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 #include "misc.h"
  25
  26 /*
  27  * Structure name                       Path
  28  * --------------------------------------------------------------------------
  29  * btrfs_supported_static_feature_attrs /sys/fs/btrfs/features
  30  * btrfs_supported_feature_attrs        /sys/fs/btrfs/features and
  31  *                                      /sys/fs/btrfs/<uuid>/features
  32  * btrfs_attrs                          /sys/fs/btrfs/<uuid>
  33  * devid_attrs                          /sys/fs/btrfs/<uuid>/devinfo/<devid>
  34  * allocation_attrs                     /sys/fs/btrfs/<uuid>/allocation
  35  * qgroup_attrs                         /sys/fs/btrfs/<uuid>/qgroups/<level>_<qgroupid>
  36  * space_info_attrs                     /sys/fs/btrfs/<uuid>/allocation/<bg-type>
  37  * raid_attrs                           /sys/fs/btrfs/<uuid>/allocation/<bg-type>/<bg-profile>
  38  * discard_attrs                        /sys/fs/btrfs/<uuid>/discard
  39  *
  40  * When built with BTRFS_CONFIG_DEBUG:
  41  *
  42  * btrfs_debug_feature_attrs            /sys/fs/btrfs/debug
  43  * btrfs_debug_mount_attrs              /sys/fs/btrfs/<uuid>/debug
  44  */
  45
  46 struct btrfs_feature_attr {
  47         struct kobj_attribute kobj_attr;
  48         enum btrfs_feature_set feature_set;
  49         u64 feature_bit;
  50 };
  51
  52 /* For raid type sysfs entries */
  53 struct raid_kobject {
  54         u64 flags;
  55         struct kobject kobj;
  56 };
  57
  58 #define __INIT_KOBJ_ATTR(_name, _mode, _show, _store)                   \
  59 {                                                                       \
  60         .attr   = { .name = __stringify(_name), .mode = _mode },        \
  61         .show   = _show,                                                \
  62         .store  = _store,                                               \
  63 }
  64
  65 #define BTRFS_ATTR_W(_prefix, _name, _store)                            \
  66         static struct kobj_attribute btrfs_attr_##_prefix##_##_name =   \
  67                         __INIT_KOBJ_ATTR(_name, 0200, NULL, _store)
  68
  69 #define BTRFS_ATTR_RW(_prefix, _name, _show, _store)                    \
  70         static struct kobj_attribute btrfs_attr_##_prefix##_##_name =   \
  71                         __INIT_KOBJ_ATTR(_name, 0644, _show, _store)
  72
  73 #define BTRFS_ATTR(_prefix, _name, _show)                               \
  74         static struct kobj_attribute btrfs_attr_##_prefix##_##_name =   \
  75                         __INIT_KOBJ_ATTR(_name, 0444, _show, NULL)
  76
  77 #define BTRFS_ATTR_PTR(_prefix, _name)                                  \
  78         (&btrfs_attr_##_prefix##_##_name.attr)
  79
  80 #define BTRFS_FEAT_ATTR(_name, _feature_set, _feature_prefix, _feature_bit)  \
  81 static struct btrfs_feature_attr btrfs_attr_features_##_name = {             \
  82         .kobj_attr = __INIT_KOBJ_ATTR(_name, S_IRUGO,                        \
  83                                       btrfs_feature_attr_show,               \
  84                                       btrfs_feature_attr_store),             \
  85         .feature_set    = _feature_set,                                      \
  86         .feature_bit    = _feature_prefix ##_## _feature_bit,                \
  87 }
  88 #define BTRFS_FEAT_ATTR_PTR(_name)                                           \
  89         (&btrfs_attr_features_##_name.kobj_attr.attr)
  90
  91 #define BTRFS_FEAT_ATTR_COMPAT(name, feature) \
  92         BTRFS_FEAT_ATTR(name, FEAT_COMPAT, BTRFS_FEATURE_COMPAT, feature)
  93 #define BTRFS_FEAT_ATTR_COMPAT_RO(name, feature) \
  94         BTRFS_FEAT_ATTR(name, FEAT_COMPAT_RO, BTRFS_FEATURE_COMPAT_RO, feature)
  95 #define BTRFS_FEAT_ATTR_INCOMPAT(name, feature) \
  96         BTRFS_FEAT_ATTR(name, FEAT_INCOMPAT, BTRFS_FEATURE_INCOMPAT, feature)
  97
  98 static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj);
  99 static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj);
 100 static struct kobject *get_btrfs_kobj(struct kobject *kobj);
 101
 102 static struct btrfs_feature_attr *to_btrfs_feature_attr(struct kobj_attribute *a)
 103 {
 104         return container_of(a, struct btrfs_feature_attr, kobj_attr);
 105 }
 106
 107 static struct kobj_attribute *attr_to_btrfs_attr(struct attribute *attr)
 108 {
 109         return container_of(attr, struct kobj_attribute, attr);
 110 }
 111
 112 static struct btrfs_feature_attr *attr_to_btrfs_feature_attr(
 113                 struct attribute *attr)
 114 {
 115         return to_btrfs_feature_attr(attr_to_btrfs_attr(attr));
 116 }
 117
 118 static u64 get_features(struct btrfs_fs_info *fs_info,
 119                         enum btrfs_feature_set set)
 120 {
 121         struct btrfs_super_block *disk_super = fs_info->super_copy;
 122         if (set == FEAT_COMPAT)
 123                 return btrfs_super_compat_flags(disk_super);
 124         else if (set == FEAT_COMPAT_RO)
 125                 return btrfs_super_compat_ro_flags(disk_super);
 126         else
 127                 return btrfs_super_incompat_flags(disk_super);
 128 }
 129
 130 static void set_features(struct btrfs_fs_info *fs_info,
 131                          enum btrfs_feature_set set, u64 features)
 132 {
 133         struct btrfs_super_block *disk_super = fs_info->super_copy;
 134         if (set == FEAT_COMPAT)
 135                 btrfs_set_super_compat_flags(disk_super, features);
 136         else if (set == FEAT_COMPAT_RO)
 137                 btrfs_set_super_compat_ro_flags(disk_super, features);
 138         else
 139                 btrfs_set_super_incompat_flags(disk_super, features);
 140 }
 141
 142 static int can_modify_feature(struct btrfs_feature_attr *fa)
 143 {
 144         int val = 0;
 145         u64 set, clear;
 146         switch (fa->feature_set) {
 147         case FEAT_COMPAT:
 148                 set = BTRFS_FEATURE_COMPAT_SAFE_SET;
 149                 clear = BTRFS_FEATURE_COMPAT_SAFE_CLEAR;
 150                 break;
 151         case FEAT_COMPAT_RO:
 152                 set = BTRFS_FEATURE_COMPAT_RO_SAFE_SET;
 153                 clear = BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR;
 154                 break;
 155         case FEAT_INCOMPAT:
 156                 set = BTRFS_FEATURE_INCOMPAT_SAFE_SET;
 157                 clear = BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR;
 158                 break;
 159         default:
 160                 pr_warn("btrfs: sysfs: unknown feature set %d\n",
 161                                 fa->feature_set);
 162                 return 0;
 163         }
 164
 165         if (set & fa->feature_bit)
 166                 val |= 1;
 167         if (clear & fa->feature_bit)
 168                 val |= 2;
 169
 170         return val;
 171 }
 172
 173 static ssize_t btrfs_feature_attr_show(struct kobject *kobj,
 174                                        struct kobj_attribute *a, char *buf)
 175 {
 176         int val = 0;
 177         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 178         struct btrfs_feature_attr *fa = to_btrfs_feature_attr(a);
 179         if (fs_info) {
 180                 u64 features = get_features(fs_info, fa->feature_set);
 181                 if (features & fa->feature_bit)
 182                         val = 1;
 183         } else
 184                 val = can_modify_feature(fa);
 185
 186         return sysfs_emit(buf, "%d\n", val);
 187 }
 188
 189 static ssize_t btrfs_feature_attr_store(struct kobject *kobj,
 190                                         struct kobj_attribute *a,
 191                                         const char *buf, size_t count)
 192 {
 193         struct btrfs_fs_info *fs_info;
 194         struct btrfs_feature_attr *fa = to_btrfs_feature_attr(a);
 195         u64 features, set, clear;
 196         unsigned long val;
 197         int ret;
 198
 199         fs_info = to_fs_info(kobj);
 200         if (!fs_info)
 201                 return -EPERM;
 202
 203         if (sb_rdonly(fs_info->sb))
 204                 return -EROFS;
 205
 206         ret = kstrtoul(skip_spaces(buf), 0, &val);
 207         if (ret)
 208                 return ret;
 209
 210         if (fa->feature_set == FEAT_COMPAT) {
 211                 set = BTRFS_FEATURE_COMPAT_SAFE_SET;
 212                 clear = BTRFS_FEATURE_COMPAT_SAFE_CLEAR;
 213         } else if (fa->feature_set == FEAT_COMPAT_RO) {
 214                 set = BTRFS_FEATURE_COMPAT_RO_SAFE_SET;
 215                 clear = BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR;
 216         } else {
 217                 set = BTRFS_FEATURE_INCOMPAT_SAFE_SET;
 218                 clear = BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR;
 219         }
 220
 221         features = get_features(fs_info, fa->feature_set);
 222
 223         /* Nothing to do */
 224         if ((val && (features & fa->feature_bit)) ||
 225             (!val && !(features & fa->feature_bit)))
 226                 return count;
 227
 228         if ((val && !(set & fa->feature_bit)) ||
 229             (!val && !(clear & fa->feature_bit))) {
 230                 btrfs_info(fs_info,
 231                         "%sabling feature %s on mounted fs is not supported.",
 232                         val ? "En" : "Dis", fa->kobj_attr.attr.name);
 233                 return -EPERM;
 234         }
 235
 236         btrfs_info(fs_info, "%s %s feature flag",
 237                    val ? "Setting" : "Clearing", fa->kobj_attr.attr.name);
 238
 239         spin_lock(&fs_info->super_lock);
 240         features = get_features(fs_info, fa->feature_set);
 241         if (val)
 242                 features |= fa->feature_bit;
 243         else
 244                 features &= ~fa->feature_bit;
 245         set_features(fs_info, fa->feature_set, features);
 246         spin_unlock(&fs_info->super_lock);
 247
 248         /*
 249          * We don't want to do full transaction commit from inside sysfs
 250          */
 251         btrfs_set_pending(fs_info, COMMIT);
 252         wake_up_process(fs_info->transaction_kthread);
 253
 254         return count;
 255 }
 256
 257 static umode_t btrfs_feature_visible(struct kobject *kobj,
 258                                      struct attribute *attr, int unused)
 259 {
 260         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 261         umode_t mode = attr->mode;
 262
 263         if (fs_info) {
 264                 struct btrfs_feature_attr *fa;
 265                 u64 features;
 266
 267                 fa = attr_to_btrfs_feature_attr(attr);
 268                 features = get_features(fs_info, fa->feature_set);
 269
 270                 if (can_modify_feature(fa))
 271                         mode |= S_IWUSR;
 272                 else if (!(features & fa->feature_bit))
 273                         mode = 0;
 274         }
 275
 276         return mode;
 277 }
 278
 279 BTRFS_FEAT_ATTR_INCOMPAT(default_subvol, DEFAULT_SUBVOL);
 280 BTRFS_FEAT_ATTR_INCOMPAT(mixed_groups, MIXED_GROUPS);
 281 BTRFS_FEAT_ATTR_INCOMPAT(compress_lzo, COMPRESS_LZO);
 282 BTRFS_FEAT_ATTR_INCOMPAT(compress_zstd, COMPRESS_ZSTD);
 283 BTRFS_FEAT_ATTR_INCOMPAT(extended_iref, EXTENDED_IREF);
 284 BTRFS_FEAT_ATTR_INCOMPAT(raid56, RAID56);
 285 BTRFS_FEAT_ATTR_INCOMPAT(skinny_metadata, SKINNY_METADATA);
 286 BTRFS_FEAT_ATTR_INCOMPAT(no_holes, NO_HOLES);
 287 BTRFS_FEAT_ATTR_INCOMPAT(metadata_uuid, METADATA_UUID);
 288 BTRFS_FEAT_ATTR_COMPAT_RO(free_space_tree, FREE_SPACE_TREE);
 289 BTRFS_FEAT_ATTR_INCOMPAT(raid1c34, RAID1C34);
 290 #ifdef CONFIG_BLK_DEV_ZONED
 291 BTRFS_FEAT_ATTR_INCOMPAT(zoned, ZONED);
 292 #endif
 293 #ifdef CONFIG_BTRFS_DEBUG
 294 /* Remove once support for extent tree v2 is feature complete */
 295 BTRFS_FEAT_ATTR_INCOMPAT(extent_tree_v2, EXTENT_TREE_V2);
 296 #endif
 297 #ifdef CONFIG_FS_VERITY
 298 BTRFS_FEAT_ATTR_COMPAT_RO(verity, VERITY);
 299 #endif
 300
 301 /*
 302  * Features which depend on feature bits and may differ between each fs.
 303  *
 304  * /sys/fs/btrfs/features      - all available features implemented by this version
 305  * /sys/fs/btrfs/UUID/features - features of the fs which are enabled or
 306  *                               can be changed on a mounted filesystem.
 307  */
 308 static struct attribute *btrfs_supported_feature_attrs[] = {
 309         BTRFS_FEAT_ATTR_PTR(default_subvol),
 310         BTRFS_FEAT_ATTR_PTR(mixed_groups),
 311         BTRFS_FEAT_ATTR_PTR(compress_lzo),
 312         BTRFS_FEAT_ATTR_PTR(compress_zstd),
 313         BTRFS_FEAT_ATTR_PTR(extended_iref),
 314         BTRFS_FEAT_ATTR_PTR(raid56),
 315         BTRFS_FEAT_ATTR_PTR(skinny_metadata),
 316         BTRFS_FEAT_ATTR_PTR(no_holes),
 317         BTRFS_FEAT_ATTR_PTR(metadata_uuid),
 318         BTRFS_FEAT_ATTR_PTR(free_space_tree),
 319         BTRFS_FEAT_ATTR_PTR(raid1c34),
 320 #ifdef CONFIG_BLK_DEV_ZONED
 321         BTRFS_FEAT_ATTR_PTR(zoned),
 322 #endif
 323 #ifdef CONFIG_BTRFS_DEBUG
 324         BTRFS_FEAT_ATTR_PTR(extent_tree_v2),
 325 #endif
 326 #ifdef CONFIG_FS_VERITY
 327         BTRFS_FEAT_ATTR_PTR(verity),
 328 #endif
 329         NULL
 330 };
 331
 332 static const struct attribute_group btrfs_feature_attr_group = {
 333         .name = "features",
 334         .is_visible = btrfs_feature_visible,
 335         .attrs = btrfs_supported_feature_attrs,
 336 };
 337
 338 static ssize_t rmdir_subvol_show(struct kobject *kobj,
 339                                  struct kobj_attribute *ka, char *buf)
 340 {
 341         return sysfs_emit(buf, "0\n");
 342 }
 343 BTRFS_ATTR(static_feature, rmdir_subvol, rmdir_subvol_show);
 344
 345 static ssize_t supported_checksums_show(struct kobject *kobj,
 346                                         struct kobj_attribute *a, char *buf)
 347 {
 348         ssize_t ret = 0;
 349         int i;
 350
 351         for (i = 0; i < btrfs_get_num_csums(); i++) {
 352                 /*
 353                  * This "trick" only works as long as 'enum btrfs_csum_type' has
 354                  * no holes in it
 355                  */
 356                 ret += sysfs_emit_at(buf, ret, "%s%s", (i == 0 ? "" : " "),
 357                                      btrfs_super_csum_name(i));
 358
 359         }
 360
 361         ret += sysfs_emit_at(buf, ret, "\n");
 362         return ret;
 363 }
 364 BTRFS_ATTR(static_feature, supported_checksums, supported_checksums_show);
 365
 366 static ssize_t send_stream_version_show(struct kobject *kobj,
 367                                         struct kobj_attribute *ka, char *buf)
 368 {
 369         return sysfs_emit(buf, "%d\n", BTRFS_SEND_STREAM_VERSION);
 370 }
 371 BTRFS_ATTR(static_feature, send_stream_version, send_stream_version_show);
 372
 373 static const char *rescue_opts[] = {
 374         "usebackuproot",
 375         "nologreplay",
 376         "ignorebadroots",
 377         "ignoredatacsums",
 378         "all",
 379 };
 380
 381 static ssize_t supported_rescue_options_show(struct kobject *kobj,
 382                                              struct kobj_attribute *a,
 383                                              char *buf)
 384 {
 385         ssize_t ret = 0;
 386         int i;
 387
 388         for (i = 0; i < ARRAY_SIZE(rescue_opts); i++)
 389                 ret += sysfs_emit_at(buf, ret, "%s%s", (i ? " " : ""), rescue_opts[i]);
 390         ret += sysfs_emit_at(buf, ret, "\n");
 391         return ret;
 392 }
 393 BTRFS_ATTR(static_feature, supported_rescue_options,
 394            supported_rescue_options_show);
 395
 396 static ssize_t supported_sectorsizes_show(struct kobject *kobj,
 397                                           struct kobj_attribute *a,
 398                                           char *buf)
 399 {
 400         ssize_t ret = 0;
 401
 402         /* An artificial limit to only support 4K and PAGE_SIZE */
 403         if (PAGE_SIZE > SZ_4K)
 404                 ret += sysfs_emit_at(buf, ret, "%u ", SZ_4K);
 405         ret += sysfs_emit_at(buf, ret, "%lu\n", PAGE_SIZE);
 406
 407         return ret;
 408 }
 409 BTRFS_ATTR(static_feature, supported_sectorsizes,
 410            supported_sectorsizes_show);
 411
 412 /*
 413  * Features which only depend on kernel version.
 414  *
 415  * These are listed in /sys/fs/btrfs/features along with
 416  * btrfs_supported_feature_attrs.
 417  */
 418 static struct attribute *btrfs_supported_static_feature_attrs[] = {
 419         BTRFS_ATTR_PTR(static_feature, rmdir_subvol),
 420         BTRFS_ATTR_PTR(static_feature, supported_checksums),
 421         BTRFS_ATTR_PTR(static_feature, send_stream_version),
 422         BTRFS_ATTR_PTR(static_feature, supported_rescue_options),
 423         BTRFS_ATTR_PTR(static_feature, supported_sectorsizes),
 424         NULL
 425 };
 426
 427 static const struct attribute_group btrfs_static_feature_attr_group = {
 428         .name = "features",
 429         .attrs = btrfs_supported_static_feature_attrs,
 430 };
 431
 432 /*
 433  * Discard statistics and tunables
 434  */
 435 #define discard_to_fs_info(_kobj)       to_fs_info(get_btrfs_kobj(_kobj))
 436
 437 static ssize_t btrfs_discardable_bytes_show(struct kobject *kobj,
 438                                             struct kobj_attribute *a,
 439                                             char *buf)
 440 {
 441         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 442
 443         return sysfs_emit(buf, "%lld\n",
 444                         atomic64_read(&fs_info->discard_ctl.discardable_bytes));
 445 }
 446 BTRFS_ATTR(discard, discardable_bytes, btrfs_discardable_bytes_show);
 447
 448 static ssize_t btrfs_discardable_extents_show(struct kobject *kobj,
 449                                               struct kobj_attribute *a,
 450                                               char *buf)
 451 {
 452         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 453
 454         return sysfs_emit(buf, "%d\n",
 455                         atomic_read(&fs_info->discard_ctl.discardable_extents));
 456 }
 457 BTRFS_ATTR(discard, discardable_extents, btrfs_discardable_extents_show);
 458
 459 static ssize_t btrfs_discard_bitmap_bytes_show(struct kobject *kobj,
 460                                                struct kobj_attribute *a,
 461                                                char *buf)
 462 {
 463         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 464
 465         return sysfs_emit(buf, "%llu\n",
 466                           fs_info->discard_ctl.discard_bitmap_bytes);
 467 }
 468 BTRFS_ATTR(discard, discard_bitmap_bytes, btrfs_discard_bitmap_bytes_show);
 469
 470 static ssize_t btrfs_discard_bytes_saved_show(struct kobject *kobj,
 471                                               struct kobj_attribute *a,
 472                                               char *buf)
 473 {
 474         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 475
 476         return sysfs_emit(buf, "%lld\n",
 477                 atomic64_read(&fs_info->discard_ctl.discard_bytes_saved));
 478 }
 479 BTRFS_ATTR(discard, discard_bytes_saved, btrfs_discard_bytes_saved_show);
 480
 481 static ssize_t btrfs_discard_extent_bytes_show(struct kobject *kobj,
 482                                                struct kobj_attribute *a,
 483                                                char *buf)
 484 {
 485         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 486
 487         return sysfs_emit(buf, "%llu\n",
 488                           fs_info->discard_ctl.discard_extent_bytes);
 489 }
 490 BTRFS_ATTR(discard, discard_extent_bytes, btrfs_discard_extent_bytes_show);
 491
 492 static ssize_t btrfs_discard_iops_limit_show(struct kobject *kobj,
 493                                              struct kobj_attribute *a,
 494                                              char *buf)
 495 {
 496         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 497
 498         return sysfs_emit(buf, "%u\n",
 499                           READ_ONCE(fs_info->discard_ctl.iops_limit));
 500 }
 501
 502 static ssize_t btrfs_discard_iops_limit_store(struct kobject *kobj,
 503                                               struct kobj_attribute *a,
 504                                               const char *buf, size_t len)
 505 {
 506         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 507         struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
 508         u32 iops_limit;
 509         int ret;
 510
 511         ret = kstrtou32(buf, 10, &iops_limit);
 512         if (ret)
 513                 return -EINVAL;
 514
 515         WRITE_ONCE(discard_ctl->iops_limit, iops_limit);
 516         btrfs_discard_calc_delay(discard_ctl);
 517         btrfs_discard_schedule_work(discard_ctl, true);
 518         return len;
 519 }
 520 BTRFS_ATTR_RW(discard, iops_limit, btrfs_discard_iops_limit_show,
 521               btrfs_discard_iops_limit_store);
 522
 523 static ssize_t btrfs_discard_kbps_limit_show(struct kobject *kobj,
 524                                              struct kobj_attribute *a,
 525                                              char *buf)
 526 {
 527         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 528
 529         return sysfs_emit(buf, "%u\n",
 530                           READ_ONCE(fs_info->discard_ctl.kbps_limit));
 531 }
 532
 533 static ssize_t btrfs_discard_kbps_limit_store(struct kobject *kobj,
 534                                               struct kobj_attribute *a,
 535                                               const char *buf, size_t len)
 536 {
 537         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 538         struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
 539         u32 kbps_limit;
 540         int ret;
 541
 542         ret = kstrtou32(buf, 10, &kbps_limit);
 543         if (ret)
 544                 return -EINVAL;
 545
 546         WRITE_ONCE(discard_ctl->kbps_limit, kbps_limit);
 547         btrfs_discard_schedule_work(discard_ctl, true);
 548         return len;
 549 }
 550 BTRFS_ATTR_RW(discard, kbps_limit, btrfs_discard_kbps_limit_show,
 551               btrfs_discard_kbps_limit_store);
 552
 553 static ssize_t btrfs_discard_max_discard_size_show(struct kobject *kobj,
 554                                                    struct kobj_attribute *a,
 555                                                    char *buf)
 556 {
 557         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 558
 559         return sysfs_emit(buf, "%llu\n",
 560                           READ_ONCE(fs_info->discard_ctl.max_discard_size));
 561 }
 562
 563 static ssize_t btrfs_discard_max_discard_size_store(struct kobject *kobj,
 564                                                     struct kobj_attribute *a,
 565                                                     const char *buf, size_t len)
 566 {
 567         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 568         struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
 569         u64 max_discard_size;
 570         int ret;
 571
 572         ret = kstrtou64(buf, 10, &max_discard_size);
 573         if (ret)
 574                 return -EINVAL;
 575
 576         WRITE_ONCE(discard_ctl->max_discard_size, max_discard_size);
 577
 578         return len;
 579 }
 580 BTRFS_ATTR_RW(discard, max_discard_size, btrfs_discard_max_discard_size_show,
 581               btrfs_discard_max_discard_size_store);
 582
 583 /*
 584  * Per-filesystem stats for discard (when mounted with discard=async).
 585  *
 586  * Path: /sys/fs/btrfs/<uuid>/discard/
 587  */
 588 static const struct attribute *discard_attrs[] = {
 589         BTRFS_ATTR_PTR(discard, discardable_bytes),
 590         BTRFS_ATTR_PTR(discard, discardable_extents),
 591         BTRFS_ATTR_PTR(discard, discard_bitmap_bytes),
 592         BTRFS_ATTR_PTR(discard, discard_bytes_saved),
 593         BTRFS_ATTR_PTR(discard, discard_extent_bytes),
 594         BTRFS_ATTR_PTR(discard, iops_limit),
 595         BTRFS_ATTR_PTR(discard, kbps_limit),
 596         BTRFS_ATTR_PTR(discard, max_discard_size),
 597         NULL,
 598 };
 599
 600 #ifdef CONFIG_BTRFS_DEBUG
 601
 602 /*
 603  * Per-filesystem runtime debugging exported via sysfs.
 604  *
 605  * Path: /sys/fs/btrfs/UUID/debug/
 606  */
 607 static const struct attribute *btrfs_debug_mount_attrs[] = {
 608         NULL,
 609 };
 610
 611 /*
 612  * Runtime debugging exported via sysfs, applies to all mounted filesystems.
 613  *
 614  * Path: /sys/fs/btrfs/debug
 615  */
 616 static struct attribute *btrfs_debug_feature_attrs[] = {
 617         NULL
 618 };
 619
 620 static const struct attribute_group btrfs_debug_feature_attr_group = {
 621         .name = "debug",
 622         .attrs = btrfs_debug_feature_attrs,
 623 };
 624
 625 #endif
 626
 627 static ssize_t btrfs_show_u64(u64 *value_ptr, spinlock_t *lock, char *buf)
 628 {
 629         u64 val;
 630         if (lock)
 631                 spin_lock(lock);
 632         val = *value_ptr;
 633         if (lock)
 634                 spin_unlock(lock);
 635         return sysfs_emit(buf, "%llu\n", val);
 636 }
 637
 638 static ssize_t global_rsv_size_show(struct kobject *kobj,
 639                                     struct kobj_attribute *ka, char *buf)
 640 {
 641         struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent);
 642         struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
 643         return btrfs_show_u64(&block_rsv->size, &block_rsv->lock, buf);
 644 }
 645 BTRFS_ATTR(allocation, global_rsv_size, global_rsv_size_show);
 646
 647 static ssize_t global_rsv_reserved_show(struct kobject *kobj,
 648                                         struct kobj_attribute *a, char *buf)
 649 {
 650         struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent);
 651         struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
 652         return btrfs_show_u64(&block_rsv->reserved, &block_rsv->lock, buf);
 653 }
 654 BTRFS_ATTR(allocation, global_rsv_reserved, global_rsv_reserved_show);
 655
 656 #define to_space_info(_kobj) container_of(_kobj, struct btrfs_space_info, kobj)
 657 #define to_raid_kobj(_kobj) container_of(_kobj, struct raid_kobject, kobj)
 658
 659 static ssize_t raid_bytes_show(struct kobject *kobj,
 660                                struct kobj_attribute *attr, char *buf);
 661 BTRFS_ATTR(raid, total_bytes, raid_bytes_show);
 662 BTRFS_ATTR(raid, used_bytes, raid_bytes_show);
 663
 664 static ssize_t raid_bytes_show(struct kobject *kobj,
 665                                struct kobj_attribute *attr, char *buf)
 666
 667 {
 668         struct btrfs_space_info *sinfo = to_space_info(kobj->parent);
 669         struct btrfs_block_group *block_group;
 670         int index = btrfs_bg_flags_to_raid_index(to_raid_kobj(kobj)->flags);
 671         u64 val = 0;
 672
 673         down_read(&sinfo->groups_sem);
 674         list_for_each_entry(block_group, &sinfo->block_groups[index], list) {
 675                 if (&attr->attr == BTRFS_ATTR_PTR(raid, total_bytes))
 676                         val += block_group->length;
 677                 else
 678                         val += block_group->used;
 679         }
 680         up_read(&sinfo->groups_sem);
 681         return sysfs_emit(buf, "%llu\n", val);
 682 }
 683
 684 /*
 685  * Allocation information about block group profiles.
 686  *
 687  * Path: /sys/fs/btrfs/<uuid>/allocation/<bg-type>/<bg-profile>/
 688  */
 689 static struct attribute *raid_attrs[] = {
 690         BTRFS_ATTR_PTR(raid, total_bytes),
 691         BTRFS_ATTR_PTR(raid, used_bytes),
 692         NULL
 693 };
 694 ATTRIBUTE_GROUPS(raid);
 695
 696 static void release_raid_kobj(struct kobject *kobj)
 697 {
 698         kfree(to_raid_kobj(kobj));
 699 }
 700
 701 static struct kobj_type btrfs_raid_ktype = {
 702         .sysfs_ops = &kobj_sysfs_ops,
 703         .release = release_raid_kobj,
 704         .default_groups = raid_groups,
 705 };
 706
 707 #define SPACE_INFO_ATTR(field)                                          \
 708 static ssize_t btrfs_space_info_show_##field(struct kobject *kobj,      \
 709                                              struct kobj_attribute *a,  \
 710                                              char *buf)                 \
 711 {                                                                       \
 712         struct btrfs_space_info *sinfo = to_space_info(kobj);           \
 713         return btrfs_show_u64(&sinfo->field, &sinfo->lock, buf);        \
 714 }                                                                       \
 715 BTRFS_ATTR(space_info, field, btrfs_space_info_show_##field)
 716
 717 static ssize_t btrfs_chunk_size_show(struct kobject *kobj,
 718                                      struct kobj_attribute *a, char *buf)
 719 {
 720         struct btrfs_space_info *sinfo = to_space_info(kobj);
 721
 722         return sysfs_emit(buf, "%llu\n", READ_ONCE(sinfo->chunk_size));
 723 }
 724
 725 /*
 726  * Store new chunk size in space info. Can be called on a read-only filesystem.
 727  *
 728  * If the new chunk size value is larger than 10% of free space it is reduced
 729  * to match that limit. Alignment must be to 256M and the system chunk size
 730  * cannot be set.
 731  */
 732 static ssize_t btrfs_chunk_size_store(struct kobject *kobj,
 733                                       struct kobj_attribute *a,
 734                                       const char *buf, size_t len)
 735 {
 736         struct btrfs_space_info *space_info = to_space_info(kobj);
 737         struct btrfs_fs_info *fs_info = to_fs_info(get_btrfs_kobj(kobj));
 738         char *retptr;
 739         u64 val;
 740
 741         if (!capable(CAP_SYS_ADMIN))
 742                 return -EPERM;
 743
 744         if (!fs_info->fs_devices)
 745                 return -EINVAL;
 746
 747         if (btrfs_is_zoned(fs_info))
 748                 return -EINVAL;
 749
 750         /* System block type must not be changed. */
 751         if (space_info->flags & BTRFS_BLOCK_GROUP_SYSTEM)
 752                 return -EPERM;
 753
 754         val = memparse(buf, &retptr);
 755         /* There could be trailing '\n', also catch any typos after the value */
 756         retptr = skip_spaces(retptr);
 757         if (*retptr != 0 || val == 0)
 758                 return -EINVAL;
 759
 760         val = min(val, BTRFS_MAX_DATA_CHUNK_SIZE);
 761
 762         /* Limit stripe size to 10% of available space. */
 763         val = min(div_factor(fs_info->fs_devices->total_rw_bytes, 1), val);
 764
 765         /* Must be multiple of 256M. */
 766         val &= ~((u64)SZ_256M - 1);
 767
 768         /* Must be at least 256M. */
 769         if (val < SZ_256M)
 770                 return -EINVAL;
 771
 772         btrfs_update_space_info_chunk_size(space_info, val);
 773
 774         return len;
 775 }
 776
 777 #ifdef CONFIG_BTRFS_DEBUG
 778 /*
 779  * Request chunk allocation with current chunk size.
 780  */
 781 static ssize_t btrfs_force_chunk_alloc_store(struct kobject *kobj,
 782                                              struct kobj_attribute *a,
 783                                              const char *buf, size_t len)
 784 {
 785         struct btrfs_space_info *space_info = to_space_info(kobj);
 786         struct btrfs_fs_info *fs_info = to_fs_info(get_btrfs_kobj(kobj));
 787         struct btrfs_trans_handle *trans;
 788         bool val;
 789         int ret;
 790
 791         if (!capable(CAP_SYS_ADMIN))
 792                 return -EPERM;
 793
 794         if (sb_rdonly(fs_info->sb))
 795                 return -EROFS;
 796
 797         ret = kstrtobool(buf, &val);
 798         if (ret)
 799                 return ret;
 800
 801         if (!val)
 802                 return -EINVAL;
 803
 804         /*
 805          * This is unsafe to be called from sysfs context and may cause
 806          * unexpected problems.
 807          */
 808         trans = btrfs_start_transaction(fs_info->tree_root, 0);
 809         if (IS_ERR(trans))
 810                 return PTR_ERR(trans);
 811         ret = btrfs_force_chunk_alloc(trans, space_info->flags);
 812         btrfs_end_transaction(trans);
 813
 814         if (ret == 1)
 815                 return len;
 816
 817         return -ENOSPC;
 818 }
 819 BTRFS_ATTR_W(space_info, force_chunk_alloc, btrfs_force_chunk_alloc_store);
 820
 821 #endif
 822
 823 SPACE_INFO_ATTR(flags);
 824 SPACE_INFO_ATTR(total_bytes);
 825 SPACE_INFO_ATTR(bytes_used);
 826 SPACE_INFO_ATTR(bytes_pinned);
 827 SPACE_INFO_ATTR(bytes_reserved);
 828 SPACE_INFO_ATTR(bytes_may_use);
 829 SPACE_INFO_ATTR(bytes_readonly);
 830 SPACE_INFO_ATTR(bytes_zone_unusable);
 831 SPACE_INFO_ATTR(disk_used);
 832 SPACE_INFO_ATTR(disk_total);
 833 BTRFS_ATTR_RW(space_info, chunk_size, btrfs_chunk_size_show, btrfs_chunk_size_store);
 834
 835 static ssize_t btrfs_sinfo_bg_reclaim_threshold_show(struct kobject *kobj,
 836                                                      struct kobj_attribute *a,
 837                                                      char *buf)
 838 {
 839         struct btrfs_space_info *space_info = to_space_info(kobj);
 840         ssize_t ret;
 841
 842         ret = sysfs_emit(buf, "%d\n", READ_ONCE(space_info->bg_reclaim_threshold));
 843
 844         return ret;
 845 }
 846
 847 static ssize_t btrfs_sinfo_bg_reclaim_threshold_store(struct kobject *kobj,
 848                                                       struct kobj_attribute *a,
 849                                                       const char *buf, size_t len)
 850 {
 851         struct btrfs_space_info *space_info = to_space_info(kobj);
 852         int thresh;
 853         int ret;
 854
 855         ret = kstrtoint(buf, 10, &thresh);
 856         if (ret)
 857                 return ret;
 858
 859         if (thresh < 0 || thresh > 100)
 860                 return -EINVAL;
 861
 862         WRITE_ONCE(space_info->bg_reclaim_threshold, thresh);
 863
 864         return len;
 865 }
 866
 867 BTRFS_ATTR_RW(space_info, bg_reclaim_threshold,
 868               btrfs_sinfo_bg_reclaim_threshold_show,
 869               btrfs_sinfo_bg_reclaim_threshold_store);
 870
 871 /*
 872  * Allocation information about block group types.
 873  *
 874  * Path: /sys/fs/btrfs/<uuid>/allocation/<bg-type>/
 875  */
 876 static struct attribute *space_info_attrs[] = {
 877         BTRFS_ATTR_PTR(space_info, flags),
 878         BTRFS_ATTR_PTR(space_info, total_bytes),
 879         BTRFS_ATTR_PTR(space_info, bytes_used),
 880         BTRFS_ATTR_PTR(space_info, bytes_pinned),
 881         BTRFS_ATTR_PTR(space_info, bytes_reserved),
 882         BTRFS_ATTR_PTR(space_info, bytes_may_use),
 883         BTRFS_ATTR_PTR(space_info, bytes_readonly),
 884         BTRFS_ATTR_PTR(space_info, bytes_zone_unusable),
 885         BTRFS_ATTR_PTR(space_info, disk_used),
 886         BTRFS_ATTR_PTR(space_info, disk_total),
 887         BTRFS_ATTR_PTR(space_info, bg_reclaim_threshold),
 888         BTRFS_ATTR_PTR(space_info, chunk_size),
 889 #ifdef CONFIG_BTRFS_DEBUG
 890         BTRFS_ATTR_PTR(space_info, force_chunk_alloc),
 891 #endif
 892         NULL,
 893 };
 894 ATTRIBUTE_GROUPS(space_info);
 895
 896 static void space_info_release(struct kobject *kobj)
 897 {
 898         struct btrfs_space_info *sinfo = to_space_info(kobj);
 899         kfree(sinfo);
 900 }
 901
 902 static struct kobj_type space_info_ktype = {
 903         .sysfs_ops = &kobj_sysfs_ops,
 904         .release = space_info_release,
 905         .default_groups = space_info_groups,
 906 };
 907
 908 /*
 909  * Allocation information about block groups.
 910  *
 911  * Path: /sys/fs/btrfs/<uuid>/allocation/
 912  */
 913 static const struct attribute *allocation_attrs[] = {
 914         BTRFS_ATTR_PTR(allocation, global_rsv_reserved),
 915         BTRFS_ATTR_PTR(allocation, global_rsv_size),
 916         NULL,
 917 };
 918
 919 static ssize_t btrfs_label_show(struct kobject *kobj,
 920                                 struct kobj_attribute *a, char *buf)
 921 {
 922         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 923         char *label = fs_info->super_copy->label;
 924         ssize_t ret;
 925
 926         spin_lock(&fs_info->super_lock);
 927         ret = sysfs_emit(buf, label[0] ? "%s\n" : "%s", label);
 928         spin_unlock(&fs_info->super_lock);
 929
 930         return ret;
 931 }
 932
 933 static ssize_t btrfs_label_store(struct kobject *kobj,
 934                                  struct kobj_attribute *a,
 935                                  const char *buf, size_t len)
 936 {
 937         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 938         size_t p_len;
 939
 940         if (!fs_info)
 941                 return -EPERM;
 942
 943         if (sb_rdonly(fs_info->sb))
 944                 return -EROFS;
 945
 946         /*
 947          * p_len is the len until the first occurrence of either
 948          * '\n' or '\0'
 949          */
 950         p_len = strcspn(buf, "\n");
 951
 952         if (p_len >= BTRFS_LABEL_SIZE)
 953                 return -EINVAL;
 954
 955         spin_lock(&fs_info->super_lock);
 956         memset(fs_info->super_copy->label, 0, BTRFS_LABEL_SIZE);
 957         memcpy(fs_info->super_copy->label, buf, p_len);
 958         spin_unlock(&fs_info->super_lock);
 959
 960         /*
 961          * We don't want to do full transaction commit from inside sysfs
 962          */
 963         btrfs_set_pending(fs_info, COMMIT);
 964         wake_up_process(fs_info->transaction_kthread);
 965
 966         return len;
 967 }
 968 BTRFS_ATTR_RW(, label, btrfs_label_show, btrfs_label_store);
 969
 970 static ssize_t btrfs_nodesize_show(struct kobject *kobj,
 971                                 struct kobj_attribute *a, char *buf)
 972 {
 973         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 974
 975         return sysfs_emit(buf, "%u\n", fs_info->super_copy->nodesize);
 976 }
 977
 978 BTRFS_ATTR(, nodesize, btrfs_nodesize_show);
 979
 980 static ssize_t btrfs_sectorsize_show(struct kobject *kobj,
 981                                 struct kobj_attribute *a, char *buf)
 982 {
 983         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 984
 985         return sysfs_emit(buf, "%u\n", fs_info->super_copy->sectorsize);
 986 }
 987
 988 BTRFS_ATTR(, sectorsize, btrfs_sectorsize_show);
 989
 990 static ssize_t btrfs_commit_stats_show(struct kobject *kobj,
 991                                        struct kobj_attribute *a, char *buf)
 992 {
 993         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 994
 995         return sysfs_emit(buf,
 996                 "commits %llu\n"
 997                 "last_commit_ms %llu\n"
 998                 "max_commit_ms %llu\n"
 999                 "total_commit_ms %llu\n",
1000                 fs_info->commit_stats.commit_count,
1001                 div_u64(fs_info->commit_stats.last_commit_dur, NSEC_PER_MSEC),
1002                 div_u64(fs_info->commit_stats.max_commit_dur, NSEC_PER_MSEC),
1003                 div_u64(fs_info->commit_stats.total_commit_dur, NSEC_PER_MSEC));
1004 }
1005
1006 static ssize_t btrfs_commit_stats_store(struct kobject *kobj,
1007                                         struct kobj_attribute *a,
1008                                         const char *buf, size_t len)
1009 {
1010         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1011         unsigned long val;
1012         int ret;
1013
1014         if (!fs_info)
1015                 return -EPERM;
1016
1017         if (!capable(CAP_SYS_RESOURCE))
1018                 return -EPERM;
1019
1020         ret = kstrtoul(buf, 10, &val);
1021         if (ret)
1022                 return ret;
1023         if (val)
1024                 return -EINVAL;
1025
1026         WRITE_ONCE(fs_info->commit_stats.max_commit_dur, 0);
1027
1028         return len;
1029 }
1030 BTRFS_ATTR_RW(, commit_stats, btrfs_commit_stats_show, btrfs_commit_stats_store);
1031
1032 static ssize_t btrfs_clone_alignment_show(struct kobject *kobj,
1033                                 struct kobj_attribute *a, char *buf)
1034 {
1035         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1036
1037         return sysfs_emit(buf, "%u\n", fs_info->super_copy->sectorsize);
1038 }
1039
1040 BTRFS_ATTR(, clone_alignment, btrfs_clone_alignment_show);
1041
1042 static ssize_t quota_override_show(struct kobject *kobj,
1043                                    struct kobj_attribute *a, char *buf)
1044 {
1045         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1046         int quota_override;
1047
1048         quota_override = test_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
1049         return sysfs_emit(buf, "%d\n", quota_override);
1050 }
1051
1052 static ssize_t quota_override_store(struct kobject *kobj,
1053                                     struct kobj_attribute *a,
1054                                     const char *buf, size_t len)
1055 {
1056         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1057         unsigned long knob;
1058         int err;
1059
1060         if (!fs_info)
1061                 return -EPERM;
1062
1063         if (!capable(CAP_SYS_RESOURCE))
1064                 return -EPERM;
1065
1066         err = kstrtoul(buf, 10, &knob);
1067         if (err)
1068                 return err;
1069         if (knob > 1)
1070                 return -EINVAL;
1071
1072         if (knob)
1073                 set_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
1074         else
1075                 clear_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
1076
1077         return len;
1078 }
1079
1080 BTRFS_ATTR_RW(, quota_override, quota_override_show, quota_override_store);
1081
1082 static ssize_t btrfs_metadata_uuid_show(struct kobject *kobj,
1083                                 struct kobj_attribute *a, char *buf)
1084 {
1085         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1086
1087         return sysfs_emit(buf, "%pU\n", fs_info->fs_devices->metadata_uuid);
1088 }
1089
1090 BTRFS_ATTR(, metadata_uuid, btrfs_metadata_uuid_show);
1091
1092 static ssize_t btrfs_checksum_show(struct kobject *kobj,
1093                                    struct kobj_attribute *a, char *buf)
1094 {
1095         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1096         u16 csum_type = btrfs_super_csum_type(fs_info->super_copy);
1097
1098         return sysfs_emit(buf, "%s (%s)\n",
1099                           btrfs_super_csum_name(csum_type),
1100                           crypto_shash_driver_name(fs_info->csum_shash));
1101 }
1102
1103 BTRFS_ATTR(, checksum, btrfs_checksum_show);
1104
1105 static ssize_t btrfs_exclusive_operation_show(struct kobject *kobj,
1106                 struct kobj_attribute *a, char *buf)
1107 {
1108         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1109         const char *str;
1110
1111         switch (READ_ONCE(fs_info->exclusive_operation)) {
1112                 case  BTRFS_EXCLOP_NONE:
1113                         str = "none\n";
1114                         break;
1115                 case BTRFS_EXCLOP_BALANCE:
1116                         str = "balance\n";
1117                         break;
1118                 case BTRFS_EXCLOP_BALANCE_PAUSED:
1119                         str = "balance paused\n";
1120                         break;
1121                 case BTRFS_EXCLOP_DEV_ADD:
1122                         str = "device add\n";
1123                         break;
1124                 case BTRFS_EXCLOP_DEV_REMOVE:
1125                         str = "device remove\n";
1126                         break;
1127                 case BTRFS_EXCLOP_DEV_REPLACE:
1128                         str = "device replace\n";
1129                         break;
1130                 case BTRFS_EXCLOP_RESIZE:
1131                         str = "resize\n";
1132                         break;
1133                 case BTRFS_EXCLOP_SWAP_ACTIVATE:
1134                         str = "swap activate\n";
1135                         break;
1136                 default:
1137                         str = "UNKNOWN\n";
1138                         break;
1139         }
1140         return sysfs_emit(buf, "%s", str);
1141 }
1142 BTRFS_ATTR(, exclusive_operation, btrfs_exclusive_operation_show);
1143
1144 static ssize_t btrfs_generation_show(struct kobject *kobj,
1145                                      struct kobj_attribute *a, char *buf)
1146 {
1147         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1148
1149         return sysfs_emit(buf, "%llu\n", fs_info->generation);
1150 }
1151 BTRFS_ATTR(, generation, btrfs_generation_show);
1152
1153 static const char * const btrfs_read_policy_name[] = { "pid" };
1154
1155 static ssize_t btrfs_read_policy_show(struct kobject *kobj,
1156                                       struct kobj_attribute *a, char *buf)
1157 {
1158         struct btrfs_fs_devices *fs_devices = to_fs_devs(kobj);
1159         ssize_t ret = 0;
1160         int i;
1161
1162         for (i = 0; i < BTRFS_NR_READ_POLICY; i++) {
1163                 if (fs_devices->read_policy == i)
1164                         ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s[%s]",
1165                                          (ret == 0 ? "" : " "),
1166                                          btrfs_read_policy_name[i]);
1167                 else
1168                         ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%s",
1169                                          (ret == 0 ? "" : " "),
1170                                          btrfs_read_policy_name[i]);
1171         }
1172
1173         ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
1174
1175         return ret;
1176 }
1177
1178 static ssize_t btrfs_read_policy_store(struct kobject *kobj,
1179                                        struct kobj_attribute *a,
1180                                        const char *buf, size_t len)
1181 {
1182         struct btrfs_fs_devices *fs_devices = to_fs_devs(kobj);
1183         int i;
1184
1185         for (i = 0; i < BTRFS_NR_READ_POLICY; i++) {
1186                 if (sysfs_streq(buf, btrfs_read_policy_name[i])) {
1187                         if (i != fs_devices->read_policy) {
1188                                 fs_devices->read_policy = i;
1189                                 btrfs_info(fs_devices->fs_info,
1190                                            "read policy set to '%s'",
1191                                            btrfs_read_policy_name[i]);
1192                         }
1193                         return len;
1194                 }
1195         }
1196
1197         return -EINVAL;
1198 }
1199 BTRFS_ATTR_RW(, read_policy, btrfs_read_policy_show, btrfs_read_policy_store);
1200
1201 static ssize_t btrfs_bg_reclaim_threshold_show(struct kobject *kobj,
1202                                                struct kobj_attribute *a,
1203                                                char *buf)
1204 {
1205         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1206         ssize_t ret;
1207
1208         ret = sysfs_emit(buf, "%d\n", READ_ONCE(fs_info->bg_reclaim_threshold));
1209
1210         return ret;
1211 }
1212
1213 static ssize_t btrfs_bg_reclaim_threshold_store(struct kobject *kobj,
1214                                                 struct kobj_attribute *a,
1215                                                 const char *buf, size_t len)
1216 {
1217         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1218         int thresh;
1219         int ret;
1220
1221         ret = kstrtoint(buf, 10, &thresh);
1222         if (ret)
1223                 return ret;
1224
1225         if (thresh != 0 && (thresh <= 50 || thresh > 100))
1226                 return -EINVAL;
1227
1228         WRITE_ONCE(fs_info->bg_reclaim_threshold, thresh);
1229
1230         return len;
1231 }
1232 BTRFS_ATTR_RW(, bg_reclaim_threshold, btrfs_bg_reclaim_threshold_show,
1233               btrfs_bg_reclaim_threshold_store);
1234
1235 /*
1236  * Per-filesystem information and stats.
1237  *
1238  * Path: /sys/fs/btrfs/<uuid>/
1239  */
1240 static const struct attribute *btrfs_attrs[] = {
1241         BTRFS_ATTR_PTR(, label),
1242         BTRFS_ATTR_PTR(, nodesize),
1243         BTRFS_ATTR_PTR(, sectorsize),
1244         BTRFS_ATTR_PTR(, clone_alignment),
1245         BTRFS_ATTR_PTR(, quota_override),
1246         BTRFS_ATTR_PTR(, metadata_uuid),
1247         BTRFS_ATTR_PTR(, checksum),
1248         BTRFS_ATTR_PTR(, exclusive_operation),
1249         BTRFS_ATTR_PTR(, generation),
1250         BTRFS_ATTR_PTR(, read_policy),
1251         BTRFS_ATTR_PTR(, bg_reclaim_threshold),
1252         BTRFS_ATTR_PTR(, commit_stats),
1253         NULL,
1254 };
1255
1256 static void btrfs_release_fsid_kobj(struct kobject *kobj)
1257 {
1258         struct btrfs_fs_devices *fs_devs = to_fs_devs(kobj);
1259
1260         memset(&fs_devs->fsid_kobj, 0, sizeof(struct kobject));
1261         complete(&fs_devs->kobj_unregister);
1262 }
1263
1264 static struct kobj_type btrfs_ktype = {
1265         .sysfs_ops      = &kobj_sysfs_ops,
1266         .release        = btrfs_release_fsid_kobj,
1267 };
1268
1269 static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj)
1270 {
1271         if (kobj->ktype != &btrfs_ktype)
1272                 return NULL;
1273         return container_of(kobj, struct btrfs_fs_devices, fsid_kobj);
1274 }
1275
1276 static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj)
1277 {
1278         if (kobj->ktype != &btrfs_ktype)
1279                 return NULL;
1280         return to_fs_devs(kobj)->fs_info;
1281 }
1282
1283 static struct kobject *get_btrfs_kobj(struct kobject *kobj)
1284 {
1285         while (kobj) {
1286                 if (kobj->ktype == &btrfs_ktype)
1287                         return kobj;
1288                 kobj = kobj->parent;
1289         }
1290         return NULL;
1291 }
1292
1293 #define NUM_FEATURE_BITS 64
1294 #define BTRFS_FEATURE_NAME_MAX 13
1295 static char btrfs_unknown_feature_names[FEAT_MAX][NUM_FEATURE_BITS][BTRFS_FEATURE_NAME_MAX];
1296 static struct btrfs_feature_attr btrfs_feature_attrs[FEAT_MAX][NUM_FEATURE_BITS];
1297
1298 static_assert(ARRAY_SIZE(btrfs_unknown_feature_names) ==
1299               ARRAY_SIZE(btrfs_feature_attrs));
1300 static_assert(ARRAY_SIZE(btrfs_unknown_feature_names[0]) ==
1301               ARRAY_SIZE(btrfs_feature_attrs[0]));
1302
1303 static const u64 supported_feature_masks[FEAT_MAX] = {
1304         [FEAT_COMPAT]    = BTRFS_FEATURE_COMPAT_SUPP,
1305         [FEAT_COMPAT_RO] = BTRFS_FEATURE_COMPAT_RO_SUPP,
1306         [FEAT_INCOMPAT]  = BTRFS_FEATURE_INCOMPAT_SUPP,
1307 };
1308
1309 static int addrm_unknown_feature_attrs(struct btrfs_fs_info *fs_info, bool add)
1310 {
1311         int set;
1312
1313         for (set = 0; set < FEAT_MAX; set++) {
1314                 int i;
1315                 struct attribute *attrs[2];
1316                 struct attribute_group agroup = {
1317                         .name = "features",
1318                         .attrs = attrs,
1319                 };
1320                 u64 features = get_features(fs_info, set);
1321                 features &= ~supported_feature_masks[set];
1322
1323                 if (!features)
1324                         continue;
1325
1326                 attrs[1] = NULL;
1327                 for (i = 0; i < NUM_FEATURE_BITS; i++) {
1328                         struct btrfs_feature_attr *fa;
1329
1330                         if (!(features & (1ULL << i)))
1331                                 continue;
1332
1333                         fa = &btrfs_feature_attrs[set][i];
1334                         attrs[0] = &fa->kobj_attr.attr;
1335                         if (add) {
1336                                 int ret;
1337                                 ret = sysfs_merge_group(&fs_info->fs_devices->fsid_kobj,
1338                                                         &agroup);
1339                                 if (ret)
1340                                         return ret;
1341                         } else
1342                                 sysfs_unmerge_group(&fs_info->fs_devices->fsid_kobj,
1343                                                     &agroup);
1344                 }
1345
1346         }
1347         return 0;
1348 }
1349
1350 static void __btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs)
1351 {
1352         if (fs_devs->devinfo_kobj) {
1353                 kobject_del(fs_devs->devinfo_kobj);
1354                 kobject_put(fs_devs->devinfo_kobj);
1355                 fs_devs->devinfo_kobj = NULL;
1356         }
1357
1358         if (fs_devs->devices_kobj) {
1359                 kobject_del(fs_devs->devices_kobj);
1360                 kobject_put(fs_devs->devices_kobj);
1361                 fs_devs->devices_kobj = NULL;
1362         }
1363
1364         if (fs_devs->fsid_kobj.state_initialized) {
1365                 kobject_del(&fs_devs->fsid_kobj);
1366                 kobject_put(&fs_devs->fsid_kobj);
1367                 wait_for_completion(&fs_devs->kobj_unregister);
1368         }
1369 }
1370
1371 /* when fs_devs is NULL it will remove all fsid kobject */
1372 void btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs)
1373 {
1374         struct list_head *fs_uuids = btrfs_get_fs_uuids();
1375
1376         if (fs_devs) {
1377                 __btrfs_sysfs_remove_fsid(fs_devs);
1378                 return;
1379         }
1380
1381         list_for_each_entry(fs_devs, fs_uuids, fs_list) {
1382                 __btrfs_sysfs_remove_fsid(fs_devs);
1383         }
1384 }
1385
1386 static void btrfs_sysfs_remove_fs_devices(struct btrfs_fs_devices *fs_devices)
1387 {
1388         struct btrfs_device *device;
1389         struct btrfs_fs_devices *seed;
1390
1391         list_for_each_entry(device, &fs_devices->devices, dev_list)
1392                 btrfs_sysfs_remove_device(device);
1393
1394         list_for_each_entry(seed, &fs_devices->seed_list, seed_list) {
1395                 list_for_each_entry(device, &seed->devices, dev_list)
1396                         btrfs_sysfs_remove_device(device);
1397         }
1398 }
1399
1400 void btrfs_sysfs_remove_mounted(struct btrfs_fs_info *fs_info)
1401 {
1402         struct kobject *fsid_kobj = &fs_info->fs_devices->fsid_kobj;
1403
1404         sysfs_remove_link(fsid_kobj, "bdi");
1405
1406         if (fs_info->space_info_kobj) {
1407                 sysfs_remove_files(fs_info->space_info_kobj, allocation_attrs);
1408                 kobject_del(fs_info->space_info_kobj);
1409                 kobject_put(fs_info->space_info_kobj);
1410         }
1411         if (fs_info->discard_kobj) {
1412                 sysfs_remove_files(fs_info->discard_kobj, discard_attrs);
1413                 kobject_del(fs_info->discard_kobj);
1414                 kobject_put(fs_info->discard_kobj);
1415         }
1416 #ifdef CONFIG_BTRFS_DEBUG
1417         if (fs_info->debug_kobj) {
1418                 sysfs_remove_files(fs_info->debug_kobj, btrfs_debug_mount_attrs);
1419                 kobject_del(fs_info->debug_kobj);
1420                 kobject_put(fs_info->debug_kobj);
1421         }
1422 #endif
1423         addrm_unknown_feature_attrs(fs_info, false);
1424         sysfs_remove_group(fsid_kobj, &btrfs_feature_attr_group);
1425         sysfs_remove_files(fsid_kobj, btrfs_attrs);
1426         btrfs_sysfs_remove_fs_devices(fs_info->fs_devices);
1427 }
1428
1429 static const char * const btrfs_feature_set_names[FEAT_MAX] = {
1430         [FEAT_COMPAT]    = "compat",
1431         [FEAT_COMPAT_RO] = "compat_ro",
1432         [FEAT_INCOMPAT]  = "incompat",
1433 };
1434
1435 const char *btrfs_feature_set_name(enum btrfs_feature_set set)
1436 {
1437         return btrfs_feature_set_names[set];
1438 }
1439
1440 char *btrfs_printable_features(enum btrfs_feature_set set, u64 flags)
1441 {
1442         size_t bufsize = 4096; /* safe max, 64 names * 64 bytes */
1443         int len = 0;
1444         int i;
1445         char *str;
1446
1447         str = kmalloc(bufsize, GFP_KERNEL);
1448         if (!str)
1449                 return str;
1450
1451         for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
1452                 const char *name;
1453
1454                 if (!(flags & (1ULL << i)))
1455                         continue;
1456
1457                 name = btrfs_feature_attrs[set][i].kobj_attr.attr.name;
1458                 len += scnprintf(str + len, bufsize - len, "%s%s",
1459                                 len ? "," : "", name);
1460         }
1461
1462         return str;
1463 }
1464
1465 static void init_feature_attrs(void)
1466 {
1467         struct btrfs_feature_attr *fa;
1468         int set, i;
1469
1470         memset(btrfs_feature_attrs, 0, sizeof(btrfs_feature_attrs));
1471         memset(btrfs_unknown_feature_names, 0,
1472                sizeof(btrfs_unknown_feature_names));
1473
1474         for (i = 0; btrfs_supported_feature_attrs[i]; i++) {
1475                 struct btrfs_feature_attr *sfa;
1476                 struct attribute *a = btrfs_supported_feature_attrs[i];
1477                 int bit;
1478                 sfa = attr_to_btrfs_feature_attr(a);
1479                 bit = ilog2(sfa->feature_bit);
1480                 fa = &btrfs_feature_attrs[sfa->feature_set][bit];
1481
1482                 fa->kobj_attr.attr.name = sfa->kobj_attr.attr.name;
1483         }
1484
1485         for (set = 0; set < FEAT_MAX; set++) {
1486                 for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
1487                         char *name = btrfs_unknown_feature_names[set][i];
1488                         fa = &btrfs_feature_attrs[set][i];
1489
1490                         if (fa->kobj_attr.attr.name)
1491                                 continue;
1492
1493                         snprintf(name, BTRFS_FEATURE_NAME_MAX, "%s:%u",
1494                                  btrfs_feature_set_names[set], i);
1495
1496                         fa->kobj_attr.attr.name = name;
1497                         fa->kobj_attr.attr.mode = S_IRUGO;
1498                         fa->feature_set = set;
1499                         fa->feature_bit = 1ULL << i;
1500                 }
1501         }
1502 }
1503
1504 /*
1505  * Create a sysfs entry for a given block group type at path
1506  * /sys/fs/btrfs/UUID/allocation/data/TYPE
1507  */
1508 void btrfs_sysfs_add_block_group_type(struct btrfs_block_group *cache)
1509 {
1510         struct btrfs_fs_info *fs_info = cache->fs_info;
1511         struct btrfs_space_info *space_info = cache->space_info;
1512         struct raid_kobject *rkobj;
1513         const int index = btrfs_bg_flags_to_raid_index(cache->flags);
1514         unsigned int nofs_flag;
1515         int ret;
1516
1517         /*
1518          * Setup a NOFS context because kobject_add(), deep in its call chain,
1519          * does GFP_KERNEL allocations, and we are often called in a context
1520          * where if reclaim is triggered we can deadlock (we are either holding
1521          * a transaction handle or some lock required for a transaction
1522          * commit).
1523          */
1524         nofs_flag = memalloc_nofs_save();
1525
1526         rkobj = kzalloc(sizeof(*rkobj), GFP_NOFS);
1527         if (!rkobj) {
1528                 memalloc_nofs_restore(nofs_flag);
1529                 btrfs_warn(cache->fs_info,
1530                                 "couldn't alloc memory for raid level kobject");
1531                 return;
1532         }
1533
1534         rkobj->flags = cache->flags;
1535         kobject_init(&rkobj->kobj, &btrfs_raid_ktype);
1536
1537         /*
1538          * We call this either on mount, or if we've created a block group for a
1539          * new index type while running (i.e. when restriping).  The running
1540          * case is tricky because we could race with other threads, so we need
1541          * to have this check to make sure we didn't already init the kobject.
1542          *
1543          * We don't have to protect on the free side because it only happens on
1544          * unmount.
1545          */
1546         spin_lock(&space_info->lock);
1547         if (space_info->block_group_kobjs[index]) {
1548                 spin_unlock(&space_info->lock);
1549                 kobject_put(&rkobj->kobj);
1550                 return;
1551         } else {
1552                 space_info->block_group_kobjs[index] = &rkobj->kobj;
1553         }
1554         spin_unlock(&space_info->lock);
1555
1556         ret = kobject_add(&rkobj->kobj, &space_info->kobj, "%s",
1557                           btrfs_bg_type_to_raid_name(rkobj->flags));
1558         memalloc_nofs_restore(nofs_flag);
1559         if (ret) {
1560                 spin_lock(&space_info->lock);
1561                 space_info->block_group_kobjs[index] = NULL;
1562                 spin_unlock(&space_info->lock);
1563                 kobject_put(&rkobj->kobj);
1564                 btrfs_warn(fs_info,
1565                         "failed to add kobject for block cache, ignoring");
1566                 return;
1567         }
1568 }
1569
1570 /*
1571  * Remove sysfs directories for all block group types of a given space info and
1572  * the space info as well
1573  */
1574 void btrfs_sysfs_remove_space_info(struct btrfs_space_info *space_info)
1575 {
1576         int i;
1577
1578         for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) {
1579                 struct kobject *kobj;
1580
1581                 kobj = space_info->block_group_kobjs[i];
1582                 space_info->block_group_kobjs[i] = NULL;
1583                 if (kobj) {
1584                         kobject_del(kobj);
1585                         kobject_put(kobj);
1586                 }
1587         }
1588         kobject_del(&space_info->kobj);
1589         kobject_put(&space_info->kobj);
1590 }
1591
1592 static const char *alloc_name(u64 flags)
1593 {
1594         switch (flags) {
1595         case BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA:
1596                 return "mixed";
1597         case BTRFS_BLOCK_GROUP_METADATA:
1598                 return "metadata";
1599         case BTRFS_BLOCK_GROUP_DATA:
1600                 return "data";
1601         case BTRFS_BLOCK_GROUP_SYSTEM:
1602                 return "system";
1603         default:
1604                 WARN_ON(1);
1605                 return "invalid-combination";
1606         }
1607 }
1608
1609 /*
1610  * Create a sysfs entry for a space info type at path
1611  * /sys/fs/btrfs/UUID/allocation/TYPE
1612  */
1613 int btrfs_sysfs_add_space_info_type(struct btrfs_fs_info *fs_info,
1614                                     struct btrfs_space_info *space_info)
1615 {
1616         int ret;
1617
1618         ret = kobject_init_and_add(&space_info->kobj, &space_info_ktype,
1619                                    fs_info->space_info_kobj, "%s",
1620                                    alloc_name(space_info->flags));
1621         if (ret) {
1622                 kobject_put(&space_info->kobj);
1623                 return ret;
1624         }
1625
1626         return 0;
1627 }
1628
1629 void btrfs_sysfs_remove_device(struct btrfs_device *device)
1630 {
1631         struct kobject *devices_kobj;
1632
1633         /*
1634          * Seed fs_devices devices_kobj aren't used, fetch kobject from the
1635          * fs_info::fs_devices.
1636          */
1637         devices_kobj = device->fs_info->fs_devices->devices_kobj;
1638         ASSERT(devices_kobj);
1639
1640         if (device->bdev)
1641                 sysfs_remove_link(devices_kobj, bdev_kobj(device->bdev)->name);
1642
1643         if (device->devid_kobj.state_initialized) {
1644                 kobject_del(&device->devid_kobj);
1645                 kobject_put(&device->devid_kobj);
1646                 wait_for_completion(&device->kobj_unregister);
1647         }
1648 }
1649
1650 static ssize_t btrfs_devinfo_in_fs_metadata_show(struct kobject *kobj,
1651                                                  struct kobj_attribute *a,
1652                                                  char *buf)
1653 {
1654         int val;
1655         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1656                                                    devid_kobj);
1657
1658         val = !!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state);
1659
1660         return sysfs_emit(buf, "%d\n", val);
1661 }
1662 BTRFS_ATTR(devid, in_fs_metadata, btrfs_devinfo_in_fs_metadata_show);
1663
1664 static ssize_t btrfs_devinfo_missing_show(struct kobject *kobj,
1665                                         struct kobj_attribute *a, char *buf)
1666 {
1667         int val;
1668         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1669                                                    devid_kobj);
1670
1671         val = !!test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state);
1672
1673         return sysfs_emit(buf, "%d\n", val);
1674 }
1675 BTRFS_ATTR(devid, missing, btrfs_devinfo_missing_show);
1676
1677 static ssize_t btrfs_devinfo_replace_target_show(struct kobject *kobj,
1678                                                  struct kobj_attribute *a,
1679                                                  char *buf)
1680 {
1681         int val;
1682         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1683                                                    devid_kobj);
1684
1685         val = !!test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state);
1686
1687         return sysfs_emit(buf, "%d\n", val);
1688 }
1689 BTRFS_ATTR(devid, replace_target, btrfs_devinfo_replace_target_show);
1690
1691 static ssize_t btrfs_devinfo_scrub_speed_max_show(struct kobject *kobj,
1692                                              struct kobj_attribute *a,
1693                                              char *buf)
1694 {
1695         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1696                                                    devid_kobj);
1697
1698         return sysfs_emit(buf, "%llu\n", READ_ONCE(device->scrub_speed_max));
1699 }
1700
1701 static ssize_t btrfs_devinfo_scrub_speed_max_store(struct kobject *kobj,
1702                                               struct kobj_attribute *a,
1703                                               const char *buf, size_t len)
1704 {
1705         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1706                                                    devid_kobj);
1707         char *endptr;
1708         unsigned long long limit;
1709
1710         limit = memparse(buf, &endptr);
1711         WRITE_ONCE(device->scrub_speed_max, limit);
1712         return len;
1713 }
1714 BTRFS_ATTR_RW(devid, scrub_speed_max, btrfs_devinfo_scrub_speed_max_show,
1715               btrfs_devinfo_scrub_speed_max_store);
1716
1717 static ssize_t btrfs_devinfo_writeable_show(struct kobject *kobj,
1718                                             struct kobj_attribute *a, char *buf)
1719 {
1720         int val;
1721         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1722                                                    devid_kobj);
1723
1724         val = !!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state);
1725
1726         return sysfs_emit(buf, "%d\n", val);
1727 }
1728 BTRFS_ATTR(devid, writeable, btrfs_devinfo_writeable_show);
1729
1730 static ssize_t btrfs_devinfo_fsid_show(struct kobject *kobj,
1731                                        struct kobj_attribute *a, char *buf)
1732 {
1733         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1734                                                    devid_kobj);
1735
1736         return sysfs_emit(buf, "%pU\n", device->fs_devices->fsid);
1737 }
1738 BTRFS_ATTR(devid, fsid, btrfs_devinfo_fsid_show);
1739
1740 static ssize_t btrfs_devinfo_error_stats_show(struct kobject *kobj,
1741                 struct kobj_attribute *a, char *buf)
1742 {
1743         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1744                                                    devid_kobj);
1745
1746         if (!device->dev_stats_valid)
1747                 return sysfs_emit(buf, "invalid\n");
1748
1749         /*
1750          * Print all at once so we get a snapshot of all values from the same
1751          * time. Keep them in sync and in order of definition of
1752          * btrfs_dev_stat_values.
1753          */
1754         return sysfs_emit(buf,
1755                 "write_errs %d\n"
1756                 "read_errs %d\n"
1757                 "flush_errs %d\n"
1758                 "corruption_errs %d\n"
1759                 "generation_errs %d\n",
1760                 btrfs_dev_stat_read(device, BTRFS_DEV_STAT_WRITE_ERRS),
1761                 btrfs_dev_stat_read(device, BTRFS_DEV_STAT_READ_ERRS),
1762                 btrfs_dev_stat_read(device, BTRFS_DEV_STAT_FLUSH_ERRS),
1763                 btrfs_dev_stat_read(device, BTRFS_DEV_STAT_CORRUPTION_ERRS),
1764                 btrfs_dev_stat_read(device, BTRFS_DEV_STAT_GENERATION_ERRS));
1765 }
1766 BTRFS_ATTR(devid, error_stats, btrfs_devinfo_error_stats_show);
1767
1768 /*
1769  * Information about one device.
1770  *
1771  * Path: /sys/fs/btrfs/<uuid>/devinfo/<devid>/
1772  */
1773 static struct attribute *devid_attrs[] = {
1774         BTRFS_ATTR_PTR(devid, error_stats),
1775         BTRFS_ATTR_PTR(devid, fsid),
1776         BTRFS_ATTR_PTR(devid, in_fs_metadata),
1777         BTRFS_ATTR_PTR(devid, missing),
1778         BTRFS_ATTR_PTR(devid, replace_target),
1779         BTRFS_ATTR_PTR(devid, scrub_speed_max),
1780         BTRFS_ATTR_PTR(devid, writeable),
1781         NULL
1782 };
1783 ATTRIBUTE_GROUPS(devid);
1784
1785 static void btrfs_release_devid_kobj(struct kobject *kobj)
1786 {
1787         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1788                                                    devid_kobj);
1789
1790         memset(&device->devid_kobj, 0, sizeof(struct kobject));
1791         complete(&device->kobj_unregister);
1792 }
1793
1794 static struct kobj_type devid_ktype = {
1795         .sysfs_ops      = &kobj_sysfs_ops,
1796         .default_groups = devid_groups,
1797         .release        = btrfs_release_devid_kobj,
1798 };
1799
1800 int btrfs_sysfs_add_device(struct btrfs_device *device)
1801 {
1802         int ret;
1803         unsigned int nofs_flag;
1804         struct kobject *devices_kobj;
1805         struct kobject *devinfo_kobj;
1806
1807         /*
1808          * Make sure we use the fs_info::fs_devices to fetch the kobjects even
1809          * for the seed fs_devices
1810          */
1811         devices_kobj = device->fs_info->fs_devices->devices_kobj;
1812         devinfo_kobj = device->fs_info->fs_devices->devinfo_kobj;
1813         ASSERT(devices_kobj);
1814         ASSERT(devinfo_kobj);
1815
1816         nofs_flag = memalloc_nofs_save();
1817
1818         if (device->bdev) {
1819                 struct kobject *disk_kobj = bdev_kobj(device->bdev);
1820
1821                 ret = sysfs_create_link(devices_kobj, disk_kobj, disk_kobj->name);
1822                 if (ret) {
1823                         btrfs_warn(device->fs_info,
1824                                 "creating sysfs device link for devid %llu failed: %d",
1825                                 device->devid, ret);
1826                         goto out;
1827                 }
1828         }
1829
1830         init_completion(&device->kobj_unregister);
1831         ret = kobject_init_and_add(&device->devid_kobj, &devid_ktype,
1832                                    devinfo_kobj, "%llu", device->devid);
1833         if (ret) {
1834                 kobject_put(&device->devid_kobj);
1835                 btrfs_warn(device->fs_info,
1836                            "devinfo init for devid %llu failed: %d",
1837                            device->devid, ret);
1838         }
1839
1840 out:
1841         memalloc_nofs_restore(nofs_flag);
1842         return ret;
1843 }
1844
1845 static int btrfs_sysfs_add_fs_devices(struct btrfs_fs_devices *fs_devices)
1846 {
1847         int ret;
1848         struct btrfs_device *device;
1849         struct btrfs_fs_devices *seed;
1850
1851         list_for_each_entry(device, &fs_devices->devices, dev_list) {
1852                 ret = btrfs_sysfs_add_device(device);
1853                 if (ret)
1854                         goto fail;
1855         }
1856
1857         list_for_each_entry(seed, &fs_devices->seed_list, seed_list) {
1858                 list_for_each_entry(device, &seed->devices, dev_list) {
1859                         ret = btrfs_sysfs_add_device(device);
1860                         if (ret)
1861                                 goto fail;
1862                 }
1863         }
1864
1865         return 0;
1866
1867 fail:
1868         btrfs_sysfs_remove_fs_devices(fs_devices);
1869         return ret;
1870 }
1871
1872 void btrfs_kobject_uevent(struct block_device *bdev, enum kobject_action action)
1873 {
1874         int ret;
1875
1876         ret = kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, action);
1877         if (ret)
1878                 pr_warn("BTRFS: Sending event '%d' to kobject: '%s' (%p): failed\n",
1879                         action, kobject_name(&disk_to_dev(bdev->bd_disk)->kobj),
1880                         &disk_to_dev(bdev->bd_disk)->kobj);
1881 }
1882
1883 void btrfs_sysfs_update_sprout_fsid(struct btrfs_fs_devices *fs_devices)
1884
1885 {
1886         char fsid_buf[BTRFS_UUID_UNPARSED_SIZE];
1887
1888         /*
1889          * Sprouting changes fsid of the mounted filesystem, rename the fsid
1890          * directory
1891          */
1892         snprintf(fsid_buf, BTRFS_UUID_UNPARSED_SIZE, "%pU", fs_devices->fsid);
1893         if (kobject_rename(&fs_devices->fsid_kobj, fsid_buf))
1894                 btrfs_warn(fs_devices->fs_info,
1895                                 "sysfs: failed to create fsid for sprout");
1896 }
1897
1898 void btrfs_sysfs_update_devid(struct btrfs_device *device)
1899 {
1900         char tmp[24];
1901
1902         snprintf(tmp, sizeof(tmp), "%llu", device->devid);
1903
1904         if (kobject_rename(&device->devid_kobj, tmp))
1905                 btrfs_warn(device->fs_devices->fs_info,
1906                            "sysfs: failed to update devid for %llu",
1907                            device->devid);
1908 }
1909
1910 /* /sys/fs/btrfs/ entry */
1911 static struct kset *btrfs_kset;
1912
1913 /*
1914  * Creates:
1915  *              /sys/fs/btrfs/UUID
1916  *
1917  * Can be called by the device discovery thread.
1918  */
1919 int btrfs_sysfs_add_fsid(struct btrfs_fs_devices *fs_devs)
1920 {
1921         int error;
1922
1923         init_completion(&fs_devs->kobj_unregister);
1924         fs_devs->fsid_kobj.kset = btrfs_kset;
1925         error = kobject_init_and_add(&fs_devs->fsid_kobj, &btrfs_ktype, NULL,
1926                                      "%pU", fs_devs->fsid);
1927         if (error) {
1928                 kobject_put(&fs_devs->fsid_kobj);
1929                 return error;
1930         }
1931
1932         fs_devs->devices_kobj = kobject_create_and_add("devices",
1933                                                        &fs_devs->fsid_kobj);
1934         if (!fs_devs->devices_kobj) {
1935                 btrfs_err(fs_devs->fs_info,
1936                           "failed to init sysfs device interface");
1937                 btrfs_sysfs_remove_fsid(fs_devs);
1938                 return -ENOMEM;
1939         }
1940
1941         fs_devs->devinfo_kobj = kobject_create_and_add("devinfo",
1942                                                        &fs_devs->fsid_kobj);
1943         if (!fs_devs->devinfo_kobj) {
1944                 btrfs_err(fs_devs->fs_info,
1945                           "failed to init sysfs devinfo kobject");
1946                 btrfs_sysfs_remove_fsid(fs_devs);
1947                 return -ENOMEM;
1948         }
1949
1950         return 0;
1951 }
1952
1953 int btrfs_sysfs_add_mounted(struct btrfs_fs_info *fs_info)
1954 {
1955         int error;
1956         struct btrfs_fs_devices *fs_devs = fs_info->fs_devices;
1957         struct kobject *fsid_kobj = &fs_devs->fsid_kobj;
1958
1959         error = btrfs_sysfs_add_fs_devices(fs_devs);
1960         if (error)
1961                 return error;
1962
1963         error = sysfs_create_files(fsid_kobj, btrfs_attrs);
1964         if (error) {
1965                 btrfs_sysfs_remove_fs_devices(fs_devs);
1966                 return error;
1967         }
1968
1969         error = sysfs_create_group(fsid_kobj,
1970                                    &btrfs_feature_attr_group);
1971         if (error)
1972                 goto failure;
1973
1974 #ifdef CONFIG_BTRFS_DEBUG
1975         fs_info->debug_kobj = kobject_create_and_add("debug", fsid_kobj);
1976         if (!fs_info->debug_kobj) {
1977                 error = -ENOMEM;
1978                 goto failure;
1979         }
1980
1981         error = sysfs_create_files(fs_info->debug_kobj, btrfs_debug_mount_attrs);
1982         if (error)
1983                 goto failure;
1984 #endif
1985
1986         /* Discard directory */
1987         fs_info->discard_kobj = kobject_create_and_add("discard", fsid_kobj);
1988         if (!fs_info->discard_kobj) {
1989                 error = -ENOMEM;
1990                 goto failure;
1991         }
1992
1993         error = sysfs_create_files(fs_info->discard_kobj, discard_attrs);
1994         if (error)
1995                 goto failure;
1996
1997         error = addrm_unknown_feature_attrs(fs_info, true);
1998         if (error)
1999                 goto failure;
2000
2001         error = sysfs_create_link(fsid_kobj, &fs_info->sb->s_bdi->dev->kobj, "bdi");
2002         if (error)
2003                 goto failure;
2004
2005         fs_info->space_info_kobj = kobject_create_and_add("allocation",
2006                                                   fsid_kobj);
2007         if (!fs_info->space_info_kobj) {
2008                 error = -ENOMEM;
2009                 goto failure;
2010         }
2011
2012         error = sysfs_create_files(fs_info->space_info_kobj, allocation_attrs);
2013         if (error)
2014                 goto failure;
2015
2016         return 0;
2017 failure:
2018         btrfs_sysfs_remove_mounted(fs_info);
2019         return error;
2020 }
2021
2022 static inline struct btrfs_fs_info *qgroup_kobj_to_fs_info(struct kobject *kobj)
2023 {
2024         return to_fs_info(kobj->parent->parent);
2025 }
2026
2027 #define QGROUP_ATTR(_member, _show_name)                                        \
2028 static ssize_t btrfs_qgroup_show_##_member(struct kobject *qgroup_kobj,         \
2029                                            struct kobj_attribute *a,            \
2030                                            char *buf)                           \
2031 {                                                                               \
2032         struct btrfs_fs_info *fs_info = qgroup_kobj_to_fs_info(qgroup_kobj);    \
2033         struct btrfs_qgroup *qgroup = container_of(qgroup_kobj,                 \
2034                         struct btrfs_qgroup, kobj);                             \
2035         return btrfs_show_u64(&qgroup->_member, &fs_info->qgroup_lock, buf);    \
2036 }                                                                               \
2037 BTRFS_ATTR(qgroup, _show_name, btrfs_qgroup_show_##_member)
2038
2039 #define QGROUP_RSV_ATTR(_name, _type)                                           \
2040 static ssize_t btrfs_qgroup_rsv_show_##_name(struct kobject *qgroup_kobj,       \
2041                                              struct kobj_attribute *a,          \
2042                                              char *buf)                         \
2043 {                                                                               \
2044         struct btrfs_fs_info *fs_info = qgroup_kobj_to_fs_info(qgroup_kobj);    \
2045         struct btrfs_qgroup *qgroup = container_of(qgroup_kobj,                 \
2046                         struct btrfs_qgroup, kobj);                             \
2047         return btrfs_show_u64(&qgroup->rsv.values[_type],                       \
2048                         &fs_info->qgroup_lock, buf);                            \
2049 }                                                                               \
2050 BTRFS_ATTR(qgroup, rsv_##_name, btrfs_qgroup_rsv_show_##_name)
2051
2052 QGROUP_ATTR(rfer, referenced);
2053 QGROUP_ATTR(excl, exclusive);
2054 QGROUP_ATTR(max_rfer, max_referenced);
2055 QGROUP_ATTR(max_excl, max_exclusive);
2056 QGROUP_ATTR(lim_flags, limit_flags);
2057 QGROUP_RSV_ATTR(data, BTRFS_QGROUP_RSV_DATA);
2058 QGROUP_RSV_ATTR(meta_pertrans, BTRFS_QGROUP_RSV_META_PERTRANS);
2059 QGROUP_RSV_ATTR(meta_prealloc, BTRFS_QGROUP_RSV_META_PREALLOC);
2060
2061 /*
2062  * Qgroup information.
2063  *
2064  * Path: /sys/fs/btrfs/<uuid>/qgroups/<level>_<qgroupid>/
2065  */
2066 static struct attribute *qgroup_attrs[] = {
2067         BTRFS_ATTR_PTR(qgroup, referenced),
2068         BTRFS_ATTR_PTR(qgroup, exclusive),
2069         BTRFS_ATTR_PTR(qgroup, max_referenced),
2070         BTRFS_ATTR_PTR(qgroup, max_exclusive),
2071         BTRFS_ATTR_PTR(qgroup, limit_flags),
2072         BTRFS_ATTR_PTR(qgroup, rsv_data),
2073         BTRFS_ATTR_PTR(qgroup, rsv_meta_pertrans),
2074         BTRFS_ATTR_PTR(qgroup, rsv_meta_prealloc),
2075         NULL
2076 };
2077 ATTRIBUTE_GROUPS(qgroup);
2078
2079 static void qgroup_release(struct kobject *kobj)
2080 {
2081         struct btrfs_qgroup *qgroup = container_of(kobj, struct btrfs_qgroup, kobj);
2082
2083         memset(&qgroup->kobj, 0, sizeof(*kobj));
2084 }
2085
2086 static struct kobj_type qgroup_ktype = {
2087         .sysfs_ops = &kobj_sysfs_ops,
2088         .release = qgroup_release,
2089         .default_groups = qgroup_groups,
2090 };
2091
2092 int btrfs_sysfs_add_one_qgroup(struct btrfs_fs_info *fs_info,
2093                                 struct btrfs_qgroup *qgroup)
2094 {
2095         struct kobject *qgroups_kobj = fs_info->qgroups_kobj;
2096         int ret;
2097
2098         if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
2099                 return 0;
2100         if (qgroup->kobj.state_initialized)
2101                 return 0;
2102         if (!qgroups_kobj)
2103                 return -EINVAL;
2104
2105         ret = kobject_init_and_add(&qgroup->kobj, &qgroup_ktype, qgroups_kobj,
2106                         "%hu_%llu", btrfs_qgroup_level(qgroup->qgroupid),
2107                         btrfs_qgroup_subvolid(qgroup->qgroupid));
2108         if (ret < 0)
2109                 kobject_put(&qgroup->kobj);
2110
2111         return ret;
2112 }
2113
2114 void btrfs_sysfs_del_qgroups(struct btrfs_fs_info *fs_info)
2115 {
2116         struct btrfs_qgroup *qgroup;
2117         struct btrfs_qgroup *next;
2118
2119         if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
2120                 return;
2121
2122         rbtree_postorder_for_each_entry_safe(qgroup, next,
2123                                              &fs_info->qgroup_tree, node)
2124                 btrfs_sysfs_del_one_qgroup(fs_info, qgroup);
2125         if (fs_info->qgroups_kobj) {
2126                 kobject_del(fs_info->qgroups_kobj);
2127                 kobject_put(fs_info->qgroups_kobj);
2128                 fs_info->qgroups_kobj = NULL;
2129         }
2130 }
2131
2132 /* Called when qgroups get initialized, thus there is no need for locking */
2133 int btrfs_sysfs_add_qgroups(struct btrfs_fs_info *fs_info)
2134 {
2135         struct kobject *fsid_kobj = &fs_info->fs_devices->fsid_kobj;
2136         struct btrfs_qgroup *qgroup;
2137         struct btrfs_qgroup *next;
2138         int ret = 0;
2139
2140         if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
2141                 return 0;
2142
2143         ASSERT(fsid_kobj);
2144         if (fs_info->qgroups_kobj)
2145                 return 0;
2146
2147         fs_info->qgroups_kobj = kobject_create_and_add("qgroups", fsid_kobj);
2148         if (!fs_info->qgroups_kobj) {
2149                 ret = -ENOMEM;
2150                 goto out;
2151         }
2152         rbtree_postorder_for_each_entry_safe(qgroup, next,
2153                                              &fs_info->qgroup_tree, node) {
2154                 ret = btrfs_sysfs_add_one_qgroup(fs_info, qgroup);
2155                 if (ret < 0)
2156                         goto out;
2157         }
2158
2159 out:
2160         if (ret < 0)
2161                 btrfs_sysfs_del_qgroups(fs_info);
2162         return ret;
2163 }
2164
2165 void btrfs_sysfs_del_one_qgroup(struct btrfs_fs_info *fs_info,
2166                                 struct btrfs_qgroup *qgroup)
2167 {
2168         if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
2169                 return;
2170
2171         if (qgroup->kobj.state_initialized) {
2172                 kobject_del(&qgroup->kobj);
2173                 kobject_put(&qgroup->kobj);
2174         }
2175 }
2176
2177 /*
2178  * Change per-fs features in /sys/fs/btrfs/UUID/features to match current
2179  * values in superblock. Call after any changes to incompat/compat_ro flags
2180  */
2181 void btrfs_sysfs_feature_update(struct btrfs_fs_info *fs_info,
2182                 u64 bit, enum btrfs_feature_set set)
2183 {
2184         struct btrfs_fs_devices *fs_devs;
2185         struct kobject *fsid_kobj;
2186         u64 __maybe_unused features;
2187         int __maybe_unused ret;
2188
2189         if (!fs_info)
2190                 return;
2191
2192         /*
2193          * See 14e46e04958df74 and e410e34fad913dd, feature bit updates are not
2194          * safe when called from some contexts (eg. balance)
2195          */
2196         features = get_features(fs_info, set);
2197         ASSERT(bit & supported_feature_masks[set]);
2198
2199         fs_devs = fs_info->fs_devices;
2200         fsid_kobj = &fs_devs->fsid_kobj;
2201
2202         if (!fsid_kobj->state_initialized)
2203                 return;
2204
2205         /*
2206          * FIXME: this is too heavy to update just one value, ideally we'd like
2207          * to use sysfs_update_group but some refactoring is needed first.
2208          */
2209         sysfs_remove_group(fsid_kobj, &btrfs_feature_attr_group);
2210         ret = sysfs_create_group(fsid_kobj, &btrfs_feature_attr_group);
2211 }
2212
2213 int __init btrfs_init_sysfs(void)
2214 {
2215         int ret;
2216
2217         btrfs_kset = kset_create_and_add("btrfs", NULL, fs_kobj);
2218         if (!btrfs_kset)
2219                 return -ENOMEM;
2220
2221         init_feature_attrs();
2222         ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
2223         if (ret)
2224                 goto out2;
2225         ret = sysfs_merge_group(&btrfs_kset->kobj,
2226                                 &btrfs_static_feature_attr_group);
2227         if (ret)
2228                 goto out_remove_group;
2229
2230 #ifdef CONFIG_BTRFS_DEBUG
2231         ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_debug_feature_attr_group);
2232         if (ret)
2233                 goto out2;
2234 #endif
2235
2236         return 0;
2237
2238 out_remove_group:
2239         sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
2240 out2:
2241         kset_unregister(btrfs_kset);
2242
2243         return ret;
2244 }
2245
2246 void __cold btrfs_exit_sysfs(void)
2247 {
2248         sysfs_unmerge_group(&btrfs_kset->kobj,
2249                             &btrfs_static_feature_attr_group);
2250         sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
2251 #ifdef CONFIG_BTRFS_DEBUG
2252         sysfs_remove_group(&btrfs_kset->kobj, &btrfs_debug_feature_attr_group);
2253 #endif
2254         kset_unregister(btrfs_kset);
2255 }