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 "transaction.h"
  18 #include "sysfs.h"
  19 #include "volumes.h"
  20 #include "space-info.h"
  21 #include "block-group.h"
  22 #include "qgroup.h"
  23
  24 struct btrfs_feature_attr {
  25         struct kobj_attribute kobj_attr;
  26         enum btrfs_feature_set feature_set;
  27         u64 feature_bit;
  28 };
  29
  30 /* For raid type sysfs entries */
  31 struct raid_kobject {
  32         u64 flags;
  33         struct kobject kobj;
  34 };
  35
  36 #define __INIT_KOBJ_ATTR(_name, _mode, _show, _store)                   \
  37 {                                                                       \
  38         .attr   = { .name = __stringify(_name), .mode = _mode },        \
  39         .show   = _show,                                                \
  40         .store  = _store,                                               \
  41 }
  42
  43 #define BTRFS_ATTR_RW(_prefix, _name, _show, _store)                    \
  44         static struct kobj_attribute btrfs_attr_##_prefix##_##_name =   \
  45                         __INIT_KOBJ_ATTR(_name, 0644, _show, _store)
  46
  47 #define BTRFS_ATTR(_prefix, _name, _show)                               \
  48         static struct kobj_attribute btrfs_attr_##_prefix##_##_name =   \
  49                         __INIT_KOBJ_ATTR(_name, 0444, _show, NULL)
  50
  51 #define BTRFS_ATTR_PTR(_prefix, _name)                                  \
  52         (&btrfs_attr_##_prefix##_##_name.attr)
  53
  54 #define BTRFS_FEAT_ATTR(_name, _feature_set, _feature_prefix, _feature_bit)  \
  55 static struct btrfs_feature_attr btrfs_attr_features_##_name = {             \
  56         .kobj_attr = __INIT_KOBJ_ATTR(_name, S_IRUGO,                        \
  57                                       btrfs_feature_attr_show,               \
  58                                       btrfs_feature_attr_store),             \
  59         .feature_set    = _feature_set,                                      \
  60         .feature_bit    = _feature_prefix ##_## _feature_bit,                \
  61 }
  62 #define BTRFS_FEAT_ATTR_PTR(_name)                                           \
  63         (&btrfs_attr_features_##_name.kobj_attr.attr)
  64
  65 #define BTRFS_FEAT_ATTR_COMPAT(name, feature) \
  66         BTRFS_FEAT_ATTR(name, FEAT_COMPAT, BTRFS_FEATURE_COMPAT, feature)
  67 #define BTRFS_FEAT_ATTR_COMPAT_RO(name, feature) \
  68         BTRFS_FEAT_ATTR(name, FEAT_COMPAT_RO, BTRFS_FEATURE_COMPAT_RO, feature)
  69 #define BTRFS_FEAT_ATTR_INCOMPAT(name, feature) \
  70         BTRFS_FEAT_ATTR(name, FEAT_INCOMPAT, BTRFS_FEATURE_INCOMPAT, feature)
  71
  72 static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj);
  73 static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj);
  74
  75 static struct btrfs_feature_attr *to_btrfs_feature_attr(struct kobj_attribute *a)
  76 {
  77         return container_of(a, struct btrfs_feature_attr, kobj_attr);
  78 }
  79
  80 static struct kobj_attribute *attr_to_btrfs_attr(struct attribute *attr)
  81 {
  82         return container_of(attr, struct kobj_attribute, attr);
  83 }
  84
  85 static struct btrfs_feature_attr *attr_to_btrfs_feature_attr(
  86                 struct attribute *attr)
  87 {
  88         return to_btrfs_feature_attr(attr_to_btrfs_attr(attr));
  89 }
  90
  91 static u64 get_features(struct btrfs_fs_info *fs_info,
  92                         enum btrfs_feature_set set)
  93 {
  94         struct btrfs_super_block *disk_super = fs_info->super_copy;
  95         if (set == FEAT_COMPAT)
  96                 return btrfs_super_compat_flags(disk_super);
  97         else if (set == FEAT_COMPAT_RO)
  98                 return btrfs_super_compat_ro_flags(disk_super);
  99         else
 100                 return btrfs_super_incompat_flags(disk_super);
 101 }
 102
 103 static void set_features(struct btrfs_fs_info *fs_info,
 104                          enum btrfs_feature_set set, u64 features)
 105 {
 106         struct btrfs_super_block *disk_super = fs_info->super_copy;
 107         if (set == FEAT_COMPAT)
 108                 btrfs_set_super_compat_flags(disk_super, features);
 109         else if (set == FEAT_COMPAT_RO)
 110                 btrfs_set_super_compat_ro_flags(disk_super, features);
 111         else
 112                 btrfs_set_super_incompat_flags(disk_super, features);
 113 }
 114
 115 static int can_modify_feature(struct btrfs_feature_attr *fa)
 116 {
 117         int val = 0;
 118         u64 set, clear;
 119         switch (fa->feature_set) {
 120         case FEAT_COMPAT:
 121                 set = BTRFS_FEATURE_COMPAT_SAFE_SET;
 122                 clear = BTRFS_FEATURE_COMPAT_SAFE_CLEAR;
 123                 break;
 124         case FEAT_COMPAT_RO:
 125                 set = BTRFS_FEATURE_COMPAT_RO_SAFE_SET;
 126                 clear = BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR;
 127                 break;
 128         case FEAT_INCOMPAT:
 129                 set = BTRFS_FEATURE_INCOMPAT_SAFE_SET;
 130                 clear = BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR;
 131                 break;
 132         default:
 133                 pr_warn("btrfs: sysfs: unknown feature set %d\n",
 134                                 fa->feature_set);
 135                 return 0;
 136         }
 137
 138         if (set & fa->feature_bit)
 139                 val |= 1;
 140         if (clear & fa->feature_bit)
 141                 val |= 2;
 142
 143         return val;
 144 }
 145
 146 static ssize_t btrfs_feature_attr_show(struct kobject *kobj,
 147                                        struct kobj_attribute *a, char *buf)
 148 {
 149         int val = 0;
 150         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 151         struct btrfs_feature_attr *fa = to_btrfs_feature_attr(a);
 152         if (fs_info) {
 153                 u64 features = get_features(fs_info, fa->feature_set);
 154                 if (features & fa->feature_bit)
 155                         val = 1;
 156         } else
 157                 val = can_modify_feature(fa);
 158
 159         return scnprintf(buf, PAGE_SIZE, "%d\n", val);
 160 }
 161
 162 static ssize_t btrfs_feature_attr_store(struct kobject *kobj,
 163                                         struct kobj_attribute *a,
 164                                         const char *buf, size_t count)
 165 {
 166         struct btrfs_fs_info *fs_info;
 167         struct btrfs_feature_attr *fa = to_btrfs_feature_attr(a);
 168         u64 features, set, clear;
 169         unsigned long val;
 170         int ret;
 171
 172         fs_info = to_fs_info(kobj);
 173         if (!fs_info)
 174                 return -EPERM;
 175
 176         if (sb_rdonly(fs_info->sb))
 177                 return -EROFS;
 178
 179         ret = kstrtoul(skip_spaces(buf), 0, &val);
 180         if (ret)
 181                 return ret;
 182
 183         if (fa->feature_set == FEAT_COMPAT) {
 184                 set = BTRFS_FEATURE_COMPAT_SAFE_SET;
 185                 clear = BTRFS_FEATURE_COMPAT_SAFE_CLEAR;
 186         } else if (fa->feature_set == FEAT_COMPAT_RO) {
 187                 set = BTRFS_FEATURE_COMPAT_RO_SAFE_SET;
 188                 clear = BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR;
 189         } else {
 190                 set = BTRFS_FEATURE_INCOMPAT_SAFE_SET;
 191                 clear = BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR;
 192         }
 193
 194         features = get_features(fs_info, fa->feature_set);
 195
 196         /* Nothing to do */
 197         if ((val && (features & fa->feature_bit)) ||
 198             (!val && !(features & fa->feature_bit)))
 199                 return count;
 200
 201         if ((val && !(set & fa->feature_bit)) ||
 202             (!val && !(clear & fa->feature_bit))) {
 203                 btrfs_info(fs_info,
 204                         "%sabling feature %s on mounted fs is not supported.",
 205                         val ? "En" : "Dis", fa->kobj_attr.attr.name);
 206                 return -EPERM;
 207         }
 208
 209         btrfs_info(fs_info, "%s %s feature flag",
 210                    val ? "Setting" : "Clearing", fa->kobj_attr.attr.name);
 211
 212         spin_lock(&fs_info->super_lock);
 213         features = get_features(fs_info, fa->feature_set);
 214         if (val)
 215                 features |= fa->feature_bit;
 216         else
 217                 features &= ~fa->feature_bit;
 218         set_features(fs_info, fa->feature_set, features);
 219         spin_unlock(&fs_info->super_lock);
 220
 221         /*
 222          * We don't want to do full transaction commit from inside sysfs
 223          */
 224         btrfs_set_pending(fs_info, COMMIT);
 225         wake_up_process(fs_info->transaction_kthread);
 226
 227         return count;
 228 }
 229
 230 static umode_t btrfs_feature_visible(struct kobject *kobj,
 231                                      struct attribute *attr, int unused)
 232 {
 233         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 234         umode_t mode = attr->mode;
 235
 236         if (fs_info) {
 237                 struct btrfs_feature_attr *fa;
 238                 u64 features;
 239
 240                 fa = attr_to_btrfs_feature_attr(attr);
 241                 features = get_features(fs_info, fa->feature_set);
 242
 243                 if (can_modify_feature(fa))
 244                         mode |= S_IWUSR;
 245                 else if (!(features & fa->feature_bit))
 246                         mode = 0;
 247         }
 248
 249         return mode;
 250 }
 251
 252 BTRFS_FEAT_ATTR_INCOMPAT(mixed_backref, MIXED_BACKREF);
 253 BTRFS_FEAT_ATTR_INCOMPAT(default_subvol, DEFAULT_SUBVOL);
 254 BTRFS_FEAT_ATTR_INCOMPAT(mixed_groups, MIXED_GROUPS);
 255 BTRFS_FEAT_ATTR_INCOMPAT(compress_lzo, COMPRESS_LZO);
 256 BTRFS_FEAT_ATTR_INCOMPAT(compress_zstd, COMPRESS_ZSTD);
 257 BTRFS_FEAT_ATTR_INCOMPAT(big_metadata, BIG_METADATA);
 258 BTRFS_FEAT_ATTR_INCOMPAT(extended_iref, EXTENDED_IREF);
 259 BTRFS_FEAT_ATTR_INCOMPAT(raid56, RAID56);
 260 BTRFS_FEAT_ATTR_INCOMPAT(skinny_metadata, SKINNY_METADATA);
 261 BTRFS_FEAT_ATTR_INCOMPAT(no_holes, NO_HOLES);
 262 BTRFS_FEAT_ATTR_INCOMPAT(metadata_uuid, METADATA_UUID);
 263 BTRFS_FEAT_ATTR_COMPAT_RO(free_space_tree, FREE_SPACE_TREE);
 264 BTRFS_FEAT_ATTR_INCOMPAT(raid1c34, RAID1C34);
 265
 266 static struct attribute *btrfs_supported_feature_attrs[] = {
 267         BTRFS_FEAT_ATTR_PTR(mixed_backref),
 268         BTRFS_FEAT_ATTR_PTR(default_subvol),
 269         BTRFS_FEAT_ATTR_PTR(mixed_groups),
 270         BTRFS_FEAT_ATTR_PTR(compress_lzo),
 271         BTRFS_FEAT_ATTR_PTR(compress_zstd),
 272         BTRFS_FEAT_ATTR_PTR(big_metadata),
 273         BTRFS_FEAT_ATTR_PTR(extended_iref),
 274         BTRFS_FEAT_ATTR_PTR(raid56),
 275         BTRFS_FEAT_ATTR_PTR(skinny_metadata),
 276         BTRFS_FEAT_ATTR_PTR(no_holes),
 277         BTRFS_FEAT_ATTR_PTR(metadata_uuid),
 278         BTRFS_FEAT_ATTR_PTR(free_space_tree),
 279         BTRFS_FEAT_ATTR_PTR(raid1c34),
 280         NULL
 281 };
 282
 283 /*
 284  * Features which depend on feature bits and may differ between each fs.
 285  *
 286  * /sys/fs/btrfs/features lists all available features of this kernel while
 287  * /sys/fs/btrfs/UUID/features shows features of the fs which are enabled or
 288  * can be changed online.
 289  */
 290 static const struct attribute_group btrfs_feature_attr_group = {
 291         .name = "features",
 292         .is_visible = btrfs_feature_visible,
 293         .attrs = btrfs_supported_feature_attrs,
 294 };
 295
 296 static ssize_t rmdir_subvol_show(struct kobject *kobj,
 297                                  struct kobj_attribute *ka, char *buf)
 298 {
 299         return scnprintf(buf, PAGE_SIZE, "0\n");
 300 }
 301 BTRFS_ATTR(static_feature, rmdir_subvol, rmdir_subvol_show);
 302
 303 static ssize_t supported_checksums_show(struct kobject *kobj,
 304                                         struct kobj_attribute *a, char *buf)
 305 {
 306         ssize_t ret = 0;
 307         int i;
 308
 309         for (i = 0; i < btrfs_get_num_csums(); i++) {
 310                 /*
 311                  * This "trick" only works as long as 'enum btrfs_csum_type' has
 312                  * no holes in it
 313                  */
 314                 ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%s",
 315                                 (i == 0 ? "" : " "), btrfs_super_csum_name(i));
 316
 317         }
 318
 319         ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
 320         return ret;
 321 }
 322 BTRFS_ATTR(static_feature, supported_checksums, supported_checksums_show);
 323
 324 static struct attribute *btrfs_supported_static_feature_attrs[] = {
 325         BTRFS_ATTR_PTR(static_feature, rmdir_subvol),
 326         BTRFS_ATTR_PTR(static_feature, supported_checksums),
 327         NULL
 328 };
 329
 330 /*
 331  * Features which only depend on kernel version.
 332  *
 333  * These are listed in /sys/fs/btrfs/features along with
 334  * btrfs_feature_attr_group
 335  */
 336 static const struct attribute_group btrfs_static_feature_attr_group = {
 337         .name = "features",
 338         .attrs = btrfs_supported_static_feature_attrs,
 339 };
 340
 341 #ifdef CONFIG_BTRFS_DEBUG
 342
 343 /*
 344  * Discard statistics and tunables
 345  */
 346 #define discard_to_fs_info(_kobj)       to_fs_info((_kobj)->parent->parent)
 347
 348 static ssize_t btrfs_discardable_bytes_show(struct kobject *kobj,
 349                                             struct kobj_attribute *a,
 350                                             char *buf)
 351 {
 352         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 353
 354         return scnprintf(buf, PAGE_SIZE, "%lld\n",
 355                         atomic64_read(&fs_info->discard_ctl.discardable_bytes));
 356 }
 357 BTRFS_ATTR(discard, discardable_bytes, btrfs_discardable_bytes_show);
 358
 359 static ssize_t btrfs_discardable_extents_show(struct kobject *kobj,
 360                                               struct kobj_attribute *a,
 361                                               char *buf)
 362 {
 363         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 364
 365         return scnprintf(buf, PAGE_SIZE, "%d\n",
 366                         atomic_read(&fs_info->discard_ctl.discardable_extents));
 367 }
 368 BTRFS_ATTR(discard, discardable_extents, btrfs_discardable_extents_show);
 369
 370 static ssize_t btrfs_discard_bitmap_bytes_show(struct kobject *kobj,
 371                                                struct kobj_attribute *a,
 372                                                char *buf)
 373 {
 374         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 375
 376         return scnprintf(buf, PAGE_SIZE, "%lld\n",
 377                         fs_info->discard_ctl.discard_bitmap_bytes);
 378 }
 379 BTRFS_ATTR(discard, discard_bitmap_bytes, btrfs_discard_bitmap_bytes_show);
 380
 381 static ssize_t btrfs_discard_bytes_saved_show(struct kobject *kobj,
 382                                               struct kobj_attribute *a,
 383                                               char *buf)
 384 {
 385         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 386
 387         return scnprintf(buf, PAGE_SIZE, "%lld\n",
 388                 atomic64_read(&fs_info->discard_ctl.discard_bytes_saved));
 389 }
 390 BTRFS_ATTR(discard, discard_bytes_saved, btrfs_discard_bytes_saved_show);
 391
 392 static ssize_t btrfs_discard_extent_bytes_show(struct kobject *kobj,
 393                                                struct kobj_attribute *a,
 394                                                char *buf)
 395 {
 396         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 397
 398         return scnprintf(buf, PAGE_SIZE, "%lld\n",
 399                         fs_info->discard_ctl.discard_extent_bytes);
 400 }
 401 BTRFS_ATTR(discard, discard_extent_bytes, btrfs_discard_extent_bytes_show);
 402
 403 static ssize_t btrfs_discard_iops_limit_show(struct kobject *kobj,
 404                                              struct kobj_attribute *a,
 405                                              char *buf)
 406 {
 407         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 408
 409         return scnprintf(buf, PAGE_SIZE, "%u\n",
 410                         READ_ONCE(fs_info->discard_ctl.iops_limit));
 411 }
 412
 413 static ssize_t btrfs_discard_iops_limit_store(struct kobject *kobj,
 414                                               struct kobj_attribute *a,
 415                                               const char *buf, size_t len)
 416 {
 417         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 418         struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
 419         u32 iops_limit;
 420         int ret;
 421
 422         ret = kstrtou32(buf, 10, &iops_limit);
 423         if (ret)
 424                 return -EINVAL;
 425
 426         WRITE_ONCE(discard_ctl->iops_limit, iops_limit);
 427
 428         return len;
 429 }
 430 BTRFS_ATTR_RW(discard, iops_limit, btrfs_discard_iops_limit_show,
 431               btrfs_discard_iops_limit_store);
 432
 433 static ssize_t btrfs_discard_kbps_limit_show(struct kobject *kobj,
 434                                              struct kobj_attribute *a,
 435                                              char *buf)
 436 {
 437         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 438
 439         return scnprintf(buf, PAGE_SIZE, "%u\n",
 440                         READ_ONCE(fs_info->discard_ctl.kbps_limit));
 441 }
 442
 443 static ssize_t btrfs_discard_kbps_limit_store(struct kobject *kobj,
 444                                               struct kobj_attribute *a,
 445                                               const char *buf, size_t len)
 446 {
 447         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 448         struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
 449         u32 kbps_limit;
 450         int ret;
 451
 452         ret = kstrtou32(buf, 10, &kbps_limit);
 453         if (ret)
 454                 return -EINVAL;
 455
 456         WRITE_ONCE(discard_ctl->kbps_limit, kbps_limit);
 457
 458         return len;
 459 }
 460 BTRFS_ATTR_RW(discard, kbps_limit, btrfs_discard_kbps_limit_show,
 461               btrfs_discard_kbps_limit_store);
 462
 463 static ssize_t btrfs_discard_max_discard_size_show(struct kobject *kobj,
 464                                                    struct kobj_attribute *a,
 465                                                    char *buf)
 466 {
 467         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 468
 469         return scnprintf(buf, PAGE_SIZE, "%llu\n",
 470                         READ_ONCE(fs_info->discard_ctl.max_discard_size));
 471 }
 472
 473 static ssize_t btrfs_discard_max_discard_size_store(struct kobject *kobj,
 474                                                     struct kobj_attribute *a,
 475                                                     const char *buf, size_t len)
 476 {
 477         struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 478         struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
 479         u64 max_discard_size;
 480         int ret;
 481
 482         ret = kstrtou64(buf, 10, &max_discard_size);
 483         if (ret)
 484                 return -EINVAL;
 485
 486         WRITE_ONCE(discard_ctl->max_discard_size, max_discard_size);
 487
 488         return len;
 489 }
 490 BTRFS_ATTR_RW(discard, max_discard_size, btrfs_discard_max_discard_size_show,
 491               btrfs_discard_max_discard_size_store);
 492
 493 static const struct attribute *discard_debug_attrs[] = {
 494         BTRFS_ATTR_PTR(discard, discardable_bytes),
 495         BTRFS_ATTR_PTR(discard, discardable_extents),
 496         BTRFS_ATTR_PTR(discard, discard_bitmap_bytes),
 497         BTRFS_ATTR_PTR(discard, discard_bytes_saved),
 498         BTRFS_ATTR_PTR(discard, discard_extent_bytes),
 499         BTRFS_ATTR_PTR(discard, iops_limit),
 500         BTRFS_ATTR_PTR(discard, kbps_limit),
 501         BTRFS_ATTR_PTR(discard, max_discard_size),
 502         NULL,
 503 };
 504
 505 /*
 506  * Runtime debugging exported via sysfs
 507  *
 508  * /sys/fs/btrfs/debug - applies to module or all filesystems
 509  * /sys/fs/btrfs/UUID  - applies only to the given filesystem
 510  */
 511 static const struct attribute *btrfs_debug_mount_attrs[] = {
 512         NULL,
 513 };
 514
 515 static struct attribute *btrfs_debug_feature_attrs[] = {
 516         NULL
 517 };
 518
 519 static const struct attribute_group btrfs_debug_feature_attr_group = {
 520         .name = "debug",
 521         .attrs = btrfs_debug_feature_attrs,
 522 };
 523
 524 #endif
 525
 526 static ssize_t btrfs_show_u64(u64 *value_ptr, spinlock_t *lock, char *buf)
 527 {
 528         u64 val;
 529         if (lock)
 530                 spin_lock(lock);
 531         val = *value_ptr;
 532         if (lock)
 533                 spin_unlock(lock);
 534         return scnprintf(buf, PAGE_SIZE, "%llu\n", val);
 535 }
 536
 537 static ssize_t global_rsv_size_show(struct kobject *kobj,
 538                                     struct kobj_attribute *ka, char *buf)
 539 {
 540         struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent);
 541         struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
 542         return btrfs_show_u64(&block_rsv->size, &block_rsv->lock, buf);
 543 }
 544 BTRFS_ATTR(allocation, global_rsv_size, global_rsv_size_show);
 545
 546 static ssize_t global_rsv_reserved_show(struct kobject *kobj,
 547                                         struct kobj_attribute *a, char *buf)
 548 {
 549         struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent);
 550         struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
 551         return btrfs_show_u64(&block_rsv->reserved, &block_rsv->lock, buf);
 552 }
 553 BTRFS_ATTR(allocation, global_rsv_reserved, global_rsv_reserved_show);
 554
 555 #define to_space_info(_kobj) container_of(_kobj, struct btrfs_space_info, kobj)
 556 #define to_raid_kobj(_kobj) container_of(_kobj, struct raid_kobject, kobj)
 557
 558 static ssize_t raid_bytes_show(struct kobject *kobj,
 559                                struct kobj_attribute *attr, char *buf);
 560 BTRFS_ATTR(raid, total_bytes, raid_bytes_show);
 561 BTRFS_ATTR(raid, used_bytes, raid_bytes_show);
 562
 563 static ssize_t raid_bytes_show(struct kobject *kobj,
 564                                struct kobj_attribute *attr, char *buf)
 565
 566 {
 567         struct btrfs_space_info *sinfo = to_space_info(kobj->parent);
 568         struct btrfs_block_group *block_group;
 569         int index = btrfs_bg_flags_to_raid_index(to_raid_kobj(kobj)->flags);
 570         u64 val = 0;
 571
 572         down_read(&sinfo->groups_sem);
 573         list_for_each_entry(block_group, &sinfo->block_groups[index], list) {
 574                 if (&attr->attr == BTRFS_ATTR_PTR(raid, total_bytes))
 575                         val += block_group->length;
 576                 else
 577                         val += block_group->used;
 578         }
 579         up_read(&sinfo->groups_sem);
 580         return scnprintf(buf, PAGE_SIZE, "%llu\n", val);
 581 }
 582
 583 static struct attribute *raid_attrs[] = {
 584         BTRFS_ATTR_PTR(raid, total_bytes),
 585         BTRFS_ATTR_PTR(raid, used_bytes),
 586         NULL
 587 };
 588 ATTRIBUTE_GROUPS(raid);
 589
 590 static void release_raid_kobj(struct kobject *kobj)
 591 {
 592         kfree(to_raid_kobj(kobj));
 593 }
 594
 595 static struct kobj_type btrfs_raid_ktype = {
 596         .sysfs_ops = &kobj_sysfs_ops,
 597         .release = release_raid_kobj,
 598         .default_groups = raid_groups,
 599 };
 600
 601 #define SPACE_INFO_ATTR(field)                                          \
 602 static ssize_t btrfs_space_info_show_##field(struct kobject *kobj,      \
 603                                              struct kobj_attribute *a,  \
 604                                              char *buf)                 \
 605 {                                                                       \
 606         struct btrfs_space_info *sinfo = to_space_info(kobj);           \
 607         return btrfs_show_u64(&sinfo->field, &sinfo->lock, buf);        \
 608 }                                                                       \
 609 BTRFS_ATTR(space_info, field, btrfs_space_info_show_##field)
 610
 611 static ssize_t btrfs_space_info_show_total_bytes_pinned(struct kobject *kobj,
 612                                                        struct kobj_attribute *a,
 613                                                        char *buf)
 614 {
 615         struct btrfs_space_info *sinfo = to_space_info(kobj);
 616         s64 val = percpu_counter_sum(&sinfo->total_bytes_pinned);
 617         return scnprintf(buf, PAGE_SIZE, "%lld\n", val);
 618 }
 619
 620 SPACE_INFO_ATTR(flags);
 621 SPACE_INFO_ATTR(total_bytes);
 622 SPACE_INFO_ATTR(bytes_used);
 623 SPACE_INFO_ATTR(bytes_pinned);
 624 SPACE_INFO_ATTR(bytes_reserved);
 625 SPACE_INFO_ATTR(bytes_may_use);
 626 SPACE_INFO_ATTR(bytes_readonly);
 627 SPACE_INFO_ATTR(disk_used);
 628 SPACE_INFO_ATTR(disk_total);
 629 BTRFS_ATTR(space_info, total_bytes_pinned,
 630            btrfs_space_info_show_total_bytes_pinned);
 631
 632 static struct attribute *space_info_attrs[] = {
 633         BTRFS_ATTR_PTR(space_info, flags),
 634         BTRFS_ATTR_PTR(space_info, total_bytes),
 635         BTRFS_ATTR_PTR(space_info, bytes_used),
 636         BTRFS_ATTR_PTR(space_info, bytes_pinned),
 637         BTRFS_ATTR_PTR(space_info, bytes_reserved),
 638         BTRFS_ATTR_PTR(space_info, bytes_may_use),
 639         BTRFS_ATTR_PTR(space_info, bytes_readonly),
 640         BTRFS_ATTR_PTR(space_info, disk_used),
 641         BTRFS_ATTR_PTR(space_info, disk_total),
 642         BTRFS_ATTR_PTR(space_info, total_bytes_pinned),
 643         NULL,
 644 };
 645 ATTRIBUTE_GROUPS(space_info);
 646
 647 static void space_info_release(struct kobject *kobj)
 648 {
 649         struct btrfs_space_info *sinfo = to_space_info(kobj);
 650         percpu_counter_destroy(&sinfo->total_bytes_pinned);
 651         kfree(sinfo);
 652 }
 653
 654 static struct kobj_type space_info_ktype = {
 655         .sysfs_ops = &kobj_sysfs_ops,
 656         .release = space_info_release,
 657         .default_groups = space_info_groups,
 658 };
 659
 660 static const struct attribute *allocation_attrs[] = {
 661         BTRFS_ATTR_PTR(allocation, global_rsv_reserved),
 662         BTRFS_ATTR_PTR(allocation, global_rsv_size),
 663         NULL,
 664 };
 665
 666 static ssize_t btrfs_label_show(struct kobject *kobj,
 667                                 struct kobj_attribute *a, char *buf)
 668 {
 669         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 670         char *label = fs_info->super_copy->label;
 671         ssize_t ret;
 672
 673         spin_lock(&fs_info->super_lock);
 674         ret = scnprintf(buf, PAGE_SIZE, label[0] ? "%s\n" : "%s", label);
 675         spin_unlock(&fs_info->super_lock);
 676
 677         return ret;
 678 }
 679
 680 static ssize_t btrfs_label_store(struct kobject *kobj,
 681                                  struct kobj_attribute *a,
 682                                  const char *buf, size_t len)
 683 {
 684         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 685         size_t p_len;
 686
 687         if (!fs_info)
 688                 return -EPERM;
 689
 690         if (sb_rdonly(fs_info->sb))
 691                 return -EROFS;
 692
 693         /*
 694          * p_len is the len until the first occurrence of either
 695          * '\n' or '\0'
 696          */
 697         p_len = strcspn(buf, "\n");
 698
 699         if (p_len >= BTRFS_LABEL_SIZE)
 700                 return -EINVAL;
 701
 702         spin_lock(&fs_info->super_lock);
 703         memset(fs_info->super_copy->label, 0, BTRFS_LABEL_SIZE);
 704         memcpy(fs_info->super_copy->label, buf, p_len);
 705         spin_unlock(&fs_info->super_lock);
 706
 707         /*
 708          * We don't want to do full transaction commit from inside sysfs
 709          */
 710         btrfs_set_pending(fs_info, COMMIT);
 711         wake_up_process(fs_info->transaction_kthread);
 712
 713         return len;
 714 }
 715 BTRFS_ATTR_RW(, label, btrfs_label_show, btrfs_label_store);
 716
 717 static ssize_t btrfs_nodesize_show(struct kobject *kobj,
 718                                 struct kobj_attribute *a, char *buf)
 719 {
 720         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 721
 722         return scnprintf(buf, PAGE_SIZE, "%u\n", fs_info->super_copy->nodesize);
 723 }
 724
 725 BTRFS_ATTR(, nodesize, btrfs_nodesize_show);
 726
 727 static ssize_t btrfs_sectorsize_show(struct kobject *kobj,
 728                                 struct kobj_attribute *a, char *buf)
 729 {
 730         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 731
 732         return scnprintf(buf, PAGE_SIZE, "%u\n",
 733                          fs_info->super_copy->sectorsize);
 734 }
 735
 736 BTRFS_ATTR(, sectorsize, btrfs_sectorsize_show);
 737
 738 static ssize_t btrfs_clone_alignment_show(struct kobject *kobj,
 739                                 struct kobj_attribute *a, char *buf)
 740 {
 741         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 742
 743         return scnprintf(buf, PAGE_SIZE, "%u\n", fs_info->super_copy->sectorsize);
 744 }
 745
 746 BTRFS_ATTR(, clone_alignment, btrfs_clone_alignment_show);
 747
 748 static ssize_t quota_override_show(struct kobject *kobj,
 749                                    struct kobj_attribute *a, char *buf)
 750 {
 751         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 752         int quota_override;
 753
 754         quota_override = test_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
 755         return scnprintf(buf, PAGE_SIZE, "%d\n", quota_override);
 756 }
 757
 758 static ssize_t quota_override_store(struct kobject *kobj,
 759                                     struct kobj_attribute *a,
 760                                     const char *buf, size_t len)
 761 {
 762         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 763         unsigned long knob;
 764         int err;
 765
 766         if (!fs_info)
 767                 return -EPERM;
 768
 769         if (!capable(CAP_SYS_RESOURCE))
 770                 return -EPERM;
 771
 772         err = kstrtoul(buf, 10, &knob);
 773         if (err)
 774                 return err;
 775         if (knob > 1)
 776                 return -EINVAL;
 777
 778         if (knob)
 779                 set_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
 780         else
 781                 clear_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
 782
 783         return len;
 784 }
 785
 786 BTRFS_ATTR_RW(, quota_override, quota_override_show, quota_override_store);
 787
 788 static ssize_t btrfs_metadata_uuid_show(struct kobject *kobj,
 789                                 struct kobj_attribute *a, char *buf)
 790 {
 791         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 792
 793         return scnprintf(buf, PAGE_SIZE, "%pU\n",
 794                         fs_info->fs_devices->metadata_uuid);
 795 }
 796
 797 BTRFS_ATTR(, metadata_uuid, btrfs_metadata_uuid_show);
 798
 799 static ssize_t btrfs_checksum_show(struct kobject *kobj,
 800                                    struct kobj_attribute *a, char *buf)
 801 {
 802         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 803         u16 csum_type = btrfs_super_csum_type(fs_info->super_copy);
 804
 805         return scnprintf(buf, PAGE_SIZE, "%s (%s)\n",
 806                         btrfs_super_csum_name(csum_type),
 807                         crypto_shash_driver_name(fs_info->csum_shash));
 808 }
 809
 810 BTRFS_ATTR(, checksum, btrfs_checksum_show);
 811
 812 static const struct attribute *btrfs_attrs[] = {
 813         BTRFS_ATTR_PTR(, label),
 814         BTRFS_ATTR_PTR(, nodesize),
 815         BTRFS_ATTR_PTR(, sectorsize),
 816         BTRFS_ATTR_PTR(, clone_alignment),
 817         BTRFS_ATTR_PTR(, quota_override),
 818         BTRFS_ATTR_PTR(, metadata_uuid),
 819         BTRFS_ATTR_PTR(, checksum),
 820         NULL,
 821 };
 822
 823 static void btrfs_release_fsid_kobj(struct kobject *kobj)
 824 {
 825         struct btrfs_fs_devices *fs_devs = to_fs_devs(kobj);
 826
 827         memset(&fs_devs->fsid_kobj, 0, sizeof(struct kobject));
 828         complete(&fs_devs->kobj_unregister);
 829 }
 830
 831 static struct kobj_type btrfs_ktype = {
 832         .sysfs_ops      = &kobj_sysfs_ops,
 833         .release        = btrfs_release_fsid_kobj,
 834 };
 835
 836 static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj)
 837 {
 838         if (kobj->ktype != &btrfs_ktype)
 839                 return NULL;
 840         return container_of(kobj, struct btrfs_fs_devices, fsid_kobj);
 841 }
 842
 843 static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj)
 844 {
 845         if (kobj->ktype != &btrfs_ktype)
 846                 return NULL;
 847         return to_fs_devs(kobj)->fs_info;
 848 }
 849
 850 #define NUM_FEATURE_BITS 64
 851 #define BTRFS_FEATURE_NAME_MAX 13
 852 static char btrfs_unknown_feature_names[FEAT_MAX][NUM_FEATURE_BITS][BTRFS_FEATURE_NAME_MAX];
 853 static struct btrfs_feature_attr btrfs_feature_attrs[FEAT_MAX][NUM_FEATURE_BITS];
 854
 855 static const u64 supported_feature_masks[FEAT_MAX] = {
 856         [FEAT_COMPAT]    = BTRFS_FEATURE_COMPAT_SUPP,
 857         [FEAT_COMPAT_RO] = BTRFS_FEATURE_COMPAT_RO_SUPP,
 858         [FEAT_INCOMPAT]  = BTRFS_FEATURE_INCOMPAT_SUPP,
 859 };
 860
 861 static int addrm_unknown_feature_attrs(struct btrfs_fs_info *fs_info, bool add)
 862 {
 863         int set;
 864
 865         for (set = 0; set < FEAT_MAX; set++) {
 866                 int i;
 867                 struct attribute *attrs[2];
 868                 struct attribute_group agroup = {
 869                         .name = "features",
 870                         .attrs = attrs,
 871                 };
 872                 u64 features = get_features(fs_info, set);
 873                 features &= ~supported_feature_masks[set];
 874
 875                 if (!features)
 876                         continue;
 877
 878                 attrs[1] = NULL;
 879                 for (i = 0; i < NUM_FEATURE_BITS; i++) {
 880                         struct btrfs_feature_attr *fa;
 881
 882                         if (!(features & (1ULL << i)))
 883                                 continue;
 884
 885                         fa = &btrfs_feature_attrs[set][i];
 886                         attrs[0] = &fa->kobj_attr.attr;
 887                         if (add) {
 888                                 int ret;
 889                                 ret = sysfs_merge_group(&fs_info->fs_devices->fsid_kobj,
 890                                                         &agroup);
 891                                 if (ret)
 892                                         return ret;
 893                         } else
 894                                 sysfs_unmerge_group(&fs_info->fs_devices->fsid_kobj,
 895                                                     &agroup);
 896                 }
 897
 898         }
 899         return 0;
 900 }
 901
 902 static void __btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs)
 903 {
 904         if (fs_devs->devinfo_kobj) {
 905                 kobject_del(fs_devs->devinfo_kobj);
 906                 kobject_put(fs_devs->devinfo_kobj);
 907                 fs_devs->devinfo_kobj = NULL;
 908         }
 909
 910         if (fs_devs->devices_kobj) {
 911                 kobject_del(fs_devs->devices_kobj);
 912                 kobject_put(fs_devs->devices_kobj);
 913                 fs_devs->devices_kobj = NULL;
 914         }
 915
 916         if (fs_devs->fsid_kobj.state_initialized) {
 917                 kobject_del(&fs_devs->fsid_kobj);
 918                 kobject_put(&fs_devs->fsid_kobj);
 919                 wait_for_completion(&fs_devs->kobj_unregister);
 920         }
 921 }
 922
 923 /* when fs_devs is NULL it will remove all fsid kobject */
 924 void btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs)
 925 {
 926         struct list_head *fs_uuids = btrfs_get_fs_uuids();
 927
 928         if (fs_devs) {
 929                 __btrfs_sysfs_remove_fsid(fs_devs);
 930                 return;
 931         }
 932
 933         list_for_each_entry(fs_devs, fs_uuids, fs_list) {
 934                 __btrfs_sysfs_remove_fsid(fs_devs);
 935         }
 936 }
 937
 938 void btrfs_sysfs_remove_mounted(struct btrfs_fs_info *fs_info)
 939 {
 940         struct kobject *fsid_kobj = &fs_info->fs_devices->fsid_kobj;
 941
 942         btrfs_reset_fs_info_ptr(fs_info);
 943
 944         sysfs_remove_link(fsid_kobj, "bdi");
 945
 946         if (fs_info->space_info_kobj) {
 947                 sysfs_remove_files(fs_info->space_info_kobj, allocation_attrs);
 948                 kobject_del(fs_info->space_info_kobj);
 949                 kobject_put(fs_info->space_info_kobj);
 950         }
 951 #ifdef CONFIG_BTRFS_DEBUG
 952         if (fs_info->discard_debug_kobj) {
 953                 sysfs_remove_files(fs_info->discard_debug_kobj,
 954                                    discard_debug_attrs);
 955                 kobject_del(fs_info->discard_debug_kobj);
 956                 kobject_put(fs_info->discard_debug_kobj);
 957         }
 958         if (fs_info->debug_kobj) {
 959                 sysfs_remove_files(fs_info->debug_kobj, btrfs_debug_mount_attrs);
 960                 kobject_del(fs_info->debug_kobj);
 961                 kobject_put(fs_info->debug_kobj);
 962         }
 963 #endif
 964         addrm_unknown_feature_attrs(fs_info, false);
 965         sysfs_remove_group(fsid_kobj, &btrfs_feature_attr_group);
 966         sysfs_remove_files(fsid_kobj, btrfs_attrs);
 967         btrfs_sysfs_remove_devices_dir(fs_info->fs_devices, NULL);
 968 }
 969
 970 static const char * const btrfs_feature_set_names[FEAT_MAX] = {
 971         [FEAT_COMPAT]    = "compat",
 972         [FEAT_COMPAT_RO] = "compat_ro",
 973         [FEAT_INCOMPAT]  = "incompat",
 974 };
 975
 976 const char * const btrfs_feature_set_name(enum btrfs_feature_set set)
 977 {
 978         return btrfs_feature_set_names[set];
 979 }
 980
 981 char *btrfs_printable_features(enum btrfs_feature_set set, u64 flags)
 982 {
 983         size_t bufsize = 4096; /* safe max, 64 names * 64 bytes */
 984         int len = 0;
 985         int i;
 986         char *str;
 987
 988         str = kmalloc(bufsize, GFP_KERNEL);
 989         if (!str)
 990                 return str;
 991
 992         for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
 993                 const char *name;
 994
 995                 if (!(flags & (1ULL << i)))
 996                         continue;
 997
 998                 name = btrfs_feature_attrs[set][i].kobj_attr.attr.name;
 999                 len += scnprintf(str + len, bufsize - len, "%s%s",
1000                                 len ? "," : "", name);
1001         }
1002
1003         return str;
1004 }
1005
1006 static void init_feature_attrs(void)
1007 {
1008         struct btrfs_feature_attr *fa;
1009         int set, i;
1010
1011         BUILD_BUG_ON(ARRAY_SIZE(btrfs_unknown_feature_names) !=
1012                      ARRAY_SIZE(btrfs_feature_attrs));
1013         BUILD_BUG_ON(ARRAY_SIZE(btrfs_unknown_feature_names[0]) !=
1014                      ARRAY_SIZE(btrfs_feature_attrs[0]));
1015
1016         memset(btrfs_feature_attrs, 0, sizeof(btrfs_feature_attrs));
1017         memset(btrfs_unknown_feature_names, 0,
1018                sizeof(btrfs_unknown_feature_names));
1019
1020         for (i = 0; btrfs_supported_feature_attrs[i]; i++) {
1021                 struct btrfs_feature_attr *sfa;
1022                 struct attribute *a = btrfs_supported_feature_attrs[i];
1023                 int bit;
1024                 sfa = attr_to_btrfs_feature_attr(a);
1025                 bit = ilog2(sfa->feature_bit);
1026                 fa = &btrfs_feature_attrs[sfa->feature_set][bit];
1027
1028                 fa->kobj_attr.attr.name = sfa->kobj_attr.attr.name;
1029         }
1030
1031         for (set = 0; set < FEAT_MAX; set++) {
1032                 for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
1033                         char *name = btrfs_unknown_feature_names[set][i];
1034                         fa = &btrfs_feature_attrs[set][i];
1035
1036                         if (fa->kobj_attr.attr.name)
1037                                 continue;
1038
1039                         snprintf(name, BTRFS_FEATURE_NAME_MAX, "%s:%u",
1040                                  btrfs_feature_set_names[set], i);
1041
1042                         fa->kobj_attr.attr.name = name;
1043                         fa->kobj_attr.attr.mode = S_IRUGO;
1044                         fa->feature_set = set;
1045                         fa->feature_bit = 1ULL << i;
1046                 }
1047         }
1048 }
1049
1050 /*
1051  * Create a sysfs entry for a given block group type at path
1052  * /sys/fs/btrfs/UUID/allocation/data/TYPE
1053  */
1054 void btrfs_sysfs_add_block_group_type(struct btrfs_block_group *cache)
1055 {
1056         struct btrfs_fs_info *fs_info = cache->fs_info;
1057         struct btrfs_space_info *space_info = cache->space_info;
1058         struct raid_kobject *rkobj;
1059         const int index = btrfs_bg_flags_to_raid_index(cache->flags);
1060         unsigned int nofs_flag;
1061         int ret;
1062
1063         /*
1064          * Setup a NOFS context because kobject_add(), deep in its call chain,
1065          * does GFP_KERNEL allocations, and we are often called in a context
1066          * where if reclaim is triggered we can deadlock (we are either holding
1067          * a transaction handle or some lock required for a transaction
1068          * commit).
1069          */
1070         nofs_flag = memalloc_nofs_save();
1071
1072         rkobj = kzalloc(sizeof(*rkobj), GFP_NOFS);
1073         if (!rkobj) {
1074                 memalloc_nofs_restore(nofs_flag);
1075                 btrfs_warn(cache->fs_info,
1076                                 "couldn't alloc memory for raid level kobject");
1077                 return;
1078         }
1079
1080         rkobj->flags = cache->flags;
1081         kobject_init(&rkobj->kobj, &btrfs_raid_ktype);
1082         ret = kobject_add(&rkobj->kobj, &space_info->kobj, "%s",
1083                           btrfs_bg_type_to_raid_name(rkobj->flags));
1084         memalloc_nofs_restore(nofs_flag);
1085         if (ret) {
1086                 kobject_put(&rkobj->kobj);
1087                 btrfs_warn(fs_info,
1088                         "failed to add kobject for block cache, ignoring");
1089                 return;
1090         }
1091
1092         space_info->block_group_kobjs[index] = &rkobj->kobj;
1093 }
1094
1095 /*
1096  * Remove sysfs directories for all block group types of a given space info and
1097  * the space info as well
1098  */
1099 void btrfs_sysfs_remove_space_info(struct btrfs_space_info *space_info)
1100 {
1101         int i;
1102
1103         for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) {
1104                 struct kobject *kobj;
1105
1106                 kobj = space_info->block_group_kobjs[i];
1107                 space_info->block_group_kobjs[i] = NULL;
1108                 if (kobj) {
1109                         kobject_del(kobj);
1110                         kobject_put(kobj);
1111                 }
1112         }
1113         kobject_del(&space_info->kobj);
1114         kobject_put(&space_info->kobj);
1115 }
1116
1117 static const char *alloc_name(u64 flags)
1118 {
1119         switch (flags) {
1120         case BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA:
1121                 return "mixed";
1122         case BTRFS_BLOCK_GROUP_METADATA:
1123                 return "metadata";
1124         case BTRFS_BLOCK_GROUP_DATA:
1125                 return "data";
1126         case BTRFS_BLOCK_GROUP_SYSTEM:
1127                 return "system";
1128         default:
1129                 WARN_ON(1);
1130                 return "invalid-combination";
1131         };
1132 }
1133
1134 /*
1135  * Create a sysfs entry for a space info type at path
1136  * /sys/fs/btrfs/UUID/allocation/TYPE
1137  */
1138 int btrfs_sysfs_add_space_info_type(struct btrfs_fs_info *fs_info,
1139                                     struct btrfs_space_info *space_info)
1140 {
1141         int ret;
1142
1143         ret = kobject_init_and_add(&space_info->kobj, &space_info_ktype,
1144                                    fs_info->space_info_kobj, "%s",
1145                                    alloc_name(space_info->flags));
1146         if (ret) {
1147                 kobject_put(&space_info->kobj);
1148                 return ret;
1149         }
1150
1151         return 0;
1152 }
1153
1154 /* when one_device is NULL, it removes all device links */
1155
1156 int btrfs_sysfs_remove_devices_dir(struct btrfs_fs_devices *fs_devices,
1157                 struct btrfs_device *one_device)
1158 {
1159         struct hd_struct *disk;
1160         struct kobject *disk_kobj;
1161
1162         if (!fs_devices->devices_kobj)
1163                 return -EINVAL;
1164
1165         if (one_device) {
1166                 if (one_device->bdev) {
1167                         disk = one_device->bdev->bd_part;
1168                         disk_kobj = &part_to_dev(disk)->kobj;
1169                         sysfs_remove_link(fs_devices->devices_kobj,
1170                                           disk_kobj->name);
1171                 }
1172
1173                 kobject_del(&one_device->devid_kobj);
1174                 kobject_put(&one_device->devid_kobj);
1175
1176                 wait_for_completion(&one_device->kobj_unregister);
1177
1178                 return 0;
1179         }
1180
1181         list_for_each_entry(one_device, &fs_devices->devices, dev_list) {
1182
1183                 if (one_device->bdev) {
1184                         disk = one_device->bdev->bd_part;
1185                         disk_kobj = &part_to_dev(disk)->kobj;
1186                         sysfs_remove_link(fs_devices->devices_kobj,
1187                                           disk_kobj->name);
1188                 }
1189                 kobject_del(&one_device->devid_kobj);
1190                 kobject_put(&one_device->devid_kobj);
1191
1192                 wait_for_completion(&one_device->kobj_unregister);
1193         }
1194
1195         return 0;
1196 }
1197
1198 static ssize_t btrfs_devinfo_in_fs_metadata_show(struct kobject *kobj,
1199                                                  struct kobj_attribute *a,
1200                                                  char *buf)
1201 {
1202         int val;
1203         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1204                                                    devid_kobj);
1205
1206         val = !!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state);
1207
1208         return scnprintf(buf, PAGE_SIZE, "%d\n", val);
1209 }
1210 BTRFS_ATTR(devid, in_fs_metadata, btrfs_devinfo_in_fs_metadata_show);
1211
1212 static ssize_t btrfs_devinfo_missing_show(struct kobject *kobj,
1213                                         struct kobj_attribute *a, char *buf)
1214 {
1215         int val;
1216         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1217                                                    devid_kobj);
1218
1219         val = !!test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state);
1220
1221         return scnprintf(buf, PAGE_SIZE, "%d\n", val);
1222 }
1223 BTRFS_ATTR(devid, missing, btrfs_devinfo_missing_show);
1224
1225 static ssize_t btrfs_devinfo_replace_target_show(struct kobject *kobj,
1226                                                  struct kobj_attribute *a,
1227                                                  char *buf)
1228 {
1229         int val;
1230         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1231                                                    devid_kobj);
1232
1233         val = !!test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state);
1234
1235         return scnprintf(buf, PAGE_SIZE, "%d\n", val);
1236 }
1237 BTRFS_ATTR(devid, replace_target, btrfs_devinfo_replace_target_show);
1238
1239 static ssize_t btrfs_devinfo_writeable_show(struct kobject *kobj,
1240                                             struct kobj_attribute *a, char *buf)
1241 {
1242         int val;
1243         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1244                                                    devid_kobj);
1245
1246         val = !!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state);
1247
1248         return scnprintf(buf, PAGE_SIZE, "%d\n", val);
1249 }
1250 BTRFS_ATTR(devid, writeable, btrfs_devinfo_writeable_show);
1251
1252 static struct attribute *devid_attrs[] = {
1253         BTRFS_ATTR_PTR(devid, in_fs_metadata),
1254         BTRFS_ATTR_PTR(devid, missing),
1255         BTRFS_ATTR_PTR(devid, replace_target),
1256         BTRFS_ATTR_PTR(devid, writeable),
1257         NULL
1258 };
1259 ATTRIBUTE_GROUPS(devid);
1260
1261 static void btrfs_release_devid_kobj(struct kobject *kobj)
1262 {
1263         struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1264                                                    devid_kobj);
1265
1266         memset(&device->devid_kobj, 0, sizeof(struct kobject));
1267         complete(&device->kobj_unregister);
1268 }
1269
1270 static struct kobj_type devid_ktype = {
1271         .sysfs_ops      = &kobj_sysfs_ops,
1272         .default_groups = devid_groups,
1273         .release        = btrfs_release_devid_kobj,
1274 };
1275
1276 int btrfs_sysfs_add_devices_dir(struct btrfs_fs_devices *fs_devices,
1277                                 struct btrfs_device *one_device)
1278 {
1279         int error = 0;
1280         struct btrfs_device *dev;
1281         unsigned int nofs_flag;
1282
1283         nofs_flag = memalloc_nofs_save();
1284         list_for_each_entry(dev, &fs_devices->devices, dev_list) {
1285
1286                 if (one_device && one_device != dev)
1287                         continue;
1288
1289                 if (dev->bdev) {
1290                         struct hd_struct *disk;
1291                         struct kobject *disk_kobj;
1292
1293                         disk = dev->bdev->bd_part;
1294                         disk_kobj = &part_to_dev(disk)->kobj;
1295
1296                         error = sysfs_create_link(fs_devices->devices_kobj,
1297                                                   disk_kobj, disk_kobj->name);
1298                         if (error)
1299                                 break;
1300                 }
1301
1302                 init_completion(&dev->kobj_unregister);
1303                 error = kobject_init_and_add(&dev->devid_kobj, &devid_ktype,
1304                                              fs_devices->devinfo_kobj, "%llu",
1305                                              dev->devid);
1306                 if (error) {
1307                         kobject_put(&dev->devid_kobj);
1308                         break;
1309                 }
1310         }
1311         memalloc_nofs_restore(nofs_flag);
1312
1313         return error;
1314 }
1315
1316 void btrfs_kobject_uevent(struct block_device *bdev, enum kobject_action action)
1317 {
1318         int ret;
1319
1320         ret = kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, action);
1321         if (ret)
1322                 pr_warn("BTRFS: Sending event '%d' to kobject: '%s' (%p): failed\n",
1323                         action, kobject_name(&disk_to_dev(bdev->bd_disk)->kobj),
1324                         &disk_to_dev(bdev->bd_disk)->kobj);
1325 }
1326
1327 void btrfs_sysfs_update_sprout_fsid(struct btrfs_fs_devices *fs_devices,
1328                                     const u8 *fsid)
1329 {
1330         char fsid_buf[BTRFS_UUID_UNPARSED_SIZE];
1331
1332         /*
1333          * Sprouting changes fsid of the mounted filesystem, rename the fsid
1334          * directory
1335          */
1336         snprintf(fsid_buf, BTRFS_UUID_UNPARSED_SIZE, "%pU", fsid);
1337         if (kobject_rename(&fs_devices->fsid_kobj, fsid_buf))
1338                 btrfs_warn(fs_devices->fs_info,
1339                                 "sysfs: failed to create fsid for sprout");
1340 }
1341
1342 void btrfs_sysfs_update_devid(struct btrfs_device *device)
1343 {
1344         char tmp[24];
1345
1346         snprintf(tmp, sizeof(tmp), "%llu", device->devid);
1347
1348         if (kobject_rename(&device->devid_kobj, tmp))
1349                 btrfs_warn(device->fs_devices->fs_info,
1350                            "sysfs: failed to update devid for %llu",
1351                            device->devid);
1352 }
1353
1354 /* /sys/fs/btrfs/ entry */
1355 static struct kset *btrfs_kset;
1356
1357 /*
1358  * Creates:
1359  *              /sys/fs/btrfs/UUID
1360  *
1361  * Can be called by the device discovery thread.
1362  */
1363 int btrfs_sysfs_add_fsid(struct btrfs_fs_devices *fs_devs)
1364 {
1365         int error;
1366
1367         init_completion(&fs_devs->kobj_unregister);
1368         fs_devs->fsid_kobj.kset = btrfs_kset;
1369         error = kobject_init_and_add(&fs_devs->fsid_kobj, &btrfs_ktype, NULL,
1370                                      "%pU", fs_devs->fsid);
1371         if (error) {
1372                 kobject_put(&fs_devs->fsid_kobj);
1373                 return error;
1374         }
1375
1376         fs_devs->devices_kobj = kobject_create_and_add("devices",
1377                                                        &fs_devs->fsid_kobj);
1378         if (!fs_devs->devices_kobj) {
1379                 btrfs_err(fs_devs->fs_info,
1380                           "failed to init sysfs device interface");
1381                 btrfs_sysfs_remove_fsid(fs_devs);
1382                 return -ENOMEM;
1383         }
1384
1385         fs_devs->devinfo_kobj = kobject_create_and_add("devinfo",
1386                                                        &fs_devs->fsid_kobj);
1387         if (!fs_devs->devinfo_kobj) {
1388                 btrfs_err(fs_devs->fs_info,
1389                           "failed to init sysfs devinfo kobject");
1390                 btrfs_sysfs_remove_fsid(fs_devs);
1391                 return -ENOMEM;
1392         }
1393
1394         return 0;
1395 }
1396
1397 int btrfs_sysfs_add_mounted(struct btrfs_fs_info *fs_info)
1398 {
1399         int error;
1400         struct btrfs_fs_devices *fs_devs = fs_info->fs_devices;
1401         struct kobject *fsid_kobj = &fs_devs->fsid_kobj;
1402
1403         btrfs_set_fs_info_ptr(fs_info);
1404
1405         error = btrfs_sysfs_add_devices_dir(fs_devs, NULL);
1406         if (error)
1407                 return error;
1408
1409         error = sysfs_create_files(fsid_kobj, btrfs_attrs);
1410         if (error) {
1411                 btrfs_sysfs_remove_devices_dir(fs_devs, NULL);
1412                 return error;
1413         }
1414
1415         error = sysfs_create_group(fsid_kobj,
1416                                    &btrfs_feature_attr_group);
1417         if (error)
1418                 goto failure;
1419
1420 #ifdef CONFIG_BTRFS_DEBUG
1421         fs_info->debug_kobj = kobject_create_and_add("debug", fsid_kobj);
1422         if (!fs_info->debug_kobj) {
1423                 error = -ENOMEM;
1424                 goto failure;
1425         }
1426
1427         error = sysfs_create_files(fs_info->debug_kobj, btrfs_debug_mount_attrs);
1428         if (error)
1429                 goto failure;
1430
1431         /* Discard directory */
1432         fs_info->discard_debug_kobj = kobject_create_and_add("discard",
1433                                                      fs_info->debug_kobj);
1434         if (!fs_info->discard_debug_kobj) {
1435                 error = -ENOMEM;
1436                 goto failure;
1437         }
1438
1439         error = sysfs_create_files(fs_info->discard_debug_kobj,
1440                                    discard_debug_attrs);
1441         if (error)
1442                 goto failure;
1443 #endif
1444
1445         error = addrm_unknown_feature_attrs(fs_info, true);
1446         if (error)
1447                 goto failure;
1448
1449         error = sysfs_create_link(fsid_kobj, &fs_info->sb->s_bdi->dev->kobj, "bdi");
1450         if (error)
1451                 goto failure;
1452
1453         fs_info->space_info_kobj = kobject_create_and_add("allocation",
1454                                                   fsid_kobj);
1455         if (!fs_info->space_info_kobj) {
1456                 error = -ENOMEM;
1457                 goto failure;
1458         }
1459
1460         error = sysfs_create_files(fs_info->space_info_kobj, allocation_attrs);
1461         if (error)
1462                 goto failure;
1463
1464         return 0;
1465 failure:
1466         btrfs_sysfs_remove_mounted(fs_info);
1467         return error;
1468 }
1469
1470 static inline struct btrfs_fs_info *qgroup_kobj_to_fs_info(struct kobject *kobj)
1471 {
1472         return to_fs_info(kobj->parent->parent);
1473 }
1474
1475 #define QGROUP_ATTR(_member, _show_name)                                        \
1476 static ssize_t btrfs_qgroup_show_##_member(struct kobject *qgroup_kobj,         \
1477                                            struct kobj_attribute *a,            \
1478                                            char *buf)                           \
1479 {                                                                               \
1480         struct btrfs_fs_info *fs_info = qgroup_kobj_to_fs_info(qgroup_kobj);    \
1481         struct btrfs_qgroup *qgroup = container_of(qgroup_kobj,                 \
1482                         struct btrfs_qgroup, kobj);                             \
1483         return btrfs_show_u64(&qgroup->_member, &fs_info->qgroup_lock, buf);    \
1484 }                                                                               \
1485 BTRFS_ATTR(qgroup, _show_name, btrfs_qgroup_show_##_member)
1486
1487 #define QGROUP_RSV_ATTR(_name, _type)                                           \
1488 static ssize_t btrfs_qgroup_rsv_show_##_name(struct kobject *qgroup_kobj,       \
1489                                              struct kobj_attribute *a,          \
1490                                              char *buf)                         \
1491 {                                                                               \
1492         struct btrfs_fs_info *fs_info = qgroup_kobj_to_fs_info(qgroup_kobj);    \
1493         struct btrfs_qgroup *qgroup = container_of(qgroup_kobj,                 \
1494                         struct btrfs_qgroup, kobj);                             \
1495         return btrfs_show_u64(&qgroup->rsv.values[_type],                       \
1496                         &fs_info->qgroup_lock, buf);                            \
1497 }                                                                               \
1498 BTRFS_ATTR(qgroup, rsv_##_name, btrfs_qgroup_rsv_show_##_name)
1499
1500 QGROUP_ATTR(rfer, referenced);
1501 QGROUP_ATTR(excl, exclusive);
1502 QGROUP_ATTR(max_rfer, max_referenced);
1503 QGROUP_ATTR(max_excl, max_exclusive);
1504 QGROUP_ATTR(lim_flags, limit_flags);
1505 QGROUP_RSV_ATTR(data, BTRFS_QGROUP_RSV_DATA);
1506 QGROUP_RSV_ATTR(meta_pertrans, BTRFS_QGROUP_RSV_META_PERTRANS);
1507 QGROUP_RSV_ATTR(meta_prealloc, BTRFS_QGROUP_RSV_META_PREALLOC);
1508
1509 static struct attribute *qgroup_attrs[] = {
1510         BTRFS_ATTR_PTR(qgroup, referenced),
1511         BTRFS_ATTR_PTR(qgroup, exclusive),
1512         BTRFS_ATTR_PTR(qgroup, max_referenced),
1513         BTRFS_ATTR_PTR(qgroup, max_exclusive),
1514         BTRFS_ATTR_PTR(qgroup, limit_flags),
1515         BTRFS_ATTR_PTR(qgroup, rsv_data),
1516         BTRFS_ATTR_PTR(qgroup, rsv_meta_pertrans),
1517         BTRFS_ATTR_PTR(qgroup, rsv_meta_prealloc),
1518         NULL
1519 };
1520 ATTRIBUTE_GROUPS(qgroup);
1521
1522 static void qgroup_release(struct kobject *kobj)
1523 {
1524         struct btrfs_qgroup *qgroup = container_of(kobj, struct btrfs_qgroup, kobj);
1525
1526         memset(&qgroup->kobj, 0, sizeof(*kobj));
1527 }
1528
1529 static struct kobj_type qgroup_ktype = {
1530         .sysfs_ops = &kobj_sysfs_ops,
1531         .release = qgroup_release,
1532         .default_groups = qgroup_groups,
1533 };
1534
1535 int btrfs_sysfs_add_one_qgroup(struct btrfs_fs_info *fs_info,
1536                                 struct btrfs_qgroup *qgroup)
1537 {
1538         struct kobject *qgroups_kobj = fs_info->qgroups_kobj;
1539         int ret;
1540
1541         if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
1542                 return 0;
1543         if (qgroup->kobj.state_initialized)
1544                 return 0;
1545         if (!qgroups_kobj)
1546                 return -EINVAL;
1547
1548         ret = kobject_init_and_add(&qgroup->kobj, &qgroup_ktype, qgroups_kobj,
1549                         "%hu_%llu", btrfs_qgroup_level(qgroup->qgroupid),
1550                         btrfs_qgroup_subvolid(qgroup->qgroupid));
1551         if (ret < 0)
1552                 kobject_put(&qgroup->kobj);
1553
1554         return ret;
1555 }
1556
1557 void btrfs_sysfs_del_qgroups(struct btrfs_fs_info *fs_info)
1558 {
1559         struct btrfs_qgroup *qgroup;
1560         struct btrfs_qgroup *next;
1561
1562         if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
1563                 return;
1564
1565         rbtree_postorder_for_each_entry_safe(qgroup, next,
1566                                              &fs_info->qgroup_tree, node)
1567                 btrfs_sysfs_del_one_qgroup(fs_info, qgroup);
1568         if (fs_info->qgroups_kobj) {
1569                 kobject_del(fs_info->qgroups_kobj);
1570                 kobject_put(fs_info->qgroups_kobj);
1571                 fs_info->qgroups_kobj = NULL;
1572         }
1573 }
1574
1575 /* Called when qgroups get initialized, thus there is no need for locking */
1576 int btrfs_sysfs_add_qgroups(struct btrfs_fs_info *fs_info)
1577 {
1578         struct kobject *fsid_kobj = &fs_info->fs_devices->fsid_kobj;
1579         struct btrfs_qgroup *qgroup;
1580         struct btrfs_qgroup *next;
1581         int ret = 0;
1582
1583         if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
1584                 return 0;
1585
1586         ASSERT(fsid_kobj);
1587         if (fs_info->qgroups_kobj)
1588                 return 0;
1589
1590         fs_info->qgroups_kobj = kobject_create_and_add("qgroups", fsid_kobj);
1591         if (!fs_info->qgroups_kobj) {
1592                 ret = -ENOMEM;
1593                 goto out;
1594         }
1595         rbtree_postorder_for_each_entry_safe(qgroup, next,
1596                                              &fs_info->qgroup_tree, node) {
1597                 ret = btrfs_sysfs_add_one_qgroup(fs_info, qgroup);
1598                 if (ret < 0)
1599                         goto out;
1600         }
1601
1602 out:
1603         if (ret < 0)
1604                 btrfs_sysfs_del_qgroups(fs_info);
1605         return ret;
1606 }
1607
1608 void btrfs_sysfs_del_one_qgroup(struct btrfs_fs_info *fs_info,
1609                                 struct btrfs_qgroup *qgroup)
1610 {
1611         if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
1612                 return;
1613
1614         if (qgroup->kobj.state_initialized) {
1615                 kobject_del(&qgroup->kobj);
1616                 kobject_put(&qgroup->kobj);
1617         }
1618 }
1619
1620 /*
1621  * Change per-fs features in /sys/fs/btrfs/UUID/features to match current
1622  * values in superblock. Call after any changes to incompat/compat_ro flags
1623  */
1624 void btrfs_sysfs_feature_update(struct btrfs_fs_info *fs_info,
1625                 u64 bit, enum btrfs_feature_set set)
1626 {
1627         struct btrfs_fs_devices *fs_devs;
1628         struct kobject *fsid_kobj;
1629         u64 features;
1630         int ret;
1631
1632         if (!fs_info)
1633                 return;
1634
1635         features = get_features(fs_info, set);
1636         ASSERT(bit & supported_feature_masks[set]);
1637
1638         fs_devs = fs_info->fs_devices;
1639         fsid_kobj = &fs_devs->fsid_kobj;
1640
1641         if (!fsid_kobj->state_initialized)
1642                 return;
1643
1644         /*
1645          * FIXME: this is too heavy to update just one value, ideally we'd like
1646          * to use sysfs_update_group but some refactoring is needed first.
1647          */
1648         sysfs_remove_group(fsid_kobj, &btrfs_feature_attr_group);
1649         ret = sysfs_create_group(fsid_kobj, &btrfs_feature_attr_group);
1650 }
1651
1652 int __init btrfs_init_sysfs(void)
1653 {
1654         int ret;
1655
1656         btrfs_kset = kset_create_and_add("btrfs", NULL, fs_kobj);
1657         if (!btrfs_kset)
1658                 return -ENOMEM;
1659
1660         init_feature_attrs();
1661         ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
1662         if (ret)
1663                 goto out2;
1664         ret = sysfs_merge_group(&btrfs_kset->kobj,
1665                                 &btrfs_static_feature_attr_group);
1666         if (ret)
1667                 goto out_remove_group;
1668
1669 #ifdef CONFIG_BTRFS_DEBUG
1670         ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_debug_feature_attr_group);
1671         if (ret)
1672                 goto out2;
1673 #endif
1674
1675         return 0;
1676
1677 out_remove_group:
1678         sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
1679 out2:
1680         kset_unregister(btrfs_kset);
1681
1682         return ret;
1683 }
1684
1685 void __cold btrfs_exit_sysfs(void)
1686 {
1687         sysfs_unmerge_group(&btrfs_kset->kobj,
1688                             &btrfs_static_feature_attr_group);
1689         sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
1690 #ifdef CONFIG_BTRFS_DEBUG
1691         sysfs_remove_group(&btrfs_kset->kobj, &btrfs_debug_feature_attr_group);
1692 #endif
1693         kset_unregister(btrfs_kset);
1694 }
1695