops = &kobj_sysfs_ops,
1894         .release = qgroup_release,
1895         .default_groups = qgroup_groups,
1896 };
1897
1898 int btrfs_sysfs_add_one_qgroup(struct btrfs_fs_info *fs_info,
1899                                 struct btrfs_qgroup *qgroup)
1900 {
1901         struct kobject *qgroups_kobj = fs_info->qgroups_kobj;
1902         int ret;
1903
1904         if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
1905                 return 0;
1906         if (qgroup->kobj.state_initialized)
1907                 return 0;
1908         if (!qgroups_kobj)
1909                 return -EINVAL;
1910
1911         ret = kobject_init_and_add(&qgroup->kobj, &qgroup_ktype, qgroups_kobj,
1912                         "%hu_%llu", btrfs_qgroup_level(qgroup->qgroupid),
1913                         btrfs_qgroup_subvolid(qgroup->qgroupid));
1914         if (ret < 0)
1915                 kobject_put(&qgroup->kobj);
1916
1917         return ret;
1918 }
1919
1920 void btrfs_sysfs_del_qgroups(struct btrfs_fs_info *fs_info)
1921 {
1922         struct btrfs_qgroup *qgroup;
1923         struct btrfs_qgroup *next;
1924
1925         if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
1926                 return;
1927
1928         rbtree_postorder_for_each_entry_safe(qgroup, next,
1929                                              &fs_info->qgroup_tree, node)
1930                 btrfs_sysfs_del_one_qgroup(fs_info, qgroup);
1931         if (fs_info->qgroups_kobj) {
1932                 kobject_del(fs_info->qgroups_kobj);
1933                 kobject_put(fs_info->qgroups_kobj);
1934                 fs_info->qgroups_kobj = NULL;
1935         }
1936 }
1937
1938 /* Called when qgroups get initialized, thus there is no need for locking */
1939 int btrfs_sysfs_add_qgroups(struct btrfs_fs_info *fs_info)
1940 {
1941         struct kobject *fsid_kobj = &fs_info->fs_devices->fsid_kobj;
1942         struct btrfs_qgroup *qgroup;
1943         struct btrfs_qgroup *next;
1944         int ret = 0;
1945
1946         if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
1947                 return 0;
1948
1949         ASSERT(fsid_kobj);
1950         if (fs_info->qgroups_kobj)
1951                 return 0;
1952
1953         fs_info->qgroups_kobj = kobject_create_and_add("qgroups", fsid_kobj);
1954         if (!fs_info->qgroups_kobj) {
1955                 ret = -ENOMEM;
1956                 goto out;
1957         }
1958         rbtree_postorder_for_each_entry_safe(qgroup, next,
1959                                              &fs_info->qgroup_tree, node) {
1960                 ret = btrfs_sysfs_add_one_qgroup(fs_info, qgroup);
1961                 if (ret < 0)
1962                         goto out;
1963         }
1964
1965 out:
1966         if (ret < 0)
1967                 btrfs_sysfs_del_qgroups(fs_info);
1968         return ret;
1969 }
1970
1971 void btrfs_sysfs_del_one_qgroup(struct btrfs_fs_info *fs_info,
1972                                 struct btrfs_qgroup *qgroup)
1973 {
1974         if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
1975                 return;
1976
1977         if (qgroup->kobj.state_initialized) {
1978                 kobject_del(&qgroup->kobj);
1979                 kobject_put(&qgroup->kobj);
1980         }
1981 }
1982
1983 /*
1984  * Change per-fs features in /sys/fs/btrfs/UUID/features to match current
1985  * values in superblock. Call after any changes to incompat/compat_ro flags
1986  */
1987 void btrfs_sysfs_feature_update(struct btrfs_fs_info *fs_info,
1988                 u64 bit, enum btrfs_feature_set set)
1989 {
1990         struct btrfs_fs_devices *fs_devs;
1991         struct kobject *fsid_kobj;
1992         u64 __maybe_unused features;
1993         int __maybe_unused ret;
1994
1995         if (!fs_info)
1996                 return;
1997
1998         /*
1999          * See 14e46e04958df74 and e410e34fad913dd, feature bit updates are not
2000          * safe when called from some contexts (eg. balance)
2001          */
2002         features = get_features(fs_info, set);
2003         ASSERT(bit & supported_feature_masks[set]);
2004
2005         fs_devs = fs_info->fs_devices;
2006         fsid_kobj = &fs_devs->fsid_kobj;
2007
2008         if (!fsid_kobj->state_initialized)
2009                 return;
2010
2011         /*
2012          * FIXME: this is too heavy to update just one value, ideally we'd like
2013          * to use sysfs_update_group but some refactoring is needed first.
2014          */
2015         sysfs_remove_group(fsid_kobj, &btrfs_feature_attr_group);
2016         ret = sysfs_create_group(fsid_kobj, &btrfs_feature_attr_group);
2017 }
2018
2019 int __init btrfs_init_sysfs(void)
2020 {
2021         int ret;
2022
2023         btrfs_kset = kset_create_and_add("btrfs", NULL, fs_kobj);
2024         if (!btrfs_kset)
2025                 return -ENOMEM;
2026
2027         init_feature_attrs();
2028         ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
2029         if (ret)
2030                 goto out2;
2031         ret = sysfs_merge_group(&btrfs_kset->kobj,
2032                                 &btrfs_static_feature_attr_group);
2033         if (ret)
2034                 goto out_remove_group;
2035
2036 #ifdef CONFIG_BTRFS_DEBUG
2037         ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_debug_feature_attr_group);
2038         if (ret)
2039                 goto out2;
2040 #endif
2041
2042         return 0;
2043
2044 out_remove_group:
2045         sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
2046 out2:
2047         kset_unregister(btrfs_kset);
2048
2049         return ret;
2050 }
2051
2052 void __cold btrfs_exit_sysfs(void)
2053 {
2054         sysfs_unmerge_group(&btrfs_kset->kobj,
2055                             &btrfs_static_feature_attr_group);
2056         sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
2057 #ifdef CONFIG_BTRFS_DEBUG
2058         sysfs_remove_group(&btrfs_kset->kobj, &btrfs_debug_feature_attr_group);
2059 #endif
2060         kset_unregister(btrfs_kset);
2061 }
2062