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         /* An artificial limit to only support 4K and PAGE_SIZE */
 398         if (PAGE_SIZE > SZ_4K)
 399                 ret += sysfs_emit_at(buf, ret, "%u ", SZ_4K);
 400         ret += sysfs_emit_at(buf, 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 sysfs_emit(buf, "%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 sysfs_emit(buf, "%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 sysfs_emit(buf, "%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 sysfs_emit(buf, "%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 sysfs_emit(buf, "%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 sysfs_emit(buf, "%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 sysfs_emit(buf, "%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 sysfs_emit(buf, "%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 sysfs_emit(buf, "%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 sysfs_emit(buf, "%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 static ssize_t btrfs_sinfo_bg_reclaim_threshold_show(struct kobject *kobj,
 724                                                      struct kobj_attribute *a,
 725                                                      char *buf)
 726 {
 727         struct btrfs_space_info *space_info = to_space_info(kobj);
 728         ssize_t ret;
 729
 730         ret = sysfs_emit(buf, "%d\n", READ_ONCE(space_info->bg_reclaim_threshold));
 731
 732         return ret;
 733 }
 734
 735 static ssize_t btrfs_sinfo_bg_reclaim_threshold_store(struct kobject *kobj,
 736                                                       struct kobj_attribute *a,
 737                                                       const char *buf, size_t len)
 738 {
 739         struct btrfs_space_info *space_info = to_space_info(kobj);
 740         int thresh;
 741         int ret;
 742
 743         ret = kstrtoint(buf, 10, &thresh);
 744         if (ret)
 745                 return ret;
 746
 747         if (thresh < 0 || thresh > 100)
 748                 return -EINVAL;
 749
 750         WRITE_ONCE(space_info->bg_reclaim_threshold, thresh);
 751
 752         return len;
 753 }
 754
 755 BTRFS_ATTR_RW(space_info, bg_reclaim_threshold,
 756               btrfs_sinfo_bg_reclaim_threshold_show,
 757               btrfs_sinfo_bg_reclaim_threshold_store);
 758
 759 /*
 760  * Allocation information about block group types.
 761  *
 762  * Path: /sys/fs/btrfs/<uuid>/allocation/<bg-type>/
 763  */
 764 static struct attribute *space_info_attrs[] = {
 765         BTRFS_ATTR_PTR(space_info, flags),
 766         BTRFS_ATTR_PTR(space_info, total_bytes),
 767         BTRFS_ATTR_PTR(space_info, bytes_used),
 768         BTRFS_ATTR_PTR(space_info, bytes_pinned),
 769         BTRFS_ATTR_PTR(space_info, bytes_reserved),
 770         BTRFS_ATTR_PTR(space_info, bytes_may_use),
 771         BTRFS_ATTR_PTR(space_info, bytes_readonly),
 772         BTRFS_ATTR_PTR(space_info, bytes_zone_unusable),
 773         BTRFS_ATTR_PTR(space_info, disk_used),
 774         BTRFS_ATTR_PTR(space_info, disk_total),
 775         BTRFS_ATTR_PTR(space_info, bg_reclaim_threshold),
 776         NULL,
 777 };
 778 ATTRIBUTE_GROUPS(space_info);
 779
 780 static void space_info_release(struct kobject *kobj)
 781 {
 782         struct btrfs_space_info *sinfo = to_space_info(kobj);
 783         kfree(sinfo);
 784 }
 785
 786 static struct kobj_type space_info_ktype = {
 787         .sysfs_ops = &kobj_sysfs_ops,
 788         .release = space_info_release,
 789         .default_groups = space_info_groups,
 790 };
 791
 792 /*
 793  * Allocation information about block groups.
 794  *
 795  * Path: /sys/fs/btrfs/<uuid>/allocation/
 796  */
 797 static const struct attribute *allocation_attrs[] = {
 798         BTRFS_ATTR_PTR(allocation, global_rsv_reserved),
 799         BTRFS_ATTR_PTR(allocation, global_rsv_size),
 800         NULL,
 801 };
 802
 803 static ssize_t btrfs_label_show(struct kobject *kobj,
 804                                 struct kobj_attribute *a, char *buf)
 805 {
 806         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 807         char *label = fs_info->super_copy->label;
 808         ssize_t ret;
 809
 810         spin_lock(&fs_info->super_lock);
 811         ret = sysfs_emit(buf, label[0] ? "%s\n" : "%s", label);
 812         spin_unlock(&fs_info->super_lock);
 813
 814         return ret;
 815 }
 816
 817 static ssize_t btrfs_label_store(struct kobject *kobj,
 818                                  struct kobj_attribute *a,
 819                                  const char *buf, size_t len)
 820 {
 821         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 822         size_t p_len;
 823
 824         if (!fs_info)
 825                 return -EPERM;
 826
 827         if (sb_rdonly(fs_info->sb))
 828                 return -EROFS;
 829
 830         /*
 831          * p_len is the len until the first occurrence of either
 832          * '\n' or '\0'
 833          */
 834         p_len = strcspn(buf, "\n");
 835
 836         if (p_len >= BTRFS_LABEL_SIZE)
 837                 return -EINVAL;
 838
 839         spin_lock(&fs_info->super_lock);
 840         memset(fs_info->super_copy->label, 0, BTRFS_LABEL_SIZE);
 841         memcpy(fs_info->super_copy->label, buf, p_len);
 842         spin_unlock(&fs_info->super_lock);
 843
 844         /*
 845          * We don't want to do full transaction commit from inside sysfs
 846          */
 847         btrfs_set_pending(fs_info, COMMIT);
 848         wake_up_process(fs_info->transaction_kthread);
 849
 850         return len;
 851 }
 852 BTRFS_ATTR_RW(, label, btrfs_label_show, btrfs_label_store);
 853
 854 static ssize_t btrfs_nodesize_show(struct kobject *kobj,
 855                                 struct kobj_attribute *a, char *buf)
 856 {
 857         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 858
 859         return sysfs_emit(buf, "%u\n", fs_info->super_copy->nodesize);
 860 }
 861
 862 BTRFS_ATTR(, nodesize, btrfs_nodesize_show);
 863
 864 static ssize_t btrfs_sectorsize_show(struct kobject *kobj,
 865                                 struct kobj_attribute *a, char *buf)
 866 {
 867         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 868
 869         return sysfs_emit(buf, "%u\n", fs_info->super_copy->sectorsize);
 870 }
 871
 872 BTRFS_ATTR(, sectorsize, btrfs_sectorsize_show);
 873
 874 static ssize_t btrfs_clone_alignment_show(struct kobject *kobj,
 875                                 struct kobj_attribute *a, char *buf)
 876 {
 877         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 878
 879         return sysfs_emit(buf, "%u\n", fs_info->super_copy->sectorsize);
 880 }
 881
 882 BTRFS_ATTR(, clone_alignment, btrfs_clone_alignment_show);
 883
 884 static ssize_t quota_override_show(struct kobject *kobj,
 885                                    struct kobj_attribute *a, char *buf)
 886 {
 887         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 888         int quota_override;
 889
 890         quota_override = test_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
 891         return sysfs_emit(buf, "%d\n", quota_override);
 892 }
 893
 894 static ssize_t quota_override_store(struct kobject *kobj,
 895                                     struct kobj_attribute *a,
 896                                     const char *buf, size_t len)
 897 {
 898         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 899         unsigned long knob;
 900         int err;
 901
 902         if (!fs_info)
 903                 return -EPERM;
 904
 905         if (!capable(CAP_SYS_RESOURCE))
 906                 return -EPERM;
 907
 908         err = kstrtoul(buf, 10, &knob);
 909         if (err)
 910                 return err;
 911         if (knob > 1)
 912                 return -EINVAL;
 913
 914         if (knob)
 915                 set_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
 916         else
 917                 clear_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
 918
 919         return len;
 920 }
 921
 922 BTRFS_ATTR_RW(, quota_override, quota_override_show, quota_override_store);
 923
 924 static ssize_t btrfs_metadata_uuid_show(struct kobject *kobj,
 925                                 struct kobj_attribute *a, char *buf)
 926 {
 927         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 928
 929         return sysfs_emit(buf, "%pU\n", fs_info->fs_devices->metadata_uuid);
 930 }
 931
 932 BTRFS_ATTR(, metadata_uuid, btrfs_metadata_uuid_show);
 933
 934 static ssize_t btrfs_checksum_show(struct kobject *kobj,
 935                                    struct kobj_attribute *a, char *buf)
 936 {
 937         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 938         u16 csum_type = btrfs_super_csum_type(fs_info->super_copy);
 939
 940         return sysfs_emit(buf, "%s (%s)\n",
 941                           btrfs_super_csum_name(csum_type),
 942                           crypto_shash_driver_name(fs_info->csum_shash));
 943 }
 944
 945 BTRFS_ATTR(, checksum, btrfs_checksum_show);
 946
 947 static ssize_t btrfs_exclusive_operation_show(struct kobject *kobj,
 948                 struct kobj_attribute *a, char *buf)
 949 {
 950         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 951         const char *str;
 952
 953         switch (READ_ONCE(fs_info->exclusive_operation)) {
 954                 case  BTRFS_EXCLOP_NONE:
 955                         str = "none\n";
 956                         break;
 957                 case BTRFS_EXCLOP_BALANCE:
 958                         str = "balance\n";
 959                         break;
 960                 case BTRFS_EXCLOP_BALANCE_PAUSED:
 961                         str = "balance paused\n";
 962                         break;
 963                 case BTRFS_EXCLOP_DEV_ADD:
 964                         str = "device add\n";
 965                         break;
 966                 case BTRFS_EXCLOP_DEV_REMOVE:
 967                         str = "device remove\n";
 968                         break;
 969                 case BTRFS_EXCLOP_DEV_REPLACE:
 970                         str = "device replace\n";
 971                         break;
 972                 case BTRFS_EXCLOP_RESIZE:
 973                         str = "resize\n";
 974                         break;
 975                 case BTRFS_EXCLOP_SWAP_ACTIVATE:
 976                         str = "swap activate\n";
 977                         break;
 978                 default:
 979                         str = "UNKNOWN\n";
 980                         break;
 981         }
 982         return sysfs_emit(buf, "%s", str);
 983 }
 984 BTRFS_ATTR(, exclusive_operation, btrfs_exclusive_operation_show);
 985
 986 static ssize_t btrfs_generation_show(struct kobject *kobj,
 987                                      struct kobj_attribute *a, char *buf)
 988 {
 989         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 990
 991         return sysfs_emit(buf, "%llu\n", fs_info->generation);
 992 }
 993 BTRFS_ATTR(, generation, btrfs_generation_show);
 994
 995 /*
 996  * Look for an exact string @string in @buffer with possible leading or
 997  * trailing whitespace
 998  */
 999 static bool strmatch(const char *buffer, const char *string)
1000 {
1001         const size_t len = strlen(string);
1002
1003         /* Skip leading whitespace */
1004         buffer = skip_spaces(buffer);
1005
1006         /* Match entire string, check if the rest is whitespace or empty */
1007         if (strncmp(string, buffer, len) == 0 &&
1008             strlen(skip_spaces(buffer + len)) == 0)
1009                 return true;
1010
1011         return false;
1012 }
1013
1014 static const char * const btrfs_read_policy_name[] = { "pid" };
1015
1016 static ssize_t btrfs_read_policy_show(struct kobject *kobj,
1017                                       struct kobj_attribute *a, char *buf)
1018 {
1019         struct btrfs_fs_devices *fs_devices = to_fs_devs(kobj);
1020         ssize_t ret = 0;
1021         int i;
1022
1023         for (i = 0; i < BTRFS_NR_READ_POLICY; i++) {
1024                 if (fs_devices->read_policy == i)
1025                         ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s[%s]",
1026                                          (ret == 0 ? "" : " "),
1027                                          btrfs_read_policy_name[i]);
1028                 else
1029                         ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%s",
1030                                          (ret == 0 ? "" : " "),
1031                                          btrfs_read_policy_name[i]);
1032         }
1033
1034         ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
1035
1036         return ret;
1037 }
1038
1039 static ssize_t btrfs_read_policy_store(struct kobject *kobj,
1040                                        struct kobj_attribute *a,
1041                                        const char *buf, size_t len)
1042 {
1043         struct btrfs_fs_devices *fs_devices = to_fs_devs(kobj);
1044         int i;
1045
1046         for (i = 0; i < BTRFS_NR_READ_POLICY; i++) {
1047                 if (strmatch(buf, btrfs_read_policy_name[i])) {
1048                         if (i != fs_devices->read_policy) {
1049                                 fs_devices->read_policy = i;
1050                                 btrfs_info(fs_devices->fs_info,
1051                                            "read policy set to '%s'",
1052                                            btrfs_read_policy_name[i]);
1053                         }
1054                         return len;
1055                 }
1056         }
1057
1058         return -EINVAL;
1059 }
1060 BTRFS_ATTR_RW(, read_policy, btrfs_read_policy_show, btrfs_read_policy_store);
1061
1062 static ssize_t btrfs_bg_reclaim_threshold_show(struct kobject *kobj,
1063                                                struct kobj_attribute *a,
1064                                                char *buf)
1065 {
1066         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1067         ssize_t ret;
1068
1069         ret = sysfs_emit(buf, "%d\n", READ_ONCE(fs_info->bg_reclaim_threshold));
1070
1071         return ret;
1072 }
1073
1074 static ssize_t btrfs_bg_reclaim_threshold_store(struct kobject *kobj,
1075                                                 struct kobj_attribute *a,
1076                                                 const char *buf, size_t len)
1077 {
1078         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1079         int thresh;
1080         int ret;
1081
1082         ret = kstrtoint(buf, 10, &thresh);
1083         if (ret)
1084                 return ret;
1085
1086         if (thresh != 0 && (thresh <= 50 || thresh > 100))
1087                 return -EINVAL;
1088
1089         WRITE_ONCE(fs_info->bg_reclaim_threshold, thresh);
1090
1091         return len;
1092 }
1093 BTRFS_ATTR_RW(, bg_reclaim_threshold, btrfs_bg_reclaim_threshold_show,
1094               btrfs_bg_reclaim_threshold_store);
1095
1096 /*
1097  * Per-filesystem information and stats.
1098  *
1099  * Path: /sys/fs/btrfs/<uuid>/
1100  */
1101 static const struct attribute *btrfs_attrs[] = {
1102         BTRFS_ATTR_PTR(, label),
1103         BTRFS_ATTR_PTR(, nodesize),
1104         BTRFS_ATTR_PTR(, sectorsize),
1105         BTRFS_ATTR_PTR(, clone_alignment),
1106         BTRFS_ATTR_PTR(, quota_override),
1107         BTRFS_ATTR_PTR(, metadata_uuid),
1108         BTRFS_ATTR_PTR(, checksum),
1109         BTRFS_ATTR_PTR(, exclusive_operation),
1110         BTRFS_ATTR_PTR(, generation),
1111         BTRFS_ATTR_PTR(, read_policy),
1112         BTRFS_ATTR_PTR(, bg_reclaim_threshold),
1113         NULL,
1114 };
1115
1116 static void btrfs_release_fsid_kobj(struct kobject *kobj)
1117 {
1118         struct btrfs_fs_devices *fs_devs = to_fs_devs(kobj);
1119
1120         memset(&fs_devs->fsid_kobj, 0, sizeof(struct kobject));
1121         complete(&fs_devs->kobj_unregister);
1122 }
1123
1124 static struct kobj_type btrfs_ktype = {
1125         .sysfs_ops      = &kobj_sysfs_ops,
1126         .release        = btrfs_release_fsid_kobj,
1127 };
1128
1129 static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj)
1130 {
1131         if (kobj->ktype != &btrfs_ktype)
1132                 return NULL;
1133         return container_of(kobj, struct btrfs_fs_devices, fsid_kobj);
1134 }
1135
1136 static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj)
1137 {
1138         if (kobj->ktype != &btrfs_ktype)
1139                 return NULL;
1140         return to_fs_devs(kobj)->fs_info;
1141 }
1142
1143 #define NUM_FEATURE_BITS 64
1144 #define BTRFS_FEATURE_NAME_MAX 13
1145 static char btrfs_unknown_feature_names[FEAT_MAX][NUM_FEATURE_BITS][BTRFS_FEATURE_NAME_MAX];
1146 static struct btrfs_feature_attr btrfs_feature_attrs[FEAT_MAX][NUM_FEATURE_BITS];
1147
1148 static_assert(ARRAY_SIZE(btrfs_unknown_feature_names) ==
1149               ARRAY_SIZE(btrfs_feature_attrs));
1150 static_assert(ARRAY_SIZE(btrfs_unknown_feature_names[0]) ==
1151               ARRAY_SIZE(btrfs_feature_attrs[0]));
1152
1153 static const u64 supported_feature_masks[FEAT_MAX] = {
1154         [FEAT_COMPAT]    = BTRFS_FEATURE_COMPAT_SUPP,
1155         [FEAT_COMPAT_RO] = BTRFS_FEATURE_COMPAT_RO_SUPP,
1156         [FEAT_INCOMPAT]  = BTRFS_FEATURE_INCOMPAT_SUPP,
1157 };
1158
1159 static int addrm_unknown_feature_attrs(struct btrfs_fs_info *fs_info, bool add)
1160 {
1161         int set;
1162
1163         for (set = 0; set < FEAT_MAX; set++) {
1164                 int i;
1165                 struct attribute *attrs[2];
1166                 struct attribute_group agroup = {
1167                         .name = "features",
1168                         .attrs = attrs,
1169                 };
1170                 u64 features = get_features(fs_info, set);
1171                 features &= ~supported_feature_masks[set];
1172
1173                 if (!features)
1174                         continue;
1175
1176                 attrs[1] = NULL;
1177                 for (i = 0; i < NUM_FEATURE_BITS; i++) {
1178                         struct btrfs_feature_attr *fa;
1179
1180                         if (!(features & (1ULL << i)))
1181                                 continue;
1182
1183                         fa = &btrfs_feature_attrs[set][i];
1184                         attrs[0] = &fa->kobj_attr.attr;
1185                         if (add) {
1186                                 int ret;
1187                                 ret = sysfs_merge_group(&fs_info->fs_devices->fsid_kobj,
1188                                                         &agroup);
1189                                 if (ret)
1190                                         return ret;
1191                         } else
1192                                 sysfs_unmerge_group(&fs_info->fs_devices->fsid_kobj,
1193                                                     &agroup);
1194                 }
1195
1196         }
1197         return 0;
1198 }
1199
1200 static void __btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs)
1201 {
1202         if (fs_devs->devinfo_kobj) {
1203                 kobject_del(fs_devs->devinfo_kobj);
1204                 kobject_put(fs_devs->devinfo_kobj);
1205                 fs_devs->devinfo_kobj = NULL;
1206         }
1207
1208         if (fs_devs->devices_kobj) {
1209                 kobject_del(fs_devs->devices_kobj);
1210                 kobject_put(fs_devs->devices_kobj);
1211                 fs_devs->devices_kobj = NULL;
1212         }
1213
1214         if (fs_devs->fsid_kobj.state_initialized) {
1215                 kobject_del(&fs_devs->fsid_kobj);
1216                 kobject_put(&fs_devs->fsid_kobj);
1217                 wait_for_completion(&fs_devs->kobj_unregister);
1218         }
1219 }
1220
1221 /* when fs_devs is NULL it will remove all fsid kobject */
1222 void btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs)
1223 {
1224         struct list_head *fs_uuids = btrfs_get_fs_uuids();
1225
1226         if (fs_devs) {
1227                 __btrfs_sysfs_remove_fsid(fs_devs);
1228                 return;
1229         }
1230
1231         list_for_each_entry(fs_devs, fs_uuids, fs_list) {
1232                 __btrfs_sysfs_remove_fsid(fs_devs);
1233         }
1234 }
1235
1236 static void btrfs_sysfs_remove_fs_devices(struct btrfs_fs_devices *fs_devices)
1237 {
1238         struct btrfs_device *device;
1239         struct btrfs_fs_devices *seed;
1240
1241         list_for_each_entry(device, &fs_devices->devices, dev_list)
1242                 btrfs_sysfs_remove_device(device);
1243
1244         list_for_each_entry(seed, &fs_devices->seed_list, seed_list) {
1245                 list_for_each_entry(device, &seed->devices, dev_list)
1246                         btrfs_sysfs_remove_device(device);
1247         }
1248 }
1249
1250 void btrfs_sysfs_remove_mounted(struct btrfs_fs_info *fs_info)
1251 {
1252         struct kobject *fsid_kobj = &fs_info->fs_devices->fsid_kobj;
1253
1254         sysfs_remove_link(fsid_kobj, "bdi");
1255
1256         if (fs_info->space_info_kobj) {
1257                 sysfs_remove_files(fs_info->space_info_kobj, allocation_attrs);
1258                 kobject_del(fs_info->space_info_kobj);
1259                 kobject_put(fs_info->space_info_kobj);
1260         }
1261 #ifdef CONFIG_BTRFS_DEBUG
1262         if (fs_info->discard_debug_kobj) {
1263                 sysfs_remove_files(fs_info->discard_debug_kobj,
1264                                    discard_debug_attrs);
1265                 kobject_del(fs_info->discard_debug_kobj);
1266                 kobject_put(fs_info->discard_debug_kobj);
1267         }
1268         if (fs_info->debug_kobj) {
1269                 sysfs_remove_files(fs_info->debug_kobj, btrfs_debug_mount_attrs);
1270                 kobject_del(fs_info->debug_kobj);
1271                 kobject_put(fs_info->debug_kobj);
1272         }
1273 #endif
1274         addrm_unknown_feature_attrs(fs_info, false);
1275         sysfs_remove_group(fsid_kobj, &btrfs_feature_attr_group);
1276         sysfs_remove_files(fsid_kobj, btrfs_attrs);
1277         btrfs_sysfs_remove_fs_devices(fs_info->fs_devices);
1278 }
1279
1280 static const char * const btrfs_feature_set_names[FEAT_MAX] = {
1281         [FEAT_COMPAT]    = "compat",
1282         [FEAT_COMPAT_RO] = "compat_ro",
1283         [FEAT_INCOMPAT]  = "incompat",
1284 };
1285
1286 const char *btrfs_feature_set_name(enum btrfs_feature_set set)
1287 {
1288         return btrfs_feature_set_names[set];
1289 }
1290
1291 char *btrfs_printable_features(enum btrfs_feature_set set, u64 flags)
1292 {
1293         size_t bufsize = 4096; /* safe max, 64 names * 64 bytes */
1294         int len = 0;
1295         int i;
1296         char *str;
1297
1298         str = kmalloc(bufsize, GFP_KERNEL);
1299         if (!str)
1300                 return str;
1301
1302         for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
1303                 const char *name;
1304
1305                 if (!(flags & (1ULL << i)))
1306                         continue;
1307
1308                 name = btrfs_feature_attrs[set][i].kobj_attr.attr.name;
1309                 len += scnprintf(str + len, bufsize - len, "%s%s",
1310                                 len ? "," : "", name);
1311         }
1312
1313         return str;
1314 }
1315
1316 static void init_feature_attrs(void)
1317 {
1318         struct btrfs_feature_attr *fa;
1319         int set, i;
1320
1321         memset(btrfs_feature_attrs, 0, sizeof(btrfs_feature_attrs));
1322         memset(btrfs_unknown_feature_names, 0,
1323                sizeof(btrfs_unknown_feature_names));
1324
1325         for (i = 0; btrfs_supported_feature_attrs[i]; i++) {
1326                 struct btrfs_feature_attr *sfa;
1327                 struct attribute *a = btrfs_supported_feature_attrs[i];
1328                 int bit;
1329                 sfa = attr_to_btrfs_feature_attr(a);
1330                 bit = ilog2(sfa->feature_bit);
1331                 fa = &btrfs_feature_attrs[sfa->feature_set][bit];
1332
1333                 fa->kobj_attr.attr.name = sfa->kobj_attr.attr.name;
1334         }
1335
1336         for (set = 0; set < FEAT_MAX; set++) {
1337                 for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
1338                         char *name = btrfs_unknown_feature_names[set][i];
1339                         fa = &btrfs_feature_attrs[set][i];
1340
1341                         if (fa->kobj_attr.attr.name)
1342                                 continue;
1343
1344                         snprintf(name, BTRFS_FEATURE_NAME_MAX, "%s:%u",
1345                                  btrfs_feature_set_names[set], i);
1346
1347                         fa->kobj_attr.attr.name = name;
1348                         fa->kobj_attr.attr.mode = S_IRUGO;
1349                         fa->feature_set = set;
1350                         fa->feature_bit = 1ULL << i;
1351                 }
1352         }
1353 }
1354
1355 /*
1356  * Create a sysfs entry for a given block group type at path
1357  * /sys/fs/btrfs/UUID/allocation/data/TYPE
1358  */
1359 void btrfs_sysfs_add_block_group_type(struct btrfs_block_group *cache)
1360 {
1361         struct btrfs_fs_info *fs_info = cache->fs_info;
1362         struct btrfs_space_info *space_info = cache->space_info;
1363         struct raid_kobject *rkobj;
1364         const int index = btrfs_bg_flags_to_raid_index(cache->flags);
1365         unsigned int nofs_flag;
1366         int ret;
1367
1368         /*
1369          * Setup a NOFS context because kobject_add(), deep in its call chain,
1370          * does GFP_KERNEL allocations, and we are often called in a context
1371          * where if reclaim is triggered we can deadlock (we are either holding
1372          * a transaction handle or some lock required for a transaction
1373          * commit).
1374          */
1375         nofs_flag = memalloc_nofs_save();
1376
1377         rkobj = kzalloc(sizeof(*rkobj), GFP_NOFS);
1378         if (!rkobj) {
1379                 memalloc_nofs_restore(nofs_flag);
1380                 btrfs_warn(cache->fs_info,
1381                                 "couldn't alloc memory for raid level kobject");
1382                 return;
1383         }
1384
1385         rkobj->flags = cache->flags;
1386         kobject_init(&rkobj->kobj, &btrfs_raid_ktype);
1387
1388         /*
1389          * We call this either on mount, or if we've created a block group for a
1390          * new index type while running (i.e. when restriping).  The running
1391          * case is tricky because we could race with other threads, so we need
1392          * to have this check to make sure we didn't already init the kobject.
1393          *
1394          * We don't have to protect on the free side because it only happens on
1395          * unmount.
1396          */
1397         spin_lock(&space_info->lock);
1398         if (space_info->block_group_kobjs[index]) {
1399                 spin_unlock(&space_info->lock);
1400                 kobject_put(&rkobj->kobj);
1401                 return;
1402         } else {
1403                 space_info->block_group_kobjs[index] = &rkobj->kobj;
1404         }
1405         spin_unlock(&space_info->lock);
1406
1407         ret = kobject_add(&rkobj->kobj, &space_info->kobj, "%s",
1408                           btrfs_bg_type_to_raid_name(rkobj->flags));
1409         memalloc_nofs_restore(nofs_flag);
1410         if (ret) {
1411                 spin_lock(&space_info->lock);
1412                 space_info->block_group_kobjs[index] = NULL;
1413                 spin_unlock(&space_info->lock);
1414                 kobject_put(&rkobj->kobj);
1415                 btrfs_warn(fs_info,
1416                         "failed to add kobject for block cache, ignoring");
1417                 return;
1418         }
1419 }
1420
1421 /*
1422  * Remove sysfs directories for all block group types of a given space info and
1423  * the space info as well
1424  */
1425 void btrfs_sysfs_remove_space_info(struct btrfs_space_info *space_info)
1426 {
1427         int i;
1428
1429         for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) {
1430                 struct kobject *kobj;
1431
1432                 kobj = space_info->block_group_kobjs[i];
1433                 space_info->block_group_kobjs[i] = NULL;
1434                 if (kobj) {
1435                         kobject_del(kobj);
1436                         kobject_put(kobj);
1437                 }
1438         }
1439         kobject_del(&space_info->kobj);
1440         kobject_put(&space_info->kobj);
1441 }
1442
1443 static const char *alloc_name(u64 flags)
1444 {
1445         switch (flags) {
1446         case BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA:
1447                 return "mixed";
1448         case BTRFS_BLOCK_GROUP_METADATA:
1449                 return "metadata";
1450         case BTRFS_BLOCK_GROUP_DATA:
1451                 return "data";
1452         case BTRFS_BLOCK_GROUP_SYSTEM:
1453                 return "system";
1454         default:
1455                 WARN_ON(1);
1456                 return "invalid-combination";
1457         }
1458 }
1459
1460 /*
1461  * Create a sysfs entry for a space info type at path
1462  * /sys/fs/btrfs/UUID/allocation/TYPE
1463  */
1464 int btrfs_sysfs_add_space_info_type(struct btrfs_fs_info *fs_info,
1465                                     struct btrfs_space_info *space_info)
1466 {
1467         int ret;
1468
1469         ret = kobject_init_and_add(&space_info->kobj, &space_info_ktype,
1470                                    fs_info->space_info_kobj, "%s",
1471                                    alloc_name(space_info->flags));
1472         if (ret) {
1473                 kobject_put(&space_info->kobj);
1474                 return ret;
1475         }
1476
1477         return 0;
1478 }
1479
1480 void btrfs_sysfs_remove_device(struct btrfs_device *device)
1481 {
1482         struct kobject *devices_kobj;
1483
1484         /*
1485          * Seed fs_devices devices_kobj aren't used, fetch kobject from the
1486          * fs_info::fs_devices.
1487          */
1488         devices_kobj = device->fs_info->fs_devices->devices_kobj;
1489         ASSERT(devices_kobj);
1490
1491         if (device->bdev)
1492                 sysfs_remove_link(devices_kobj, bdev_kobj(device->bdev)->name);
1493
1494         if (device->devid_kobj.state_initialized) {
1495                 kobject_del(&device->devid_kobj);
1496                 kobject_put(&device->devid_kobj);
1497                 wait_for_completion(&device->kobj_unregister);
1498         }
1499 }
1500
1501 static ssize_t btrfs_devinfo_in_fs_metadata_show(struct kobject *kobj,
1502                                                  struct kobj_attribute *a,
1503                                                  char *buf)
1504 {
1505         int val;
1506         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1507                                                    devid_kobj);
1508
1509         val = !!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state);
1510
1511         return sysfs_emit(buf, "%d\n", val);
1512 }
1513 BTRFS_ATTR(devid, in_fs_metadata, btrfs_devinfo_in_fs_metadata_show);
1514
1515 static ssize_t btrfs_devinfo_missing_show(struct kobject *kobj,
1516                                         struct kobj_attribute *a, char *buf)
1517 {
1518         int val;
1519         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1520                                                    devid_kobj);
1521
1522         val = !!test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state);
1523
1524         return sysfs_emit(buf, "%d\n", val);
1525 }
1526 BTRFS_ATTR(devid, missing, btrfs_devinfo_missing_show);
1527
1528 static ssize_t btrfs_devinfo_replace_target_show(struct kobject *kobj,
1529                                                  struct kobj_attribute *a,
1530                                                  char *buf)
1531 {
1532         int val;
1533         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1534                                                    devid_kobj);
1535
1536         val = !!test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state);
1537
1538         return sysfs_emit(buf, "%d\n", val);
1539 }
1540 BTRFS_ATTR(devid, replace_target, btrfs_devinfo_replace_target_show);
1541
1542 static ssize_t btrfs_devinfo_scrub_speed_max_show(struct kobject *kobj,
1543                                              struct kobj_attribute *a,
1544                                              char *buf)
1545 {
1546         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1547                                                    devid_kobj);
1548
1549         return sysfs_emit(buf, "%llu\n", READ_ONCE(device->scrub_speed_max));
1550 }
1551
1552 static ssize_t btrfs_devinfo_scrub_speed_max_store(struct kobject *kobj,
1553                                               struct kobj_attribute *a,
1554                                               const char *buf, size_t len)
1555 {
1556         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1557                                                    devid_kobj);
1558         char *endptr;
1559         unsigned long long limit;
1560
1561         limit = memparse(buf, &endptr);
1562         WRITE_ONCE(device->scrub_speed_max, limit);
1563         return len;
1564 }
1565 BTRFS_ATTR_RW(devid, scrub_speed_max, btrfs_devinfo_scrub_speed_max_show,
1566               btrfs_devinfo_scrub_speed_max_store);
1567
1568 static ssize_t btrfs_devinfo_writeable_show(struct kobject *kobj,
1569                                             struct kobj_attribute *a, char *buf)
1570 {
1571         int val;
1572         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1573                                                    devid_kobj);
1574
1575         val = !!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state);
1576
1577         return sysfs_emit(buf, "%d\n", val);
1578 }
1579 BTRFS_ATTR(devid, writeable, btrfs_devinfo_writeable_show);
1580
1581 static ssize_t btrfs_devinfo_fsid_show(struct kobject *kobj,
1582                                        struct kobj_attribute *a, char *buf)
1583 {
1584         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1585                                                    devid_kobj);
1586
1587         return sysfs_emit(buf, "%pU\n", device->fs_devices->fsid);
1588 }
1589 BTRFS_ATTR(devid, fsid, btrfs_devinfo_fsid_show);
1590
1591 static ssize_t btrfs_devinfo_error_stats_show(struct kobject *kobj,
1592                 struct kobj_attribute *a, char *buf)
1593 {
1594         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1595                                                    devid_kobj);
1596
1597         if (!device->dev_stats_valid)
1598                 return sysfs_emit(buf, "invalid\n");
1599
1600         /*
1601          * Print all at once so we get a snapshot of all values from the same
1602          * time. Keep them in sync and in order of definition of
1603          * btrfs_dev_stat_values.
1604          */
1605         return sysfs_emit(buf,
1606                 "write_errs %d\n"
1607                 "read_errs %d\n"
1608                 "flush_errs %d\n"
1609                 "corruption_errs %d\n"
1610                 "generation_errs %d\n",
1611                 btrfs_dev_stat_read(device, BTRFS_DEV_STAT_WRITE_ERRS),
1612                 btrfs_dev_stat_read(device, BTRFS_DEV_STAT_READ_ERRS),
1613                 btrfs_dev_stat_read(device, BTRFS_DEV_STAT_FLUSH_ERRS),
1614                 btrfs_dev_stat_read(device, BTRFS_DEV_STAT_CORRUPTION_ERRS),
1615                 btrfs_dev_stat_read(device, BTRFS_DEV_STAT_GENERATION_ERRS));
1616 }
1617 BTRFS_ATTR(devid, error_stats, btrfs_devinfo_error_stats_show);
1618
1619 /*
1620  * Information about one device.
1621  *
1622  * Path: /sys/fs/btrfs/<uuid>/devinfo/<devid>/
1623  */
1624 static struct attribute *devid_attrs[] = {
1625         BTRFS_ATTR_PTR(devid, error_stats),
1626         BTRFS_ATTR_PTR(devid, fsid),
1627         BTRFS_ATTR_PTR(devid, in_fs_metadata),
1628         BTRFS_ATTR_PTR(devid, missing),
1629         BTRFS_ATTR_PTR(devid, replace_target),
1630         BTRFS_ATTR_PTR(devid, scrub_speed_max),
1631         BTRFS_ATTR_PTR(devid, writeable),
1632         NULL
1633 };
1634 ATTRIBUTE_GROUPS(devid);
1635
1636 static void btrfs_release_devid_kobj(struct kobject *kobj)
1637 {
1638         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1639                                                    devid_kobj);
1640
1641         memset(&device->devid_kobj, 0, sizeof(struct kobject));
1642         complete(&device->kobj_unregister);
1643 }
1644
1645 static struct kobj_type devid_ktype = {
1646         .sysfs_ops      = &kobj_sysfs_ops,
1647         .default_groups = devid_groups,
1648         .release        = btrfs_release_devid_kobj,
1649 };
1650
1651 int btrfs_sysfs_add_device(struct btrfs_device *device)
1652 {
1653         int ret;
1654         unsigned int nofs_flag;
1655         struct kobject *devices_kobj;
1656         struct kobject *devinfo_kobj;
1657
1658         /*
1659          * Make sure we use the fs_info::fs_devices to fetch the kobjects even
1660          * for the seed fs_devices
1661          */
1662         devices_kobj = device->fs_info->fs_devices->devices_kobj;
1663         devinfo_kobj = device->fs_info->fs_devices->devinfo_kobj;
1664         ASSERT(devices_kobj);
1665         ASSERT(devinfo_kobj);
1666
1667         nofs_flag = memalloc_nofs_save();
1668
1669         if (device->bdev) {
1670                 struct kobject *disk_kobj = bdev_kobj(device->bdev);
1671
1672                 ret = sysfs_create_link(devices_kobj, disk_kobj, disk_kobj->name);
1673                 if (ret) {
1674                         btrfs_warn(device->fs_info,
1675                                 "creating sysfs device link for devid %llu failed: %d",
1676                                 device->devid, ret);
1677                         goto out;
1678                 }
1679         }
1680
1681         init_completion(&device->kobj_unregister);
1682         ret = kobject_init_and_add(&device->devid_kobj, &devid_ktype,
1683                                    devinfo_kobj, "%llu", device->devid);
1684         if (ret) {
1685                 kobject_put(&device->devid_kobj);
1686                 btrfs_warn(device->fs_info,
1687                            "devinfo init for devid %llu failed: %d",
1688                            device->devid, ret);
1689         }
1690
1691 out:
1692         memalloc_nofs_restore(nofs_flag);
1693         return ret;
1694 }
1695
1696 static int btrfs_sysfs_add_fs_devices(struct btrfs_fs_devices *fs_devices)
1697 {
1698         int ret;
1699         struct btrfs_device *device;
1700         struct btrfs_fs_devices *seed;
1701
1702         list_for_each_entry(device, &fs_devices->devices, dev_list) {
1703                 ret = btrfs_sysfs_add_device(device);
1704                 if (ret)
1705                         goto fail;
1706         }
1707
1708         list_for_each_entry(seed, &fs_devices->seed_list, seed_list) {
1709                 list_for_each_entry(device, &seed->devices, dev_list) {
1710                         ret = btrfs_sysfs_add_device(device);
1711                         if (ret)
1712                                 goto fail;
1713                 }
1714         }
1715
1716         return 0;
1717
1718 fail:
1719         btrfs_sysfs_remove_fs_devices(fs_devices);
1720         return ret;
1721 }
1722
1723 void btrfs_kobject_uevent(struct block_device *bdev, enum kobject_action action)
1724 {
1725         int ret;
1726
1727         ret = kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, action);
1728         if (ret)
1729                 pr_warn("BTRFS: Sending event '%d' to kobject: '%s' (%p): failed\n",
1730                         action, kobject_name(&disk_to_dev(bdev->bd_disk)->kobj),
1731                         &disk_to_dev(bdev->bd_disk)->kobj);
1732 }
1733
1734 void btrfs_sysfs_update_sprout_fsid(struct btrfs_fs_devices *fs_devices)
1735
1736 {
1737         char fsid_buf[BTRFS_UUID_UNPARSED_SIZE];
1738
1739         /*
1740          * Sprouting changes fsid of the mounted filesystem, rename the fsid
1741          * directory
1742          */
1743         snprintf(fsid_buf, BTRFS_UUID_UNPARSED_SIZE, "%pU", fs_devices->fsid);
1744         if (kobject_rename(&fs_devices->fsid_kobj, fsid_buf))
1745                 btrfs_warn(fs_devices->fs_info,
1746                                 "sysfs: failed to create fsid for sprout");
1747 }
1748
1749 void btrfs_sysfs_update_devid(struct btrfs_device *device)
1750 {
1751         char tmp[24];
1752
1753         snprintf(tmp, sizeof(tmp), "%llu", device->devid);
1754
1755         if (kobject_rename(&device->devid_kobj, tmp))
1756                 btrfs_warn(device->fs_devices->fs_info,
1757                            "sysfs: failed to update devid for %llu",
1758                            device->devid);
1759 }
1760
1761 /* /sys/fs/btrfs/ entry */
1762 static struct kset *btrfs_kset;
1763
1764 /*
1765  * Creates:
1766  *              /sys/fs/btrfs/UUID
1767  *
1768  * Can be called by the device discovery thread.
1769  */
1770 int btrfs_sysfs_add_fsid(struct btrfs_fs_devices *fs_devs)
1771 {
1772         int error;
1773
1774         init_completion(&fs_devs->kobj_unregister);
1775         fs_devs->fsid_kobj.kset = btrfs_kset;
1776         error = kobject_init_and_add(&fs_devs->fsid_kobj, &btrfs_ktype, NULL,
1777                                      "%pU", fs_devs->fsid);
1778         if (error) {
1779                 kobject_put(&fs_devs->fsid_kobj);
1780                 return error;
1781         }
1782
1783         fs_devs->devices_kobj = kobject_create_and_add("devices",
1784                                                        &fs_devs->fsid_kobj);
1785         if (!fs_devs->devices_kobj) {
1786                 btrfs_err(fs_devs->fs_info,
1787                           "failed to init sysfs device interface");
1788                 btrfs_sysfs_remove_fsid(fs_devs);
1789                 return -ENOMEM;
1790         }
1791
1792         fs_devs->devinfo_kobj = kobject_create_and_add("devinfo",
1793                                                        &fs_devs->fsid_kobj);
1794         if (!fs_devs->devinfo_kobj) {
1795                 btrfs_err(fs_devs->fs_info,
1796                           "failed to init sysfs devinfo kobject");
1797                 btrfs_sysfs_remove_fsid(fs_devs);
1798                 return -ENOMEM;
1799         }
1800
1801         return 0;
1802 }
1803
1804 int btrfs_sysfs_add_mounted(struct btrfs_fs_info *fs_info)
1805 {
1806         int error;
1807         struct btrfs_fs_devices *fs_devs = fs_info->fs_devices;
1808         struct kobject *fsid_kobj = &fs_devs->fsid_kobj;
1809
1810         error = btrfs_sysfs_add_fs_devices(fs_devs);
1811         if (error)
1812                 return error;
1813
1814         error = sysfs_create_files(fsid_kobj, btrfs_attrs);
1815         if (error) {
1816                 btrfs_sysfs_remove_fs_devices(fs_devs);
1817                 return error;
1818         }
1819
1820         error = sysfs_create_group(fsid_kobj,
1821                                    &btrfs_feature_attr_group);
1822         if (error)
1823                 goto failure;
1824
1825 #ifdef CONFIG_BTRFS_DEBUG
1826         fs_info->debug_kobj = kobject_create_and_add("debug", fsid_kobj);
1827         if (!fs_info->debug_kobj) {
1828                 error = -ENOMEM;
1829                 goto failure;
1830         }
1831
1832         error = sysfs_create_files(fs_info->debug_kobj, btrfs_debug_mount_attrs);
1833         if (error)
1834                 goto failure;
1835
1836         /* Discard directory */
1837         fs_info->discard_debug_kobj = kobject_create_and_add("discard",
1838                                                      fs_info->debug_kobj);
1839         if (!fs_info->discard_debug_kobj) {
1840                 error = -ENOMEM;
1841                 goto failure;
1842         }
1843
1844         error = sysfs_create_files(fs_info->discard_debug_kobj,
1845                                    discard_debug_attrs);
1846         if (error)
1847                 goto failure;
1848 #endif
1849
1850         error = addrm_unknown_feature_attrs(fs_info, true);
1851         if (error)
1852                 goto failure;
1853
1854         error = sysfs_create_link(fsid_kobj, &fs_info->sb->s_bdi->dev->kobj, "bdi");
1855         if (error)
1856                 goto failure;
1857
1858         fs_info->space_info_kobj = kobject_create_and_add("allocation",
1859                                                   fsid_kobj);
1860         if (!fs_info->space_info_kobj) {
1861                 error = -ENOMEM;
1862                 goto failure;
1863         }
1864
1865         error = sysfs_create_files(fs_info->space_info_kobj, allocation_attrs);
1866         if (error)
1867                 goto failure;
1868
1869         return 0;
1870 failure:
1871         btrfs_sysfs_remove_mounted(fs_info);
1872         return error;
1873 }
1874
1875 static inline struct btrfs_fs_info *qgroup_kobj_to_fs_info(struct kobject *kobj)
1876 {
1877         return to_fs_info(kobj->parent->parent);
1878 }
1879
1880 #define QGROUP_ATTR(_member, _show_name)                                        \
1881 static ssize_t btrfs_qgroup_show_##_member(struct kobject *qgroup_kobj,         \
1882                                            struct kobj_attribute *a,            \
1883                                            char *buf)                           \
1884 {                                                                               \
1885         struct btrfs_fs_info *fs_info = qgroup_kobj_to_fs_info(qgroup_kobj);    \
1886         struct btrfs_qgroup *qgroup = container_of(qgroup_kobj,                 \
1887                         struct btrfs_qgroup, kobj);                             \
1888         return btrfs_show_u64(&qgroup->_member, &fs_info->qgroup_lock, buf);    \
1889 }                                                                               \
1890 BTRFS_ATTR(qgroup, _show_name, btrfs_qgroup_show_##_member)
1891
1892 #define QGROUP_RSV_ATTR(_name, _type)                                           \
1893 static ssize_t btrfs_qgroup_rsv_show_##_name(struct kobject *qgroup_kobj,       \
1894                                              struct kobj_attribute *a,          \
1895                                              char *buf)                         \
1896 {                                                                               \
1897         struct btrfs_fs_info *fs_info = qgroup_kobj_to_fs_info(qgroup_kobj);    \
1898         struct btrfs_qgroup *qgroup = container_of(qgroup_kobj,                 \
1899                         struct btrfs_qgroup, kobj);                             \
1900         return btrfs_show_u64(&qgroup->rsv.values[_type],                       \
1901                         &fs_info->qgroup_lock, buf);                            \
1902 }                                                                               \
1903 BTRFS_ATTR(qgroup, rsv_##_name, btrfs_qgroup_rsv_show_##_name)
1904
1905 QGROUP_ATTR(rfer, referenced);
1906 QGROUP_ATTR(excl, exclusive);
1907 QGROUP_ATTR(max_rfer, max_referenced);
1908 QGROUP_ATTR(max_excl, max_exclusive);
1909 QGROUP_ATTR(lim_flags, limit_flags);
1910 QGROUP_RSV_ATTR(data, BTRFS_QGROUP_RSV_DATA);
1911 QGROUP_RSV_ATTR(meta_pertrans, BTRFS_QGROUP_RSV_META_PERTRANS);
1912 QGROUP_RSV_ATTR(meta_prealloc, BTRFS_QGROUP_RSV_META_PREALLOC);
1913
1914 /*
1915  * Qgroup information.
1916  *
1917  * Path: /sys/fs/btrfs/<uuid>/qgroups/<level>_<qgroupid>/
1918  */
1919 static struct attribute *qgroup_attrs[] = {
1920         BTRFS_ATTR_PTR(qgroup, referenced),
1921         BTRFS_ATTR_PTR(qgroup, exclusive),
1922         BTRFS_ATTR_PTR(qgroup, max_referenced),
1923         BTRFS_ATTR_PTR(qgroup, max_exclusive),
1924         BTRFS_ATTR_PTR(qgroup, limit_flags),
1925         BTRFS_ATTR_PTR(qgroup, rsv_data),
1926         BTRFS_ATTR_PTR(qgroup, rsv_meta_pertrans),
1927         BTRFS_ATTR_PTR(qgroup, rsv_meta_prealloc),
1928         NULL
1929 };
1930 ATTRIBUTE_GROUPS(qgroup);
1931
1932 static void qgroup_release(struct kobject *kobj)
1933 {
1934         struct btrfs_qgroup *qgroup = container_of(kobj, struct btrfs_qgroup, kobj);
1935
1936         memset(&qgroup->kobj, 0, sizeof(*kobj));
1937 }
1938
1939 static struct kobj_type qgroup_ktype = {
1940         .sysfs_ops = &kobj_sysfs_ops,
1941         .release = qgroup_release,
1942         .default_groups = qgroup_groups,
1943 };
1944
1945 int btrfs_sysfs_add_one_qgroup(struct btrfs_fs_info *fs_info,
1946                                 struct btrfs_qgroup *qgroup)
1947 {
1948         struct kobject *qgroups_kobj = fs_info->qgroups_kobj;
1949         int ret;
1950
1951         if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
1952                 return 0;
1953         if (qgroup->kobj.state_initialized)
1954                 return 0;
1955         if (!qgroups_kobj)
1956                 return -EINVAL;
1957
1958         ret = kobject_init_and_add(&qgroup->kobj, &qgroup_ktype, qgroups_kobj,
1959                         "%hu_%llu", btrfs_qgroup_level(qgroup->qgroupid),
1960                         btrfs_qgroup_subvolid(qgroup->qgroupid));
1961         if (ret < 0)
1962                 kobject_put(&qgroup->kobj);
1963
1964         return ret;
1965 }
1966
1967 void btrfs_sysfs_del_qgroups(struct btrfs_fs_info *fs_info)
1968 {
1969         struct btrfs_qgroup *qgroup;
1970         struct btrfs_qgroup *next;
1971
1972         if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
1973                 return;
1974
1975         rbtree_postorder_for_each_entry_safe(qgroup, next,
1976                                              &fs_info->qgroup_tree, node)
1977                 btrfs_sysfs_del_one_qgroup(fs_info, qgroup);
1978         if (fs_info->qgroups_kobj) {
1979                 kobject_del(fs_info->qgroups_kobj);
1980                 kobject_put(fs_info->qgroups_kobj);
1981                 fs_info->qgroups_kobj = NULL;
1982         }
1983 }
1984
1985 /* Called when qgroups get initialized, thus there is no need for locking */
1986 int btrfs_sysfs_add_qgroups(struct btrfs_fs_info *fs_info)
1987 {
1988         struct kobject *fsid_kobj = &fs_info->fs_devices->fsid_kobj;
1989         struct btrfs_qgroup *qgroup;
1990         struct btrfs_qgroup *next;
1991         int ret = 0;
1992
1993         if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
1994                 return 0;
1995
1996         ASSERT(fsid_kobj);
1997         if (fs_info->qgroups_kobj)
1998                 return 0;
1999
2000         fs_info->qgroups_kobj = kobject_create_and_add("qgroups", fsid_kobj);
2001         if (!fs_info->qgroups_kobj) {
2002                 ret = -ENOMEM;
2003                 goto out;
2004         }
2005         rbtree_postorder_for_each_entry_safe(qgroup, next,
2006                                              &fs_info->qgroup_tree, node) {
2007                 ret = btrfs_sysfs_add_one_qgroup(fs_info, qgroup);
2008                 if (ret < 0)
2009                         goto out;
2010         }
2011
2012 out:
2013         if (ret < 0)
2014                 btrfs_sysfs_del_qgroups(fs_info);
2015         return ret;
2016 }
2017
2018 void btrfs_sysfs_del_one_qgroup(struct btrfs_fs_info *fs_info,
2019                                 struct btrfs_qgroup *qgroup)
2020 {
2021         if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
2022                 return;
2023
2024         if (qgroup->kobj.state_initialized) {
2025                 kobject_del(&qgroup->kobj);
2026                 kobject_put(&qgroup->kobj);
2027         }
2028 }
2029
2030 /*
2031  * Change per-fs features in /sys/fs/btrfs/UUID/features to match current
2032  * values in superblock. Call after any changes to incompat/compat_ro flags
2033  */
2034 void btrfs_sysfs_feature_update(struct btrfs_fs_info *fs_info,
2035                 u64 bit, enum btrfs_feature_set set)
2036 {
2037         struct btrfs_fs_devices *fs_devs;
2038         struct kobject *fsid_kobj;
2039         u64 __maybe_unused features;
2040         int __maybe_unused ret;
2041
2042         if (!fs_info)
2043                 return;
2044
2045         /*
2046          * See 14e46e04958df74 and e410e34fad913dd, feature bit updates are not
2047          * safe when called from some contexts (eg. balance)
2048          */
2049         features = get_features(fs_info, set);
2050         ASSERT(bit & supported_feature_masks[set]);
2051
2052         fs_devs = fs_info->fs_devices;
2053         fsid_kobj = &fs_devs->fsid_kobj;
2054
2055         if (!fsid_kobj->state_initialized)
2056                 return;
2057
2058         /*
2059          * FIXME: this is too heavy to update just one value, ideally we'd like
2060          * to use sysfs_update_group but some refactoring is needed first.
2061          */
2062         sysfs_remove_group(fsid_kobj, &btrfs_feature_attr_group);
2063         ret = sysfs_create_group(fsid_kobj, &btrfs_feature_attr_group);
2064 }
2065
2066 int __init btrfs_init_sysfs(void)
2067 {
2068         int ret;
2069
2070         btrfs_kset = kset_create_and_add("btrfs", NULL, fs_kobj);
2071         if (!btrfs_kset)
2072                 return -ENOMEM;
2073
2074         init_feature_attrs();
2075         ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
2076         if (ret)
2077                 goto out2;
2078         ret = sysfs_merge_group(&btrfs_kset->kobj,
2079                                 &btrfs_static_feature_attr_group);
2080         if (ret)
2081                 goto out_remove_group;
2082
2083 #ifdef CONFIG_BTRFS_DEBUG
2084         ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_debug_feature_attr_group);
2085         if (ret)
2086                 goto out2;
2087 #endif
2088
2089         return 0;
2090
2091 out_remove_group:
2092         sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
2093 out2:
2094         kset_unregister(btrfs_kset);
2095
2096         return ret;
2097 }
2098
2099 void __cold btrfs_exit_sysfs(void)
2100 {
2101         sysfs_unmerge_group(&btrfs_kset->kobj,
2102                             &btrfs_static_feature_attr_group);
2103         sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
2104 #ifdef CONFIG_BTRFS_DEBUG
2105         sysfs_remove_group(&btrfs_kset->kobj, &btrfs_debug_feature_attr_group);
2106 #endif
2107         kset_unregister(btrfs_kset);
2108 }
2109