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#include "messages.h"
 
  14#include "ctree.h"
  15#include "discard.h"
  16#include "disk-io.h"
  17#include "send.h"
  18#include "transaction.h"
  19#include "sysfs.h"
  20#include "volumes.h"
  21#include "space-info.h"
  22#include "block-group.h"
  23#include "qgroup.h"
  24#include "misc.h"
  25#include "fs.h"
  26#include "accessors.h"
  27
  28/*
  29 * Structure name                       Path
  30 * --------------------------------------------------------------------------
  31 * btrfs_supported_static_feature_attrs /sys/fs/btrfs/features
  32 * btrfs_supported_feature_attrs	/sys/fs/btrfs/features and
  33 *					/sys/fs/btrfs/<uuid>/features
  34 * btrfs_attrs				/sys/fs/btrfs/<uuid>
  35 * devid_attrs				/sys/fs/btrfs/<uuid>/devinfo/<devid>
  36 * allocation_attrs			/sys/fs/btrfs/<uuid>/allocation
  37 * qgroup_attrs				/sys/fs/btrfs/<uuid>/qgroups/<level>_<qgroupid>
  38 * space_info_attrs			/sys/fs/btrfs/<uuid>/allocation/<bg-type>
  39 * raid_attrs				/sys/fs/btrfs/<uuid>/allocation/<bg-type>/<bg-profile>
  40 * discard_attrs			/sys/fs/btrfs/<uuid>/discard
  41 *
  42 * When built with BTRFS_CONFIG_DEBUG:
  43 *
  44 * btrfs_debug_feature_attrs		/sys/fs/btrfs/debug
  45 * btrfs_debug_mount_attrs		/sys/fs/btrfs/<uuid>/debug
  46 */
  47
  48struct btrfs_feature_attr {
  49	struct kobj_attribute kobj_attr;
  50	enum btrfs_feature_set feature_set;
  51	u64 feature_bit;
  52};
  53
  54/* For raid type sysfs entries */
  55struct raid_kobject {
  56	u64 flags;
  57	struct kobject kobj;
  58};
  59
  60#define __INIT_KOBJ_ATTR(_name, _mode, _show, _store)			\
  61{									\
  62	.attr	= { .name = __stringify(_name), .mode = _mode },	\
  63	.show	= _show,						\
  64	.store	= _store,						\
  65}
  66
  67#define BTRFS_ATTR_W(_prefix, _name, _store)			        \
  68	static struct kobj_attribute btrfs_attr_##_prefix##_##_name =	\
  69			__INIT_KOBJ_ATTR(_name, 0200, NULL, _store)
  70
  71#define BTRFS_ATTR_RW(_prefix, _name, _show, _store)			\
  72	static struct kobj_attribute btrfs_attr_##_prefix##_##_name =	\
  73			__INIT_KOBJ_ATTR(_name, 0644, _show, _store)
  74
  75#define BTRFS_ATTR(_prefix, _name, _show)				\
  76	static struct kobj_attribute btrfs_attr_##_prefix##_##_name =	\
  77			__INIT_KOBJ_ATTR(_name, 0444, _show, NULL)
  78
  79#define BTRFS_ATTR_PTR(_prefix, _name)					\
  80	(&btrfs_attr_##_prefix##_##_name.attr)
  81
  82#define BTRFS_FEAT_ATTR(_name, _feature_set, _feature_prefix, _feature_bit)  \
  83static struct btrfs_feature_attr btrfs_attr_features_##_name = {	     \
  84	.kobj_attr = __INIT_KOBJ_ATTR(_name, S_IRUGO,			     \
  85				      btrfs_feature_attr_show,		     \
  86				      btrfs_feature_attr_store),	     \
  87	.feature_set	= _feature_set,					     \
  88	.feature_bit	= _feature_prefix ##_## _feature_bit,		     \
  89}
  90#define BTRFS_FEAT_ATTR_PTR(_name)					     \
  91	(&btrfs_attr_features_##_name.kobj_attr.attr)
  92
  93#define BTRFS_FEAT_ATTR_COMPAT(name, feature) \
  94	BTRFS_FEAT_ATTR(name, FEAT_COMPAT, BTRFS_FEATURE_COMPAT, feature)
  95#define BTRFS_FEAT_ATTR_COMPAT_RO(name, feature) \
  96	BTRFS_FEAT_ATTR(name, FEAT_COMPAT_RO, BTRFS_FEATURE_COMPAT_RO, feature)
  97#define BTRFS_FEAT_ATTR_INCOMPAT(name, feature) \
  98	BTRFS_FEAT_ATTR(name, FEAT_INCOMPAT, BTRFS_FEATURE_INCOMPAT, feature)
  99
 100static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj);
 101static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj);
 102static struct kobject *get_btrfs_kobj(struct kobject *kobj);
 103
 104static struct btrfs_feature_attr *to_btrfs_feature_attr(struct kobj_attribute *a)
 105{
 106	return container_of(a, struct btrfs_feature_attr, kobj_attr);
 107}
 108
 109static struct kobj_attribute *attr_to_btrfs_attr(struct attribute *attr)
 110{
 111	return container_of(attr, struct kobj_attribute, attr);
 112}
 113
 114static struct btrfs_feature_attr *attr_to_btrfs_feature_attr(
 115		struct attribute *attr)
 116{
 117	return to_btrfs_feature_attr(attr_to_btrfs_attr(attr));
 118}
 119
 120static u64 get_features(struct btrfs_fs_info *fs_info,
 121			enum btrfs_feature_set set)
 122{
 123	struct btrfs_super_block *disk_super = fs_info->super_copy;
 124	if (set == FEAT_COMPAT)
 125		return btrfs_super_compat_flags(disk_super);
 126	else if (set == FEAT_COMPAT_RO)
 127		return btrfs_super_compat_ro_flags(disk_super);
 128	else
 129		return btrfs_super_incompat_flags(disk_super);
 130}
 131
 132static void set_features(struct btrfs_fs_info *fs_info,
 133			 enum btrfs_feature_set set, u64 features)
 134{
 135	struct btrfs_super_block *disk_super = fs_info->super_copy;
 136	if (set == FEAT_COMPAT)
 137		btrfs_set_super_compat_flags(disk_super, features);
 138	else if (set == FEAT_COMPAT_RO)
 139		btrfs_set_super_compat_ro_flags(disk_super, features);
 140	else
 141		btrfs_set_super_incompat_flags(disk_super, features);
 142}
 143
 144static int can_modify_feature(struct btrfs_feature_attr *fa)
 145{
 146	int val = 0;
 147	u64 set, clear;
 148	switch (fa->feature_set) {
 149	case FEAT_COMPAT:
 150		set = BTRFS_FEATURE_COMPAT_SAFE_SET;
 151		clear = BTRFS_FEATURE_COMPAT_SAFE_CLEAR;
 152		break;
 153	case FEAT_COMPAT_RO:
 154		set = BTRFS_FEATURE_COMPAT_RO_SAFE_SET;
 155		clear = BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR;
 156		break;
 157	case FEAT_INCOMPAT:
 158		set = BTRFS_FEATURE_INCOMPAT_SAFE_SET;
 159		clear = BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR;
 160		break;
 161	default:
 162		pr_warn("btrfs: sysfs: unknown feature set %d\n",
 163				fa->feature_set);
 164		return 0;
 165	}
 166
 167	if (set & fa->feature_bit)
 168		val |= 1;
 169	if (clear & fa->feature_bit)
 170		val |= 2;
 171
 172	return val;
 173}
 174
 175static ssize_t btrfs_feature_attr_show(struct kobject *kobj,
 176				       struct kobj_attribute *a, char *buf)
 177{
 178	int val = 0;
 179	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 180	struct btrfs_feature_attr *fa = to_btrfs_feature_attr(a);
 181	if (fs_info) {
 182		u64 features = get_features(fs_info, fa->feature_set);
 183		if (features & fa->feature_bit)
 184			val = 1;
 185	} else
 186		val = can_modify_feature(fa);
 187
 188	return sysfs_emit(buf, "%d\n", val);
 189}
 190
 191static ssize_t btrfs_feature_attr_store(struct kobject *kobj,
 192					struct kobj_attribute *a,
 193					const char *buf, size_t count)
 194{
 195	struct btrfs_fs_info *fs_info;
 196	struct btrfs_feature_attr *fa = to_btrfs_feature_attr(a);
 197	u64 features, set, clear;
 198	unsigned long val;
 199	int ret;
 200
 201	fs_info = to_fs_info(kobj);
 202	if (!fs_info)
 203		return -EPERM;
 204
 205	if (sb_rdonly(fs_info->sb))
 206		return -EROFS;
 207
 208	ret = kstrtoul(skip_spaces(buf), 0, &val);
 209	if (ret)
 210		return ret;
 211
 212	if (fa->feature_set == FEAT_COMPAT) {
 213		set = BTRFS_FEATURE_COMPAT_SAFE_SET;
 214		clear = BTRFS_FEATURE_COMPAT_SAFE_CLEAR;
 215	} else if (fa->feature_set == FEAT_COMPAT_RO) {
 216		set = BTRFS_FEATURE_COMPAT_RO_SAFE_SET;
 217		clear = BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR;
 218	} else {
 219		set = BTRFS_FEATURE_INCOMPAT_SAFE_SET;
 220		clear = BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR;
 221	}
 222
 223	features = get_features(fs_info, fa->feature_set);
 224
 225	/* Nothing to do */
 226	if ((val && (features & fa->feature_bit)) ||
 227	    (!val && !(features & fa->feature_bit)))
 228		return count;
 229
 230	if ((val && !(set & fa->feature_bit)) ||
 231	    (!val && !(clear & fa->feature_bit))) {
 232		btrfs_info(fs_info,
 233			"%sabling feature %s on mounted fs is not supported.",
 234			val ? "En" : "Dis", fa->kobj_attr.attr.name);
 235		return -EPERM;
 236	}
 237
 238	btrfs_info(fs_info, "%s %s feature flag",
 239		   val ? "Setting" : "Clearing", fa->kobj_attr.attr.name);
 240
 241	spin_lock(&fs_info->super_lock);
 242	features = get_features(fs_info, fa->feature_set);
 243	if (val)
 244		features |= fa->feature_bit;
 245	else
 246		features &= ~fa->feature_bit;
 247	set_features(fs_info, fa->feature_set, features);
 248	spin_unlock(&fs_info->super_lock);
 249
 250	/*
 251	 * We don't want to do full transaction commit from inside sysfs
 252	 */
 253	set_bit(BTRFS_FS_NEED_TRANS_COMMIT, &fs_info->flags);
 254	wake_up_process(fs_info->transaction_kthread);
 255
 256	return count;
 257}
 258
 259static umode_t btrfs_feature_visible(struct kobject *kobj,
 260				     struct attribute *attr, int unused)
 261{
 262	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 263	umode_t mode = attr->mode;
 264
 265	if (fs_info) {
 266		struct btrfs_feature_attr *fa;
 267		u64 features;
 268
 269		fa = attr_to_btrfs_feature_attr(attr);
 270		features = get_features(fs_info, fa->feature_set);
 271
 272		if (can_modify_feature(fa))
 273			mode |= S_IWUSR;
 274		else if (!(features & fa->feature_bit))
 275			mode = 0;
 276	}
 277
 278	return mode;
 279}
 280
 281BTRFS_FEAT_ATTR_INCOMPAT(default_subvol, DEFAULT_SUBVOL);
 282BTRFS_FEAT_ATTR_INCOMPAT(mixed_groups, MIXED_GROUPS);
 283BTRFS_FEAT_ATTR_INCOMPAT(compress_lzo, COMPRESS_LZO);
 284BTRFS_FEAT_ATTR_INCOMPAT(compress_zstd, COMPRESS_ZSTD);
 285BTRFS_FEAT_ATTR_INCOMPAT(extended_iref, EXTENDED_IREF);
 286BTRFS_FEAT_ATTR_INCOMPAT(raid56, RAID56);
 287BTRFS_FEAT_ATTR_INCOMPAT(skinny_metadata, SKINNY_METADATA);
 288BTRFS_FEAT_ATTR_INCOMPAT(no_holes, NO_HOLES);
 289BTRFS_FEAT_ATTR_INCOMPAT(metadata_uuid, METADATA_UUID);
 290BTRFS_FEAT_ATTR_COMPAT_RO(free_space_tree, FREE_SPACE_TREE);
 291BTRFS_FEAT_ATTR_COMPAT_RO(block_group_tree, BLOCK_GROUP_TREE);
 292BTRFS_FEAT_ATTR_INCOMPAT(raid1c34, RAID1C34);
 293#ifdef CONFIG_BLK_DEV_ZONED
 294BTRFS_FEAT_ATTR_INCOMPAT(zoned, ZONED);
 295#endif
 296#ifdef CONFIG_BTRFS_DEBUG
 297/* Remove once support for extent tree v2 is feature complete */
 298BTRFS_FEAT_ATTR_INCOMPAT(extent_tree_v2, EXTENT_TREE_V2);
 299#endif
 300#ifdef CONFIG_FS_VERITY
 301BTRFS_FEAT_ATTR_COMPAT_RO(verity, VERITY);
 302#endif
 303
 304/*
 305 * Features which depend on feature bits and may differ between each fs.
 306 *
 307 * /sys/fs/btrfs/features      - all available features implemented by this version
 308 * /sys/fs/btrfs/UUID/features - features of the fs which are enabled or
 309 *                               can be changed on a mounted filesystem.
 310 */
 311static struct attribute *btrfs_supported_feature_attrs[] = {
 312	BTRFS_FEAT_ATTR_PTR(default_subvol),
 313	BTRFS_FEAT_ATTR_PTR(mixed_groups),
 314	BTRFS_FEAT_ATTR_PTR(compress_lzo),
 315	BTRFS_FEAT_ATTR_PTR(compress_zstd),
 316	BTRFS_FEAT_ATTR_PTR(extended_iref),
 317	BTRFS_FEAT_ATTR_PTR(raid56),
 318	BTRFS_FEAT_ATTR_PTR(skinny_metadata),
 319	BTRFS_FEAT_ATTR_PTR(no_holes),
 320	BTRFS_FEAT_ATTR_PTR(metadata_uuid),
 321	BTRFS_FEAT_ATTR_PTR(free_space_tree),
 322	BTRFS_FEAT_ATTR_PTR(raid1c34),
 323	BTRFS_FEAT_ATTR_PTR(block_group_tree),
 324#ifdef CONFIG_BLK_DEV_ZONED
 325	BTRFS_FEAT_ATTR_PTR(zoned),
 326#endif
 327#ifdef CONFIG_BTRFS_DEBUG
 328	BTRFS_FEAT_ATTR_PTR(extent_tree_v2),
 329#endif
 330#ifdef CONFIG_FS_VERITY
 331	BTRFS_FEAT_ATTR_PTR(verity),
 332#endif
 333	NULL
 334};
 335
 336static const struct attribute_group btrfs_feature_attr_group = {
 337	.name = "features",
 338	.is_visible = btrfs_feature_visible,
 339	.attrs = btrfs_supported_feature_attrs,
 340};
 341
 342static ssize_t rmdir_subvol_show(struct kobject *kobj,
 343				 struct kobj_attribute *ka, char *buf)
 344{
 345	return sysfs_emit(buf, "0\n");
 346}
 347BTRFS_ATTR(static_feature, rmdir_subvol, rmdir_subvol_show);
 348
 349static ssize_t supported_checksums_show(struct kobject *kobj,
 350					struct kobj_attribute *a, char *buf)
 351{
 352	ssize_t ret = 0;
 353	int i;
 354
 355	for (i = 0; i < btrfs_get_num_csums(); i++) {
 356		/*
 357		 * This "trick" only works as long as 'enum btrfs_csum_type' has
 358		 * no holes in it
 359		 */
 360		ret += sysfs_emit_at(buf, ret, "%s%s", (i == 0 ? "" : " "),
 361				     btrfs_super_csum_name(i));
 362
 363	}
 364
 365	ret += sysfs_emit_at(buf, ret, "\n");
 366	return ret;
 367}
 368BTRFS_ATTR(static_feature, supported_checksums, supported_checksums_show);
 369
 370static ssize_t send_stream_version_show(struct kobject *kobj,
 371					struct kobj_attribute *ka, char *buf)
 372{
 373	return sysfs_emit(buf, "%d\n", BTRFS_SEND_STREAM_VERSION);
 374}
 375BTRFS_ATTR(static_feature, send_stream_version, send_stream_version_show);
 376
 377static const char *rescue_opts[] = {
 378	"usebackuproot",
 379	"nologreplay",
 380	"ignorebadroots",
 381	"ignoredatacsums",
 382	"all",
 383};
 384
 385static ssize_t supported_rescue_options_show(struct kobject *kobj,
 386					     struct kobj_attribute *a,
 387					     char *buf)
 388{
 389	ssize_t ret = 0;
 390	int i;
 391
 392	for (i = 0; i < ARRAY_SIZE(rescue_opts); i++)
 393		ret += sysfs_emit_at(buf, ret, "%s%s", (i ? " " : ""), rescue_opts[i]);
 394	ret += sysfs_emit_at(buf, ret, "\n");
 395	return ret;
 396}
 397BTRFS_ATTR(static_feature, supported_rescue_options,
 398	   supported_rescue_options_show);
 399
 400static ssize_t supported_sectorsizes_show(struct kobject *kobj,
 401					  struct kobj_attribute *a,
 402					  char *buf)
 403{
 404	ssize_t ret = 0;
 405
 406	/* An artificial limit to only support 4K and PAGE_SIZE */
 407	if (PAGE_SIZE > SZ_4K)
 408		ret += sysfs_emit_at(buf, ret, "%u ", SZ_4K);
 409	ret += sysfs_emit_at(buf, ret, "%lu\n", PAGE_SIZE);
 410
 411	return ret;
 412}
 413BTRFS_ATTR(static_feature, supported_sectorsizes,
 414	   supported_sectorsizes_show);
 415
 416/*
 417 * Features which only depend on kernel version.
 418 *
 419 * These are listed in /sys/fs/btrfs/features along with
 420 * btrfs_supported_feature_attrs.
 421 */
 422static struct attribute *btrfs_supported_static_feature_attrs[] = {
 423	BTRFS_ATTR_PTR(static_feature, rmdir_subvol),
 424	BTRFS_ATTR_PTR(static_feature, supported_checksums),
 425	BTRFS_ATTR_PTR(static_feature, send_stream_version),
 426	BTRFS_ATTR_PTR(static_feature, supported_rescue_options),
 427	BTRFS_ATTR_PTR(static_feature, supported_sectorsizes),
 428	NULL
 429};
 430
 431static const struct attribute_group btrfs_static_feature_attr_group = {
 432	.name = "features",
 433	.attrs = btrfs_supported_static_feature_attrs,
 434};
 435
 436/*
 437 * Discard statistics and tunables
 438 */
 439#define discard_to_fs_info(_kobj)	to_fs_info(get_btrfs_kobj(_kobj))
 440
 441static ssize_t btrfs_discardable_bytes_show(struct kobject *kobj,
 442					    struct kobj_attribute *a,
 443					    char *buf)
 444{
 445	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 446
 447	return sysfs_emit(buf, "%lld\n",
 448			atomic64_read(&fs_info->discard_ctl.discardable_bytes));
 449}
 450BTRFS_ATTR(discard, discardable_bytes, btrfs_discardable_bytes_show);
 451
 452static ssize_t btrfs_discardable_extents_show(struct kobject *kobj,
 453					      struct kobj_attribute *a,
 454					      char *buf)
 455{
 456	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 457
 458	return sysfs_emit(buf, "%d\n",
 459			atomic_read(&fs_info->discard_ctl.discardable_extents));
 460}
 461BTRFS_ATTR(discard, discardable_extents, btrfs_discardable_extents_show);
 462
 463static ssize_t btrfs_discard_bitmap_bytes_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 sysfs_emit(buf, "%llu\n",
 470			  fs_info->discard_ctl.discard_bitmap_bytes);
 471}
 472BTRFS_ATTR(discard, discard_bitmap_bytes, btrfs_discard_bitmap_bytes_show);
 473
 474static ssize_t btrfs_discard_bytes_saved_show(struct kobject *kobj,
 475					      struct kobj_attribute *a,
 476					      char *buf)
 477{
 478	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 479
 480	return sysfs_emit(buf, "%lld\n",
 481		atomic64_read(&fs_info->discard_ctl.discard_bytes_saved));
 482}
 483BTRFS_ATTR(discard, discard_bytes_saved, btrfs_discard_bytes_saved_show);
 484
 485static ssize_t btrfs_discard_extent_bytes_show(struct kobject *kobj,
 486					       struct kobj_attribute *a,
 487					       char *buf)
 488{
 489	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 490
 491	return sysfs_emit(buf, "%llu\n",
 492			  fs_info->discard_ctl.discard_extent_bytes);
 493}
 494BTRFS_ATTR(discard, discard_extent_bytes, btrfs_discard_extent_bytes_show);
 495
 496static ssize_t btrfs_discard_iops_limit_show(struct kobject *kobj,
 497					     struct kobj_attribute *a,
 498					     char *buf)
 499{
 500	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 501
 502	return sysfs_emit(buf, "%u\n",
 503			  READ_ONCE(fs_info->discard_ctl.iops_limit));
 504}
 505
 506static ssize_t btrfs_discard_iops_limit_store(struct kobject *kobj,
 507					      struct kobj_attribute *a,
 508					      const char *buf, size_t len)
 509{
 510	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 511	struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
 512	u32 iops_limit;
 513	int ret;
 514
 515	ret = kstrtou32(buf, 10, &iops_limit);
 516	if (ret)
 517		return -EINVAL;
 518
 519	WRITE_ONCE(discard_ctl->iops_limit, iops_limit);
 520	btrfs_discard_calc_delay(discard_ctl);
 521	btrfs_discard_schedule_work(discard_ctl, true);
 522	return len;
 523}
 524BTRFS_ATTR_RW(discard, iops_limit, btrfs_discard_iops_limit_show,
 525	      btrfs_discard_iops_limit_store);
 526
 527static ssize_t btrfs_discard_kbps_limit_show(struct kobject *kobj,
 528					     struct kobj_attribute *a,
 529					     char *buf)
 530{
 531	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 532
 533	return sysfs_emit(buf, "%u\n",
 534			  READ_ONCE(fs_info->discard_ctl.kbps_limit));
 535}
 536
 537static ssize_t btrfs_discard_kbps_limit_store(struct kobject *kobj,
 538					      struct kobj_attribute *a,
 539					      const char *buf, size_t len)
 540{
 541	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 542	struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
 543	u32 kbps_limit;
 544	int ret;
 545
 546	ret = kstrtou32(buf, 10, &kbps_limit);
 547	if (ret)
 548		return -EINVAL;
 549
 550	WRITE_ONCE(discard_ctl->kbps_limit, kbps_limit);
 551	btrfs_discard_schedule_work(discard_ctl, true);
 552	return len;
 553}
 554BTRFS_ATTR_RW(discard, kbps_limit, btrfs_discard_kbps_limit_show,
 555	      btrfs_discard_kbps_limit_store);
 556
 557static ssize_t btrfs_discard_max_discard_size_show(struct kobject *kobj,
 558						   struct kobj_attribute *a,
 559						   char *buf)
 560{
 561	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 562
 563	return sysfs_emit(buf, "%llu\n",
 564			  READ_ONCE(fs_info->discard_ctl.max_discard_size));
 565}
 566
 567static ssize_t btrfs_discard_max_discard_size_store(struct kobject *kobj,
 568						    struct kobj_attribute *a,
 569						    const char *buf, size_t len)
 570{
 571	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 572	struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
 573	u64 max_discard_size;
 574	int ret;
 575
 576	ret = kstrtou64(buf, 10, &max_discard_size);
 577	if (ret)
 578		return -EINVAL;
 579
 580	WRITE_ONCE(discard_ctl->max_discard_size, max_discard_size);
 581
 582	return len;
 583}
 584BTRFS_ATTR_RW(discard, max_discard_size, btrfs_discard_max_discard_size_show,
 585	      btrfs_discard_max_discard_size_store);
 586
 587/*
 588 * Per-filesystem stats for discard (when mounted with discard=async).
 589 *
 590 * Path: /sys/fs/btrfs/<uuid>/discard/
 591 */
 592static const struct attribute *discard_attrs[] = {
 593	BTRFS_ATTR_PTR(discard, discardable_bytes),
 594	BTRFS_ATTR_PTR(discard, discardable_extents),
 595	BTRFS_ATTR_PTR(discard, discard_bitmap_bytes),
 596	BTRFS_ATTR_PTR(discard, discard_bytes_saved),
 597	BTRFS_ATTR_PTR(discard, discard_extent_bytes),
 598	BTRFS_ATTR_PTR(discard, iops_limit),
 599	BTRFS_ATTR_PTR(discard, kbps_limit),
 600	BTRFS_ATTR_PTR(discard, max_discard_size),
 601	NULL,
 602};
 603
 604#ifdef CONFIG_BTRFS_DEBUG
 605
 606/*
 607 * Per-filesystem runtime debugging exported via sysfs.
 608 *
 609 * Path: /sys/fs/btrfs/UUID/debug/
 610 */
 611static const struct attribute *btrfs_debug_mount_attrs[] = {
 612	NULL,
 613};
 614
 615/*
 616 * Runtime debugging exported via sysfs, applies to all mounted filesystems.
 617 *
 618 * Path: /sys/fs/btrfs/debug
 619 */
 620static struct attribute *btrfs_debug_feature_attrs[] = {
 621	NULL
 622};
 623
 624static const struct attribute_group btrfs_debug_feature_attr_group = {
 625	.name = "debug",
 626	.attrs = btrfs_debug_feature_attrs,
 627};
 628
 629#endif
 630
 631static ssize_t btrfs_show_u64(u64 *value_ptr, spinlock_t *lock, char *buf)
 632{
 633	u64 val;
 634	if (lock)
 635		spin_lock(lock);
 636	val = *value_ptr;
 637	if (lock)
 638		spin_unlock(lock);
 639	return sysfs_emit(buf, "%llu\n", val);
 640}
 641
 642static ssize_t global_rsv_size_show(struct kobject *kobj,
 643				    struct kobj_attribute *ka, char *buf)
 644{
 645	struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent);
 646	struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
 647	return btrfs_show_u64(&block_rsv->size, &block_rsv->lock, buf);
 648}
 649BTRFS_ATTR(allocation, global_rsv_size, global_rsv_size_show);
 650
 651static ssize_t global_rsv_reserved_show(struct kobject *kobj,
 652					struct kobj_attribute *a, char *buf)
 653{
 654	struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent);
 655	struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
 656	return btrfs_show_u64(&block_rsv->reserved, &block_rsv->lock, buf);
 657}
 658BTRFS_ATTR(allocation, global_rsv_reserved, global_rsv_reserved_show);
 659
 660#define to_space_info(_kobj) container_of(_kobj, struct btrfs_space_info, kobj)
 661#define to_raid_kobj(_kobj) container_of(_kobj, struct raid_kobject, kobj)
 662
 663static ssize_t raid_bytes_show(struct kobject *kobj,
 664			       struct kobj_attribute *attr, char *buf);
 665BTRFS_ATTR(raid, total_bytes, raid_bytes_show);
 666BTRFS_ATTR(raid, used_bytes, raid_bytes_show);
 667
 668static ssize_t raid_bytes_show(struct kobject *kobj,
 669			       struct kobj_attribute *attr, char *buf)
 670
 671{
 672	struct btrfs_space_info *sinfo = to_space_info(kobj->parent);
 673	struct btrfs_block_group *block_group;
 674	int index = btrfs_bg_flags_to_raid_index(to_raid_kobj(kobj)->flags);
 675	u64 val = 0;
 676
 677	down_read(&sinfo->groups_sem);
 678	list_for_each_entry(block_group, &sinfo->block_groups[index], list) {
 679		if (&attr->attr == BTRFS_ATTR_PTR(raid, total_bytes))
 680			val += block_group->length;
 681		else
 682			val += block_group->used;
 683	}
 684	up_read(&sinfo->groups_sem);
 685	return sysfs_emit(buf, "%llu\n", val);
 686}
 687
 688/*
 689 * Allocation information about block group profiles.
 690 *
 691 * Path: /sys/fs/btrfs/<uuid>/allocation/<bg-type>/<bg-profile>/
 692 */
 693static struct attribute *raid_attrs[] = {
 694	BTRFS_ATTR_PTR(raid, total_bytes),
 695	BTRFS_ATTR_PTR(raid, used_bytes),
 696	NULL
 697};
 698ATTRIBUTE_GROUPS(raid);
 699
 700static void release_raid_kobj(struct kobject *kobj)
 701{
 702	kfree(to_raid_kobj(kobj));
 703}
 704
 705static struct kobj_type btrfs_raid_ktype = {
 706	.sysfs_ops = &kobj_sysfs_ops,
 707	.release = release_raid_kobj,
 708	.default_groups = raid_groups,
 709};
 710
 711#define SPACE_INFO_ATTR(field)						\
 712static ssize_t btrfs_space_info_show_##field(struct kobject *kobj,	\
 713					     struct kobj_attribute *a,	\
 714					     char *buf)			\
 715{									\
 716	struct btrfs_space_info *sinfo = to_space_info(kobj);		\
 717	return btrfs_show_u64(&sinfo->field, &sinfo->lock, buf);	\
 718}									\
 719BTRFS_ATTR(space_info, field, btrfs_space_info_show_##field)
 720
 721static ssize_t btrfs_chunk_size_show(struct kobject *kobj,
 722				     struct kobj_attribute *a, char *buf)
 723{
 724	struct btrfs_space_info *sinfo = to_space_info(kobj);
 725
 726	return sysfs_emit(buf, "%llu\n", READ_ONCE(sinfo->chunk_size));
 727}
 728
 729/*
 730 * Store new chunk size in space info. Can be called on a read-only filesystem.
 731 *
 732 * If the new chunk size value is larger than 10% of free space it is reduced
 733 * to match that limit. Alignment must be to 256M and the system chunk size
 734 * cannot be set.
 735 */
 736static ssize_t btrfs_chunk_size_store(struct kobject *kobj,
 737				      struct kobj_attribute *a,
 738				      const char *buf, size_t len)
 739{
 740	struct btrfs_space_info *space_info = to_space_info(kobj);
 741	struct btrfs_fs_info *fs_info = to_fs_info(get_btrfs_kobj(kobj));
 742	char *retptr;
 743	u64 val;
 744
 745	if (!capable(CAP_SYS_ADMIN))
 746		return -EPERM;
 747
 748	if (!fs_info->fs_devices)
 749		return -EINVAL;
 750
 751	if (btrfs_is_zoned(fs_info))
 752		return -EINVAL;
 753
 754	/* System block type must not be changed. */
 755	if (space_info->flags & BTRFS_BLOCK_GROUP_SYSTEM)
 756		return -EPERM;
 757
 758	val = memparse(buf, &retptr);
 759	/* There could be trailing '\n', also catch any typos after the value */
 760	retptr = skip_spaces(retptr);
 761	if (*retptr != 0 || val == 0)
 762		return -EINVAL;
 763
 764	val = min(val, BTRFS_MAX_DATA_CHUNK_SIZE);
 765
 766	/* Limit stripe size to 10% of available space. */
 767	val = min(mult_perc(fs_info->fs_devices->total_rw_bytes, 10), val);
 768
 769	/* Must be multiple of 256M. */
 770	val &= ~((u64)SZ_256M - 1);
 771
 772	/* Must be at least 256M. */
 773	if (val < SZ_256M)
 774		return -EINVAL;
 775
 776	btrfs_update_space_info_chunk_size(space_info, val);
 777
 778	return len;
 779}
 780
 781#ifdef CONFIG_BTRFS_DEBUG
 782/*
 783 * Request chunk allocation with current chunk size.
 784 */
 785static ssize_t btrfs_force_chunk_alloc_store(struct kobject *kobj,
 786					     struct kobj_attribute *a,
 787					     const char *buf, size_t len)
 788{
 789	struct btrfs_space_info *space_info = to_space_info(kobj);
 790	struct btrfs_fs_info *fs_info = to_fs_info(get_btrfs_kobj(kobj));
 791	struct btrfs_trans_handle *trans;
 792	bool val;
 793	int ret;
 794
 795	if (!capable(CAP_SYS_ADMIN))
 796		return -EPERM;
 797
 798	if (sb_rdonly(fs_info->sb))
 799		return -EROFS;
 800
 801	ret = kstrtobool(buf, &val);
 802	if (ret)
 803		return ret;
 804
 805	if (!val)
 806		return -EINVAL;
 807
 808	/*
 809	 * This is unsafe to be called from sysfs context and may cause
 810	 * unexpected problems.
 811	 */
 812	trans = btrfs_start_transaction(fs_info->tree_root, 0);
 813	if (IS_ERR(trans))
 814		return PTR_ERR(trans);
 815	ret = btrfs_force_chunk_alloc(trans, space_info->flags);
 816	btrfs_end_transaction(trans);
 817
 818	if (ret == 1)
 819		return len;
 820
 821	return -ENOSPC;
 822}
 823BTRFS_ATTR_W(space_info, force_chunk_alloc, btrfs_force_chunk_alloc_store);
 824
 825#endif
 826
 827SPACE_INFO_ATTR(flags);
 828SPACE_INFO_ATTR(total_bytes);
 829SPACE_INFO_ATTR(bytes_used);
 830SPACE_INFO_ATTR(bytes_pinned);
 831SPACE_INFO_ATTR(bytes_reserved);
 832SPACE_INFO_ATTR(bytes_may_use);
 833SPACE_INFO_ATTR(bytes_readonly);
 834SPACE_INFO_ATTR(bytes_zone_unusable);
 835SPACE_INFO_ATTR(disk_used);
 836SPACE_INFO_ATTR(disk_total);
 837BTRFS_ATTR_RW(space_info, chunk_size, btrfs_chunk_size_show, btrfs_chunk_size_store);
 838
 839static ssize_t btrfs_sinfo_bg_reclaim_threshold_show(struct kobject *kobj,
 840						     struct kobj_attribute *a,
 841						     char *buf)
 842{
 843	struct btrfs_space_info *space_info = to_space_info(kobj);
 844
 845	return sysfs_emit(buf, "%d\n", READ_ONCE(space_info->bg_reclaim_threshold));
 846}
 847
 848static ssize_t btrfs_sinfo_bg_reclaim_threshold_store(struct kobject *kobj,
 849						      struct kobj_attribute *a,
 850						      const char *buf, size_t len)
 851{
 852	struct btrfs_space_info *space_info = to_space_info(kobj);
 853	int thresh;
 854	int ret;
 855
 856	ret = kstrtoint(buf, 10, &thresh);
 857	if (ret)
 858		return ret;
 859
 860	if (thresh < 0 || thresh > 100)
 861		return -EINVAL;
 862
 863	WRITE_ONCE(space_info->bg_reclaim_threshold, thresh);
 864
 865	return len;
 866}
 867
 868BTRFS_ATTR_RW(space_info, bg_reclaim_threshold,
 869	      btrfs_sinfo_bg_reclaim_threshold_show,
 870	      btrfs_sinfo_bg_reclaim_threshold_store);
 871
 872/*
 873 * Allocation information about block group types.
 874 *
 875 * Path: /sys/fs/btrfs/<uuid>/allocation/<bg-type>/
 876 */
 877static struct attribute *space_info_attrs[] = {
 878	BTRFS_ATTR_PTR(space_info, flags),
 879	BTRFS_ATTR_PTR(space_info, total_bytes),
 880	BTRFS_ATTR_PTR(space_info, bytes_used),
 881	BTRFS_ATTR_PTR(space_info, bytes_pinned),
 882	BTRFS_ATTR_PTR(space_info, bytes_reserved),
 883	BTRFS_ATTR_PTR(space_info, bytes_may_use),
 884	BTRFS_ATTR_PTR(space_info, bytes_readonly),
 885	BTRFS_ATTR_PTR(space_info, bytes_zone_unusable),
 886	BTRFS_ATTR_PTR(space_info, disk_used),
 887	BTRFS_ATTR_PTR(space_info, disk_total),
 888	BTRFS_ATTR_PTR(space_info, bg_reclaim_threshold),
 889	BTRFS_ATTR_PTR(space_info, chunk_size),
 890#ifdef CONFIG_BTRFS_DEBUG
 891	BTRFS_ATTR_PTR(space_info, force_chunk_alloc),
 892#endif
 893	NULL,
 894};
 895ATTRIBUTE_GROUPS(space_info);
 896
 897static void space_info_release(struct kobject *kobj)
 898{
 899	struct btrfs_space_info *sinfo = to_space_info(kobj);
 900	kfree(sinfo);
 901}
 902
 903static struct kobj_type space_info_ktype = {
 904	.sysfs_ops = &kobj_sysfs_ops,
 905	.release = space_info_release,
 906	.default_groups = space_info_groups,
 907};
 908
 909/*
 910 * Allocation information about block groups.
 911 *
 912 * Path: /sys/fs/btrfs/<uuid>/allocation/
 913 */
 914static const struct attribute *allocation_attrs[] = {
 915	BTRFS_ATTR_PTR(allocation, global_rsv_reserved),
 916	BTRFS_ATTR_PTR(allocation, global_rsv_size),
 917	NULL,
 918};
 919
 920static ssize_t btrfs_label_show(struct kobject *kobj,
 921				struct kobj_attribute *a, char *buf)
 922{
 923	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 924	char *label = fs_info->super_copy->label;
 925	ssize_t ret;
 926
 927	spin_lock(&fs_info->super_lock);
 928	ret = sysfs_emit(buf, label[0] ? "%s\n" : "%s", label);
 929	spin_unlock(&fs_info->super_lock);
 930
 931	return ret;
 932}
 933
 934static ssize_t btrfs_label_store(struct kobject *kobj,
 935				 struct kobj_attribute *a,
 936				 const char *buf, size_t len)
 937{
 938	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 939	size_t p_len;
 940
 941	if (!fs_info)
 942		return -EPERM;
 943
 944	if (sb_rdonly(fs_info->sb))
 945		return -EROFS;
 946
 947	/*
 948	 * p_len is the len until the first occurrence of either
 949	 * '\n' or '\0'
 950	 */
 951	p_len = strcspn(buf, "\n");
 952
 953	if (p_len >= BTRFS_LABEL_SIZE)
 954		return -EINVAL;
 955
 956	spin_lock(&fs_info->super_lock);
 957	memset(fs_info->super_copy->label, 0, BTRFS_LABEL_SIZE);
 958	memcpy(fs_info->super_copy->label, buf, p_len);
 959	spin_unlock(&fs_info->super_lock);
 960
 961	/*
 962	 * We don't want to do full transaction commit from inside sysfs
 963	 */
 964	set_bit(BTRFS_FS_NEED_TRANS_COMMIT, &fs_info->flags);
 965	wake_up_process(fs_info->transaction_kthread);
 966
 967	return len;
 968}
 969BTRFS_ATTR_RW(, label, btrfs_label_show, btrfs_label_store);
 970
 971static ssize_t btrfs_nodesize_show(struct kobject *kobj,
 972				struct kobj_attribute *a, char *buf)
 973{
 974	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 975
 976	return sysfs_emit(buf, "%u\n", fs_info->super_copy->nodesize);
 977}
 978
 979BTRFS_ATTR(, nodesize, btrfs_nodesize_show);
 980
 981static ssize_t btrfs_sectorsize_show(struct kobject *kobj,
 982				struct kobj_attribute *a, char *buf)
 983{
 984	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 985
 986	return sysfs_emit(buf, "%u\n", fs_info->super_copy->sectorsize);
 987}
 988
 989BTRFS_ATTR(, sectorsize, btrfs_sectorsize_show);
 990
 991static ssize_t btrfs_commit_stats_show(struct kobject *kobj,
 992				       struct kobj_attribute *a, char *buf)
 993{
 994	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 995
 996	return sysfs_emit(buf,
 997		"commits %llu\n"
 998		"last_commit_ms %llu\n"
 999		"max_commit_ms %llu\n"
1000		"total_commit_ms %llu\n",
1001		fs_info->commit_stats.commit_count,
1002		div_u64(fs_info->commit_stats.last_commit_dur, NSEC_PER_MSEC),
1003		div_u64(fs_info->commit_stats.max_commit_dur, NSEC_PER_MSEC),
1004		div_u64(fs_info->commit_stats.total_commit_dur, NSEC_PER_MSEC));
1005}
1006
1007static ssize_t btrfs_commit_stats_store(struct kobject *kobj,
1008					struct kobj_attribute *a,
1009					const char *buf, size_t len)
1010{
1011	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1012	unsigned long val;
1013	int ret;
1014
1015	if (!fs_info)
1016		return -EPERM;
1017
1018	if (!capable(CAP_SYS_RESOURCE))
1019		return -EPERM;
1020
1021	ret = kstrtoul(buf, 10, &val);
1022	if (ret)
1023		return ret;
1024	if (val)
1025		return -EINVAL;
1026
1027	WRITE_ONCE(fs_info->commit_stats.max_commit_dur, 0);
1028
1029	return len;
1030}
1031BTRFS_ATTR_RW(, commit_stats, btrfs_commit_stats_show, btrfs_commit_stats_store);
1032
1033static ssize_t btrfs_clone_alignment_show(struct kobject *kobj,
1034				struct kobj_attribute *a, char *buf)
1035{
1036	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1037
1038	return sysfs_emit(buf, "%u\n", fs_info->super_copy->sectorsize);
1039}
1040
1041BTRFS_ATTR(, clone_alignment, btrfs_clone_alignment_show);
1042
1043static ssize_t quota_override_show(struct kobject *kobj,
1044				   struct kobj_attribute *a, char *buf)
1045{
1046	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1047	int quota_override;
1048
1049	quota_override = test_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
1050	return sysfs_emit(buf, "%d\n", quota_override);
1051}
1052
1053static ssize_t quota_override_store(struct kobject *kobj,
1054				    struct kobj_attribute *a,
1055				    const char *buf, size_t len)
1056{
1057	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1058	unsigned long knob;
1059	int err;
1060
1061	if (!fs_info)
1062		return -EPERM;
1063
1064	if (!capable(CAP_SYS_RESOURCE))
1065		return -EPERM;
1066
1067	err = kstrtoul(buf, 10, &knob);
1068	if (err)
1069		return err;
1070	if (knob > 1)
1071		return -EINVAL;
1072
1073	if (knob)
1074		set_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
1075	else
1076		clear_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
1077
1078	return len;
1079}
1080
1081BTRFS_ATTR_RW(, quota_override, quota_override_show, quota_override_store);
1082
1083static ssize_t btrfs_metadata_uuid_show(struct kobject *kobj,
1084				struct kobj_attribute *a, char *buf)
1085{
1086	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1087
1088	return sysfs_emit(buf, "%pU\n", fs_info->fs_devices->metadata_uuid);
1089}
1090
1091BTRFS_ATTR(, metadata_uuid, btrfs_metadata_uuid_show);
1092
1093static ssize_t btrfs_checksum_show(struct kobject *kobj,
1094				   struct kobj_attribute *a, char *buf)
1095{
1096	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1097	u16 csum_type = btrfs_super_csum_type(fs_info->super_copy);
1098
1099	return sysfs_emit(buf, "%s (%s)\n",
1100			  btrfs_super_csum_name(csum_type),
1101			  crypto_shash_driver_name(fs_info->csum_shash));
1102}
1103
1104BTRFS_ATTR(, checksum, btrfs_checksum_show);
1105
1106static ssize_t btrfs_exclusive_operation_show(struct kobject *kobj,
1107		struct kobj_attribute *a, char *buf)
1108{
1109	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1110	const char *str;
1111
1112	switch (READ_ONCE(fs_info->exclusive_operation)) {
1113		case  BTRFS_EXCLOP_NONE:
1114			str = "none\n";
1115			break;
1116		case BTRFS_EXCLOP_BALANCE:
1117			str = "balance\n";
1118			break;
1119		case BTRFS_EXCLOP_BALANCE_PAUSED:
1120			str = "balance paused\n";
1121			break;
1122		case BTRFS_EXCLOP_DEV_ADD:
1123			str = "device add\n";
1124			break;
1125		case BTRFS_EXCLOP_DEV_REMOVE:
1126			str = "device remove\n";
1127			break;
1128		case BTRFS_EXCLOP_DEV_REPLACE:
1129			str = "device replace\n";
1130			break;
1131		case BTRFS_EXCLOP_RESIZE:
1132			str = "resize\n";
1133			break;
1134		case BTRFS_EXCLOP_SWAP_ACTIVATE:
1135			str = "swap activate\n";
1136			break;
1137		default:
1138			str = "UNKNOWN\n";
1139			break;
1140	}
1141	return sysfs_emit(buf, "%s", str);
1142}
1143BTRFS_ATTR(, exclusive_operation, btrfs_exclusive_operation_show);
1144
1145static ssize_t btrfs_generation_show(struct kobject *kobj,
1146				     struct kobj_attribute *a, char *buf)
1147{
1148	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1149
1150	return sysfs_emit(buf, "%llu\n", fs_info->generation);
1151}
1152BTRFS_ATTR(, generation, btrfs_generation_show);
1153
1154static const char * const btrfs_read_policy_name[] = { "pid" };
1155
1156static ssize_t btrfs_read_policy_show(struct kobject *kobj,
1157				      struct kobj_attribute *a, char *buf)
1158{
1159	struct btrfs_fs_devices *fs_devices = to_fs_devs(kobj);
1160	ssize_t ret = 0;
1161	int i;
1162
1163	for (i = 0; i < BTRFS_NR_READ_POLICY; i++) {
1164		if (fs_devices->read_policy == i)
1165			ret += sysfs_emit_at(buf, ret, "%s[%s]",
1166					 (ret == 0 ? "" : " "),
1167					 btrfs_read_policy_name[i]);
1168		else
1169			ret += sysfs_emit_at(buf, ret, "%s%s",
1170					 (ret == 0 ? "" : " "),
1171					 btrfs_read_policy_name[i]);
1172	}
1173
1174	ret += sysfs_emit_at(buf, ret, "\n");
1175
1176	return ret;
1177}
1178
1179static ssize_t btrfs_read_policy_store(struct kobject *kobj,
1180				       struct kobj_attribute *a,
1181				       const char *buf, size_t len)
1182{
1183	struct btrfs_fs_devices *fs_devices = to_fs_devs(kobj);
1184	int i;
1185
1186	for (i = 0; i < BTRFS_NR_READ_POLICY; i++) {
1187		if (sysfs_streq(buf, btrfs_read_policy_name[i])) {
1188			if (i != fs_devices->read_policy) {
1189				fs_devices->read_policy = i;
1190				btrfs_info(fs_devices->fs_info,
1191					   "read policy set to '%s'",
1192					   btrfs_read_policy_name[i]);
1193			}
1194			return len;
1195		}
1196	}
1197
1198	return -EINVAL;
1199}
1200BTRFS_ATTR_RW(, read_policy, btrfs_read_policy_show, btrfs_read_policy_store);
1201
1202static ssize_t btrfs_bg_reclaim_threshold_show(struct kobject *kobj,
1203					       struct kobj_attribute *a,
1204					       char *buf)
1205{
1206	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1207
1208	return sysfs_emit(buf, "%d\n", READ_ONCE(fs_info->bg_reclaim_threshold));
1209}
1210
1211static ssize_t btrfs_bg_reclaim_threshold_store(struct kobject *kobj,
1212						struct kobj_attribute *a,
1213						const char *buf, size_t len)
1214{
1215	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1216	int thresh;
1217	int ret;
1218
1219	ret = kstrtoint(buf, 10, &thresh);
1220	if (ret)
1221		return ret;
1222
1223	if (thresh != 0 && (thresh <= 50 || thresh > 100))
1224		return -EINVAL;
1225
1226	WRITE_ONCE(fs_info->bg_reclaim_threshold, thresh);
1227
1228	return len;
1229}
1230BTRFS_ATTR_RW(, bg_reclaim_threshold, btrfs_bg_reclaim_threshold_show,
1231	      btrfs_bg_reclaim_threshold_store);
1232
1233/*
1234 * Per-filesystem information and stats.
1235 *
1236 * Path: /sys/fs/btrfs/<uuid>/
1237 */
1238static const struct attribute *btrfs_attrs[] = {
1239	BTRFS_ATTR_PTR(, label),
1240	BTRFS_ATTR_PTR(, nodesize),
1241	BTRFS_ATTR_PTR(, sectorsize),
1242	BTRFS_ATTR_PTR(, clone_alignment),
1243	BTRFS_ATTR_PTR(, quota_override),
1244	BTRFS_ATTR_PTR(, metadata_uuid),
1245	BTRFS_ATTR_PTR(, checksum),
1246	BTRFS_ATTR_PTR(, exclusive_operation),
1247	BTRFS_ATTR_PTR(, generation),
1248	BTRFS_ATTR_PTR(, read_policy),
1249	BTRFS_ATTR_PTR(, bg_reclaim_threshold),
1250	BTRFS_ATTR_PTR(, commit_stats),
1251	NULL,
1252};
1253
1254static void btrfs_release_fsid_kobj(struct kobject *kobj)
1255{
1256	struct btrfs_fs_devices *fs_devs = to_fs_devs(kobj);
1257
1258	memset(&fs_devs->fsid_kobj, 0, sizeof(struct kobject));
1259	complete(&fs_devs->kobj_unregister);
1260}
1261
1262static struct kobj_type btrfs_ktype = {
1263	.sysfs_ops	= &kobj_sysfs_ops,
1264	.release	= btrfs_release_fsid_kobj,
1265};
1266
1267static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj)
1268{
1269	if (kobj->ktype != &btrfs_ktype)
1270		return NULL;
1271	return container_of(kobj, struct btrfs_fs_devices, fsid_kobj);
1272}
1273
1274static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj)
1275{
1276	if (kobj->ktype != &btrfs_ktype)
1277		return NULL;
1278	return to_fs_devs(kobj)->fs_info;
1279}
1280
1281static struct kobject *get_btrfs_kobj(struct kobject *kobj)
1282{
1283	while (kobj) {
1284		if (kobj->ktype == &btrfs_ktype)
1285			return kobj;
1286		kobj = kobj->parent;
1287	}
1288	return NULL;
1289}
1290
1291#define NUM_FEATURE_BITS 64
1292#define BTRFS_FEATURE_NAME_MAX 13
1293static char btrfs_unknown_feature_names[FEAT_MAX][NUM_FEATURE_BITS][BTRFS_FEATURE_NAME_MAX];
1294static struct btrfs_feature_attr btrfs_feature_attrs[FEAT_MAX][NUM_FEATURE_BITS];
1295
1296static_assert(ARRAY_SIZE(btrfs_unknown_feature_names) ==
1297	      ARRAY_SIZE(btrfs_feature_attrs));
1298static_assert(ARRAY_SIZE(btrfs_unknown_feature_names[0]) ==
1299	      ARRAY_SIZE(btrfs_feature_attrs[0]));
1300
1301static const u64 supported_feature_masks[FEAT_MAX] = {
1302	[FEAT_COMPAT]    = BTRFS_FEATURE_COMPAT_SUPP,
1303	[FEAT_COMPAT_RO] = BTRFS_FEATURE_COMPAT_RO_SUPP,
1304	[FEAT_INCOMPAT]  = BTRFS_FEATURE_INCOMPAT_SUPP,
1305};
1306
1307static int addrm_unknown_feature_attrs(struct btrfs_fs_info *fs_info, bool add)
1308{
1309	int set;
1310
1311	for (set = 0; set < FEAT_MAX; set++) {
1312		int i;
1313		struct attribute *attrs[2];
1314		struct attribute_group agroup = {
1315			.name = "features",
1316			.attrs = attrs,
1317		};
1318		u64 features = get_features(fs_info, set);
1319		features &= ~supported_feature_masks[set];
1320
1321		if (!features)
1322			continue;
1323
1324		attrs[1] = NULL;
1325		for (i = 0; i < NUM_FEATURE_BITS; i++) {
1326			struct btrfs_feature_attr *fa;
1327
1328			if (!(features & (1ULL << i)))
1329				continue;
1330
1331			fa = &btrfs_feature_attrs[set][i];
1332			attrs[0] = &fa->kobj_attr.attr;
1333			if (add) {
1334				int ret;
1335				ret = sysfs_merge_group(&fs_info->fs_devices->fsid_kobj,
1336							&agroup);
1337				if (ret)
1338					return ret;
1339			} else
1340				sysfs_unmerge_group(&fs_info->fs_devices->fsid_kobj,
1341						    &agroup);
1342		}
1343
1344	}
1345	return 0;
1346}
1347
1348static void __btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs)
1349{
1350	if (fs_devs->devinfo_kobj) {
1351		kobject_del(fs_devs->devinfo_kobj);
1352		kobject_put(fs_devs->devinfo_kobj);
1353		fs_devs->devinfo_kobj = NULL;
1354	}
1355
1356	if (fs_devs->devices_kobj) {
1357		kobject_del(fs_devs->devices_kobj);
1358		kobject_put(fs_devs->devices_kobj);
1359		fs_devs->devices_kobj = NULL;
1360	}
1361
1362	if (fs_devs->fsid_kobj.state_initialized) {
1363		kobject_del(&fs_devs->fsid_kobj);
1364		kobject_put(&fs_devs->fsid_kobj);
1365		wait_for_completion(&fs_devs->kobj_unregister);
1366	}
1367}
1368
1369/* when fs_devs is NULL it will remove all fsid kobject */
1370void btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs)
1371{
1372	struct list_head *fs_uuids = btrfs_get_fs_uuids();
1373
1374	if (fs_devs) {
1375		__btrfs_sysfs_remove_fsid(fs_devs);
1376		return;
1377	}
1378
1379	list_for_each_entry(fs_devs, fs_uuids, fs_list) {
1380		__btrfs_sysfs_remove_fsid(fs_devs);
1381	}
1382}
1383
1384static void btrfs_sysfs_remove_fs_devices(struct btrfs_fs_devices *fs_devices)
1385{
1386	struct btrfs_device *device;
1387	struct btrfs_fs_devices *seed;
1388
1389	list_for_each_entry(device, &fs_devices->devices, dev_list)
1390		btrfs_sysfs_remove_device(device);
1391
1392	list_for_each_entry(seed, &fs_devices->seed_list, seed_list) {
1393		list_for_each_entry(device, &seed->devices, dev_list)
1394			btrfs_sysfs_remove_device(device);
1395	}
1396}
1397
1398void btrfs_sysfs_remove_mounted(struct btrfs_fs_info *fs_info)
1399{
1400	struct kobject *fsid_kobj = &fs_info->fs_devices->fsid_kobj;
1401
1402	sysfs_remove_link(fsid_kobj, "bdi");
1403
1404	if (fs_info->space_info_kobj) {
1405		sysfs_remove_files(fs_info->space_info_kobj, allocation_attrs);
1406		kobject_del(fs_info->space_info_kobj);
1407		kobject_put(fs_info->space_info_kobj);
1408	}
1409	if (fs_info->discard_kobj) {
1410		sysfs_remove_files(fs_info->discard_kobj, discard_attrs);
1411		kobject_del(fs_info->discard_kobj);
1412		kobject_put(fs_info->discard_kobj);
1413	}
1414#ifdef CONFIG_BTRFS_DEBUG
1415	if (fs_info->debug_kobj) {
1416		sysfs_remove_files(fs_info->debug_kobj, btrfs_debug_mount_attrs);
1417		kobject_del(fs_info->debug_kobj);
1418		kobject_put(fs_info->debug_kobj);
1419	}
1420#endif
1421	addrm_unknown_feature_attrs(fs_info, false);
1422	sysfs_remove_group(fsid_kobj, &btrfs_feature_attr_group);
1423	sysfs_remove_files(fsid_kobj, btrfs_attrs);
1424	btrfs_sysfs_remove_fs_devices(fs_info->fs_devices);
1425}
1426
1427static const char * const btrfs_feature_set_names[FEAT_MAX] = {
1428	[FEAT_COMPAT]	 = "compat",
1429	[FEAT_COMPAT_RO] = "compat_ro",
1430	[FEAT_INCOMPAT]	 = "incompat",
1431};
1432
1433const char *btrfs_feature_set_name(enum btrfs_feature_set set)
1434{
1435	return btrfs_feature_set_names[set];
1436}
1437
1438char *btrfs_printable_features(enum btrfs_feature_set set, u64 flags)
1439{
1440	size_t bufsize = 4096; /* safe max, 64 names * 64 bytes */
1441	int len = 0;
1442	int i;
1443	char *str;
1444
1445	str = kmalloc(bufsize, GFP_KERNEL);
1446	if (!str)
1447		return str;
1448
1449	for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
1450		const char *name;
1451
1452		if (!(flags & (1ULL << i)))
1453			continue;
1454
1455		name = btrfs_feature_attrs[set][i].kobj_attr.attr.name;
1456		len += scnprintf(str + len, bufsize - len, "%s%s",
1457				len ? "," : "", name);
1458	}
1459
1460	return str;
1461}
1462
1463static void init_feature_attrs(void)
1464{
1465	struct btrfs_feature_attr *fa;
1466	int set, i;
1467
1468	memset(btrfs_feature_attrs, 0, sizeof(btrfs_feature_attrs));
1469	memset(btrfs_unknown_feature_names, 0,
1470	       sizeof(btrfs_unknown_feature_names));
1471
1472	for (i = 0; btrfs_supported_feature_attrs[i]; i++) {
1473		struct btrfs_feature_attr *sfa;
1474		struct attribute *a = btrfs_supported_feature_attrs[i];
1475		int bit;
1476		sfa = attr_to_btrfs_feature_attr(a);
1477		bit = ilog2(sfa->feature_bit);
1478		fa = &btrfs_feature_attrs[sfa->feature_set][bit];
1479
1480		fa->kobj_attr.attr.name = sfa->kobj_attr.attr.name;
1481	}
1482
1483	for (set = 0; set < FEAT_MAX; set++) {
1484		for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
1485			char *name = btrfs_unknown_feature_names[set][i];
1486			fa = &btrfs_feature_attrs[set][i];
1487
1488			if (fa->kobj_attr.attr.name)
1489				continue;
1490
1491			snprintf(name, BTRFS_FEATURE_NAME_MAX, "%s:%u",
1492				 btrfs_feature_set_names[set], i);
1493
1494			fa->kobj_attr.attr.name = name;
1495			fa->kobj_attr.attr.mode = S_IRUGO;
1496			fa->feature_set = set;
1497			fa->feature_bit = 1ULL << i;
1498		}
1499	}
1500}
1501
1502/*
1503 * Create a sysfs entry for a given block group type at path
1504 * /sys/fs/btrfs/UUID/allocation/data/TYPE
1505 */
1506void btrfs_sysfs_add_block_group_type(struct btrfs_block_group *cache)
1507{
1508	struct btrfs_fs_info *fs_info = cache->fs_info;
1509	struct btrfs_space_info *space_info = cache->space_info;
1510	struct raid_kobject *rkobj;
1511	const int index = btrfs_bg_flags_to_raid_index(cache->flags);
1512	unsigned int nofs_flag;
1513	int ret;
1514
1515	/*
1516	 * Setup a NOFS context because kobject_add(), deep in its call chain,
1517	 * does GFP_KERNEL allocations, and we are often called in a context
1518	 * where if reclaim is triggered we can deadlock (we are either holding
1519	 * a transaction handle or some lock required for a transaction
1520	 * commit).
1521	 */
1522	nofs_flag = memalloc_nofs_save();
1523
1524	rkobj = kzalloc(sizeof(*rkobj), GFP_NOFS);
1525	if (!rkobj) {
1526		memalloc_nofs_restore(nofs_flag);
1527		btrfs_warn(cache->fs_info,
1528				"couldn't alloc memory for raid level kobject");
1529		return;
1530	}
1531
1532	rkobj->flags = cache->flags;
1533	kobject_init(&rkobj->kobj, &btrfs_raid_ktype);
1534
1535	/*
1536	 * We call this either on mount, or if we've created a block group for a
1537	 * new index type while running (i.e. when restriping).  The running
1538	 * case is tricky because we could race with other threads, so we need
1539	 * to have this check to make sure we didn't already init the kobject.
1540	 *
1541	 * We don't have to protect on the free side because it only happens on
1542	 * unmount.
1543	 */
1544	spin_lock(&space_info->lock);
1545	if (space_info->block_group_kobjs[index]) {
1546		spin_unlock(&space_info->lock);
1547		kobject_put(&rkobj->kobj);
1548		return;
1549	} else {
1550		space_info->block_group_kobjs[index] = &rkobj->kobj;
1551	}
1552	spin_unlock(&space_info->lock);
1553
1554	ret = kobject_add(&rkobj->kobj, &space_info->kobj, "%s",
1555			  btrfs_bg_type_to_raid_name(rkobj->flags));
1556	memalloc_nofs_restore(nofs_flag);
1557	if (ret) {
1558		spin_lock(&space_info->lock);
1559		space_info->block_group_kobjs[index] = NULL;
1560		spin_unlock(&space_info->lock);
1561		kobject_put(&rkobj->kobj);
1562		btrfs_warn(fs_info,
1563			"failed to add kobject for block cache, ignoring");
1564		return;
1565	}
1566}
1567
1568/*
1569 * Remove sysfs directories for all block group types of a given space info and
1570 * the space info as well
1571 */
1572void btrfs_sysfs_remove_space_info(struct btrfs_space_info *space_info)
1573{
1574	int i;
1575
1576	for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) {
1577		struct kobject *kobj;
1578
1579		kobj = space_info->block_group_kobjs[i];
1580		space_info->block_group_kobjs[i] = NULL;
1581		if (kobj) {
1582			kobject_del(kobj);
1583			kobject_put(kobj);
1584		}
1585	}
1586	kobject_del(&space_info->kobj);
1587	kobject_put(&space_info->kobj);
1588}
1589
1590static const char *alloc_name(u64 flags)
1591{
1592	switch (flags) {
1593	case BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA:
1594		return "mixed";
1595	case BTRFS_BLOCK_GROUP_METADATA:
1596		return "metadata";
1597	case BTRFS_BLOCK_GROUP_DATA:
1598		return "data";
1599	case BTRFS_BLOCK_GROUP_SYSTEM:
1600		return "system";
1601	default:
1602		WARN_ON(1);
1603		return "invalid-combination";
1604	}
1605}
1606
1607/*
1608 * Create a sysfs entry for a space info type at path
1609 * /sys/fs/btrfs/UUID/allocation/TYPE
1610 */
1611int btrfs_sysfs_add_space_info_type(struct btrfs_fs_info *fs_info,
1612				    struct btrfs_space_info *space_info)
1613{
1614	int ret;
1615
1616	ret = kobject_init_and_add(&space_info->kobj, &space_info_ktype,
1617				   fs_info->space_info_kobj, "%s",
1618				   alloc_name(space_info->flags));
1619	if (ret) {
1620		kobject_put(&space_info->kobj);
1621		return ret;
1622	}
1623
1624	return 0;
1625}
1626
1627void btrfs_sysfs_remove_device(struct btrfs_device *device)
1628{
1629	struct kobject *devices_kobj;
1630
1631	/*
1632	 * Seed fs_devices devices_kobj aren't used, fetch kobject from the
1633	 * fs_info::fs_devices.
1634	 */
1635	devices_kobj = device->fs_info->fs_devices->devices_kobj;
1636	ASSERT(devices_kobj);
1637
1638	if (device->bdev)
1639		sysfs_remove_link(devices_kobj, bdev_kobj(device->bdev)->name);
1640
1641	if (device->devid_kobj.state_initialized) {
1642		kobject_del(&device->devid_kobj);
1643		kobject_put(&device->devid_kobj);
1644		wait_for_completion(&device->kobj_unregister);
1645	}
1646}
1647
1648static ssize_t btrfs_devinfo_in_fs_metadata_show(struct kobject *kobj,
1649					         struct kobj_attribute *a,
1650					         char *buf)
1651{
1652	int val;
1653	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1654						   devid_kobj);
1655
1656	val = !!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state);
1657
1658	return sysfs_emit(buf, "%d\n", val);
1659}
1660BTRFS_ATTR(devid, in_fs_metadata, btrfs_devinfo_in_fs_metadata_show);
1661
1662static ssize_t btrfs_devinfo_missing_show(struct kobject *kobj,
1663					struct kobj_attribute *a, char *buf)
1664{
1665	int val;
1666	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1667						   devid_kobj);
1668
1669	val = !!test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state);
1670
1671	return sysfs_emit(buf, "%d\n", val);
1672}
1673BTRFS_ATTR(devid, missing, btrfs_devinfo_missing_show);
1674
1675static ssize_t btrfs_devinfo_replace_target_show(struct kobject *kobj,
1676					         struct kobj_attribute *a,
1677					         char *buf)
1678{
1679	int val;
1680	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1681						   devid_kobj);
1682
1683	val = !!test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state);
1684
1685	return sysfs_emit(buf, "%d\n", val);
1686}
1687BTRFS_ATTR(devid, replace_target, btrfs_devinfo_replace_target_show);
1688
1689static ssize_t btrfs_devinfo_scrub_speed_max_show(struct kobject *kobj,
1690					     struct kobj_attribute *a,
1691					     char *buf)
1692{
1693	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1694						   devid_kobj);
1695
1696	return sysfs_emit(buf, "%llu\n", READ_ONCE(device->scrub_speed_max));
1697}
1698
1699static ssize_t btrfs_devinfo_scrub_speed_max_store(struct kobject *kobj,
1700					      struct kobj_attribute *a,
1701					      const char *buf, size_t len)
1702{
1703	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1704						   devid_kobj);
1705	char *endptr;
1706	unsigned long long limit;
1707
1708	limit = memparse(buf, &endptr);
1709	WRITE_ONCE(device->scrub_speed_max, limit);
1710	return len;
1711}
1712BTRFS_ATTR_RW(devid, scrub_speed_max, btrfs_devinfo_scrub_speed_max_show,
1713	      btrfs_devinfo_scrub_speed_max_store);
1714
1715static ssize_t btrfs_devinfo_writeable_show(struct kobject *kobj,
1716					    struct kobj_attribute *a, char *buf)
1717{
1718	int val;
1719	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1720						   devid_kobj);
1721
1722	val = !!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state);
1723
1724	return sysfs_emit(buf, "%d\n", val);
1725}
1726BTRFS_ATTR(devid, writeable, btrfs_devinfo_writeable_show);
1727
1728static ssize_t btrfs_devinfo_fsid_show(struct kobject *kobj,
1729				       struct kobj_attribute *a, char *buf)
1730{
1731	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1732						   devid_kobj);
1733
1734	return sysfs_emit(buf, "%pU\n", device->fs_devices->fsid);
1735}
1736BTRFS_ATTR(devid, fsid, btrfs_devinfo_fsid_show);
1737
1738static ssize_t btrfs_devinfo_error_stats_show(struct kobject *kobj,
1739		struct kobj_attribute *a, char *buf)
1740{
1741	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1742						   devid_kobj);
1743
1744	if (!device->dev_stats_valid)
1745		return sysfs_emit(buf, "invalid\n");
1746
1747	/*
1748	 * Print all at once so we get a snapshot of all values from the same
1749	 * time. Keep them in sync and in order of definition of
1750	 * btrfs_dev_stat_values.
1751	 */
1752	return sysfs_emit(buf,
1753		"write_errs %d\n"
1754		"read_errs %d\n"
1755		"flush_errs %d\n"
1756		"corruption_errs %d\n"
1757		"generation_errs %d\n",
1758		btrfs_dev_stat_read(device, BTRFS_DEV_STAT_WRITE_ERRS),
1759		btrfs_dev_stat_read(device, BTRFS_DEV_STAT_READ_ERRS),
1760		btrfs_dev_stat_read(device, BTRFS_DEV_STAT_FLUSH_ERRS),
1761		btrfs_dev_stat_read(device, BTRFS_DEV_STAT_CORRUPTION_ERRS),
1762		btrfs_dev_stat_read(device, BTRFS_DEV_STAT_GENERATION_ERRS));
1763}
1764BTRFS_ATTR(devid, error_stats, btrfs_devinfo_error_stats_show);
1765
1766/*
1767 * Information about one device.
1768 *
1769 * Path: /sys/fs/btrfs/<uuid>/devinfo/<devid>/
1770 */
1771static struct attribute *devid_attrs[] = {
1772	BTRFS_ATTR_PTR(devid, error_stats),
1773	BTRFS_ATTR_PTR(devid, fsid),
1774	BTRFS_ATTR_PTR(devid, in_fs_metadata),
1775	BTRFS_ATTR_PTR(devid, missing),
1776	BTRFS_ATTR_PTR(devid, replace_target),
1777	BTRFS_ATTR_PTR(devid, scrub_speed_max),
1778	BTRFS_ATTR_PTR(devid, writeable),
1779	NULL
1780};
1781ATTRIBUTE_GROUPS(devid);
1782
1783static void btrfs_release_devid_kobj(struct kobject *kobj)
1784{
1785	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1786						   devid_kobj);
1787
1788	memset(&device->devid_kobj, 0, sizeof(struct kobject));
1789	complete(&device->kobj_unregister);
1790}
1791
1792static struct kobj_type devid_ktype = {
1793	.sysfs_ops	= &kobj_sysfs_ops,
1794	.default_groups = devid_groups,
1795	.release	= btrfs_release_devid_kobj,
1796};
1797
1798int btrfs_sysfs_add_device(struct btrfs_device *device)
1799{
1800	int ret;
1801	unsigned int nofs_flag;
1802	struct kobject *devices_kobj;
1803	struct kobject *devinfo_kobj;
1804
1805	/*
1806	 * Make sure we use the fs_info::fs_devices to fetch the kobjects even
1807	 * for the seed fs_devices
1808	 */
1809	devices_kobj = device->fs_info->fs_devices->devices_kobj;
1810	devinfo_kobj = device->fs_info->fs_devices->devinfo_kobj;
1811	ASSERT(devices_kobj);
1812	ASSERT(devinfo_kobj);
1813
1814	nofs_flag = memalloc_nofs_save();
1815
1816	if (device->bdev) {
1817		struct kobject *disk_kobj = bdev_kobj(device->bdev);
1818
1819		ret = sysfs_create_link(devices_kobj, disk_kobj, disk_kobj->name);
1820		if (ret) {
1821			btrfs_warn(device->fs_info,
1822				"creating sysfs device link for devid %llu failed: %d",
1823				device->devid, ret);
1824			goto out;
1825		}
1826	}
1827
1828	init_completion(&device->kobj_unregister);
1829	ret = kobject_init_and_add(&device->devid_kobj, &devid_ktype,
1830				   devinfo_kobj, "%llu", device->devid);
1831	if (ret) {
1832		kobject_put(&device->devid_kobj);
1833		btrfs_warn(device->fs_info,
1834			   "devinfo init for devid %llu failed: %d",
1835			   device->devid, ret);
1836	}
1837
1838out:
1839	memalloc_nofs_restore(nofs_flag);
1840	return ret;
1841}
1842
1843static int btrfs_sysfs_add_fs_devices(struct btrfs_fs_devices *fs_devices)
1844{
1845	int ret;
1846	struct btrfs_device *device;
1847	struct btrfs_fs_devices *seed;
1848
1849	list_for_each_entry(device, &fs_devices->devices, dev_list) {
1850		ret = btrfs_sysfs_add_device(device);
1851		if (ret)
1852			goto fail;
1853	}
1854
1855	list_for_each_entry(seed, &fs_devices->seed_list, seed_list) {
1856		list_for_each_entry(device, &seed->devices, dev_list) {
1857			ret = btrfs_sysfs_add_device(device);
1858			if (ret)
1859				goto fail;
1860		}
1861	}
1862
1863	return 0;
1864
1865fail:
1866	btrfs_sysfs_remove_fs_devices(fs_devices);
1867	return ret;
1868}
1869
1870void btrfs_kobject_uevent(struct block_device *bdev, enum kobject_action action)
1871{
1872	int ret;
1873
1874	ret = kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, action);
1875	if (ret)
1876		pr_warn("BTRFS: Sending event '%d' to kobject: '%s' (%p): failed\n",
1877			action, kobject_name(&disk_to_dev(bdev->bd_disk)->kobj),
1878			&disk_to_dev(bdev->bd_disk)->kobj);
1879}
1880
1881void btrfs_sysfs_update_sprout_fsid(struct btrfs_fs_devices *fs_devices)
1882
1883{
1884	char fsid_buf[BTRFS_UUID_UNPARSED_SIZE];
1885
1886	/*
1887	 * Sprouting changes fsid of the mounted filesystem, rename the fsid
1888	 * directory
1889	 */
1890	snprintf(fsid_buf, BTRFS_UUID_UNPARSED_SIZE, "%pU", fs_devices->fsid);
1891	if (kobject_rename(&fs_devices->fsid_kobj, fsid_buf))
1892		btrfs_warn(fs_devices->fs_info,
1893				"sysfs: failed to create fsid for sprout");
1894}
1895
1896void btrfs_sysfs_update_devid(struct btrfs_device *device)
1897{
1898	char tmp[24];
1899
1900	snprintf(tmp, sizeof(tmp), "%llu", device->devid);
1901
1902	if (kobject_rename(&device->devid_kobj, tmp))
1903		btrfs_warn(device->fs_devices->fs_info,
1904			   "sysfs: failed to update devid for %llu",
1905			   device->devid);
1906}
1907
1908/* /sys/fs/btrfs/ entry */
1909static struct kset *btrfs_kset;
1910
1911/*
1912 * Creates:
1913 *		/sys/fs/btrfs/UUID
1914 *
1915 * Can be called by the device discovery thread.
1916 */
1917int btrfs_sysfs_add_fsid(struct btrfs_fs_devices *fs_devs)
1918{
1919	int error;
1920
1921	init_completion(&fs_devs->kobj_unregister);
1922	fs_devs->fsid_kobj.kset = btrfs_kset;
1923	error = kobject_init_and_add(&fs_devs->fsid_kobj, &btrfs_ktype, NULL,
1924				     "%pU", fs_devs->fsid);
1925	if (error) {
1926		kobject_put(&fs_devs->fsid_kobj);
1927		return error;
1928	}
1929
1930	fs_devs->devices_kobj = kobject_create_and_add("devices",
1931						       &fs_devs->fsid_kobj);
1932	if (!fs_devs->devices_kobj) {
1933		btrfs_err(fs_devs->fs_info,
1934			  "failed to init sysfs device interface");
1935		btrfs_sysfs_remove_fsid(fs_devs);
1936		return -ENOMEM;
1937	}
1938
1939	fs_devs->devinfo_kobj = kobject_create_and_add("devinfo",
1940						       &fs_devs->fsid_kobj);
1941	if (!fs_devs->devinfo_kobj) {
1942		btrfs_err(fs_devs->fs_info,
1943			  "failed to init sysfs devinfo kobject");
1944		btrfs_sysfs_remove_fsid(fs_devs);
1945		return -ENOMEM;
1946	}
1947
1948	return 0;
1949}
1950
1951int btrfs_sysfs_add_mounted(struct btrfs_fs_info *fs_info)
1952{
1953	int error;
1954	struct btrfs_fs_devices *fs_devs = fs_info->fs_devices;
1955	struct kobject *fsid_kobj = &fs_devs->fsid_kobj;
1956
1957	error = btrfs_sysfs_add_fs_devices(fs_devs);
1958	if (error)
1959		return error;
1960
1961	error = sysfs_create_files(fsid_kobj, btrfs_attrs);
1962	if (error) {
1963		btrfs_sysfs_remove_fs_devices(fs_devs);
1964		return error;
1965	}
1966
1967	error = sysfs_create_group(fsid_kobj,
1968				   &btrfs_feature_attr_group);
1969	if (error)
1970		goto failure;
1971
1972#ifdef CONFIG_BTRFS_DEBUG
1973	fs_info->debug_kobj = kobject_create_and_add("debug", fsid_kobj);
1974	if (!fs_info->debug_kobj) {
1975		error = -ENOMEM;
1976		goto failure;
1977	}
1978
1979	error = sysfs_create_files(fs_info->debug_kobj, btrfs_debug_mount_attrs);
1980	if (error)
1981		goto failure;
1982#endif
1983
1984	/* Discard directory */
1985	fs_info->discard_kobj = kobject_create_and_add("discard", fsid_kobj);
1986	if (!fs_info->discard_kobj) {
1987		error = -ENOMEM;
1988		goto failure;
1989	}
1990
1991	error = sysfs_create_files(fs_info->discard_kobj, discard_attrs);
1992	if (error)
1993		goto failure;
1994
1995	error = addrm_unknown_feature_attrs(fs_info, true);
1996	if (error)
1997		goto failure;
1998
1999	error = sysfs_create_link(fsid_kobj, &fs_info->sb->s_bdi->dev->kobj, "bdi");
2000	if (error)
2001		goto failure;
2002
2003	fs_info->space_info_kobj = kobject_create_and_add("allocation",
2004						  fsid_kobj);
2005	if (!fs_info->space_info_kobj) {
2006		error = -ENOMEM;
2007		goto failure;
2008	}
2009
2010	error = sysfs_create_files(fs_info->space_info_kobj, allocation_attrs);
2011	if (error)
2012		goto failure;
2013
2014	return 0;
2015failure:
2016	btrfs_sysfs_remove_mounted(fs_info);
2017	return error;
2018}
2019
2020static ssize_t qgroup_enabled_show(struct kobject *qgroups_kobj,
2021				   struct kobj_attribute *a,
2022				   char *buf)
2023{
2024	struct btrfs_fs_info *fs_info = to_fs_info(qgroups_kobj->parent);
2025	bool enabled;
2026
2027	spin_lock(&fs_info->qgroup_lock);
2028	enabled = fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_ON;
2029	spin_unlock(&fs_info->qgroup_lock);
2030
2031	return sysfs_emit(buf, "%d\n", enabled);
2032}
2033BTRFS_ATTR(qgroups, enabled, qgroup_enabled_show);
2034
2035static ssize_t qgroup_inconsistent_show(struct kobject *qgroups_kobj,
2036					struct kobj_attribute *a,
2037					char *buf)
2038{
2039	struct btrfs_fs_info *fs_info = to_fs_info(qgroups_kobj->parent);
2040	bool inconsistent;
2041
2042	spin_lock(&fs_info->qgroup_lock);
2043	inconsistent = (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT);
2044	spin_unlock(&fs_info->qgroup_lock);
2045
2046	return sysfs_emit(buf, "%d\n", inconsistent);
2047}
2048BTRFS_ATTR(qgroups, inconsistent, qgroup_inconsistent_show);
2049
2050static ssize_t qgroup_drop_subtree_thres_show(struct kobject *qgroups_kobj,
2051					      struct kobj_attribute *a,
2052					      char *buf)
2053{
2054	struct btrfs_fs_info *fs_info = to_fs_info(qgroups_kobj->parent);
2055	u8 result;
2056
2057	spin_lock(&fs_info->qgroup_lock);
2058	result = fs_info->qgroup_drop_subtree_thres;
2059	spin_unlock(&fs_info->qgroup_lock);
2060
2061	return sysfs_emit(buf, "%d\n", result);
2062}
2063
2064static ssize_t qgroup_drop_subtree_thres_store(struct kobject *qgroups_kobj,
2065					       struct kobj_attribute *a,
2066					       const char *buf, size_t len)
2067{
2068	struct btrfs_fs_info *fs_info = to_fs_info(qgroups_kobj->parent);
2069	u8 new_thres;
2070	int ret;
2071
2072	ret = kstrtou8(buf, 10, &new_thres);
2073	if (ret)
2074		return -EINVAL;
2075
2076	if (new_thres > BTRFS_MAX_LEVEL)
2077		return -EINVAL;
2078
2079	spin_lock(&fs_info->qgroup_lock);
2080	fs_info->qgroup_drop_subtree_thres = new_thres;
2081	spin_unlock(&fs_info->qgroup_lock);
2082
2083	return len;
2084}
2085BTRFS_ATTR_RW(qgroups, drop_subtree_threshold, qgroup_drop_subtree_thres_show,
2086	      qgroup_drop_subtree_thres_store);
2087
2088/*
2089 * Qgroups global info
2090 *
2091 * Path: /sys/fs/btrfs/<uuid>/qgroups/
2092 */
2093static struct attribute *qgroups_attrs[] = {
2094	BTRFS_ATTR_PTR(qgroups, enabled),
2095	BTRFS_ATTR_PTR(qgroups, inconsistent),
2096	BTRFS_ATTR_PTR(qgroups, drop_subtree_threshold),
2097	NULL
2098};
2099ATTRIBUTE_GROUPS(qgroups);
2100
2101static void qgroups_release(struct kobject *kobj)
2102{
2103	kfree(kobj);
2104}
2105
2106static struct kobj_type qgroups_ktype = {
2107	.sysfs_ops = &kobj_sysfs_ops,
2108	.default_groups = qgroups_groups,
2109	.release = qgroups_release,
2110};
2111
2112static inline struct btrfs_fs_info *qgroup_kobj_to_fs_info(struct kobject *kobj)
2113{
2114	return to_fs_info(kobj->parent->parent);
2115}
2116
2117#define QGROUP_ATTR(_member, _show_name)					\
2118static ssize_t btrfs_qgroup_show_##_member(struct kobject *qgroup_kobj,		\
2119					   struct kobj_attribute *a,		\
2120					   char *buf)				\
2121{										\
2122	struct btrfs_fs_info *fs_info = qgroup_kobj_to_fs_info(qgroup_kobj);	\
2123	struct btrfs_qgroup *qgroup = container_of(qgroup_kobj,			\
2124			struct btrfs_qgroup, kobj);				\
2125	return btrfs_show_u64(&qgroup->_member, &fs_info->qgroup_lock, buf);	\
2126}										\
2127BTRFS_ATTR(qgroup, _show_name, btrfs_qgroup_show_##_member)
2128
2129#define QGROUP_RSV_ATTR(_name, _type)						\
2130static ssize_t btrfs_qgroup_rsv_show_##_name(struct kobject *qgroup_kobj,	\
2131					     struct kobj_attribute *a,		\
2132					     char *buf)				\
2133{										\
2134	struct btrfs_fs_info *fs_info = qgroup_kobj_to_fs_info(qgroup_kobj);	\
2135	struct btrfs_qgroup *qgroup = container_of(qgroup_kobj,			\
2136			struct btrfs_qgroup, kobj);				\
2137	return btrfs_show_u64(&qgroup->rsv.values[_type],			\
2138			&fs_info->qgroup_lock, buf);				\
2139}										\
2140BTRFS_ATTR(qgroup, rsv_##_name, btrfs_qgroup_rsv_show_##_name)
2141
2142QGROUP_ATTR(rfer, referenced);
2143QGROUP_ATTR(excl, exclusive);
2144QGROUP_ATTR(max_rfer, max_referenced);
2145QGROUP_ATTR(max_excl, max_exclusive);
2146QGROUP_ATTR(lim_flags, limit_flags);
2147QGROUP_RSV_ATTR(data, BTRFS_QGROUP_RSV_DATA);
2148QGROUP_RSV_ATTR(meta_pertrans, BTRFS_QGROUP_RSV_META_PERTRANS);
2149QGROUP_RSV_ATTR(meta_prealloc, BTRFS_QGROUP_RSV_META_PREALLOC);
2150
2151/*
2152 * Qgroup information.
2153 *
2154 * Path: /sys/fs/btrfs/<uuid>/qgroups/<level>_<qgroupid>/
2155 */
2156static struct attribute *qgroup_attrs[] = {
2157	BTRFS_ATTR_PTR(qgroup, referenced),
2158	BTRFS_ATTR_PTR(qgroup, exclusive),
2159	BTRFS_ATTR_PTR(qgroup, max_referenced),
2160	BTRFS_ATTR_PTR(qgroup, max_exclusive),
2161	BTRFS_ATTR_PTR(qgroup, limit_flags),
2162	BTRFS_ATTR_PTR(qgroup, rsv_data),
2163	BTRFS_ATTR_PTR(qgroup, rsv_meta_pertrans),
2164	BTRFS_ATTR_PTR(qgroup, rsv_meta_prealloc),
2165	NULL
2166};
2167ATTRIBUTE_GROUPS(qgroup);
2168
2169static void qgroup_release(struct kobject *kobj)
2170{
2171	struct btrfs_qgroup *qgroup = container_of(kobj, struct btrfs_qgroup, kobj);
2172
2173	memset(&qgroup->kobj, 0, sizeof(*kobj));
2174}
2175
2176static struct kobj_type qgroup_ktype = {
2177	.sysfs_ops = &kobj_sysfs_ops,
2178	.release = qgroup_release,
2179	.default_groups = qgroup_groups,
2180};
2181
2182int btrfs_sysfs_add_one_qgroup(struct btrfs_fs_info *fs_info,
2183				struct btrfs_qgroup *qgroup)
2184{
2185	struct kobject *qgroups_kobj = fs_info->qgroups_kobj;
2186	int ret;
2187
2188	if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
2189		return 0;
2190	if (qgroup->kobj.state_initialized)
2191		return 0;
2192	if (!qgroups_kobj)
2193		return -EINVAL;
2194
2195	ret = kobject_init_and_add(&qgroup->kobj, &qgroup_ktype, qgroups_kobj,
2196			"%hu_%llu", btrfs_qgroup_level(qgroup->qgroupid),
2197			btrfs_qgroup_subvolid(qgroup->qgroupid));
2198	if (ret < 0)
2199		kobject_put(&qgroup->kobj);
2200
2201	return ret;
2202}
2203
2204void btrfs_sysfs_del_qgroups(struct btrfs_fs_info *fs_info)
2205{
2206	struct btrfs_qgroup *qgroup;
2207	struct btrfs_qgroup *next;
2208
2209	if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
2210		return;
2211
2212	rbtree_postorder_for_each_entry_safe(qgroup, next,
2213					     &fs_info->qgroup_tree, node)
2214		btrfs_sysfs_del_one_qgroup(fs_info, qgroup);
2215	if (fs_info->qgroups_kobj) {
2216		kobject_del(fs_info->qgroups_kobj);
2217		kobject_put(fs_info->qgroups_kobj);
2218		fs_info->qgroups_kobj = NULL;
2219	}
2220}
2221
2222/* Called when qgroups get initialized, thus there is no need for locking */
2223int btrfs_sysfs_add_qgroups(struct btrfs_fs_info *fs_info)
2224{
2225	struct kobject *fsid_kobj = &fs_info->fs_devices->fsid_kobj;
2226	struct btrfs_qgroup *qgroup;
2227	struct btrfs_qgroup *next;
2228	int ret = 0;
2229
2230	if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
2231		return 0;
2232
2233	ASSERT(fsid_kobj);
2234	if (fs_info->qgroups_kobj)
2235		return 0;
2236
2237	fs_info->qgroups_kobj = kzalloc(sizeof(struct kobject), GFP_KERNEL);
2238	if (!fs_info->qgroups_kobj)
2239		return -ENOMEM;
2240
2241	ret = kobject_init_and_add(fs_info->qgroups_kobj, &qgroups_ktype,
2242				   fsid_kobj, "qgroups");
2243	if (ret < 0)
2244		goto out;
2245
2246	rbtree_postorder_for_each_entry_safe(qgroup, next,
2247					     &fs_info->qgroup_tree, node) {
2248		ret = btrfs_sysfs_add_one_qgroup(fs_info, qgroup);
2249		if (ret < 0)
2250			goto out;
2251	}
2252
2253out:
2254	if (ret < 0)
2255		btrfs_sysfs_del_qgroups(fs_info);
2256	return ret;
2257}
2258
2259void btrfs_sysfs_del_one_qgroup(struct btrfs_fs_info *fs_info,
2260				struct btrfs_qgroup *qgroup)
2261{
2262	if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
2263		return;
2264
2265	if (qgroup->kobj.state_initialized) {
2266		kobject_del(&qgroup->kobj);
2267		kobject_put(&qgroup->kobj);
2268	}
2269}
2270
2271/*
2272 * Change per-fs features in /sys/fs/btrfs/UUID/features to match current
2273 * values in superblock. Call after any changes to incompat/compat_ro flags
2274 */
2275void btrfs_sysfs_feature_update(struct btrfs_fs_info *fs_info,
2276		u64 bit, enum btrfs_feature_set set)
2277{
2278	struct btrfs_fs_devices *fs_devs;
2279	struct kobject *fsid_kobj;
2280	u64 __maybe_unused features;
2281	int __maybe_unused ret;
2282
2283	if (!fs_info)
2284		return;
2285
2286	/*
2287	 * See 14e46e04958df74 and e410e34fad913dd, feature bit updates are not
2288	 * safe when called from some contexts (eg. balance)
2289	 */
2290	features = get_features(fs_info, set);
2291	ASSERT(bit & supported_feature_masks[set]);
2292
2293	fs_devs = fs_info->fs_devices;
2294	fsid_kobj = &fs_devs->fsid_kobj;
2295
2296	if (!fsid_kobj->state_initialized)
2297		return;
2298
2299	/*
2300	 * FIXME: this is too heavy to update just one value, ideally we'd like
2301	 * to use sysfs_update_group but some refactoring is needed first.
2302	 */
2303	sysfs_remove_group(fsid_kobj, &btrfs_feature_attr_group);
2304	ret = sysfs_create_group(fsid_kobj, &btrfs_feature_attr_group);
2305}
2306
2307int __init btrfs_init_sysfs(void)
2308{
2309	int ret;
2310
2311	btrfs_kset = kset_create_and_add("btrfs", NULL, fs_kobj);
2312	if (!btrfs_kset)
2313		return -ENOMEM;
2314
2315	init_feature_attrs();
2316	ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
2317	if (ret)
2318		goto out2;
2319	ret = sysfs_merge_group(&btrfs_kset->kobj,
2320				&btrfs_static_feature_attr_group);
2321	if (ret)
2322		goto out_remove_group;
2323
2324#ifdef CONFIG_BTRFS_DEBUG
2325	ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_debug_feature_attr_group);
2326	if (ret) {
2327		sysfs_unmerge_group(&btrfs_kset->kobj,
2328				    &btrfs_static_feature_attr_group);
2329		goto out_remove_group;
2330	}
2331#endif
2332
2333	return 0;
2334
2335out_remove_group:
2336	sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
2337out2:
2338	kset_unregister(btrfs_kset);
2339
2340	return ret;
2341}
2342
2343void __cold btrfs_exit_sysfs(void)
2344{
2345	sysfs_unmerge_group(&btrfs_kset->kobj,
2346			    &btrfs_static_feature_attr_group);
2347	sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
2348#ifdef CONFIG_BTRFS_DEBUG
2349	sysfs_remove_group(&btrfs_kset->kobj, &btrfs_debug_feature_attr_group);
2350#endif
2351	kset_unregister(btrfs_kset);
2352}