fs/btrfs/sysfs.c

   1 /*
   2  * Copyright (C) 2007 Oracle.  All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public
   6  * License v2 as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public
  14  * License along with this program; if not, write to the
  15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  16  * Boston, MA 021110-1307, USA.
  17  */
  18
  19 #include <linux/sched.h>
  20 #include <linux/slab.h>
  21 #include <linux/spinlock.h>
  22 #include <linux/completion.h>
  23 #include <linux/buffer_head.h>
  24 #include <linux/kobject.h>
  25 #include <linux/bug.h>
  26 #include <linux/genhd.h>
  27 #include <linux/debugfs.h>
  28
  29 #include "ctree.h"
  30 #include "disk-io.h"
  31 #include "transaction.h"
  32 #include "sysfs.h"
  33 #include "volumes.h"
  34
  35 static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj);
  36
  37 static u64 get_features(struct btrfs_fs_info *fs_info,
  38                         enum btrfs_feature_set set)
  39 {
  40         struct btrfs_super_block *disk_super = fs_info->super_copy;
  41         if (set == FEAT_COMPAT)
  42                 return btrfs_super_compat_flags(disk_super);
  43         else if (set == FEAT_COMPAT_RO)
  44                 return btrfs_super_compat_ro_flags(disk_super);
  45         else
  46                 return btrfs_super_incompat_flags(disk_super);
  47 }
  48
  49 static void set_features(struct btrfs_fs_info *fs_info,
  50                          enum btrfs_feature_set set, u64 features)
  51 {
  52         struct btrfs_super_block *disk_super = fs_info->super_copy;
  53         if (set == FEAT_COMPAT)
  54                 btrfs_set_super_compat_flags(disk_super, features);
  55         else if (set == FEAT_COMPAT_RO)
  56                 btrfs_set_super_compat_ro_flags(disk_super, features);
  57         else
  58                 btrfs_set_super_incompat_flags(disk_super, features);
  59 }
  60
  61 static int can_modify_feature(struct btrfs_feature_attr *fa)
  62 {
  63         int val = 0;
  64         u64 set, clear;
  65         switch (fa->feature_set) {
  66         case FEAT_COMPAT:
  67                 set = BTRFS_FEATURE_COMPAT_SAFE_SET;
  68                 clear = BTRFS_FEATURE_COMPAT_SAFE_CLEAR;
  69                 break;
  70         case FEAT_COMPAT_RO:
  71                 set = BTRFS_FEATURE_COMPAT_RO_SAFE_SET;
  72                 clear = BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR;
  73                 break;
  74         case FEAT_INCOMPAT:
  75                 set = BTRFS_FEATURE_INCOMPAT_SAFE_SET;
  76                 clear = BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR;
  77                 break;
  78         default:
  79                 printk(KERN_WARNING "btrfs: sysfs: unknown feature set %d\n",
  80                                 fa->feature_set);
  81                 return 0;
  82         }
  83
  84         if (set & fa->feature_bit)
  85                 val |= 1;
  86         if (clear & fa->feature_bit)
  87                 val |= 2;
  88
  89         return val;
  90 }
  91
  92 static ssize_t btrfs_feature_attr_show(struct kobject *kobj,
  93                                        struct kobj_attribute *a, char *buf)
  94 {
  95         int val = 0;
  96         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
  97         struct btrfs_feature_attr *fa = to_btrfs_feature_attr(a);
  98         if (fs_info) {
  99                 u64 features = get_features(fs_info, fa->feature_set);
 100                 if (features & fa->feature_bit)
 101                         val = 1;
 102         } else
 103                 val = can_modify_feature(fa);
 104
 105         return snprintf(buf, PAGE_SIZE, "%d\n", val);
 106 }
 107
 108 static ssize_t btrfs_feature_attr_store(struct kobject *kobj,
 109                                         struct kobj_attribute *a,
 110                                         const char *buf, size_t count)
 111 {
 112         struct btrfs_fs_info *fs_info;
 113         struct btrfs_feature_attr *fa = to_btrfs_feature_attr(a);
 114         u64 features, set, clear;
 115         unsigned long val;
 116         int ret;
 117
 118         fs_info = to_fs_info(kobj);
 119         if (!fs_info)
 120                 return -EPERM;
 121
 122         ret = kstrtoul(skip_spaces(buf), 0, &val);
 123         if (ret)
 124                 return ret;
 125
 126         if (fa->feature_set == FEAT_COMPAT) {
 127                 set = BTRFS_FEATURE_COMPAT_SAFE_SET;
 128                 clear = BTRFS_FEATURE_COMPAT_SAFE_CLEAR;
 129         } else if (fa->feature_set == FEAT_COMPAT_RO) {
 130                 set = BTRFS_FEATURE_COMPAT_RO_SAFE_SET;
 131                 clear = BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR;
 132         } else {
 133                 set = BTRFS_FEATURE_INCOMPAT_SAFE_SET;
 134                 clear = BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR;
 135         }
 136
 137         features = get_features(fs_info, fa->feature_set);
 138
 139         /* Nothing to do */
 140         if ((val && (features & fa->feature_bit)) ||
 141             (!val && !(features & fa->feature_bit)))
 142                 return count;
 143
 144         if ((val && !(set & fa->feature_bit)) ||
 145             (!val && !(clear & fa->feature_bit))) {
 146                 btrfs_info(fs_info,
 147                         "%sabling feature %s on mounted fs is not supported.",
 148                         val ? "En" : "Dis", fa->kobj_attr.attr.name);
 149                 return -EPERM;
 150         }
 151
 152         btrfs_info(fs_info, "%s %s feature flag",
 153                    val ? "Setting" : "Clearing", fa->kobj_attr.attr.name);
 154
 155         spin_lock(&fs_info->super_lock);
 156         features = get_features(fs_info, fa->feature_set);
 157         if (val)
 158                 features |= fa->feature_bit;
 159         else
 160                 features &= ~fa->feature_bit;
 161         set_features(fs_info, fa->feature_set, features);
 162         spin_unlock(&fs_info->super_lock);
 163
 164         /*
 165          * We don't want to do full transaction commit from inside sysfs
 166          */
 167         btrfs_set_pending(fs_info, COMMIT);
 168         wake_up_process(fs_info->transaction_kthread);
 169
 170         return count;
 171 }
 172
 173 static umode_t btrfs_feature_visible(struct kobject *kobj,
 174                                      struct attribute *attr, int unused)
 175 {
 176         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 177         umode_t mode = attr->mode;
 178
 179         if (fs_info) {
 180                 struct btrfs_feature_attr *fa;
 181                 u64 features;
 182
 183                 fa = attr_to_btrfs_feature_attr(attr);
 184                 features = get_features(fs_info, fa->feature_set);
 185
 186                 if (can_modify_feature(fa))
 187                         mode |= S_IWUSR;
 188                 else if (!(features & fa->feature_bit))
 189                         mode = 0;
 190         }
 191
 192         return mode;
 193 }
 194
 195 BTRFS_FEAT_ATTR_INCOMPAT(mixed_backref, MIXED_BACKREF);
 196 BTRFS_FEAT_ATTR_INCOMPAT(default_subvol, DEFAULT_SUBVOL);
 197 BTRFS_FEAT_ATTR_INCOMPAT(mixed_groups, MIXED_GROUPS);
 198 BTRFS_FEAT_ATTR_INCOMPAT(compress_lzo, COMPRESS_LZO);
 199 BTRFS_FEAT_ATTR_INCOMPAT(big_metadata, BIG_METADATA);
 200 BTRFS_FEAT_ATTR_INCOMPAT(extended_iref, EXTENDED_IREF);
 201 BTRFS_FEAT_ATTR_INCOMPAT(raid56, RAID56);
 202 BTRFS_FEAT_ATTR_INCOMPAT(skinny_metadata, SKINNY_METADATA);
 203 BTRFS_FEAT_ATTR_INCOMPAT(no_holes, NO_HOLES);
 204
 205 static struct attribute *btrfs_supported_feature_attrs[] = {
 206         BTRFS_FEAT_ATTR_PTR(mixed_backref),
 207         BTRFS_FEAT_ATTR_PTR(default_subvol),
 208         BTRFS_FEAT_ATTR_PTR(mixed_groups),
 209         BTRFS_FEAT_ATTR_PTR(compress_lzo),
 210         BTRFS_FEAT_ATTR_PTR(big_metadata),
 211         BTRFS_FEAT_ATTR_PTR(extended_iref),
 212         BTRFS_FEAT_ATTR_PTR(raid56),
 213         BTRFS_FEAT_ATTR_PTR(skinny_metadata),
 214         BTRFS_FEAT_ATTR_PTR(no_holes),
 215         NULL
 216 };
 217
 218 static const struct attribute_group btrfs_feature_attr_group = {
 219         .name = "features",
 220         .is_visible = btrfs_feature_visible,
 221         .attrs = btrfs_supported_feature_attrs,
 222 };
 223
 224 static ssize_t btrfs_show_u64(u64 *value_ptr, spinlock_t *lock, char *buf)
 225 {
 226         u64 val;
 227         if (lock)
 228                 spin_lock(lock);
 229         val = *value_ptr;
 230         if (lock)
 231                 spin_unlock(lock);
 232         return snprintf(buf, PAGE_SIZE, "%llu\n", val);
 233 }
 234
 235 static ssize_t global_rsv_size_show(struct kobject *kobj,
 236                                     struct kobj_attribute *ka, char *buf)
 237 {
 238         struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent);
 239         struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
 240         return btrfs_show_u64(&block_rsv->size, &block_rsv->lock, buf);
 241 }
 242 BTRFS_ATTR(global_rsv_size, global_rsv_size_show);
 243
 244 static ssize_t global_rsv_reserved_show(struct kobject *kobj,
 245                                         struct kobj_attribute *a, char *buf)
 246 {
 247         struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent);
 248         struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
 249         return btrfs_show_u64(&block_rsv->reserved, &block_rsv->lock, buf);
 250 }
 251 BTRFS_ATTR(global_rsv_reserved, global_rsv_reserved_show);
 252
 253 #define to_space_info(_kobj) container_of(_kobj, struct btrfs_space_info, kobj)
 254 #define to_raid_kobj(_kobj) container_of(_kobj, struct raid_kobject, kobj)
 255
 256 static ssize_t raid_bytes_show(struct kobject *kobj,
 257                                struct kobj_attribute *attr, char *buf);
 258 BTRFS_RAID_ATTR(total_bytes, raid_bytes_show);
 259 BTRFS_RAID_ATTR(used_bytes, raid_bytes_show);
 260
 261 static ssize_t raid_bytes_show(struct kobject *kobj,
 262                                struct kobj_attribute *attr, char *buf)
 263
 264 {
 265         struct btrfs_space_info *sinfo = to_space_info(kobj->parent);
 266         struct btrfs_block_group_cache *block_group;
 267         int index = to_raid_kobj(kobj)->raid_type;
 268         u64 val = 0;
 269
 270         down_read(&sinfo->groups_sem);
 271         list_for_each_entry(block_group, &sinfo->block_groups[index], list) {
 272                 if (&attr->attr == BTRFS_RAID_ATTR_PTR(total_bytes))
 273                         val += block_group->key.offset;
 274                 else
 275                         val += btrfs_block_group_used(&block_group->item);
 276         }
 277         up_read(&sinfo->groups_sem);
 278         return snprintf(buf, PAGE_SIZE, "%llu\n", val);
 279 }
 280
 281 static struct attribute *raid_attributes[] = {
 282         BTRFS_RAID_ATTR_PTR(total_bytes),
 283         BTRFS_RAID_ATTR_PTR(used_bytes),
 284         NULL
 285 };
 286
 287 static void release_raid_kobj(struct kobject *kobj)
 288 {
 289         kfree(to_raid_kobj(kobj));
 290 }
 291
 292 struct kobj_type btrfs_raid_ktype = {
 293         .sysfs_ops = &kobj_sysfs_ops,
 294         .release = release_raid_kobj,
 295         .default_attrs = raid_attributes,
 296 };
 297
 298 #define SPACE_INFO_ATTR(field)                                          \
 299 static ssize_t btrfs_space_info_show_##field(struct kobject *kobj,      \
 300                                              struct kobj_attribute *a,  \
 301                                              char *buf)                 \
 302 {                                                                       \
 303         struct btrfs_space_info *sinfo = to_space_info(kobj);           \
 304         return btrfs_show_u64(&sinfo->field, &sinfo->lock, buf);        \
 305 }                                                                       \
 306 BTRFS_ATTR(field, btrfs_space_info_show_##field)
 307
 308 static ssize_t btrfs_space_info_show_total_bytes_pinned(struct kobject *kobj,
 309                                                        struct kobj_attribute *a,
 310                                                        char *buf)
 311 {
 312         struct btrfs_space_info *sinfo = to_space_info(kobj);
 313         s64 val = percpu_counter_sum(&sinfo->total_bytes_pinned);
 314         return snprintf(buf, PAGE_SIZE, "%lld\n", val);
 315 }
 316
 317 SPACE_INFO_ATTR(flags);
 318 SPACE_INFO_ATTR(total_bytes);
 319 SPACE_INFO_ATTR(bytes_used);
 320 SPACE_INFO_ATTR(bytes_pinned);
 321 SPACE_INFO_ATTR(bytes_reserved);
 322 SPACE_INFO_ATTR(bytes_may_use);
 323 SPACE_INFO_ATTR(disk_used);
 324 SPACE_INFO_ATTR(disk_total);
 325 BTRFS_ATTR(total_bytes_pinned, btrfs_space_info_show_total_bytes_pinned);
 326
 327 static struct attribute *space_info_attrs[] = {
 328         BTRFS_ATTR_PTR(flags),
 329         BTRFS_ATTR_PTR(total_bytes),
 330         BTRFS_ATTR_PTR(bytes_used),
 331         BTRFS_ATTR_PTR(bytes_pinned),
 332         BTRFS_ATTR_PTR(bytes_reserved),
 333         BTRFS_ATTR_PTR(bytes_may_use),
 334         BTRFS_ATTR_PTR(disk_used),
 335         BTRFS_ATTR_PTR(disk_total),
 336         BTRFS_ATTR_PTR(total_bytes_pinned),
 337         NULL,
 338 };
 339
 340 static void space_info_release(struct kobject *kobj)
 341 {
 342         struct btrfs_space_info *sinfo = to_space_info(kobj);
 343         percpu_counter_destroy(&sinfo->total_bytes_pinned);
 344         kfree(sinfo);
 345 }
 346
 347 struct kobj_type space_info_ktype = {
 348         .sysfs_ops = &kobj_sysfs_ops,
 349         .release = space_info_release,
 350         .default_attrs = space_info_attrs,
 351 };
 352
 353 static const struct attribute *allocation_attrs[] = {
 354         BTRFS_ATTR_PTR(global_rsv_reserved),
 355         BTRFS_ATTR_PTR(global_rsv_size),
 356         NULL,
 357 };
 358
 359 static ssize_t btrfs_label_show(struct kobject *kobj,
 360                                 struct kobj_attribute *a, char *buf)
 361 {
 362         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 363         char *label = fs_info->super_copy->label;
 364         return snprintf(buf, PAGE_SIZE, label[0] ? "%s\n" : "%s", label);
 365 }
 366
 367 static ssize_t btrfs_label_store(struct kobject *kobj,
 368                                  struct kobj_attribute *a,
 369                                  const char *buf, size_t len)
 370 {
 371         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 372         struct btrfs_trans_handle *trans;
 373         struct btrfs_root *root = fs_info->fs_root;
 374         int ret;
 375         size_t p_len;
 376
 377         if (fs_info->sb->s_flags & MS_RDONLY)
 378                 return -EROFS;
 379
 380         /*
 381          * p_len is the len until the first occurrence of either
 382          * '\n' or '\0'
 383          */
 384         p_len = strcspn(buf, "\n");
 385
 386         if (p_len >= BTRFS_LABEL_SIZE)
 387                 return -EINVAL;
 388
 389         trans = btrfs_start_transaction(root, 0);
 390         if (IS_ERR(trans))
 391                 return PTR_ERR(trans);
 392
 393         spin_lock(&root->fs_info->super_lock);
 394         memset(fs_info->super_copy->label, 0, BTRFS_LABEL_SIZE);
 395         memcpy(fs_info->super_copy->label, buf, p_len);
 396         spin_unlock(&root->fs_info->super_lock);
 397         ret = btrfs_commit_transaction(trans, root);
 398
 399         if (!ret)
 400                 return len;
 401
 402         return ret;
 403 }
 404 BTRFS_ATTR_RW(label, btrfs_label_show, btrfs_label_store);
 405
 406 static ssize_t btrfs_nodesize_show(struct kobject *kobj,
 407                                 struct kobj_attribute *a, char *buf)
 408 {
 409         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 410
 411         return snprintf(buf, PAGE_SIZE, "%u\n", fs_info->super_copy->nodesize);
 412 }
 413
 414 BTRFS_ATTR(nodesize, btrfs_nodesize_show);
 415
 416 static ssize_t btrfs_sectorsize_show(struct kobject *kobj,
 417                                 struct kobj_attribute *a, char *buf)
 418 {
 419         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 420
 421         return snprintf(buf, PAGE_SIZE, "%u\n", fs_info->super_copy->sectorsize);
 422 }
 423
 424 BTRFS_ATTR(sectorsize, btrfs_sectorsize_show);
 425
 426 static ssize_t btrfs_clone_alignment_show(struct kobject *kobj,
 427                                 struct kobj_attribute *a, char *buf)
 428 {
 429         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 430
 431         return snprintf(buf, PAGE_SIZE, "%u\n", fs_info->super_copy->sectorsize);
 432 }
 433
 434 BTRFS_ATTR(clone_alignment, btrfs_clone_alignment_show);
 435
 436 static struct attribute *btrfs_attrs[] = {
 437         BTRFS_ATTR_PTR(label),
 438         BTRFS_ATTR_PTR(nodesize),
 439         BTRFS_ATTR_PTR(sectorsize),
 440         BTRFS_ATTR_PTR(clone_alignment),
 441         NULL,
 442 };
 443
 444 static void btrfs_release_super_kobj(struct kobject *kobj)
 445 {
 446         struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 447         complete(&fs_info->kobj_unregister);
 448 }
 449
 450 static struct kobj_type btrfs_ktype = {
 451         .sysfs_ops      = &kobj_sysfs_ops,
 452         .release        = btrfs_release_super_kobj,
 453         .default_attrs  = btrfs_attrs,
 454 };
 455
 456 static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj)
 457 {
 458         if (kobj->ktype != &btrfs_ktype)
 459                 return NULL;
 460         return container_of(kobj, struct btrfs_fs_info, super_kobj);
 461 }
 462
 463 #define NUM_FEATURE_BITS 64
 464 static char btrfs_unknown_feature_names[3][NUM_FEATURE_BITS][13];
 465 static struct btrfs_feature_attr btrfs_feature_attrs[3][NUM_FEATURE_BITS];
 466
 467 static u64 supported_feature_masks[3] = {
 468         [FEAT_COMPAT]    = BTRFS_FEATURE_COMPAT_SUPP,
 469         [FEAT_COMPAT_RO] = BTRFS_FEATURE_COMPAT_RO_SUPP,
 470         [FEAT_INCOMPAT]  = BTRFS_FEATURE_INCOMPAT_SUPP,
 471 };
 472
 473 static int addrm_unknown_feature_attrs(struct btrfs_fs_info *fs_info, bool add)
 474 {
 475         int set;
 476
 477         for (set = 0; set < FEAT_MAX; set++) {
 478                 int i;
 479                 struct attribute *attrs[2];
 480                 struct attribute_group agroup = {
 481                         .name = "features",
 482                         .attrs = attrs,
 483                 };
 484                 u64 features = get_features(fs_info, set);
 485                 features &= ~supported_feature_masks[set];
 486
 487                 if (!features)
 488                         continue;
 489
 490                 attrs[1] = NULL;
 491                 for (i = 0; i < NUM_FEATURE_BITS; i++) {
 492                         struct btrfs_feature_attr *fa;
 493
 494                         if (!(features & (1ULL << i)))
 495                                 continue;
 496
 497                         fa = &btrfs_feature_attrs[set][i];
 498                         attrs[0] = &fa->kobj_attr.attr;
 499                         if (add) {
 500                                 int ret;
 501                                 ret = sysfs_merge_group(&fs_info->super_kobj,
 502                                                         &agroup);
 503                                 if (ret)
 504                                         return ret;
 505                         } else
 506                                 sysfs_unmerge_group(&fs_info->super_kobj,
 507                                                     &agroup);
 508                 }
 509
 510         }
 511         return 0;
 512 }
 513
 514 static void __btrfs_sysfs_remove_one(struct btrfs_fs_info *fs_info)
 515 {
 516         kobject_del(&fs_info->super_kobj);
 517         kobject_put(&fs_info->super_kobj);
 518         wait_for_completion(&fs_info->kobj_unregister);
 519 }
 520
 521 void btrfs_sysfs_remove_one(struct btrfs_fs_info *fs_info)
 522 {
 523         if (fs_info->space_info_kobj) {
 524                 sysfs_remove_files(fs_info->space_info_kobj, allocation_attrs);
 525                 kobject_del(fs_info->space_info_kobj);
 526                 kobject_put(fs_info->space_info_kobj);
 527         }
 528         kobject_del(fs_info->device_dir_kobj);
 529         kobject_put(fs_info->device_dir_kobj);
 530         addrm_unknown_feature_attrs(fs_info, false);
 531         sysfs_remove_group(&fs_info->super_kobj, &btrfs_feature_attr_group);
 532         __btrfs_sysfs_remove_one(fs_info);
 533 }
 534
 535 const char * const btrfs_feature_set_names[3] = {
 536         [FEAT_COMPAT]    = "compat",
 537         [FEAT_COMPAT_RO] = "compat_ro",
 538         [FEAT_INCOMPAT]  = "incompat",
 539 };
 540
 541 char *btrfs_printable_features(enum btrfs_feature_set set, u64 flags)
 542 {
 543         size_t bufsize = 4096; /* safe max, 64 names * 64 bytes */
 544         int len = 0;
 545         int i;
 546         char *str;
 547
 548         str = kmalloc(bufsize, GFP_KERNEL);
 549         if (!str)
 550                 return str;
 551
 552         for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
 553                 const char *name;
 554
 555                 if (!(flags & (1ULL << i)))
 556                         continue;
 557
 558                 name = btrfs_feature_attrs[set][i].kobj_attr.attr.name;
 559                 len += snprintf(str + len, bufsize - len, "%s%s",
 560                                 len ? "," : "", name);
 561         }
 562
 563         return str;
 564 }
 565
 566 static void init_feature_attrs(void)
 567 {
 568         struct btrfs_feature_attr *fa;
 569         int set, i;
 570
 571         BUILD_BUG_ON(ARRAY_SIZE(btrfs_unknown_feature_names) !=
 572                      ARRAY_SIZE(btrfs_feature_attrs));
 573         BUILD_BUG_ON(ARRAY_SIZE(btrfs_unknown_feature_names[0]) !=
 574                      ARRAY_SIZE(btrfs_feature_attrs[0]));
 575
 576         memset(btrfs_feature_attrs, 0, sizeof(btrfs_feature_attrs));
 577         memset(btrfs_unknown_feature_names, 0,
 578                sizeof(btrfs_unknown_feature_names));
 579
 580         for (i = 0; btrfs_supported_feature_attrs[i]; i++) {
 581                 struct btrfs_feature_attr *sfa;
 582                 struct attribute *a = btrfs_supported_feature_attrs[i];
 583                 int bit;
 584                 sfa = attr_to_btrfs_feature_attr(a);
 585                 bit = ilog2(sfa->feature_bit);
 586                 fa = &btrfs_feature_attrs[sfa->feature_set][bit];
 587
 588                 fa->kobj_attr.attr.name = sfa->kobj_attr.attr.name;
 589         }
 590
 591         for (set = 0; set < FEAT_MAX; set++) {
 592                 for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
 593                         char *name = btrfs_unknown_feature_names[set][i];
 594                         fa = &btrfs_feature_attrs[set][i];
 595
 596                         if (fa->kobj_attr.attr.name)
 597                                 continue;
 598
 599                         snprintf(name, 13, "%s:%u",
 600                                  btrfs_feature_set_names[set], i);
 601
 602                         fa->kobj_attr.attr.name = name;
 603                         fa->kobj_attr.attr.mode = S_IRUGO;
 604                         fa->feature_set = set;
 605                         fa->feature_bit = 1ULL << i;
 606                 }
 607         }
 608 }
 609
 610 int btrfs_kobj_rm_device(struct btrfs_fs_info *fs_info,
 611                 struct btrfs_device *one_device)
 612 {
 613         struct hd_struct *disk;
 614         struct kobject *disk_kobj;
 615
 616         if (!fs_info->device_dir_kobj)
 617                 return -EINVAL;
 618
 619         if (one_device && one_device->bdev) {
 620                 disk = one_device->bdev->bd_part;
 621                 disk_kobj = &part_to_dev(disk)->kobj;
 622
 623                 sysfs_remove_link(fs_info->device_dir_kobj,
 624                                                 disk_kobj->name);
 625         }
 626
 627         return 0;
 628 }
 629
 630 int btrfs_kobj_add_device(struct btrfs_fs_info *fs_info,
 631                 struct btrfs_device *one_device)
 632 {
 633         int error = 0;
 634         struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
 635         struct btrfs_device *dev;
 636
 637         if (!fs_info->device_dir_kobj)
 638                 fs_info->device_dir_kobj = kobject_create_and_add("devices",
 639                                                 &fs_info->super_kobj);
 640
 641         if (!fs_info->device_dir_kobj)
 642                 return -ENOMEM;
 643
 644         list_for_each_entry(dev, &fs_devices->devices, dev_list) {
 645                 struct hd_struct *disk;
 646                 struct kobject *disk_kobj;
 647
 648                 if (!dev->bdev)
 649                         continue;
 650
 651                 if (one_device && one_device != dev)
 652                         continue;
 653
 654                 disk = dev->bdev->bd_part;
 655                 disk_kobj = &part_to_dev(disk)->kobj;
 656
 657                 error = sysfs_create_link(fs_info->device_dir_kobj,
 658                                           disk_kobj, disk_kobj->name);
 659                 if (error)
 660                         break;
 661         }
 662
 663         return error;
 664 }
 665
 666 /* /sys/fs/btrfs/ entry */
 667 static struct kset *btrfs_kset;
 668
 669 /* /sys/kernel/debug/btrfs */
 670 static struct dentry *btrfs_debugfs_root_dentry;
 671
 672 /* Debugging tunables and exported data */
 673 u64 btrfs_debugfs_test;
 674
 675 int btrfs_sysfs_add_one(struct btrfs_fs_info *fs_info)
 676 {
 677         int error;
 678
 679         init_completion(&fs_info->kobj_unregister);
 680         fs_info->super_kobj.kset = btrfs_kset;
 681         error = kobject_init_and_add(&fs_info->super_kobj, &btrfs_ktype, NULL,
 682                                      "%pU", fs_info->fsid);
 683         if (error)
 684                 return error;
 685
 686         error = sysfs_create_group(&fs_info->super_kobj,
 687                                    &btrfs_feature_attr_group);
 688         if (error) {
 689                 __btrfs_sysfs_remove_one(fs_info);
 690                 return error;
 691         }
 692
 693         error = addrm_unknown_feature_attrs(fs_info, true);
 694         if (error)
 695                 goto failure;
 696
 697         error = btrfs_kobj_add_device(fs_info, NULL);
 698         if (error)
 699                 goto failure;
 700
 701         fs_info->space_info_kobj = kobject_create_and_add("allocation",
 702                                                   &fs_info->super_kobj);
 703         if (!fs_info->space_info_kobj) {
 704                 error = -ENOMEM;
 705                 goto failure;
 706         }
 707
 708         error = sysfs_create_files(fs_info->space_info_kobj, allocation_attrs);
 709         if (error)
 710                 goto failure;
 711
 712         return 0;
 713 failure:
 714         btrfs_sysfs_remove_one(fs_info);
 715         return error;
 716 }
 717
 718 static int btrfs_init_debugfs(void)
 719 {
 720 #ifdef CONFIG_DEBUG_FS
 721         btrfs_debugfs_root_dentry = debugfs_create_dir("btrfs", NULL);
 722         if (!btrfs_debugfs_root_dentry)
 723                 return -ENOMEM;
 724
 725         debugfs_create_u64("test", S_IRUGO | S_IWUGO, btrfs_debugfs_root_dentry,
 726                         &btrfs_debugfs_test);
 727 #endif
 728         return 0;
 729 }
 730
 731 int btrfs_init_sysfs(void)
 732 {
 733         int ret;
 734
 735         btrfs_kset = kset_create_and_add("btrfs", NULL, fs_kobj);
 736         if (!btrfs_kset)
 737                 return -ENOMEM;
 738
 739         ret = btrfs_init_debugfs();
 740         if (ret)
 741                 return ret;
 742
 743         init_feature_attrs();
 744         ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
 745
 746         return ret;
 747 }
 748
 749 void btrfs_exit_sysfs(void)
 750 {
 751         sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
 752         kset_unregister(btrfs_kset);
 753         debugfs_remove_recursive(btrfs_debugfs_root_dentry);
 754 }
 755