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 #ifdef CONFIG_BTRFS_DEBUG
 287 /* Remove once support for zoned allocation is feature complete */
 288 BTRFS_FEAT_ATTR_INCOMPAT(zoned, ZONED);
 289 /* Remove once support for extent tree v2 is feature complete */
 290 BTRFS_FEAT_ATTR_INCOMPAT(extent_tree_v2, EXTENT_TREE_V2);
 291 #endif
 292 #ifdef CONFIG_FS_VERITY
 293 BTRFS_FEAT_ATTR_COMPAT_RO(verity, VERITY);
 294 #endif
 295
 296 /*
 297  * Features which depend on feature bits and may differ between each fs.
 298  *
 299  * /sys/fs/btrfs/features      - all available features implemeted by this version
 300  * /sys/fs/btrfs/UUID/features - features of the fs which are enabled or
 301  *                               can be changed on a mounted filesystem.
 302  */
 303 static struct attribute *btrfs_supported_feature_attrs[] = {
 304         BTRFS_FEAT_ATTR_PTR(mixed_backref),
 305         BTRFS_FEAT_ATTR_PTR(default_subvol),
 306         BTRFS_FEAT_ATTR_PTR(mixed_groups),
 307         BTRFS_FEAT_ATTR_PTR(compress_lzo),
 308         BTRFS_FEAT_ATTR_PTR(compress_zstd),
 309         BTRFS_FEAT_ATTR_PTR(big_metadata),
 310         BTRFS_FEAT_ATTR_PTR(extended_iref),
 311         BTRFS_FEAT_ATTR_PTR(raid56),
 312         BTRFS_FEAT_ATTR_PTR(skinny_metadata),
 313         BTRFS_FEAT_ATTR_PTR(no_holes),
 314         BTRFS_FEAT_ATTR_PTR(metadata_uuid),
 315         BTRFS_FEAT_ATTR_PTR(free_space_tree),
 316         BTRFS_FEAT_ATTR_PTR(raid1c34),
 317 #ifdef CONFIG_BTRFS_DEBUG
 318         BTRFS_FEAT_ATTR_PTR(zoned),
 319         BTRFS_FEAT_ATTR_PTR(extent_tree_v2),
 320 #endif
 321 #ifdef CONFIG_FS_VERITY
 322         BTRFS_FEAT_ATTR_PTR(verity),
 323 #endif
 324         NULL
 325 };
 326
 327 static const struct attribute_group btrfs_feature_attr_group = {
 328         .name = "features",
 329         .is_visible = btrfs_feature_visible,
 330         .attrs = btrfs_supported_feature_attrs,
 331 };
 332
 333 static ssize_t rmdir_subvol_show(struct kobject *kobj,
 334                                  struct kobj_attribute *ka, char *buf)
 335 {
 336         return sysfs_emit(buf, "0\n");
 337 }
 338 BTRFS_ATTR(static_feature, rmdir_subvol, rmdir_subvol_show);
 339
 340 static ssize_t supported_checksums_show(struct kobject *kobj,
 341                                         struct kobj_attribute *a, char *buf)
 342 {
 343         ssize_t ret = 0;
 344         int i;
 345
 346         for (i = 0; i < btrfs_get_num_csums(); i++) {
 347                 /*
 348                  * This "trick" only works as long as 'enum btrfs_csum_type' has
 349                  * no holes in it
 350                  */
 351                 ret += sysfs_emit_at(buf, ret, "%s%s", (i == 0 ? "" : " "),
 352                                      btrfs_super_csum_name(i));
 353
 354         }
 355
 356         ret += sysfs_emit_at(buf, ret, "\n");
 357         return ret;
 358 }
 359 BTRFS_ATTR(static_feature, supported_checksums, supported_checksums_show);
 360
 361 static ssize_t send_stream_version_show(struct kobject *kobj,
 362                                         struct kobj_attribute *ka, char *buf)
 363 {
 364         return sysfs_emit(buf, "%d\n", BTRFS_SEND_STREAM_VERSION);
 365 }
 366 BTRFS_ATTR(static_feature, send_stream_version, send_stream_version_show);
 367
 368 static const char *rescue_opts[] = {
 369         "usebackuproot",
 370         "nologreplay",
 371         "ignorebadroots",
 372         "ignoredatacsums",
 373         "all",
 374 };
 375
 376 static ssize_t supported_rescue_options_show(struct kobject *kobj,
 377                                              struct kobj_attribute *a,
 378                                              char *buf)
 379 {
 380         ssize_t ret = 0;
 381         int i;
 382
 383         for (i = 0; i < ARRAY_SIZE(rescue_opts); i++)
 384                 ret += sysfs_emit_at(buf, ret, "%s%s", (i ? " " : ""), rescue_opts[i]);
 385         ret += sysfs_emit_at(buf, ret, "\n");
 386         return ret;
 387 }
 388 BTRFS_ATTR(static_feature, supported_rescue_options,
 389            supported_rescue_options_show);
 390
 391 static ssize_t supported_sectorsizes_show(struct kobject *kobj,
 392                                           struct kobj_attribute *a,
 393                                           char *buf)
 394 {
 395         ssize_t ret = 0;
 396
 397         /* 4K sector size is also supported with 64K page size */
 398         if (PAGE_SIZE == SZ_64K)
 399                 ret += sysfs_emit_at(buf, ret, "%u ", SZ_4K);
 400
 401         /* Only sectorsize == PAGE_SIZE is now supported */
 402         ret += sysfs_emit_at(buf, ret, "%lu\n", PAGE_SIZE);
 403
 404         return ret;
 405 }
 406 BTRFS_ATTR(static_feature, supported_sectorsizes,
 407            supported_sectorsizes_show);
 408
 409 /*
 410  * Features which only depend on kernel version.
 411  *
 412  * These are listed in /sys/fs/btrfs/features along with
 413  * btrfs_supported_feature_attrs.
 414  */
 415 static struct attribute *btrfs_supported_static_feature_attrs[] = {
 416         BTRFS_ATTR_PTR(static_feature, rmdir_subvol),
 417         BTRFS_ATTR_PTR(static_feature, supported_checksums),
 418         BTRFS_ATTR_PTR(static_feature, send_stream_version),
 419         BTRFS_ATTR_PTR(static_feature, supported_rescue_options),
 420         BTRFS_ATTR_PTR(static_feature, supported_sectorsizes),
 421         NULL
 422 };
 423
 424 static const struct attribute_group btrfs_static_feature_attr_group = {
 425         .name = "features",
 426         .attrs = btrfs_supported_static_feature_attrs,
 427 };
 428
 429 #ifdef CONFIG_BTRFS_DEBUG
 430
 431 /*
 432  * Discard statistics and tunables
 433  */
 434 #define discard_to_fs_info(_kobj)       to_fs_info((_kobj)->parent->parent)
 435
 436 static ssize_t btrfs_discardable_bytes_show(struct kobject *kobj,
 437                                             struct kobj_attribute *a,
 438                                             char *buf)
 439 {
 440         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 441
 442         return sysfs_emit(buf, "%lld\n",
 443                         atomic64_read(&fs_info->discard_ctl.discardable_bytes));
 444 }
 445 BTRFS_ATTR(discard, discardable_bytes, btrfs_discardable_bytes_show);
 446
 447 static ssize_t btrfs_discardable_extents_show(struct kobject *kobj,
 448                                               struct kobj_attribute *a,
 449                                               char *buf)
 450 {
 451         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 452
 453         return sysfs_emit(buf, "%d\n",
 454                         atomic_read(&fs_info->discard_ctl.discardable_extents));
 455 }
 456 BTRFS_ATTR(discard, discardable_extents, btrfs_discardable_extents_show);
 457
 458 static ssize_t btrfs_discard_bitmap_bytes_show(struct kobject *kobj,
 459                                                struct kobj_attribute *a,
 460                                                char *buf)
 461 {
 462         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 463
 464         return sysfs_emit(buf, "%llu\n",
 465                           fs_info->discard_ctl.discard_bitmap_bytes);
 466 }
 467 BTRFS_ATTR(discard, discard_bitmap_bytes, btrfs_discard_bitmap_bytes_show);
 468
 469 static ssize_t btrfs_discard_bytes_saved_show(struct kobject *kobj,
 470                                               struct kobj_attribute *a,
 471                                               char *buf)
 472 {
 473         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 474
 475         return sysfs_emit(buf, "%lld\n",
 476                 atomic64_read(&fs_info->discard_ctl.discard_bytes_saved));
 477 }
 478 BTRFS_ATTR(discard, discard_bytes_saved, btrfs_discard_bytes_saved_show);
 479
 480 static ssize_t btrfs_discard_extent_bytes_show(struct kobject *kobj,
 481                                                struct kobj_attribute *a,
 482                                                char *buf)
 483 {
 484         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 485
 486         return sysfs_emit(buf, "%llu\n",
 487                           fs_info->discard_ctl.discard_extent_bytes);
 488 }
 489 BTRFS_ATTR(discard, discard_extent_bytes, btrfs_discard_extent_bytes_show);
 490
 491 static ssize_t btrfs_discard_iops_limit_show(struct kobject *kobj,
 492                                              struct kobj_attribute *a,
 493                                              char *buf)
 494 {
 495         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 496
 497         return sysfs_emit(buf, "%u\n",
 498                           READ_ONCE(fs_info->discard_ctl.iops_limit));
 499 }
 500
 501 static ssize_t btrfs_discard_iops_limit_store(struct kobject *kobj,
 502                                               struct kobj_attribute *a,
 503                                               const char *buf, size_t len)
 504 {
 505         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 506         struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
 507         u32 iops_limit;
 508         int ret;
 509
 510         ret = kstrtou32(buf, 10, &iops_limit);
 511         if (ret)
 512                 return -EINVAL;
 513
 514         WRITE_ONCE(discard_ctl->iops_limit, iops_limit);
 515         btrfs_discard_calc_delay(discard_ctl);
 516         btrfs_discard_schedule_work(discard_ctl, true);
 517         return len;
 518 }
 519 BTRFS_ATTR_RW(discard, iops_limit, btrfs_discard_iops_limit_show,
 520               btrfs_discard_iops_limit_store);
 521
 522 static ssize_t btrfs_discard_kbps_limit_show(struct kobject *kobj,
 523                                              struct kobj_attribute *a,
 524                                              char *buf)
 525 {
 526         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 527
 528         return sysfs_emit(buf, "%u\n",
 529                           READ_ONCE(fs_info->discard_ctl.kbps_limit));
 530 }
 531
 532 static ssize_t btrfs_discard_kbps_limit_store(struct kobject *kobj,
 533                                               struct kobj_attribute *a,
 534                                               const char *buf, size_t len)
 535 {
 536         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 537         struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
 538         u32 kbps_limit;
 539         int ret;
 540
 541         ret = kstrtou32(buf, 10, &kbps_limit);
 542         if (ret)
 543                 return -EINVAL;
 544
 545         WRITE_ONCE(discard_ctl->kbps_limit, kbps_limit);
 546         btrfs_discard_schedule_work(discard_ctl, true);
 547         return len;
 548 }
 549 BTRFS_ATTR_RW(discard, kbps_limit, btrfs_discard_kbps_limit_show,
 550               btrfs_discard_kbps_limit_store);
 551
 552 static ssize_t btrfs_discard_max_discard_size_show(struct kobject *kobj,
 553                                                    struct kobj_attribute *a,
 554                                                    char *buf)
 555 {
 556         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 557
 558         return sysfs_emit(buf, "%llu\n",
 559                           READ_ONCE(fs_info->discard_ctl.max_discard_size));
 560 }
 561
 562 static ssize_t btrfs_discard_max_discard_size_store(struct kobject *kobj,
 563                                                     struct kobj_attribute *a,
 564                                                     const char *buf, size_t len)
 565 {
 566         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 567         struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
 568         u64 max_discard_size;
 569         int ret;
 570
 571         ret = kstrtou64(buf, 10, &max_discard_size);
 572         if (ret)
 573                 return -EINVAL;
 574
 575         WRITE_ONCE(discard_ctl->max_discard_size, max_discard_size);
 576
 577         return len;
 578 }
 579 BTRFS_ATTR_RW(discard, max_discard_size, btrfs_discard_max_discard_size_show,
 580               btrfs_discard_max_discard_size_store);
 581
 582 /*
 583  * Per-filesystem debugging of discard (when mounted with discard=async).
 584  *
 585  * Path: /sys/fs/btrfs/<uuid>/debug/discard/
 586  */
 587 static const struct attribute *discard_debug_attrs[] = {
 588         BTRFS_ATTR_PTR(discard, discardable_bytes),
 589         BTRFS_ATTR_PTR(discard, discardable_extents),
 590         BTRFS_ATTR_PTR(discard, discard_bitmap_bytes),
 591         BTRFS_ATTR_PTR(discard, discard_bytes_saved),
 592         BTRFS_ATTR_PTR(discard, discard_extent_bytes),
 593         BTRFS_ATTR_PTR(discard, iops_limit),
 594         BTRFS_ATTR_PTR(discard, kbps_limit),
 595         BTRFS_ATTR_PTR(discard, max_discard_size),
 596         NULL,
 597 };
 598
 599 /*
 600  * Per-filesystem runtime debugging exported via sysfs.
 601  *
 602  * Path: /sys/fs/btrfs/UUID/debug/
 603  */
 604 static const struct attribute *btrfs_debug_mount_attrs[] = {
 605         NULL,
 606 };
 607
 608 /*
 609  * Runtime debugging exported via sysfs, applies to all mounted filesystems.
 610  *
 611  * Path: /sys/fs/btrfs/debug
 612  */
 613 static struct attribute *btrfs_debug_feature_attrs[] = {
 614         NULL
 615 };
 616
 617 static const struct attribute_group btrfs_debug_feature_attr_group = {
 618         .name = "debug",
 619         .attrs = btrfs_debug_feature_attrs,
 620 };
 621
 622 #endif
 623
 624 static ssize_t btrfs_show_u64(u64 *value_ptr, spinlock_t *lock, char *buf)
 625 {
 626         u64 val;
 627         if (lock)
 628                 spin_lock(lock);
 629         val = *value_ptr;
 630         if (lock)
 631                 spin_unlock(lock);
 632         return sysfs_emit(buf, "%llu\n", val);
 633 }
 634
 635 static ssize_t global_rsv_size_show(struct kobject *kobj,
 636                                     struct kobj_attribute *ka, char *buf)
 637 {
 638         struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent);
 639         struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
 640         return btrfs_show_u64(&block_rsv->size, &block_rsv->lock, buf);
 641 }
 642 BTRFS_ATTR(allocation, global_rsv_size, global_rsv_size_show);
 643
 644 static ssize_t global_rsv_reserved_show(struct kobject *kobj,
 645                                         struct kobj_attribute *a, char *buf)
 646 {
 647         struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent);
 648         struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
 649         return btrfs_show_u64(&block_rsv->reserved, &block_rsv->lock, buf);
 650 }
 651 BTRFS_ATTR(allocation, global_rsv_reserved, global_rsv_reserved_show);
 652
 653 #define to_space_info(_kobj) container_of(_kobj, struct btrfs_space_info, kobj)
 654 #define to_raid_kobj(_kobj) container_of(_kobj, struct raid_kobject, kobj)
 655
 656 static ssize_t raid_bytes_show(struct kobject *kobj,
 657                                struct kobj_attribute *attr, char *buf);
 658 BTRFS_ATTR(raid, total_bytes, raid_bytes_show);
 659 BTRFS_ATTR(raid, used_bytes, raid_bytes_show);
 660
 661 static ssize_t raid_bytes_show(struct kobject *kobj,
 662                                struct kobj_attribute *attr, char *buf)
 663
 664 {
 665         struct btrfs_space_info *sinfo = to_space_info(kobj->parent);
 666         struct btrfs_block_group *block_group;
 667         int index = btrfs_bg_flags_to_raid_index(to_raid_kobj(kobj)->flags);
 668         u64 val = 0;
 669
 670         down_read(&sinfo->groups_sem);
 671         list_for_each_entry(block_group, &sinfo->block_groups[index], list) {
 672                 if (&attr->attr == BTRFS_ATTR_PTR(raid, total_bytes))
 673                         val += block_group->length;
 674                 else
 675                         val += block_group->used;
 676         }
 677         up_read(&sinfo->groups_sem);
 678         return sysfs_emit(buf, "%llu\n", val);
 679 }
 680
 681 /*
 682  * Allocation information about block group profiles.
 683  *
 684  * Path: /sys/fs/btrfs/<uuid>/allocation/<bg-type>/<bg-profile>/
 685  */
 686 static struct attribute *raid_attrs[] = {
 687         BTRFS_ATTR_PTR(raid, total_bytes),
 688         BTRFS_ATTR_PTR(raid, used_bytes),
 689         NULL
 690 };
 691 ATTRIBUTE_GROUPS(raid);
 692
 693 static void release_raid_kobj(struct kobject *kobj)
 694 {
 695         kfree(to_raid_kobj(kobj));
 696 }
 697
 698 static struct kobj_type btrfs_raid_ktype = {
 699         .sysfs_ops = &kobj_sysfs_ops,
 700         .release = release_raid_kobj,
 701         .default_groups = raid_groups,
 702 };
 703
 704 #define SPACE_INFO_ATTR(field)                                          \
 705 static ssize_t btrfs_space_info_show_##field(struct kobject *kobj,      \
 706                                              struct kobj_attribute *a,  \
 707                                              char *buf)                 \
 708 {                                                                       \
 709         struct btrfs_space_info *sinfo = to_space_info(kobj);           \
 710         return btrfs_show_u64(&sinfo->field, &sinfo->lock, buf);        \
 711 }                                                                       \
 712 BTRFS_ATTR(space_info, field, btrfs_space_info_show_##field)
 713
 714 SPACE_INFO_ATTR(flags);
 715 SPACE_INFO_ATTR(total_bytes);
 716 SPACE_INFO_ATTR(bytes_used);
 717 SPACE_INFO_ATTR(bytes_pinned);
 718 SPACE_INFO_ATTR(bytes_reserved);
 719 SPACE_INFO_ATTR(bytes_may_use);
 720 SPACE_INFO_ATTR(bytes_readonly);
 721 SPACE_INFO_ATTR(bytes_zone_unusable);
 722 SPACE_INFO_ATTR(disk_used);
 723 SPACE_INFO_ATTR(disk_total);
 724
 725 /*
 726  * Allocation information about block group types.
 727  *
 728  * Path: /sys/fs/btrfs/<uuid>/allocation/<bg-type>/
 729  */
 730 static struct attribute *space_info_attrs[] = {
 731         BTRFS_ATTR_PTR(space_info, flags),
 732         BTRFS_ATTR_PTR(space_info, total_bytes),
 733         BTRFS_ATTR_PTR(space_info, bytes_used),
 734         BTRFS_ATTR_PTR(space_info, bytes_pinned),
 735         BTRFS_ATTR_PTR(space_info, bytes_reserved),
 736         BTRFS_ATTR_PTR(space_info, bytes_may_use),
 737         BTRFS_ATTR_PTR(space_info, bytes_readonly),
 738         BTRFS_ATTR_PTR(space_info, bytes_zone_unusable),
 739         BTRFS_ATTR_PTR(space_info, disk_used),
 740         BTRFS_ATTR_PTR(space_info, disk_total),
 741         NULL,
 742 };
 743 ATTRIBUTE_GROUPS(space_info);
 744
 745 static void space_info_release(struct kobject *kobj)
 746 {
 747         struct btrfs_space_info *sinfo = to_space_info(kobj);
 748         kfree(sinfo);
 749 }
 750
 751 static struct kobj_type space_info_ktype = {
 752         .sysfs_ops = &kobj_sysfs_ops,
 753         .release = space_info_release,
 754         .default_groups = space_info_groups,
 755 };
 756
 757 /*
 758  * Allocation information about block groups.
 759  *
 760  * Path: /sys/fs/btrfs/<uuid>/allocation/
 761  */
 762 static const struct attribute *allocation_attrs[] = {
 763         BTRFS_ATTR_PTR(allocation, global_rsv_reserved),
 764         BTRFS_ATTR_PTR(allocation, global_rsv_size),
 765         NULL,
 766 };
 767
 768 static ssize_t btrfs_label_show(struct kobject *kobj,
 769                                 struct kobj_attribute *a, char *buf)
 770 {
 771         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 772         char *label = fs_info->super_copy->label;
 773         ssize_t ret;
 774
 775         spin_lock(&fs_info->super_lock);
 776         ret = sysfs_emit(buf, label[0] ? "%s\n" : "%s", label);
 777         spin_unlock(&fs_info->super_lock);
 778
 779         return ret;
 780 }
 781
 782 static ssize_t btrfs_label_store(struct kobject *kobj,
 783                                  struct kobj_attribute *a,
 784                                  const char *buf, size_t len)
 785 {
 786         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 787         size_t p_len;
 788
 789         if (!fs_info)
 790                 return -EPERM;
 791
 792         if (sb_rdonly(fs_info->sb))
 793                 return -EROFS;
 794
 795         /*
 796          * p_len is the len until the first occurrence of either
 797          * '\n' or '\0'
 798          */
 799         p_len = strcspn(buf, "\n");
 800
 801         if (p_len >= BTRFS_LABEL_SIZE)
 802                 return -EINVAL;
 803
 804         spin_lock(&fs_info->super_lock);
 805         memset(fs_info->super_copy->label, 0, BTRFS_LABEL_SIZE);
 806         memcpy(fs_info->super_copy->label, buf, p_len);
 807         spin_unlock(&fs_info->super_lock);
 808
 809         /*
 810          * We don't want to do full transaction commit from inside sysfs
 811          */
 812         btrfs_set_pending(fs_info, COMMIT);
 813         wake_up_process(fs_info->transaction_kthread);
 814
 815         return len;
 816 }
 817 BTRFS_ATTR_RW(, label, btrfs_label_show, btrfs_label_store);
 818
 819 static ssize_t btrfs_nodesize_show(struct kobject *kobj,
 820                                 struct kobj_attribute *a, char *buf)
 821 {
 822         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 823
 824         return sysfs_emit(buf, "%u\n", fs_info->super_copy->nodesize);
 825 }
 826
 827 BTRFS_ATTR(, nodesize, btrfs_nodesize_show);
 828
 829 static ssize_t btrfs_sectorsize_show(struct kobject *kobj,
 830                                 struct kobj_attribute *a, char *buf)
 831 {
 832         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 833
 834         return sysfs_emit(buf, "%u\n", fs_info->super_copy->sectorsize);
 835 }
 836
 837 BTRFS_ATTR(, sectorsize, btrfs_sectorsize_show);
 838
 839 static ssize_t btrfs_clone_alignment_show(struct kobject *kobj,
 840                                 struct kobj_attribute *a, char *buf)
 841 {
 842         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 843
 844         return sysfs_emit(buf, "%u\n", fs_info->super_copy->sectorsize);
 845 }
 846
 847 BTRFS_ATTR(, clone_alignment, btrfs_clone_alignment_show);
 848
 849 static ssize_t quota_override_show(struct kobject *kobj,
 850                                    struct kobj_attribute *a, char *buf)
 851 {
 852         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 853         int quota_override;
 854
 855         quota_override = test_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
 856         return sysfs_emit(buf, "%d\n", quota_override);
 857 }
 858
 859 static ssize_t quota_override_store(struct kobject *kobj,
 860                                     struct kobj_attribute *a,
 861                                     const char *buf, size_t len)
 862 {
 863         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 864         unsigned long knob;
 865         int err;
 866
 867         if (!fs_info)
 868                 return -EPERM;
 869
 870         if (!capable(CAP_SYS_RESOURCE))
 871                 return -EPERM;
 872
 873         err = kstrtoul(buf, 10, &knob);
 874         if (err)
 875                 return err;
 876         if (knob > 1)
 877                 return -EINVAL;
 878
 879         if (knob)
 880                 set_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
 881         else
 882                 clear_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
 883
 884         return len;
 885 }
 886
 887 BTRFS_ATTR_RW(, quota_override, quota_override_show, quota_override_store);
 888
 889 static ssize_t btrfs_metadata_uuid_show(struct kobject *kobj,
 890                                 struct kobj_attribute *a, char *buf)
 891 {
 892         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 893
 894         return sysfs_emit(buf, "%pU\n", 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 sysfs_emit(buf, "%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_BALANCE_PAUSED:
 926                         str = "balance paused\n";
 927                         break;
 928                 case BTRFS_EXCLOP_DEV_ADD:
 929                         str = "device add\n";
 930                         break;
 931                 case BTRFS_EXCLOP_DEV_REMOVE:
 932                         str = "device remove\n";
 933                         break;
 934                 case BTRFS_EXCLOP_DEV_REPLACE:
 935                         str = "device replace\n";
 936                         break;
 937                 case BTRFS_EXCLOP_RESIZE:
 938                         str = "resize\n";
 939                         break;
 940                 case BTRFS_EXCLOP_SWAP_ACTIVATE:
 941                         str = "swap activate\n";
 942                         break;
 943                 default:
 944                         str = "UNKNOWN\n";
 945                         break;
 946         }
 947         return sysfs_emit(buf, "%s", str);
 948 }
 949 BTRFS_ATTR(, exclusive_operation, btrfs_exclusive_operation_show);
 950
 951 static ssize_t btrfs_generation_show(struct kobject *kobj,
 952                                      struct kobj_attribute *a, char *buf)
 953 {
 954         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 955
 956         return sysfs_emit(buf, "%llu\n", fs_info->generation);
 957 }
 958 BTRFS_ATTR(, generation, btrfs_generation_show);
 959
 960 /*
 961  * Look for an exact string @string in @buffer with possible leading or
 962  * trailing whitespace
 963  */
 964 static bool strmatch(const char *buffer, const char *string)
 965 {
 966         const size_t len = strlen(string);
 967
 968         /* Skip leading whitespace */
 969         buffer = skip_spaces(buffer);
 970
 971         /* Match entire string, check if the rest is whitespace or empty */
 972         if (strncmp(string, buffer, len) == 0 &&
 973             strlen(skip_spaces(buffer + len)) == 0)
 974                 return true;
 975
 976         return false;
 977 }
 978
 979 static const char * const btrfs_read_policy_name[] = { "pid" };
 980
 981 static ssize_t btrfs_read_policy_show(struct kobject *kobj,
 982                                       struct kobj_attribute *a, char *buf)
 983 {
 984         struct btrfs_fs_devices *fs_devices = to_fs_devs(kobj);
 985         ssize_t ret = 0;
 986         int i;
 987
 988         for (i = 0; i < BTRFS_NR_READ_POLICY; i++) {
 989                 if (fs_devices->read_policy == i)
 990                         ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s[%s]",
 991                                          (ret == 0 ? "" : " "),
 992                                          btrfs_read_policy_name[i]);
 993                 else
 994                         ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%s",
 995                                          (ret == 0 ? "" : " "),
 996                                          btrfs_read_policy_name[i]);
 997         }
 998
 999         ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
1000
1001         return ret;
1002 }
1003
1004 static ssize_t btrfs_read_policy_store(struct kobject *kobj,
1005                                        struct kobj_attribute *a,
1006                                        const char *buf, size_t len)
1007 {
1008         struct btrfs_fs_devices *fs_devices = to_fs_devs(kobj);
1009         int i;
1010
1011         for (i = 0; i < BTRFS_NR_READ_POLICY; i++) {
1012                 if (strmatch(buf, btrfs_read_policy_name[i])) {
1013                         if (i != fs_devices->read_policy) {
1014                                 fs_devices->read_policy = i;
1015                                 btrfs_info(fs_devices->fs_info,
1016                                            "read policy set to '%s'",
1017                                            btrfs_read_policy_name[i]);
1018                         }
1019                         return len;
1020                 }
1021         }
1022
1023         return -EINVAL;
1024 }
1025 BTRFS_ATTR_RW(, read_policy, btrfs_read_policy_show, btrfs_read_policy_store);
1026
1027 static ssize_t btrfs_bg_reclaim_threshold_show(struct kobject *kobj,
1028                                                struct kobj_attribute *a,
1029                                                char *buf)
1030 {
1031         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1032         ssize_t ret;
1033
1034         ret = sysfs_emit(buf, "%d\n", READ_ONCE(fs_info->bg_reclaim_threshold));
1035
1036         return ret;
1037 }
1038
1039 static ssize_t btrfs_bg_reclaim_threshold_store(struct kobject *kobj,
1040                                                 struct kobj_attribute *a,
1041                                                 const char *buf, size_t len)
1042 {
1043         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1044         int thresh;
1045         int ret;
1046
1047         ret = kstrtoint(buf, 10, &thresh);
1048         if (ret)
1049                 return ret;
1050
1051         if (thresh != 0 && (thresh <= 50 || thresh > 100))
1052                 return -EINVAL;
1053
1054         WRITE_ONCE(fs_info->bg_reclaim_threshold, thresh);
1055
1056         return len;
1057 }
1058 BTRFS_ATTR_RW(, bg_reclaim_threshold, btrfs_bg_reclaim_threshold_show,
1059               btrfs_bg_reclaim_threshold_store);
1060
1061 /*
1062  * Per-filesystem information and stats.
1063  *
1064  * Path: /sys/fs/btrfs/<uuid>/
1065  */
1066 static const struct attribute *btrfs_attrs[] = {
1067         BTRFS_ATTR_PTR(, label),
1068         BTRFS_ATTR_PTR(, nodesize),
1069         BTRFS_ATTR_PTR(, sectorsize),
1070         BTRFS_ATTR_PTR(, clone_alignment),
1071         BTRFS_ATTR_PTR(, quota_override),
1072         BTRFS_ATTR_PTR(, metadata_uuid),
1073         BTRFS_ATTR_PTR(, checksum),
1074         BTRFS_ATTR_PTR(, exclusive_operation),
1075         BTRFS_ATTR_PTR(, generation),
1076         BTRFS_ATTR_PTR(, read_policy),
1077         BTRFS_ATTR_PTR(, bg_reclaim_threshold),
1078         NULL,
1079 };
1080
1081 static void btrfs_release_fsid_kobj(struct kobject *kobj)
1082 {
1083         struct btrfs_fs_devices *fs_devs = to_fs_devs(kobj);
1084
1085         memset(&fs_devs->fsid_kobj, 0, sizeof(struct kobject));
1086         complete(&fs_devs->kobj_unregister);
1087 }
1088
1089 static struct kobj_type btrfs_ktype = {
1090         .sysfs_ops      = &kobj_sysfs_ops,
1091         .release        = btrfs_release_fsid_kobj,
1092 };
1093
1094 static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj)
1095 {
1096         if (kobj->ktype != &btrfs_ktype)
1097                 return NULL;
1098         return container_of(kobj, struct btrfs_fs_devices, fsid_kobj);
1099 }
1100
1101 static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj)
1102 {
1103         if (kobj->ktype != &btrfs_ktype)
1104                 return NULL;
1105         return to_fs_devs(kobj)->fs_info;
1106 }
1107
1108 #define NUM_FEATURE_BITS 64
1109 #define BTRFS_FEATURE_NAME_MAX 13
1110 static char btrfs_unknown_feature_names[FEAT_MAX][NUM_FEATURE_BITS][BTRFS_FEATURE_NAME_MAX];
1111 static struct btrfs_feature_attr btrfs_feature_attrs[FEAT_MAX][NUM_FEATURE_BITS];
1112
1113 static_assert(ARRAY_SIZE(btrfs_unknown_feature_names) ==
1114               ARRAY_SIZE(btrfs_feature_attrs));
1115 static_assert(ARRAY_SIZE(btrfs_unknown_feature_names[0]) ==
1116               ARRAY_SIZE(btrfs_feature_attrs[0]));
1117
1118 static const u64 supported_feature_masks[FEAT_MAX] = {
1119         [FEAT_COMPAT]    = BTRFS_FEATURE_COMPAT_SUPP,
1120         [FEAT_COMPAT_RO] = BTRFS_FEATURE_COMPAT_RO_SUPP,
1121         [FEAT_INCOMPAT]  = BTRFS_FEATURE_INCOMPAT_SUPP,
1122 };
1123
1124 static int addrm_unknown_feature_attrs(struct btrfs_fs_info *fs_info, bool add)
1125 {
1126         int set;
1127
1128         for (set = 0; set < FEAT_MAX; set++) {
1129                 int i;
1130                 struct attribute *attrs[2];
1131                 struct attribute_group agroup = {
1132                         .name = "features",
1133                         .attrs = attrs,
1134                 };
1135                 u64 features = get_features(fs_info, set);
1136                 features &= ~supported_feature_masks[set];
1137
1138                 if (!features)
1139                         continue;
1140
1141                 attrs[1] = NULL;
1142                 for (i = 0; i < NUM_FEATURE_BITS; i++) {
1143                         struct btrfs_feature_attr *fa;
1144
1145                         if (!(features & (1ULL << i)))
1146                                 continue;
1147
1148                         fa = &btrfs_feature_attrs[set][i];
1149                         attrs[0] = &fa->kobj_attr.attr;
1150                         if (add) {
1151                                 int ret;
1152                                 ret = sysfs_merge_group(&fs_info->fs_devices->fsid_kobj,
1153                                                         &agroup);
1154                                 if (ret)
1155                                         return ret;
1156                         } else
1157                                 sysfs_unmerge_group(&fs_info->fs_devices->fsid_kobj,
1158                                                     &agroup);
1159                 }
1160
1161         }
1162         return 0;
1163 }
1164
1165 static void __btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs)
1166 {
1167         if (fs_devs->devinfo_kobj) {
1168                 kobject_del(fs_devs->devinfo_kobj);
1169                 kobject_put(fs_devs->devinfo_kobj);
1170                 fs_devs->devinfo_kobj = NULL;
1171         }
1172
1173         if (fs_devs->devices_kobj) {
1174                 kobject_del(fs_devs->devices_kobj);
1175                 kobject_put(fs_devs->devices_kobj);
1176                 fs_devs->devices_kobj = NULL;
1177         }
1178
1179         if (fs_devs->fsid_kobj.state_initialized) {
1180                 kobject_del(&fs_devs->fsid_kobj);
1181                 kobject_put(&fs_devs->fsid_kobj);
1182                 wait_for_completion(&fs_devs->kobj_unregister);
1183         }
1184 }
1185
1186 /* when fs_devs is NULL it will remove all fsid kobject */
1187 void btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs)
1188 {
1189         struct list_head *fs_uuids = btrfs_get_fs_uuids();
1190
1191         if (fs_devs) {
1192                 __btrfs_sysfs_remove_fsid(fs_devs);
1193                 return;
1194         }
1195
1196         list_for_each_entry(fs_devs, fs_uuids, fs_list) {
1197                 __btrfs_sysfs_remove_fsid(fs_devs);
1198         }
1199 }
1200
1201 static void btrfs_sysfs_remove_fs_devices(struct btrfs_fs_devices *fs_devices)
1202 {
1203         struct btrfs_device *device;
1204         struct btrfs_fs_devices *seed;
1205
1206         list_for_each_entry(device, &fs_devices->devices, dev_list)
1207                 btrfs_sysfs_remove_device(device);
1208
1209         list_for_each_entry(seed, &fs_devices->seed_list, seed_list) {
1210                 list_for_each_entry(device, &seed->devices, dev_list)
1211                         btrfs_sysfs_remove_device(device);
1212         }
1213 }
1214
1215 void btrfs_sysfs_remove_mounted(struct btrfs_fs_info *fs_info)
1216 {
1217         struct kobject *fsid_kobj = &fs_info->fs_devices->fsid_kobj;
1218
1219         sysfs_remove_link(fsid_kobj, "bdi");
1220
1221         if (fs_info->space_info_kobj) {
1222                 sysfs_remove_files(fs_info->space_info_kobj, allocation_attrs);
1223                 kobject_del(fs_info->space_info_kobj);
1224                 kobject_put(fs_info->space_info_kobj);
1225         }
1226 #ifdef CONFIG_BTRFS_DEBUG
1227         if (fs_info->discard_debug_kobj) {
1228                 sysfs_remove_files(fs_info->discard_debug_kobj,
1229                                    discard_debug_attrs);
1230                 kobject_del(fs_info->discard_debug_kobj);
1231                 kobject_put(fs_info->discard_debug_kobj);
1232         }
1233         if (fs_info->debug_kobj) {
1234                 sysfs_remove_files(fs_info->debug_kobj, btrfs_debug_mount_attrs);
1235                 kobject_del(fs_info->debug_kobj);
1236                 kobject_put(fs_info->debug_kobj);
1237         }
1238 #endif
1239         addrm_unknown_feature_attrs(fs_info, false);
1240         sysfs_remove_group(fsid_kobj, &btrfs_feature_attr_group);
1241         sysfs_remove_files(fsid_kobj, btrfs_attrs);
1242         btrfs_sysfs_remove_fs_devices(fs_info->fs_devices);
1243 }
1244
1245 static const char * const btrfs_feature_set_names[FEAT_MAX] = {
1246         [FEAT_COMPAT]    = "compat",
1247         [FEAT_COMPAT_RO] = "compat_ro",
1248         [FEAT_INCOMPAT]  = "incompat",
1249 };
1250
1251 const char *btrfs_feature_set_name(enum btrfs_feature_set set)
1252 {
1253         return btrfs_feature_set_names[set];
1254 }
1255
1256 char *btrfs_printable_features(enum btrfs_feature_set set, u64 flags)
1257 {
1258         size_t bufsize = 4096; /* safe max, 64 names * 64 bytes */
1259         int len = 0;
1260         int i;
1261         char *str;
1262
1263         str = kmalloc(bufsize, GFP_KERNEL);
1264         if (!str)
1265                 return str;
1266
1267         for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
1268                 const char *name;
1269
1270                 if (!(flags & (1ULL << i)))
1271                         continue;
1272
1273                 name = btrfs_feature_attrs[set][i].kobj_attr.attr.name;
1274                 len += scnprintf(str + len, bufsize - len, "%s%s",
1275                                 len ? "," : "", name);
1276         }
1277
1278         return str;
1279 }
1280
1281 static void init_feature_attrs(void)
1282 {
1283         struct btrfs_feature_attr *fa;
1284         int set, i;
1285
1286         memset(btrfs_feature_attrs, 0, sizeof(btrfs_feature_attrs));
1287         memset(btrfs_unknown_feature_names, 0,
1288                sizeof(btrfs_unknown_feature_names));
1289
1290         for (i = 0; btrfs_supported_feature_attrs[i]; i++) {
1291                 struct btrfs_feature_attr *sfa;
1292                 struct attribute *a = btrfs_supported_feature_attrs[i];
1293                 int bit;
1294                 sfa = attr_to_btrfs_feature_attr(a);
1295                 bit = ilog2(sfa->feature_bit);
1296                 fa = &btrfs_feature_attrs[sfa->feature_set][bit];
1297
1298                 fa->kobj_attr.attr.name = sfa->kobj_attr.attr.name;
1299         }
1300
1301         for (set = 0; set < FEAT_MAX; set++) {
1302                 for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
1303                         char *name = btrfs_unknown_feature_names[set][i];
1304                         fa = &btrfs_feature_attrs[set][i];
1305
1306                         if (fa->kobj_attr.attr.name)
1307                                 continue;
1308
1309                         snprintf(name, BTRFS_FEATURE_NAME_MAX, "%s:%u",
1310                                  btrfs_feature_set_names[set], i);
1311
1312                         fa->kobj_attr.attr.name = name;
1313                         fa->kobj_attr.attr.mode = S_IRUGO;
1314                         fa->feature_set = set;
1315                         fa->feature_bit = 1ULL << i;
1316                 }
1317         }
1318 }
1319
1320 /*
1321  * Create a sysfs entry for a given block group type at path
1322  * /sys/fs/btrfs/UUID/allocation/data/TYPE
1323  */
1324 void btrfs_sysfs_add_block_group_type(struct btrfs_block_group *cache)
1325 {
1326         struct btrfs_fs_info *fs_info = cache->fs_info;
1327         struct btrfs_space_info *space_info = cache->space_info;
1328         struct raid_kobject *rkobj;
1329         const int index = btrfs_bg_flags_to_raid_index(cache->flags);
1330         unsigned int nofs_flag;
1331         int ret;
1332
1333         /*
1334          * Setup a NOFS context because kobject_add(), deep in its call chain,
1335          * does GFP_KERNEL allocations, and we are often called in a context
1336          * where if reclaim is triggered we can deadlock (we are either holding
1337          * a transaction handle or some lock required for a transaction
1338          * commit).
1339          */
1340         nofs_flag = memalloc_nofs_save();
1341
1342         rkobj = kzalloc(sizeof(*rkobj), GFP_NOFS);
1343         if (!rkobj) {
1344                 memalloc_nofs_restore(nofs_flag);
1345                 btrfs_warn(cache->fs_info,
1346                                 "couldn't alloc memory for raid level kobject");
1347                 return;
1348         }
1349
1350         rkobj->flags = cache->flags;
1351         kobject_init(&rkobj->kobj, &btrfs_raid_ktype);
1352
1353         /*
1354          * We call this either on mount, or if we've created a block group for a
1355          * new index type while running (i.e. when restriping).  The running
1356          * case is tricky because we could race with other threads, so we need
1357          * to have this check to make sure we didn't already init the kobject.
1358          *
1359          * We don't have to protect on the free side because it only happens on
1360          * unmount.
1361          */
1362         spin_lock(&space_info->lock);
1363         if (space_info->block_group_kobjs[index]) {
1364                 spin_unlock(&space_info->lock);
1365                 kobject_put(&rkobj->kobj);
1366                 return;
1367         } else {
1368                 space_info->block_group_kobjs[index] = &rkobj->kobj;
1369         }
1370         spin_unlock(&space_info->lock);
1371
1372         ret = kobject_add(&rkobj->kobj, &space_info->kobj, "%s",
1373                           btrfs_bg_type_to_raid_name(rkobj->flags));
1374         memalloc_nofs_restore(nofs_flag);
1375         if (ret) {
1376                 spin_lock(&space_info->lock);
1377                 space_info->block_group_kobjs[index] = NULL;
1378                 spin_unlock(&space_info->lock);
1379                 kobject_put(&rkobj->kobj);
1380                 btrfs_warn(fs_info,
1381                         "failed to add kobject for block cache, ignoring");
1382                 return;
1383         }
1384 }
1385
1386 /*
1387  * Remove sysfs directories for all block group types of a given space info and
1388  * the space info as well
1389  */
1390 void btrfs_sysfs_remove_space_info(struct btrfs_space_info *space_info)
1391 {
1392         int i;
1393
1394         for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) {
1395                 struct kobject *kobj;
1396
1397                 kobj = space_info->block_group_kobjs[i];
1398                 space_info->block_group_kobjs[i] = NULL;
1399                 if (kobj) {
1400                         kobject_del(kobj);
1401                         kobject_put(kobj);
1402                 }
1403         }
1404         kobject_del(&space_info->kobj);
1405         kobject_put(&space_info->kobj);
1406 }
1407
1408 static const char *alloc_name(u64 flags)
1409 {
1410         switch (flags) {
1411         case BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA:
1412                 return "mixed";
1413         case BTRFS_BLOCK_GROUP_METADATA:
1414                 return "metadata";
1415         case BTRFS_BLOCK_GROUP_DATA:
1416                 return "data";
1417         case BTRFS_BLOCK_GROUP_SYSTEM:
1418                 return "system";
1419         default:
1420                 WARN_ON(1);
1421                 return "invalid-combination";
1422         }
1423 }
1424
1425 /*
1426  * Create a sysfs entry for a space info type at path
1427  * /sys/fs/btrfs/UUID/allocation/TYPE
1428  */
1429 int btrfs_sysfs_add_space_info_type(struct btrfs_fs_info *fs_info,
1430                                     struct btrfs_space_info *space_info)
1431 {
1432         int ret;
1433
1434         ret = kobject_init_and_add(&space_info->kobj, &space_info_ktype,
1435                                    fs_info->space_info_kobj, "%s",
1436                                    alloc_name(space_info->flags));
1437         if (ret) {
1438                 kobject_put(&space_info->kobj);
1439                 return ret;
1440         }
1441
1442         return 0;
1443 }
1444
1445 void btrfs_sysfs_remove_device(struct btrfs_device *device)
1446 {
1447         struct kobject *devices_kobj;
1448
1449         /*
1450          * Seed fs_devices devices_kobj aren't used, fetch kobject from the
1451          * fs_info::fs_devices.
1452          */
1453         devices_kobj = device->fs_info->fs_devices->devices_kobj;
1454         ASSERT(devices_kobj);
1455
1456         if (device->bdev)
1457                 sysfs_remove_link(devices_kobj, bdev_kobj(device->bdev)->name);
1458
1459         if (device->devid_kobj.state_initialized) {
1460                 kobject_del(&device->devid_kobj);
1461                 kobject_put(&device->devid_kobj);
1462                 wait_for_completion(&device->kobj_unregister);
1463         }
1464 }
1465
1466 static ssize_t btrfs_devinfo_in_fs_metadata_show(struct kobject *kobj,
1467                                                  struct kobj_attribute *a,
1468                                                  char *buf)
1469 {
1470         int val;
1471         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1472                                                    devid_kobj);
1473
1474         val = !!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state);
1475
1476         return sysfs_emit(buf, "%d\n", val);
1477 }
1478 BTRFS_ATTR(devid, in_fs_metadata, btrfs_devinfo_in_fs_metadata_show);
1479
1480 static ssize_t btrfs_devinfo_missing_show(struct kobject *kobj,
1481                                         struct kobj_attribute *a, char *buf)
1482 {
1483         int val;
1484         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1485                                                    devid_kobj);
1486
1487         val = !!test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state);
1488
1489         return sysfs_emit(buf, "%d\n", val);
1490 }
1491 BTRFS_ATTR(devid, missing, btrfs_devinfo_missing_show);
1492
1493 static ssize_t btrfs_devinfo_replace_target_show(struct kobject *kobj,
1494                                                  struct kobj_attribute *a,
1495                                                  char *buf)
1496 {
1497         int val;
1498         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1499                                                    devid_kobj);
1500
1501         val = !!test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state);
1502
1503         return sysfs_emit(buf, "%d\n", val);
1504 }
1505 BTRFS_ATTR(devid, replace_target, btrfs_devinfo_replace_target_show);
1506
1507 static ssize_t btrfs_devinfo_scrub_speed_max_show(struct kobject *kobj,
1508                                              struct kobj_attribute *a,
1509                                              char *buf)
1510 {
1511         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1512                                                    devid_kobj);
1513
1514         return sysfs_emit(buf, "%llu\n", READ_ONCE(device->scrub_speed_max));
1515 }
1516
1517 static ssize_t btrfs_devinfo_scrub_speed_max_store(struct kobject *kobj,
1518                                               struct kobj_attribute *a,
1519                                               const char *buf, size_t len)
1520 {
1521         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1522                                                    devid_kobj);
1523         char *endptr;
1524         unsigned long long limit;
1525
1526         limit = memparse(buf, &endptr);
1527         WRITE_ONCE(device->scrub_speed_max, limit);
1528         return len;
1529 }
1530 BTRFS_ATTR_RW(devid, scrub_speed_max, btrfs_devinfo_scrub_speed_max_show,
1531               btrfs_devinfo_scrub_speed_max_store);
1532
1533 static ssize_t btrfs_devinfo_writeable_show(struct kobject *kobj,
1534                                             struct kobj_attribute *a, char *buf)
1535 {
1536         int val;
1537         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1538                                                    devid_kobj);
1539
1540         val = !!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state);
1541
1542         return sysfs_emit(buf, "%d\n", val);
1543 }
1544 BTRFS_ATTR(devid, writeable, btrfs_devinfo_writeable_show);
1545
1546 static ssize_t btrfs_devinfo_fsid_show(struct kobject *kobj,
1547                                        struct kobj_attribute *a, char *buf)
1548 {
1549         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1550                                                    devid_kobj);
1551
1552         return sysfs_emit(buf, "%pU\n", device->fs_devices->fsid);
1553 }
1554 BTRFS_ATTR(devid, fsid, btrfs_devinfo_fsid_show);
1555
1556 static ssize_t btrfs_devinfo_error_stats_show(struct kobject *kobj,
1557                 struct kobj_attribute *a, char *buf)
1558 {
1559         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1560                                                    devid_kobj);
1561
1562         if (!device->dev_stats_valid)
1563                 return sysfs_emit(buf, "invalid\n");
1564
1565         /*
1566          * Print all at once so we get a snapshot of all values from the same
1567          * time. Keep them in sync and in order of definition of
1568          * btrfs_dev_stat_values.
1569          */
1570         return sysfs_emit(buf,
1571                 "write_errs %d\n"
1572                 "read_errs %d\n"
1573                 "flush_errs %d\n"
1574                 "corruption_errs %d\n"
1575                 "generation_errs %d\n",
1576                 btrfs_dev_stat_read(device, BTRFS_DEV_STAT_WRITE_ERRS),
1577                 btrfs_dev_stat_read(device, BTRFS_DEV_STAT_READ_ERRS),
1578                 btrfs_dev_stat_read(device, BTRFS_DEV_STAT_FLUSH_ERRS),
1579                 btrfs_dev_stat_read(device, BTRFS_DEV_STAT_CORRUPTION_ERRS),
1580                 btrfs_dev_stat_read(device, BTRFS_DEV_STAT_GENERATION_ERRS));
1581 }
1582 BTRFS_ATTR(devid, error_stats, btrfs_devinfo_error_stats_show);
1583
1584 /*
1585  * Information about one device.
1586  *
1587  * Path: /sys/fs/btrfs/<uuid>/devinfo/<devid>/
1588  */
1589 static struct attribute *devid_attrs[] = {
1590         BTRFS_ATTR_PTR(devid, error_stats),
1591         BTRFS_ATTR_PTR(devid, fsid),
1592         BTRFS_ATTR_PTR(devid, in_fs_metadata),
1593         BTRFS_ATTR_PTR(devid, missing),
1594         BTRFS_ATTR_PTR(devid, replace_target),
1595         BTRFS_ATTR_PTR(devid, scrub_speed_max),
1596         BTRFS_ATTR_PTR(devid, writeable),
1597         NULL
1598 };
1599 ATTRIBUTE_GROUPS(devid);
1600
1601 static void btrfs_release_devid_kobj(struct kobject *kobj)
1602 {
1603         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1604                                                    devid_kobj);
1605
1606         memset(&device->devid_kobj, 0, sizeof(struct kobject));
1607         complete(&device->kobj_unregister);
1608 }
1609
1610 static struct kobj_type devid_ktype = {
1611         .sysfs_ops      = &kobj_sysfs_ops,
1612         .default_groups = devid_groups,
1613         .release        = btrfs_release_devid_kobj,
1614 };
1615
1616 int btrfs_sysfs_add_device(struct btrfs_device *device)
1617 {
1618         int ret;
1619         unsigned int nofs_flag;
1620         struct kobject *devices_kobj;
1621         struct kobject *devinfo_kobj;
1622
1623         /*
1624          * Make sure we use the fs_info::fs_devices to fetch the kobjects even
1625          * for the seed fs_devices
1626          */
1627         devices_kobj = device->fs_info->fs_devices->devices_kobj;
1628         devinfo_kobj = device->fs_info->fs_devices->devinfo_kobj;
1629         ASSERT(devices_kobj);
1630         ASSERT(devinfo_kobj);
1631
1632         nofs_flag = memalloc_nofs_save();
1633
1634         if (device->bdev) {
1635                 struct kobject *disk_kobj = bdev_kobj(device->bdev);
1636
1637                 ret = sysfs_create_link(devices_kobj, disk_kobj, disk_kobj->name);
1638                 if (ret) {
1639                         btrfs_warn(device->fs_info,
1640                                 "creating sysfs device link for devid %llu failed: %d",
1641                                 device->devid, ret);
1642                         goto out;
1643                 }
1644         }
1645
1646         init_completion(&device->kobj_unregister);
1647         ret = kobject_init_and_add(&device->devid_kobj, &devid_ktype,
1648                                    devinfo_kobj, "%llu", device->devid);
1649         if (ret) {
1650                 kobject_put(&device->devid_kobj);
1651                 btrfs_warn(device->fs_info,
1652                            "devinfo init for devid %llu failed: %d",
1653                            device->devid, ret);
1654         }
1655
1656 out:
1657         memalloc_nofs_restore(nofs_flag);
1658         return ret;
1659 }
1660
1661 static int btrfs_sysfs_add_fs_devices(struct btrfs_fs_devices *fs_devices)
1662 {
1663         int ret;
1664         struct btrfs_device *device;
1665         struct btrfs_fs_devices *seed;
1666
1667         list_for_each_entry(device, &fs_devices->devices, dev_list) {
1668                 ret = btrfs_sysfs_add_device(device);
1669                 if (ret)
1670                         goto fail;
1671         }
1672
1673         list_for_each_entry(seed, &fs_devices->seed_list, seed_list) {
1674                 list_for_each_entry(device, &seed->devices, dev_list) {
1675                         ret = btrfs_sysfs_add_device(device);
1676                         if (ret)
1677                                 goto fail;
1678                 }
1679         }
1680
1681         return 0;
1682
1683 fail:
1684         btrfs_sysfs_remove_fs_devices(fs_devices);
1685         return ret;
1686 }
1687
1688 void btrfs_kobject_uevent(struct block_device *bdev, enum kobject_action action)
1689 {
1690         int ret;
1691
1692         ret = kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, action);
1693         if (ret)
1694                 pr_warn("BTRFS: Sending event '%d' to kobject: '%s' (%p): failed\n",
1695                         action, kobject_name(&disk_to_dev(bdev->bd_disk)->kobj),
1696                         &disk_to_dev(bdev->bd_disk)->kobj);
1697 }
1698
1699 void btrfs_sysfs_update_sprout_fsid(struct btrfs_fs_devices *fs_devices)
1700
1701 {
1702         char fsid_buf[BTRFS_UUID_UNPARSED_SIZE];
1703
1704         /*
1705          * Sprouting changes fsid of the mounted filesystem, rename the fsid
1706          * directory
1707          */
1708         snprintf(fsid_buf, BTRFS_UUID_UNPARSED_SIZE, "%pU", fs_devices->fsid);
1709         if (kobject_rename(&fs_devices->fsid_kobj, fsid_buf))
1710                 btrfs_warn(fs_devices->fs_info,
1711                                 "sysfs: failed to create fsid for sprout");
1712 }
1713
1714 void btrfs_sysfs_update_devid(struct btrfs_device *device)
1715 {
1716         char tmp[24];
1717
1718         snprintf(tmp, sizeof(tmp), "%llu", device->devid);
1719
1720         if (kobject_rename(&device->devid_kobj, tmp))
1721                 btrfs_warn(device->fs_devices->fs_info,
1722                            "sysfs: failed to update devid for %llu",
1723                            device->devid);
1724 }
1725
1726 /* /sys/fs/btrfs/ entry */
1727 static struct kset *btrfs_kset;
1728
1729 /*
1730  * Creates:
1731  *              /sys/fs/btrfs/UUID
1732  *
1733  * Can be called by the device discovery thread.
1734  */
1735 int btrfs_sysfs_add_fsid(struct btrfs_fs_devices *fs_devs)
1736 {
1737         int error;
1738
1739         init_completion(&fs_devs->kobj_unregister);
1740         fs_devs->fsid_kobj.kset = btrfs_kset;
1741         error = kobject_init_and_add(&fs_devs->fsid_kobj, &btrfs_ktype, NULL,
1742                                      "%pU", fs_devs->fsid);
1743         if (error) {
1744                 kobject_put(&fs_devs->fsid_kobj);
1745                 return error;
1746         }
1747
1748         fs_devs->devices_kobj = kobject_create_and_add("devices",
1749                                                        &fs_devs->fsid_kobj);
1750         if (!fs_devs->devices_kobj) {
1751                 btrfs_err(fs_devs->fs_info,
1752                           "failed to init sysfs device interface");
1753                 btrfs_sysfs_remove_fsid(fs_devs);
1754                 return -ENOMEM;
1755         }
1756
1757         fs_devs->devinfo_kobj = kobject_create_and_add("devinfo",
1758                                                        &fs_devs->fsid_kobj);
1759         if (!fs_devs->devinfo_kobj) {
1760                 btrfs_err(fs_devs->fs_info,
1761                           "failed to init sysfs devinfo kobject");
1762                 btrfs_sysfs_remove_fsid(fs_devs);
1763                 return -ENOMEM;
1764         }
1765
1766         return 0;
1767 }
1768
1769 int btrfs_sysfs_add_mounted(struct btrfs_fs_info *fs_info)
1770 {
1771         int error;
1772         struct btrfs_fs_devices *fs_devs = fs_info->fs_devices;
1773         struct kobject *fsid_kobj = &fs_devs->fsid_kobj;
1774
1775         error = btrfs_sysfs_add_fs_devices(fs_devs);
1776         if (error)
1777                 return error;
1778
1779         error = sysfs_create_files(fsid_kobj, btrfs_attrs);
1780         if (error) {
1781                 btrfs_sysfs_remove_fs_devices(fs_devs);
1782                 return error;
1783         }
1784
1785         error = sysfs_create_group(fsid_kobj,
1786                                    &btrfs_feature_attr_group);
1787         if (error)
1788                 goto failure;
1789
1790 #ifdef CONFIG_BTRFS_DEBUG
1791         fs_info->debug_kobj = kobject_create_and_add("debug", fsid_kobj);
1792         if (!fs_info->debug_kobj) {
1793                 error = -ENOMEM;
1794                 goto failure;
1795         }
1796
1797         error = sysfs_create_files(fs_info->debug_kobj, btrfs_debug_mount_attrs);
1798         if (error)
1799                 goto failure;
1800
1801         /* Discard directory */
1802         fs_info->discard_debug_kobj = kobject_create_and_add("discard",
1803                                                      fs_info->debug_kobj);
1804         if (!fs_info->discard_debug_kobj) {
1805                 error = -ENOMEM;
1806                 goto failure;
1807         }
1808
1809         error = sysfs_create_files(fs_info->discard_debug_kobj,
1810                                    discard_debug_attrs);
1811         if (error)
1812                 goto failure;
1813 #endif
1814
1815         error = addrm_unknown_feature_attrs(fs_info, true);
1816         if (error)
1817                 goto failure;
1818
1819         error = sysfs_create_link(fsid_kobj, &fs_info->sb->s_bdi->dev->kobj, "bdi");
1820         if (error)
1821                 goto failure;
1822
1823         fs_info->space_info_kobj = kobject_create_and_add("allocation",
1824                                                   fsid_kobj);
1825         if (!fs_info->space_info_kobj) {
1826                 error = -ENOMEM;
1827                 goto failure;
1828         }
1829
1830         error = sysfs_create_files(fs_info->space_info_kobj, allocation_attrs);
1831         if (error)
1832                 goto failure;
1833
1834         return 0;
1835 failure:
1836         btrfs_sysfs_remove_mounted(fs_info);
1837         return error;
1838 }
1839
1840 static inline struct btrfs_fs_info *qgroup_kobj_to_fs_info(struct kobject *kobj)
1841 {
1842         return to_fs_info(kobj->parent->parent);
1843 }
1844
1845 #define QGROUP_ATTR(_member, _show_name)                                        \
1846 static ssize_t btrfs_qgroup_show_##_member(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->_member, &fs_info->qgroup_lock, buf);    \
1854 }                                                                               \
1855 BTRFS_ATTR(qgroup, _show_name, btrfs_qgroup_show_##_member)
1856
1857 #define QGROUP_RSV_ATTR(_name, _type)                                           \
1858 static ssize_t btrfs_qgroup_rsv_show_##_name(struct kobject *qgroup_kobj,       \
1859                                              struct kobj_attribute *a,          \
1860                                              char *buf)                         \
1861 {                                                                               \
1862         struct btrfs_fs_info *fs_info = qgroup_kobj_to_fs_info(qgroup_kobj);    \
1863         struct btrfs_qgroup *qgroup = container_of(qgroup_kobj,                 \
1864                         struct btrfs_qgroup, kobj);                             \
1865         return btrfs_show_u64(&qgroup->rsv.values[_type],                       \
1866                         &fs_info->qgroup_lock, buf);                            \
1867 }                                                                               \
1868 BTRFS_ATTR(qgroup, rsv_##_name, btrfs_qgroup_rsv_show_##_name)
1869
1870 QGROUP_ATTR(rfer, referenced);
1871 QGROUP_ATTR(excl, exclusive);
1872 QGROUP_ATTR(max_rfer, max_referenced);
1873 QGROUP_ATTR(max_excl, max_exclusive);
1874 QGROUP_ATTR(lim_flags, limit_flags);
1875 QGROUP_RSV_ATTR(data, BTRFS_QGROUP_RSV_DATA);
1876 QGROUP_RSV_ATTR(meta_pertrans, BTRFS_QGROUP_RSV_META_PERTRANS);
1877 QGROUP_RSV_ATTR(meta_prealloc, BTRFS_QGROUP_RSV_META_PREALLOC);
1878
1879 /*
1880  * Qgroup information.
1881  *
1882  * Path: /sys/fs/btrfs/<uuid>/qgroups/<level>_<qgroupid>/
1883  */
1884 static struct attribute *qgroup_attrs[] = {
1885         BTRFS_ATTR_PTR(qgroup, referenced),
1886         BTRFS_ATTR_PTR(qgroup, exclusive),
1887         BTRFS_ATTR_PTR(qgroup, max_referenced),
1888         BTRFS_ATTR_PTR(qgroup, max_exclusive),
1889         BTRFS_ATTR_PTR(qgroup, limit_flags),
1890         BTRFS_ATTR_PTR(qgroup, rsv_data),
1891         BTRFS_ATTR_PTR(qgroup, rsv_meta_pertrans),
1892         BTRFS_ATTR_PTR(qgroup, rsv_meta_prealloc),
1893         NULL
1894 };
1895 ATTRIBUTE_GROUPS(qgroup);
1896
1897 static void qgroup_release(struct kobject *kobj)
1898 {
1899         struct btrfs_qgroup *qgroup = container_of(kobj, struct btrfs_qgroup, kobj);
1900
1901         memset(&qgroup->kobj, 0, sizeof(*kobj));
1902 }
1903
1904 static struct kobj_type qgroup_ktype = {
1905         .sysfs_ops = &kobj_sysfs_ops,
1906         .release = qgroup_release,
1907         .default_groups = qgroup_groups,
1908 };
1909
1910 int btrfs_sysfs_add_one_qgroup(struct btrfs_fs_info *fs_info,
1911                                 struct btrfs_qgroup *qgroup)
1912 {
1913         struct kobject *qgroups_kobj = fs_info->qgroups_kobj;
1914         int ret;
1915
1916         if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
1917                 return 0;
1918         if (qgroup->kobj.state_initialized)
1919                 return 0;
1920         if (!qgroups_kobj)
1921                 return -EINVAL;
1922
1923         ret = kobject_init_and_add(&qgroup->kobj, &qgroup_ktype, qgroups_kobj,
1924                         "%hu_%llu", btrfs_qgroup_level(qgroup->qgroupid),
1925                         btrfs_qgroup_subvolid(qgroup->qgroupid));
1926         if (ret < 0)
1927                 kobject_put(&qgroup->kobj);
1928
1929         return ret;
1930 }
1931
1932 void btrfs_sysfs_del_qgroups(struct btrfs_fs_info *fs_info)
1933 {
1934         struct btrfs_qgroup *qgroup;
1935         struct btrfs_qgroup *next;
1936
1937         if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
1938                 return;
1939
1940         rbtree_postorder_for_each_entry_safe(qgroup, next,
1941                                              &fs_info->qgroup_tree, node)
1942                 btrfs_sysfs_del_one_qgroup(fs_info, qgroup);
1943         if (fs_info->qgroups_kobj) {
1944                 kobject_del(fs_info->qgroups_kobj);
1945                 kobject_put(fs_info->qgroups_kobj);
1946                 fs_info->qgroups_kobj = NULL;
1947         }
1948 }
1949
1950 /* Called when qgroups get initialized, thus there is no need for locking */
1951 int btrfs_sysfs_add_qgroups(struct btrfs_fs_info *fs_info)
1952 {
1953         struct kobject *fsid_kobj = &fs_info->fs_devices->fsid_kobj;
1954         struct btrfs_qgroup *qgroup;
1955         struct btrfs_qgroup *next;
1956         int ret = 0;
1957
1958         if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
1959                 return 0;
1960
1961         ASSERT(fsid_kobj);
1962         if (fs_info->qgroups_kobj)
1963                 return 0;
1964
1965         fs_info->qgroups_kobj = kobject_create_and_add("qgroups", fsid_kobj);
1966         if (!fs_info->qgroups_kobj) {
1967                 ret = -ENOMEM;
1968                 goto out;
1969         }
1970         rbtree_postorder_for_each_entry_safe(qgroup, next,
1971                                              &fs_info->qgroup_tree, node) {
1972                 ret = btrfs_sysfs_add_one_qgroup(fs_info, qgroup);
1973                 if (ret < 0)
1974                         goto out;
1975         }
1976
1977 out:
1978         if (ret < 0)
1979                 btrfs_sysfs_del_qgroups(fs_info);
1980         return ret;
1981 }
1982
1983 void btrfs_sysfs_del_one_qgroup(struct btrfs_fs_info *fs_info,
1984                                 struct btrfs_qgroup *qgroup)
1985 {
1986         if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
1987                 return;
1988
1989         if (qgroup->kobj.state_initialized) {
1990                 kobject_del(&qgroup->kobj);
1991                 kobject_put(&qgroup->kobj);
1992         }
1993 }
1994
1995 /*
1996  * Change per-fs features in /sys/fs/btrfs/UUID/features to match current
1997  * values in superblock. Call after any changes to incompat/compat_ro flags
1998  */
1999 void btrfs_sysfs_feature_update(struct btrfs_fs_info *fs_info,
2000                 u64 bit, enum btrfs_feature_set set)
2001 {
2002         struct btrfs_fs_devices *fs_devs;
2003         struct kobject *fsid_kobj;
2004         u64 __maybe_unused features;
2005         int __maybe_unused ret;
2006
2007         if (!fs_info)
2008                 return;
2009
2010         /*
2011          * See 14e46e04958df74 and e410e34fad913dd, feature bit updates are not
2012          * safe when called from some contexts (eg. balance)
2013          */
2014         features = get_features(fs_info, set);
2015         ASSERT(bit & supported_feature_masks[set]);
2016
2017         fs_devs = fs_info->fs_devices;
2018         fsid_kobj = &fs_devs->fsid_kobj;
2019
2020         if (!fsid_kobj->state_initialized)
2021                 return;
2022
2023         /*
2024          * FIXME: this is too heavy to update just one value, ideally we'd like
2025          * to use sysfs_update_group but some refactoring is needed first.
2026          */
2027         sysfs_remove_group(fsid_kobj, &btrfs_feature_attr_group);
2028         ret = sysfs_create_group(fsid_kobj, &btrfs_feature_attr_group);
2029 }
2030
2031 int __init btrfs_init_sysfs(void)
2032 {
2033         int ret;
2034
2035         btrfs_kset = kset_create_and_add("btrfs", NULL, fs_kobj);
2036         if (!btrfs_kset)
2037                 return -ENOMEM;
2038
2039         init_feature_attrs();
2040         ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
2041         if (ret)
2042                 goto out2;
2043         ret = sysfs_merge_group(&btrfs_kset->kobj,
2044                                 &btrfs_static_feature_attr_group);
2045         if (ret)
2046                 goto out_remove_group;
2047
2048 #ifdef CONFIG_BTRFS_DEBUG
2049         ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_debug_feature_attr_group);
2050         if (ret)
2051                 goto out2;
2052 #endif
2053
2054         return 0;
2055
2056 out_remove_group:
2057         sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
2058 out2:
2059         kset_unregister(btrfs_kset);
2060
2061         return ret;
2062 }
2063
2064 void __cold btrfs_exit_sysfs(void)
2065 {
2066         sysfs_unmerge_group(&btrfs_kset->kobj,
2067                             &btrfs_static_feature_attr_group);
2068         sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
2069 #ifdef CONFIG_BTRFS_DEBUG
2070         sysfs_remove_group(&btrfs_kset->kobj, &btrfs_debug_feature_attr_group);
2071 #endif
2072         kset_unregister(btrfs_kset);
2073 }
2074