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