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v6.13.7
   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 <linux/list.h>
  13#include <crypto/hash.h>
  14#include "messages.h"
  15#include "ctree.h"
  16#include "discard.h"
  17#include "disk-io.h"
  18#include "send.h"
  19#include "transaction.h"
  20#include "sysfs.h"
  21#include "volumes.h"
  22#include "space-info.h"
  23#include "block-group.h"
  24#include "qgroup.h"
  25#include "misc.h"
  26#include "fs.h"
  27#include "accessors.h"
  28
  29/*
  30 * Structure name                       Path
  31 * --------------------------------------------------------------------------
  32 * btrfs_supported_static_feature_attrs /sys/fs/btrfs/features
  33 * btrfs_supported_feature_attrs	/sys/fs/btrfs/features and
  34 *					/sys/fs/btrfs/<uuid>/features
  35 * btrfs_attrs				/sys/fs/btrfs/<uuid>
  36 * devid_attrs				/sys/fs/btrfs/<uuid>/devinfo/<devid>
  37 * allocation_attrs			/sys/fs/btrfs/<uuid>/allocation
  38 * qgroup_attrs				/sys/fs/btrfs/<uuid>/qgroups/<level>_<qgroupid>
  39 * space_info_attrs			/sys/fs/btrfs/<uuid>/allocation/<bg-type>
  40 * raid_attrs				/sys/fs/btrfs/<uuid>/allocation/<bg-type>/<bg-profile>
  41 * discard_attrs			/sys/fs/btrfs/<uuid>/discard
  42 *
  43 * When built with BTRFS_CONFIG_DEBUG:
  44 *
  45 * btrfs_debug_feature_attrs		/sys/fs/btrfs/debug
  46 * btrfs_debug_mount_attrs		/sys/fs/btrfs/<uuid>/debug
  47 */
  48
  49struct btrfs_feature_attr {
  50	struct kobj_attribute kobj_attr;
  51	enum btrfs_feature_set feature_set;
  52	u64 feature_bit;
  53};
  54
  55/* For raid type sysfs entries */
  56struct raid_kobject {
  57	u64 flags;
  58	struct kobject kobj;
  59};
  60
  61#define __INIT_KOBJ_ATTR(_name, _mode, _show, _store)			\
  62{									\
  63	.attr	= { .name = __stringify(_name), .mode = _mode },	\
  64	.show	= _show,						\
  65	.store	= _store,						\
  66}
  67
  68#define BTRFS_ATTR_W(_prefix, _name, _store)			        \
  69	static struct kobj_attribute btrfs_attr_##_prefix##_##_name =	\
  70			__INIT_KOBJ_ATTR(_name, 0200, NULL, _store)
  71
  72#define BTRFS_ATTR_RW(_prefix, _name, _show, _store)			\
  73	static struct kobj_attribute btrfs_attr_##_prefix##_##_name =	\
  74			__INIT_KOBJ_ATTR(_name, 0644, _show, _store)
  75
  76#define BTRFS_ATTR(_prefix, _name, _show)				\
  77	static struct kobj_attribute btrfs_attr_##_prefix##_##_name =	\
  78			__INIT_KOBJ_ATTR(_name, 0444, _show, NULL)
  79
  80#define BTRFS_ATTR_PTR(_prefix, _name)					\
  81	(&btrfs_attr_##_prefix##_##_name.attr)
  82
  83#define BTRFS_FEAT_ATTR(_name, _feature_set, _feature_prefix, _feature_bit)  \
  84static struct btrfs_feature_attr btrfs_attr_features_##_name = {	     \
  85	.kobj_attr = __INIT_KOBJ_ATTR(_name, S_IRUGO,			     \
  86				      btrfs_feature_attr_show,		     \
  87				      btrfs_feature_attr_store),	     \
  88	.feature_set	= _feature_set,					     \
  89	.feature_bit	= _feature_prefix ##_## _feature_bit,		     \
  90}
  91#define BTRFS_FEAT_ATTR_PTR(_name)					     \
  92	(&btrfs_attr_features_##_name.kobj_attr.attr)
  93
  94#define BTRFS_FEAT_ATTR_COMPAT(name, feature) \
  95	BTRFS_FEAT_ATTR(name, FEAT_COMPAT, BTRFS_FEATURE_COMPAT, feature)
  96#define BTRFS_FEAT_ATTR_COMPAT_RO(name, feature) \
  97	BTRFS_FEAT_ATTR(name, FEAT_COMPAT_RO, BTRFS_FEATURE_COMPAT_RO, feature)
  98#define BTRFS_FEAT_ATTR_INCOMPAT(name, feature) \
  99	BTRFS_FEAT_ATTR(name, FEAT_INCOMPAT, BTRFS_FEATURE_INCOMPAT, feature)
 100
 101static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj);
 102static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj);
 103static struct kobject *get_btrfs_kobj(struct kobject *kobj);
 104
 105static struct btrfs_feature_attr *to_btrfs_feature_attr(struct kobj_attribute *a)
 106{
 107	return container_of(a, struct btrfs_feature_attr, kobj_attr);
 108}
 109
 110static struct kobj_attribute *attr_to_btrfs_attr(struct attribute *attr)
 111{
 112	return container_of(attr, struct kobj_attribute, attr);
 113}
 114
 115static struct btrfs_feature_attr *attr_to_btrfs_feature_attr(
 116		struct attribute *attr)
 117{
 118	return to_btrfs_feature_attr(attr_to_btrfs_attr(attr));
 119}
 120
 121static u64 get_features(struct btrfs_fs_info *fs_info,
 122			enum btrfs_feature_set set)
 123{
 124	struct btrfs_super_block *disk_super = fs_info->super_copy;
 125	if (set == FEAT_COMPAT)
 126		return btrfs_super_compat_flags(disk_super);
 127	else if (set == FEAT_COMPAT_RO)
 128		return btrfs_super_compat_ro_flags(disk_super);
 129	else
 130		return btrfs_super_incompat_flags(disk_super);
 131}
 132
 133static void set_features(struct btrfs_fs_info *fs_info,
 134			 enum btrfs_feature_set set, u64 features)
 135{
 136	struct btrfs_super_block *disk_super = fs_info->super_copy;
 137	if (set == FEAT_COMPAT)
 138		btrfs_set_super_compat_flags(disk_super, features);
 139	else if (set == FEAT_COMPAT_RO)
 140		btrfs_set_super_compat_ro_flags(disk_super, features);
 141	else
 142		btrfs_set_super_incompat_flags(disk_super, features);
 143}
 144
 145static int can_modify_feature(struct btrfs_feature_attr *fa)
 146{
 147	int val = 0;
 148	u64 set, clear;
 149	switch (fa->feature_set) {
 150	case FEAT_COMPAT:
 151		set = BTRFS_FEATURE_COMPAT_SAFE_SET;
 152		clear = BTRFS_FEATURE_COMPAT_SAFE_CLEAR;
 153		break;
 154	case FEAT_COMPAT_RO:
 155		set = BTRFS_FEATURE_COMPAT_RO_SAFE_SET;
 156		clear = BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR;
 157		break;
 158	case FEAT_INCOMPAT:
 159		set = BTRFS_FEATURE_INCOMPAT_SAFE_SET;
 160		clear = BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR;
 161		break;
 162	default:
 163		pr_warn("btrfs: sysfs: unknown feature set %d\n",
 164				fa->feature_set);
 165		return 0;
 166	}
 167
 168	if (set & fa->feature_bit)
 169		val |= 1;
 170	if (clear & fa->feature_bit)
 171		val |= 2;
 172
 173	return val;
 174}
 175
 176static ssize_t btrfs_feature_attr_show(struct kobject *kobj,
 177				       struct kobj_attribute *a, char *buf)
 178{
 179	int val = 0;
 180	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 181	struct btrfs_feature_attr *fa = to_btrfs_feature_attr(a);
 182	if (fs_info) {
 183		u64 features = get_features(fs_info, fa->feature_set);
 184		if (features & fa->feature_bit)
 185			val = 1;
 186	} else
 187		val = can_modify_feature(fa);
 188
 189	return sysfs_emit(buf, "%d\n", val);
 190}
 191
 192static ssize_t btrfs_feature_attr_store(struct kobject *kobj,
 193					struct kobj_attribute *a,
 194					const char *buf, size_t count)
 195{
 196	struct btrfs_fs_info *fs_info;
 197	struct btrfs_feature_attr *fa = to_btrfs_feature_attr(a);
 198	u64 features, set, clear;
 199	unsigned long val;
 200	int ret;
 201
 202	fs_info = to_fs_info(kobj);
 203	if (!fs_info)
 204		return -EPERM;
 205
 206	if (sb_rdonly(fs_info->sb))
 207		return -EROFS;
 208
 209	ret = kstrtoul(skip_spaces(buf), 0, &val);
 210	if (ret)
 211		return ret;
 212
 213	if (fa->feature_set == FEAT_COMPAT) {
 214		set = BTRFS_FEATURE_COMPAT_SAFE_SET;
 215		clear = BTRFS_FEATURE_COMPAT_SAFE_CLEAR;
 216	} else if (fa->feature_set == FEAT_COMPAT_RO) {
 217		set = BTRFS_FEATURE_COMPAT_RO_SAFE_SET;
 218		clear = BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR;
 219	} else {
 220		set = BTRFS_FEATURE_INCOMPAT_SAFE_SET;
 221		clear = BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR;
 222	}
 223
 224	features = get_features(fs_info, fa->feature_set);
 225
 226	/* Nothing to do */
 227	if ((val && (features & fa->feature_bit)) ||
 228	    (!val && !(features & fa->feature_bit)))
 229		return count;
 230
 231	if ((val && !(set & fa->feature_bit)) ||
 232	    (!val && !(clear & fa->feature_bit))) {
 233		btrfs_info(fs_info,
 234			"%sabling feature %s on mounted fs is not supported.",
 235			val ? "En" : "Dis", fa->kobj_attr.attr.name);
 236		return -EPERM;
 237	}
 238
 239	btrfs_info(fs_info, "%s %s feature flag",
 240		   val ? "Setting" : "Clearing", fa->kobj_attr.attr.name);
 241
 242	spin_lock(&fs_info->super_lock);
 243	features = get_features(fs_info, fa->feature_set);
 244	if (val)
 245		features |= fa->feature_bit;
 246	else
 247		features &= ~fa->feature_bit;
 248	set_features(fs_info, fa->feature_set, features);
 249	spin_unlock(&fs_info->super_lock);
 250
 251	/*
 252	 * We don't want to do full transaction commit from inside sysfs
 253	 */
 254	set_bit(BTRFS_FS_NEED_TRANS_COMMIT, &fs_info->flags);
 255	wake_up_process(fs_info->transaction_kthread);
 256
 257	return count;
 258}
 259
 260static umode_t btrfs_feature_visible(struct kobject *kobj,
 261				     struct attribute *attr, int unused)
 262{
 263	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 264	umode_t mode = attr->mode;
 265
 266	if (fs_info) {
 267		struct btrfs_feature_attr *fa;
 268		u64 features;
 269
 270		fa = attr_to_btrfs_feature_attr(attr);
 271		features = get_features(fs_info, fa->feature_set);
 272
 273		if (can_modify_feature(fa))
 274			mode |= S_IWUSR;
 275		else if (!(features & fa->feature_bit))
 276			mode = 0;
 277	}
 278
 279	return mode;
 280}
 281
 
 282BTRFS_FEAT_ATTR_INCOMPAT(default_subvol, DEFAULT_SUBVOL);
 283BTRFS_FEAT_ATTR_INCOMPAT(mixed_groups, MIXED_GROUPS);
 284BTRFS_FEAT_ATTR_INCOMPAT(compress_lzo, COMPRESS_LZO);
 285BTRFS_FEAT_ATTR_INCOMPAT(compress_zstd, COMPRESS_ZSTD);
 
 286BTRFS_FEAT_ATTR_INCOMPAT(extended_iref, EXTENDED_IREF);
 287BTRFS_FEAT_ATTR_INCOMPAT(raid56, RAID56);
 288BTRFS_FEAT_ATTR_INCOMPAT(skinny_metadata, SKINNY_METADATA);
 289BTRFS_FEAT_ATTR_INCOMPAT(no_holes, NO_HOLES);
 290BTRFS_FEAT_ATTR_INCOMPAT(metadata_uuid, METADATA_UUID);
 291BTRFS_FEAT_ATTR_COMPAT_RO(free_space_tree, FREE_SPACE_TREE);
 292BTRFS_FEAT_ATTR_COMPAT_RO(block_group_tree, BLOCK_GROUP_TREE);
 293BTRFS_FEAT_ATTR_INCOMPAT(raid1c34, RAID1C34);
 294BTRFS_FEAT_ATTR_INCOMPAT(simple_quota, SIMPLE_QUOTA);
 295#ifdef CONFIG_BLK_DEV_ZONED
 296BTRFS_FEAT_ATTR_INCOMPAT(zoned, ZONED);
 297#endif
 298#ifdef CONFIG_BTRFS_EXPERIMENTAL
 299/* Remove once support for extent tree v2 is feature complete */
 300BTRFS_FEAT_ATTR_INCOMPAT(extent_tree_v2, EXTENT_TREE_V2);
 301/* Remove once support for raid stripe tree is feature complete. */
 302BTRFS_FEAT_ATTR_INCOMPAT(raid_stripe_tree, RAID_STRIPE_TREE);
 303#endif
 304#ifdef CONFIG_FS_VERITY
 305BTRFS_FEAT_ATTR_COMPAT_RO(verity, VERITY);
 306#endif
 307
 308/*
 309 * Features which depend on feature bits and may differ between each fs.
 310 *
 311 * /sys/fs/btrfs/features      - all available features implemented by this version
 312 * /sys/fs/btrfs/UUID/features - features of the fs which are enabled or
 313 *                               can be changed on a mounted filesystem.
 314 */
 315static struct attribute *btrfs_supported_feature_attrs[] = {
 
 316	BTRFS_FEAT_ATTR_PTR(default_subvol),
 317	BTRFS_FEAT_ATTR_PTR(mixed_groups),
 318	BTRFS_FEAT_ATTR_PTR(compress_lzo),
 319	BTRFS_FEAT_ATTR_PTR(compress_zstd),
 
 320	BTRFS_FEAT_ATTR_PTR(extended_iref),
 321	BTRFS_FEAT_ATTR_PTR(raid56),
 322	BTRFS_FEAT_ATTR_PTR(skinny_metadata),
 323	BTRFS_FEAT_ATTR_PTR(no_holes),
 324	BTRFS_FEAT_ATTR_PTR(metadata_uuid),
 325	BTRFS_FEAT_ATTR_PTR(free_space_tree),
 326	BTRFS_FEAT_ATTR_PTR(raid1c34),
 327	BTRFS_FEAT_ATTR_PTR(block_group_tree),
 328	BTRFS_FEAT_ATTR_PTR(simple_quota),
 329#ifdef CONFIG_BLK_DEV_ZONED
 330	BTRFS_FEAT_ATTR_PTR(zoned),
 331#endif
 332#ifdef CONFIG_BTRFS_EXPERIMENTAL
 333	BTRFS_FEAT_ATTR_PTR(extent_tree_v2),
 334	BTRFS_FEAT_ATTR_PTR(raid_stripe_tree),
 335#endif
 336#ifdef CONFIG_FS_VERITY
 337	BTRFS_FEAT_ATTR_PTR(verity),
 338#endif
 339	NULL
 340};
 341
 
 
 
 
 
 
 
 342static const struct attribute_group btrfs_feature_attr_group = {
 343	.name = "features",
 344	.is_visible = btrfs_feature_visible,
 345	.attrs = btrfs_supported_feature_attrs,
 346};
 347
 348static ssize_t rmdir_subvol_show(struct kobject *kobj,
 349				 struct kobj_attribute *ka, char *buf)
 350{
 351	return sysfs_emit(buf, "0\n");
 352}
 353BTRFS_ATTR(static_feature, rmdir_subvol, rmdir_subvol_show);
 354
 355static ssize_t supported_checksums_show(struct kobject *kobj,
 356					struct kobj_attribute *a, char *buf)
 357{
 358	ssize_t ret = 0;
 359	int i;
 360
 361	for (i = 0; i < btrfs_get_num_csums(); i++) {
 362		/*
 363		 * This "trick" only works as long as 'enum btrfs_csum_type' has
 364		 * no holes in it
 365		 */
 366		ret += sysfs_emit_at(buf, ret, "%s%s", (i == 0 ? "" : " "),
 367				     btrfs_super_csum_name(i));
 368
 369	}
 370
 371	ret += sysfs_emit_at(buf, ret, "\n");
 372	return ret;
 373}
 374BTRFS_ATTR(static_feature, supported_checksums, supported_checksums_show);
 375
 376static ssize_t send_stream_version_show(struct kobject *kobj,
 377					struct kobj_attribute *ka, char *buf)
 378{
 379	return sysfs_emit(buf, "%d\n", BTRFS_SEND_STREAM_VERSION);
 380}
 381BTRFS_ATTR(static_feature, send_stream_version, send_stream_version_show);
 382
 383static const char *rescue_opts[] = {
 384	"usebackuproot",
 385	"nologreplay",
 386	"ignorebadroots",
 387	"ignoredatacsums",
 388	"ignoremetacsums",
 389	"ignoresuperflags",
 390	"all",
 391};
 392
 393static ssize_t supported_rescue_options_show(struct kobject *kobj,
 394					     struct kobj_attribute *a,
 395					     char *buf)
 396{
 397	ssize_t ret = 0;
 398	int i;
 399
 400	for (i = 0; i < ARRAY_SIZE(rescue_opts); i++)
 401		ret += sysfs_emit_at(buf, ret, "%s%s", (i ? " " : ""), rescue_opts[i]);
 402	ret += sysfs_emit_at(buf, ret, "\n");
 
 403	return ret;
 404}
 405BTRFS_ATTR(static_feature, supported_rescue_options,
 406	   supported_rescue_options_show);
 407
 408static ssize_t supported_sectorsizes_show(struct kobject *kobj,
 409					  struct kobj_attribute *a,
 410					  char *buf)
 411{
 412	ssize_t ret = 0;
 413
 414	/* An artificial limit to only support 4K and PAGE_SIZE */
 415	if (PAGE_SIZE > SZ_4K)
 416		ret += sysfs_emit_at(buf, ret, "%u ", SZ_4K);
 417	ret += sysfs_emit_at(buf, ret, "%lu\n", PAGE_SIZE);
 418
 419	return ret;
 420}
 421BTRFS_ATTR(static_feature, supported_sectorsizes,
 422	   supported_sectorsizes_show);
 423
 424static ssize_t acl_show(struct kobject *kobj, struct kobj_attribute *a, char *buf)
 425{
 426	return sysfs_emit(buf, "%d\n", IS_ENABLED(CONFIG_BTRFS_FS_POSIX_ACL));
 427}
 428BTRFS_ATTR(static_feature, acl, acl_show);
 429
 430static ssize_t temp_fsid_supported_show(struct kobject *kobj,
 431					struct kobj_attribute *a, char *buf)
 432{
 433	return sysfs_emit(buf, "0\n");
 434}
 435BTRFS_ATTR(static_feature, temp_fsid, temp_fsid_supported_show);
 436
 437/*
 438 * Features which only depend on kernel version.
 439 *
 440 * These are listed in /sys/fs/btrfs/features along with
 441 * btrfs_supported_feature_attrs.
 442 */
 443static struct attribute *btrfs_supported_static_feature_attrs[] = {
 444	BTRFS_ATTR_PTR(static_feature, acl),
 445	BTRFS_ATTR_PTR(static_feature, rmdir_subvol),
 446	BTRFS_ATTR_PTR(static_feature, supported_checksums),
 447	BTRFS_ATTR_PTR(static_feature, send_stream_version),
 448	BTRFS_ATTR_PTR(static_feature, supported_rescue_options),
 449	BTRFS_ATTR_PTR(static_feature, supported_sectorsizes),
 450	BTRFS_ATTR_PTR(static_feature, temp_fsid),
 451	NULL
 452};
 453
 
 
 
 
 
 
 454static const struct attribute_group btrfs_static_feature_attr_group = {
 455	.name = "features",
 456	.attrs = btrfs_supported_static_feature_attrs,
 457};
 458
 
 
 459/*
 460 * Discard statistics and tunables
 461 */
 462#define discard_to_fs_info(_kobj)	to_fs_info(get_btrfs_kobj(_kobj))
 463
 464static ssize_t btrfs_discardable_bytes_show(struct kobject *kobj,
 465					    struct kobj_attribute *a,
 466					    char *buf)
 467{
 468	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 469
 470	return sysfs_emit(buf, "%lld\n",
 471			atomic64_read(&fs_info->discard_ctl.discardable_bytes));
 472}
 473BTRFS_ATTR(discard, discardable_bytes, btrfs_discardable_bytes_show);
 474
 475static ssize_t btrfs_discardable_extents_show(struct kobject *kobj,
 476					      struct kobj_attribute *a,
 477					      char *buf)
 478{
 479	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 480
 481	return sysfs_emit(buf, "%d\n",
 482			atomic_read(&fs_info->discard_ctl.discardable_extents));
 483}
 484BTRFS_ATTR(discard, discardable_extents, btrfs_discardable_extents_show);
 485
 486static ssize_t btrfs_discard_bitmap_bytes_show(struct kobject *kobj,
 487					       struct kobj_attribute *a,
 488					       char *buf)
 489{
 490	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 491
 492	return sysfs_emit(buf, "%llu\n",
 493			  fs_info->discard_ctl.discard_bitmap_bytes);
 494}
 495BTRFS_ATTR(discard, discard_bitmap_bytes, btrfs_discard_bitmap_bytes_show);
 496
 497static ssize_t btrfs_discard_bytes_saved_show(struct kobject *kobj,
 498					      struct kobj_attribute *a,
 499					      char *buf)
 500{
 501	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 502
 503	return sysfs_emit(buf, "%lld\n",
 504		atomic64_read(&fs_info->discard_ctl.discard_bytes_saved));
 505}
 506BTRFS_ATTR(discard, discard_bytes_saved, btrfs_discard_bytes_saved_show);
 507
 508static ssize_t btrfs_discard_extent_bytes_show(struct kobject *kobj,
 509					       struct kobj_attribute *a,
 510					       char *buf)
 511{
 512	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 513
 514	return sysfs_emit(buf, "%llu\n",
 515			  fs_info->discard_ctl.discard_extent_bytes);
 516}
 517BTRFS_ATTR(discard, discard_extent_bytes, btrfs_discard_extent_bytes_show);
 518
 519static ssize_t btrfs_discard_iops_limit_show(struct kobject *kobj,
 520					     struct kobj_attribute *a,
 521					     char *buf)
 522{
 523	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 524
 525	return sysfs_emit(buf, "%u\n",
 526			  READ_ONCE(fs_info->discard_ctl.iops_limit));
 527}
 528
 529static ssize_t btrfs_discard_iops_limit_store(struct kobject *kobj,
 530					      struct kobj_attribute *a,
 531					      const char *buf, size_t len)
 532{
 533	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 534	struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
 535	u32 iops_limit;
 536	int ret;
 537
 538	ret = kstrtou32(buf, 10, &iops_limit);
 539	if (ret)
 540		return -EINVAL;
 541
 542	WRITE_ONCE(discard_ctl->iops_limit, iops_limit);
 543	btrfs_discard_calc_delay(discard_ctl);
 544	btrfs_discard_schedule_work(discard_ctl, true);
 545	return len;
 546}
 547BTRFS_ATTR_RW(discard, iops_limit, btrfs_discard_iops_limit_show,
 548	      btrfs_discard_iops_limit_store);
 549
 550static ssize_t btrfs_discard_kbps_limit_show(struct kobject *kobj,
 551					     struct kobj_attribute *a,
 552					     char *buf)
 553{
 554	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 555
 556	return sysfs_emit(buf, "%u\n",
 557			  READ_ONCE(fs_info->discard_ctl.kbps_limit));
 558}
 559
 560static ssize_t btrfs_discard_kbps_limit_store(struct kobject *kobj,
 561					      struct kobj_attribute *a,
 562					      const char *buf, size_t len)
 563{
 564	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 565	struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
 566	u32 kbps_limit;
 567	int ret;
 568
 569	ret = kstrtou32(buf, 10, &kbps_limit);
 570	if (ret)
 571		return -EINVAL;
 572
 573	WRITE_ONCE(discard_ctl->kbps_limit, kbps_limit);
 574	btrfs_discard_schedule_work(discard_ctl, true);
 575	return len;
 576}
 577BTRFS_ATTR_RW(discard, kbps_limit, btrfs_discard_kbps_limit_show,
 578	      btrfs_discard_kbps_limit_store);
 579
 580static ssize_t btrfs_discard_max_discard_size_show(struct kobject *kobj,
 581						   struct kobj_attribute *a,
 582						   char *buf)
 583{
 584	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 585
 586	return sysfs_emit(buf, "%llu\n",
 587			  READ_ONCE(fs_info->discard_ctl.max_discard_size));
 588}
 589
 590static ssize_t btrfs_discard_max_discard_size_store(struct kobject *kobj,
 591						    struct kobj_attribute *a,
 592						    const char *buf, size_t len)
 593{
 594	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 595	struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
 596	u64 max_discard_size;
 597	int ret;
 598
 599	ret = kstrtou64(buf, 10, &max_discard_size);
 600	if (ret)
 601		return -EINVAL;
 602
 603	WRITE_ONCE(discard_ctl->max_discard_size, max_discard_size);
 604
 605	return len;
 606}
 607BTRFS_ATTR_RW(discard, max_discard_size, btrfs_discard_max_discard_size_show,
 608	      btrfs_discard_max_discard_size_store);
 609
 610/*
 611 * Per-filesystem stats for discard (when mounted with discard=async).
 612 *
 613 * Path: /sys/fs/btrfs/<uuid>/discard/
 614 */
 615static const struct attribute *discard_attrs[] = {
 616	BTRFS_ATTR_PTR(discard, discardable_bytes),
 617	BTRFS_ATTR_PTR(discard, discardable_extents),
 618	BTRFS_ATTR_PTR(discard, discard_bitmap_bytes),
 619	BTRFS_ATTR_PTR(discard, discard_bytes_saved),
 620	BTRFS_ATTR_PTR(discard, discard_extent_bytes),
 621	BTRFS_ATTR_PTR(discard, iops_limit),
 622	BTRFS_ATTR_PTR(discard, kbps_limit),
 623	BTRFS_ATTR_PTR(discard, max_discard_size),
 624	NULL,
 625};
 626
 627#ifdef CONFIG_BTRFS_DEBUG
 628
 629/*
 630 * Per-filesystem runtime debugging exported via sysfs.
 631 *
 632 * Path: /sys/fs/btrfs/UUID/debug/
 
 633 */
 634static const struct attribute *btrfs_debug_mount_attrs[] = {
 635	NULL,
 636};
 637
 638/*
 639 * Runtime debugging exported via sysfs, applies to all mounted filesystems.
 640 *
 641 * Path: /sys/fs/btrfs/debug
 642 */
 643static struct attribute *btrfs_debug_feature_attrs[] = {
 644	NULL
 645};
 646
 647static const struct attribute_group btrfs_debug_feature_attr_group = {
 648	.name = "debug",
 649	.attrs = btrfs_debug_feature_attrs,
 650};
 651
 652#endif
 653
 654static ssize_t btrfs_show_u64(u64 *value_ptr, spinlock_t *lock, char *buf)
 655{
 656	u64 val;
 657	if (lock)
 658		spin_lock(lock);
 659	val = *value_ptr;
 660	if (lock)
 661		spin_unlock(lock);
 662	return sysfs_emit(buf, "%llu\n", val);
 663}
 664
 665static ssize_t global_rsv_size_show(struct kobject *kobj,
 666				    struct kobj_attribute *ka, char *buf)
 667{
 668	struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent);
 669	struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
 670	return btrfs_show_u64(&block_rsv->size, &block_rsv->lock, buf);
 671}
 672BTRFS_ATTR(allocation, global_rsv_size, global_rsv_size_show);
 673
 674static ssize_t global_rsv_reserved_show(struct kobject *kobj,
 675					struct kobj_attribute *a, char *buf)
 676{
 677	struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent);
 678	struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
 679	return btrfs_show_u64(&block_rsv->reserved, &block_rsv->lock, buf);
 680}
 681BTRFS_ATTR(allocation, global_rsv_reserved, global_rsv_reserved_show);
 682
 683#define to_space_info(_kobj) container_of(_kobj, struct btrfs_space_info, kobj)
 684#define to_raid_kobj(_kobj) container_of(_kobj, struct raid_kobject, kobj)
 685
 686static ssize_t raid_bytes_show(struct kobject *kobj,
 687			       struct kobj_attribute *attr, char *buf);
 688BTRFS_ATTR(raid, total_bytes, raid_bytes_show);
 689BTRFS_ATTR(raid, used_bytes, raid_bytes_show);
 690
 691static ssize_t raid_bytes_show(struct kobject *kobj,
 692			       struct kobj_attribute *attr, char *buf)
 693
 694{
 695	struct btrfs_space_info *sinfo = to_space_info(kobj->parent);
 696	struct btrfs_block_group *block_group;
 697	int index = btrfs_bg_flags_to_raid_index(to_raid_kobj(kobj)->flags);
 698	u64 val = 0;
 699
 700	down_read(&sinfo->groups_sem);
 701	list_for_each_entry(block_group, &sinfo->block_groups[index], list) {
 702		if (&attr->attr == BTRFS_ATTR_PTR(raid, total_bytes))
 703			val += block_group->length;
 704		else
 705			val += block_group->used;
 706	}
 707	up_read(&sinfo->groups_sem);
 708	return sysfs_emit(buf, "%llu\n", val);
 709}
 710
 711/*
 712 * Allocation information about block group profiles.
 713 *
 714 * Path: /sys/fs/btrfs/<uuid>/allocation/<bg-type>/<bg-profile>/
 715 */
 716static struct attribute *raid_attrs[] = {
 717	BTRFS_ATTR_PTR(raid, total_bytes),
 718	BTRFS_ATTR_PTR(raid, used_bytes),
 719	NULL
 720};
 721ATTRIBUTE_GROUPS(raid);
 722
 723static void release_raid_kobj(struct kobject *kobj)
 724{
 725	kfree(to_raid_kobj(kobj));
 726}
 727
 728static const struct kobj_type btrfs_raid_ktype = {
 729	.sysfs_ops = &kobj_sysfs_ops,
 730	.release = release_raid_kobj,
 731	.default_groups = raid_groups,
 732};
 733
 734#define SPACE_INFO_ATTR(field)						\
 735static ssize_t btrfs_space_info_show_##field(struct kobject *kobj,	\
 736					     struct kobj_attribute *a,	\
 737					     char *buf)			\
 738{									\
 739	struct btrfs_space_info *sinfo = to_space_info(kobj);		\
 740	return btrfs_show_u64(&sinfo->field, &sinfo->lock, buf);	\
 741}									\
 742BTRFS_ATTR(space_info, field, btrfs_space_info_show_##field)
 743
 744static ssize_t btrfs_chunk_size_show(struct kobject *kobj,
 745				     struct kobj_attribute *a, char *buf)
 746{
 747	struct btrfs_space_info *sinfo = to_space_info(kobj);
 748
 749	return sysfs_emit(buf, "%llu\n", READ_ONCE(sinfo->chunk_size));
 750}
 751
 752/*
 753 * Store new chunk size in space info. Can be called on a read-only filesystem.
 754 *
 755 * If the new chunk size value is larger than 10% of free space it is reduced
 756 * to match that limit. Alignment must be to 256M and the system chunk size
 757 * cannot be set.
 758 */
 759static ssize_t btrfs_chunk_size_store(struct kobject *kobj,
 760				      struct kobj_attribute *a,
 761				      const char *buf, size_t len)
 762{
 763	struct btrfs_space_info *space_info = to_space_info(kobj);
 764	struct btrfs_fs_info *fs_info = to_fs_info(get_btrfs_kobj(kobj));
 765	char *retptr;
 766	u64 val;
 767
 768	if (!capable(CAP_SYS_ADMIN))
 769		return -EPERM;
 770
 771	if (!fs_info->fs_devices)
 772		return -EINVAL;
 773
 774	if (btrfs_is_zoned(fs_info))
 775		return -EINVAL;
 776
 777	/* System block type must not be changed. */
 778	if (space_info->flags & BTRFS_BLOCK_GROUP_SYSTEM)
 779		return -EPERM;
 780
 781	val = memparse(buf, &retptr);
 782	/* There could be trailing '\n', also catch any typos after the value */
 783	retptr = skip_spaces(retptr);
 784	if (*retptr != 0 || val == 0)
 785		return -EINVAL;
 786
 787	val = min(val, BTRFS_MAX_DATA_CHUNK_SIZE);
 788
 789	/* Limit stripe size to 10% of available space. */
 790	val = min(mult_perc(fs_info->fs_devices->total_rw_bytes, 10), val);
 791
 792	/* Must be multiple of 256M. */
 793	val &= ~((u64)SZ_256M - 1);
 794
 795	/* Must be at least 256M. */
 796	if (val < SZ_256M)
 797		return -EINVAL;
 798
 799	btrfs_update_space_info_chunk_size(space_info, val);
 800
 801	return len;
 802}
 803
 804static ssize_t btrfs_size_classes_show(struct kobject *kobj,
 805				       struct kobj_attribute *a, char *buf)
 806{
 807	struct btrfs_space_info *sinfo = to_space_info(kobj);
 808	struct btrfs_block_group *bg;
 809	u32 none = 0;
 810	u32 small = 0;
 811	u32 medium = 0;
 812	u32 large = 0;
 813
 814	for (int i = 0; i < BTRFS_NR_RAID_TYPES; ++i) {
 815		down_read(&sinfo->groups_sem);
 816		list_for_each_entry(bg, &sinfo->block_groups[i], list) {
 817			if (!btrfs_block_group_should_use_size_class(bg))
 818				continue;
 819			switch (bg->size_class) {
 820			case BTRFS_BG_SZ_NONE:
 821				none++;
 822				break;
 823			case BTRFS_BG_SZ_SMALL:
 824				small++;
 825				break;
 826			case BTRFS_BG_SZ_MEDIUM:
 827				medium++;
 828				break;
 829			case BTRFS_BG_SZ_LARGE:
 830				large++;
 831				break;
 832			}
 833		}
 834		up_read(&sinfo->groups_sem);
 835	}
 836	return sysfs_emit(buf, "none %u\n"
 837			       "small %u\n"
 838			       "medium %u\n"
 839			       "large %u\n",
 840			       none, small, medium, large);
 841}
 842
 843#ifdef CONFIG_BTRFS_DEBUG
 844/*
 845 * Request chunk allocation with current chunk size.
 846 */
 847static ssize_t btrfs_force_chunk_alloc_store(struct kobject *kobj,
 848					     struct kobj_attribute *a,
 849					     const char *buf, size_t len)
 850{
 851	struct btrfs_space_info *space_info = to_space_info(kobj);
 852	struct btrfs_fs_info *fs_info = to_fs_info(get_btrfs_kobj(kobj));
 853	struct btrfs_trans_handle *trans;
 854	bool val;
 855	int ret;
 856
 857	if (!capable(CAP_SYS_ADMIN))
 858		return -EPERM;
 859
 860	if (sb_rdonly(fs_info->sb))
 861		return -EROFS;
 862
 863	ret = kstrtobool(buf, &val);
 864	if (ret)
 865		return ret;
 866
 867	if (!val)
 868		return -EINVAL;
 869
 870	/*
 871	 * This is unsafe to be called from sysfs context and may cause
 872	 * unexpected problems.
 873	 */
 874	trans = btrfs_start_transaction(fs_info->tree_root, 0);
 875	if (IS_ERR(trans))
 876		return PTR_ERR(trans);
 877	ret = btrfs_force_chunk_alloc(trans, space_info->flags);
 878	btrfs_end_transaction(trans);
 879
 880	if (ret == 1)
 881		return len;
 882
 883	return -ENOSPC;
 884}
 885BTRFS_ATTR_W(space_info, force_chunk_alloc, btrfs_force_chunk_alloc_store);
 886
 887#endif
 888
 889SPACE_INFO_ATTR(flags);
 890SPACE_INFO_ATTR(total_bytes);
 891SPACE_INFO_ATTR(bytes_used);
 892SPACE_INFO_ATTR(bytes_pinned);
 893SPACE_INFO_ATTR(bytes_reserved);
 894SPACE_INFO_ATTR(bytes_may_use);
 895SPACE_INFO_ATTR(bytes_readonly);
 896SPACE_INFO_ATTR(bytes_zone_unusable);
 897SPACE_INFO_ATTR(disk_used);
 898SPACE_INFO_ATTR(disk_total);
 899SPACE_INFO_ATTR(reclaim_count);
 900SPACE_INFO_ATTR(reclaim_bytes);
 901SPACE_INFO_ATTR(reclaim_errors);
 902BTRFS_ATTR_RW(space_info, chunk_size, btrfs_chunk_size_show, btrfs_chunk_size_store);
 903BTRFS_ATTR(space_info, size_classes, btrfs_size_classes_show);
 904
 905static ssize_t btrfs_sinfo_bg_reclaim_threshold_show(struct kobject *kobj,
 906						     struct kobj_attribute *a,
 907						     char *buf)
 908{
 909	struct btrfs_space_info *space_info = to_space_info(kobj);
 910	ssize_t ret;
 911
 912	spin_lock(&space_info->lock);
 913	ret = sysfs_emit(buf, "%d\n", btrfs_calc_reclaim_threshold(space_info));
 914	spin_unlock(&space_info->lock);
 915	return ret;
 916}
 917
 918static ssize_t btrfs_sinfo_bg_reclaim_threshold_store(struct kobject *kobj,
 919						      struct kobj_attribute *a,
 920						      const char *buf, size_t len)
 921{
 922	struct btrfs_space_info *space_info = to_space_info(kobj);
 923	int thresh;
 924	int ret;
 925
 926	if (READ_ONCE(space_info->dynamic_reclaim))
 927		return -EINVAL;
 928
 929	ret = kstrtoint(buf, 10, &thresh);
 930	if (ret)
 931		return ret;
 932
 933	if (thresh < 0 || thresh > 100)
 934		return -EINVAL;
 935
 936	WRITE_ONCE(space_info->bg_reclaim_threshold, thresh);
 937
 938	return len;
 939}
 940
 941BTRFS_ATTR_RW(space_info, bg_reclaim_threshold,
 942	      btrfs_sinfo_bg_reclaim_threshold_show,
 943	      btrfs_sinfo_bg_reclaim_threshold_store);
 944
 945static ssize_t btrfs_sinfo_dynamic_reclaim_show(struct kobject *kobj,
 946						struct kobj_attribute *a,
 947						char *buf)
 948{
 949	struct btrfs_space_info *space_info = to_space_info(kobj);
 950
 951	return sysfs_emit(buf, "%d\n", READ_ONCE(space_info->dynamic_reclaim));
 952}
 953
 954static ssize_t btrfs_sinfo_dynamic_reclaim_store(struct kobject *kobj,
 955						 struct kobj_attribute *a,
 956						 const char *buf, size_t len)
 957{
 958	struct btrfs_space_info *space_info = to_space_info(kobj);
 959	int dynamic_reclaim;
 960	int ret;
 961
 962	ret = kstrtoint(buf, 10, &dynamic_reclaim);
 963	if (ret)
 964		return ret;
 965
 966	if (dynamic_reclaim < 0)
 967		return -EINVAL;
 968
 969	WRITE_ONCE(space_info->dynamic_reclaim, dynamic_reclaim != 0);
 970
 971	return len;
 972}
 973
 974BTRFS_ATTR_RW(space_info, dynamic_reclaim,
 975	      btrfs_sinfo_dynamic_reclaim_show,
 976	      btrfs_sinfo_dynamic_reclaim_store);
 977
 978static ssize_t btrfs_sinfo_periodic_reclaim_show(struct kobject *kobj,
 979						struct kobj_attribute *a,
 980						char *buf)
 981{
 982	struct btrfs_space_info *space_info = to_space_info(kobj);
 983
 984	return sysfs_emit(buf, "%d\n", READ_ONCE(space_info->periodic_reclaim));
 985}
 986
 987static ssize_t btrfs_sinfo_periodic_reclaim_store(struct kobject *kobj,
 988						 struct kobj_attribute *a,
 989						 const char *buf, size_t len)
 990{
 991	struct btrfs_space_info *space_info = to_space_info(kobj);
 992	int periodic_reclaim;
 993	int ret;
 994
 995	ret = kstrtoint(buf, 10, &periodic_reclaim);
 996	if (ret)
 997		return ret;
 998
 999	if (periodic_reclaim < 0)
1000		return -EINVAL;
1001
1002	WRITE_ONCE(space_info->periodic_reclaim, periodic_reclaim != 0);
1003
1004	return len;
1005}
1006
1007BTRFS_ATTR_RW(space_info, periodic_reclaim,
1008	      btrfs_sinfo_periodic_reclaim_show,
1009	      btrfs_sinfo_periodic_reclaim_store);
1010
1011/*
1012 * Allocation information about block group types.
1013 *
1014 * Path: /sys/fs/btrfs/<uuid>/allocation/<bg-type>/
1015 */
1016static struct attribute *space_info_attrs[] = {
1017	BTRFS_ATTR_PTR(space_info, flags),
1018	BTRFS_ATTR_PTR(space_info, total_bytes),
1019	BTRFS_ATTR_PTR(space_info, bytes_used),
1020	BTRFS_ATTR_PTR(space_info, bytes_pinned),
1021	BTRFS_ATTR_PTR(space_info, bytes_reserved),
1022	BTRFS_ATTR_PTR(space_info, bytes_may_use),
1023	BTRFS_ATTR_PTR(space_info, bytes_readonly),
1024	BTRFS_ATTR_PTR(space_info, bytes_zone_unusable),
1025	BTRFS_ATTR_PTR(space_info, disk_used),
1026	BTRFS_ATTR_PTR(space_info, disk_total),
1027	BTRFS_ATTR_PTR(space_info, bg_reclaim_threshold),
1028	BTRFS_ATTR_PTR(space_info, dynamic_reclaim),
1029	BTRFS_ATTR_PTR(space_info, chunk_size),
1030	BTRFS_ATTR_PTR(space_info, size_classes),
1031	BTRFS_ATTR_PTR(space_info, reclaim_count),
1032	BTRFS_ATTR_PTR(space_info, reclaim_bytes),
1033	BTRFS_ATTR_PTR(space_info, reclaim_errors),
1034	BTRFS_ATTR_PTR(space_info, periodic_reclaim),
1035#ifdef CONFIG_BTRFS_DEBUG
1036	BTRFS_ATTR_PTR(space_info, force_chunk_alloc),
1037#endif
1038	NULL,
1039};
1040ATTRIBUTE_GROUPS(space_info);
1041
1042static void space_info_release(struct kobject *kobj)
1043{
1044	struct btrfs_space_info *sinfo = to_space_info(kobj);
1045	kfree(sinfo);
1046}
1047
1048static const struct kobj_type space_info_ktype = {
1049	.sysfs_ops = &kobj_sysfs_ops,
1050	.release = space_info_release,
1051	.default_groups = space_info_groups,
1052};
1053
1054/*
1055 * Allocation information about block groups.
1056 *
1057 * Path: /sys/fs/btrfs/<uuid>/allocation/
1058 */
1059static const struct attribute *allocation_attrs[] = {
1060	BTRFS_ATTR_PTR(allocation, global_rsv_reserved),
1061	BTRFS_ATTR_PTR(allocation, global_rsv_size),
1062	NULL,
1063};
1064
1065static ssize_t btrfs_label_show(struct kobject *kobj,
1066				struct kobj_attribute *a, char *buf)
1067{
1068	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1069	char *label = fs_info->super_copy->label;
1070	ssize_t ret;
1071
1072	spin_lock(&fs_info->super_lock);
1073	ret = sysfs_emit(buf, label[0] ? "%s\n" : "%s", label);
1074	spin_unlock(&fs_info->super_lock);
1075
1076	return ret;
1077}
1078
1079static ssize_t btrfs_label_store(struct kobject *kobj,
1080				 struct kobj_attribute *a,
1081				 const char *buf, size_t len)
1082{
1083	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1084	size_t p_len;
1085
1086	if (!fs_info)
1087		return -EPERM;
1088
1089	if (sb_rdonly(fs_info->sb))
1090		return -EROFS;
1091
1092	/*
1093	 * p_len is the len until the first occurrence of either
1094	 * '\n' or '\0'
1095	 */
1096	p_len = strcspn(buf, "\n");
1097
1098	if (p_len >= BTRFS_LABEL_SIZE)
1099		return -EINVAL;
1100
1101	spin_lock(&fs_info->super_lock);
1102	memset(fs_info->super_copy->label, 0, BTRFS_LABEL_SIZE);
1103	memcpy(fs_info->super_copy->label, buf, p_len);
1104	spin_unlock(&fs_info->super_lock);
1105
1106	/*
1107	 * We don't want to do full transaction commit from inside sysfs
1108	 */
1109	set_bit(BTRFS_FS_NEED_TRANS_COMMIT, &fs_info->flags);
1110	wake_up_process(fs_info->transaction_kthread);
1111
1112	return len;
1113}
1114BTRFS_ATTR_RW(, label, btrfs_label_show, btrfs_label_store);
1115
1116static ssize_t btrfs_nodesize_show(struct kobject *kobj,
1117				struct kobj_attribute *a, char *buf)
1118{
1119	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1120
1121	return sysfs_emit(buf, "%u\n", fs_info->nodesize);
1122}
1123
1124BTRFS_ATTR(, nodesize, btrfs_nodesize_show);
1125
1126static ssize_t btrfs_sectorsize_show(struct kobject *kobj,
1127				struct kobj_attribute *a, char *buf)
1128{
1129	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1130
1131	return sysfs_emit(buf, "%u\n", fs_info->sectorsize);
 
1132}
1133
1134BTRFS_ATTR(, sectorsize, btrfs_sectorsize_show);
1135
1136static ssize_t btrfs_commit_stats_show(struct kobject *kobj,
1137				       struct kobj_attribute *a, char *buf)
1138{
1139	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1140
1141	return sysfs_emit(buf,
1142		"commits %llu\n"
1143		"last_commit_ms %llu\n"
1144		"max_commit_ms %llu\n"
1145		"total_commit_ms %llu\n",
1146		fs_info->commit_stats.commit_count,
1147		div_u64(fs_info->commit_stats.last_commit_dur, NSEC_PER_MSEC),
1148		div_u64(fs_info->commit_stats.max_commit_dur, NSEC_PER_MSEC),
1149		div_u64(fs_info->commit_stats.total_commit_dur, NSEC_PER_MSEC));
1150}
1151
1152static ssize_t btrfs_commit_stats_store(struct kobject *kobj,
1153					struct kobj_attribute *a,
1154					const char *buf, size_t len)
1155{
1156	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1157	unsigned long val;
1158	int ret;
1159
1160	if (!fs_info)
1161		return -EPERM;
1162
1163	if (!capable(CAP_SYS_RESOURCE))
1164		return -EPERM;
1165
1166	ret = kstrtoul(buf, 10, &val);
1167	if (ret)
1168		return ret;
1169	if (val)
1170		return -EINVAL;
1171
1172	WRITE_ONCE(fs_info->commit_stats.max_commit_dur, 0);
1173
1174	return len;
1175}
1176BTRFS_ATTR_RW(, commit_stats, btrfs_commit_stats_show, btrfs_commit_stats_store);
1177
1178static ssize_t btrfs_clone_alignment_show(struct kobject *kobj,
1179				struct kobj_attribute *a, char *buf)
1180{
1181	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1182
1183	return sysfs_emit(buf, "%u\n", fs_info->sectorsize);
1184}
1185
1186BTRFS_ATTR(, clone_alignment, btrfs_clone_alignment_show);
1187
1188static ssize_t quota_override_show(struct kobject *kobj,
1189				   struct kobj_attribute *a, char *buf)
1190{
1191	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1192	int quota_override;
1193
1194	quota_override = test_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
1195	return sysfs_emit(buf, "%d\n", quota_override);
1196}
1197
1198static ssize_t quota_override_store(struct kobject *kobj,
1199				    struct kobj_attribute *a,
1200				    const char *buf, size_t len)
1201{
1202	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1203	unsigned long knob;
1204	int err;
1205
1206	if (!fs_info)
1207		return -EPERM;
1208
1209	if (!capable(CAP_SYS_RESOURCE))
1210		return -EPERM;
1211
1212	err = kstrtoul(buf, 10, &knob);
1213	if (err)
1214		return err;
1215	if (knob > 1)
1216		return -EINVAL;
1217
1218	if (knob)
1219		set_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
1220	else
1221		clear_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
1222
1223	return len;
1224}
1225
1226BTRFS_ATTR_RW(, quota_override, quota_override_show, quota_override_store);
1227
1228static ssize_t btrfs_metadata_uuid_show(struct kobject *kobj,
1229				struct kobj_attribute *a, char *buf)
1230{
1231	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1232
1233	return sysfs_emit(buf, "%pU\n", fs_info->fs_devices->metadata_uuid);
 
1234}
1235
1236BTRFS_ATTR(, metadata_uuid, btrfs_metadata_uuid_show);
1237
1238static ssize_t btrfs_checksum_show(struct kobject *kobj,
1239				   struct kobj_attribute *a, char *buf)
1240{
1241	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1242	u16 csum_type = btrfs_super_csum_type(fs_info->super_copy);
1243
1244	return sysfs_emit(buf, "%s (%s)\n",
1245			  btrfs_super_csum_name(csum_type),
1246			  crypto_shash_driver_name(fs_info->csum_shash));
1247}
1248
1249BTRFS_ATTR(, checksum, btrfs_checksum_show);
1250
1251static ssize_t btrfs_exclusive_operation_show(struct kobject *kobj,
1252		struct kobj_attribute *a, char *buf)
1253{
1254	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1255	const char *str;
1256
1257	switch (READ_ONCE(fs_info->exclusive_operation)) {
1258		case  BTRFS_EXCLOP_NONE:
1259			str = "none\n";
1260			break;
1261		case BTRFS_EXCLOP_BALANCE:
1262			str = "balance\n";
1263			break;
1264		case BTRFS_EXCLOP_BALANCE_PAUSED:
1265			str = "balance paused\n";
1266			break;
1267		case BTRFS_EXCLOP_DEV_ADD:
1268			str = "device add\n";
1269			break;
1270		case BTRFS_EXCLOP_DEV_REMOVE:
1271			str = "device remove\n";
1272			break;
1273		case BTRFS_EXCLOP_DEV_REPLACE:
1274			str = "device replace\n";
1275			break;
1276		case BTRFS_EXCLOP_RESIZE:
1277			str = "resize\n";
1278			break;
1279		case BTRFS_EXCLOP_SWAP_ACTIVATE:
1280			str = "swap activate\n";
1281			break;
1282		default:
1283			str = "UNKNOWN\n";
1284			break;
1285	}
1286	return sysfs_emit(buf, "%s", str);
1287}
1288BTRFS_ATTR(, exclusive_operation, btrfs_exclusive_operation_show);
1289
1290static ssize_t btrfs_generation_show(struct kobject *kobj,
1291				     struct kobj_attribute *a, char *buf)
1292{
1293	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1294
1295	return sysfs_emit(buf, "%llu\n", btrfs_get_fs_generation(fs_info));
1296}
1297BTRFS_ATTR(, generation, btrfs_generation_show);
1298
1299static ssize_t btrfs_temp_fsid_show(struct kobject *kobj,
1300				    struct kobj_attribute *a, char *buf)
 
 
 
1301{
1302	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 
 
 
1303
1304	return sysfs_emit(buf, "%d\n", fs_info->fs_devices->temp_fsid);
 
 
 
 
 
1305}
1306BTRFS_ATTR(, temp_fsid, btrfs_temp_fsid_show);
1307
1308static const char * const btrfs_read_policy_name[] = { "pid" };
1309
1310static ssize_t btrfs_read_policy_show(struct kobject *kobj,
1311				      struct kobj_attribute *a, char *buf)
1312{
1313	struct btrfs_fs_devices *fs_devices = to_fs_devs(kobj);
1314	const enum btrfs_read_policy policy = READ_ONCE(fs_devices->read_policy);
1315	ssize_t ret = 0;
1316	int i;
1317
1318	for (i = 0; i < BTRFS_NR_READ_POLICY; i++) {
1319		if (policy == i)
1320			ret += sysfs_emit_at(buf, ret, "%s[%s]",
1321					 (ret == 0 ? "" : " "),
1322					 btrfs_read_policy_name[i]);
1323		else
1324			ret += sysfs_emit_at(buf, ret, "%s%s",
1325					 (ret == 0 ? "" : " "),
1326					 btrfs_read_policy_name[i]);
1327	}
1328
1329	ret += sysfs_emit_at(buf, ret, "\n");
1330
1331	return ret;
1332}
1333
1334static ssize_t btrfs_read_policy_store(struct kobject *kobj,
1335				       struct kobj_attribute *a,
1336				       const char *buf, size_t len)
1337{
1338	struct btrfs_fs_devices *fs_devices = to_fs_devs(kobj);
1339	int i;
1340
1341	for (i = 0; i < BTRFS_NR_READ_POLICY; i++) {
1342		if (sysfs_streq(buf, btrfs_read_policy_name[i])) {
1343			if (i != READ_ONCE(fs_devices->read_policy)) {
1344				WRITE_ONCE(fs_devices->read_policy, i);
1345				btrfs_info(fs_devices->fs_info,
1346					   "read policy set to '%s'",
1347					   btrfs_read_policy_name[i]);
1348			}
1349			return len;
1350		}
1351	}
1352
1353	return -EINVAL;
1354}
1355BTRFS_ATTR_RW(, read_policy, btrfs_read_policy_show, btrfs_read_policy_store);
1356
1357static ssize_t btrfs_bg_reclaim_threshold_show(struct kobject *kobj,
1358					       struct kobj_attribute *a,
1359					       char *buf)
1360{
1361	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 
1362
1363	return sysfs_emit(buf, "%d\n", READ_ONCE(fs_info->bg_reclaim_threshold));
 
 
1364}
1365
1366static ssize_t btrfs_bg_reclaim_threshold_store(struct kobject *kobj,
1367						struct kobj_attribute *a,
1368						const char *buf, size_t len)
1369{
1370	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1371	int thresh;
1372	int ret;
1373
1374	ret = kstrtoint(buf, 10, &thresh);
1375	if (ret)
1376		return ret;
1377
1378#ifdef CONFIG_BTRFS_DEBUG
1379	if (thresh != 0 && (thresh > 100))
1380		return -EINVAL;
1381#else
1382	if (thresh != 0 && (thresh <= 50 || thresh > 100))
1383		return -EINVAL;
1384#endif
1385
1386	WRITE_ONCE(fs_info->bg_reclaim_threshold, thresh);
1387
1388	return len;
1389}
1390BTRFS_ATTR_RW(, bg_reclaim_threshold, btrfs_bg_reclaim_threshold_show,
1391	      btrfs_bg_reclaim_threshold_store);
1392
1393#ifdef CONFIG_BTRFS_EXPERIMENTAL
1394static ssize_t btrfs_offload_csum_show(struct kobject *kobj,
1395				       struct kobj_attribute *a, char *buf)
1396{
1397	struct btrfs_fs_devices *fs_devices = to_fs_devs(kobj);
1398
1399	switch (READ_ONCE(fs_devices->offload_csum_mode)) {
1400	case BTRFS_OFFLOAD_CSUM_AUTO:
1401		return sysfs_emit(buf, "auto\n");
1402	case BTRFS_OFFLOAD_CSUM_FORCE_ON:
1403		return sysfs_emit(buf, "1\n");
1404	case BTRFS_OFFLOAD_CSUM_FORCE_OFF:
1405		return sysfs_emit(buf, "0\n");
1406	default:
1407		WARN_ON(1);
1408		return -EINVAL;
1409	}
1410}
1411
1412static ssize_t btrfs_offload_csum_store(struct kobject *kobj,
1413					struct kobj_attribute *a, const char *buf,
1414					size_t len)
1415{
1416	struct btrfs_fs_devices *fs_devices = to_fs_devs(kobj);
1417	int ret;
1418	bool val;
1419
1420	ret = kstrtobool(buf, &val);
1421	if (ret == 0)
1422		WRITE_ONCE(fs_devices->offload_csum_mode,
1423			   val ? BTRFS_OFFLOAD_CSUM_FORCE_ON : BTRFS_OFFLOAD_CSUM_FORCE_OFF);
1424	else if (ret == -EINVAL && sysfs_streq(buf, "auto"))
1425		WRITE_ONCE(fs_devices->offload_csum_mode, BTRFS_OFFLOAD_CSUM_AUTO);
1426	else
1427		return -EINVAL;
1428
1429	return len;
1430}
1431BTRFS_ATTR_RW(, offload_csum, btrfs_offload_csum_show, btrfs_offload_csum_store);
1432#endif
1433
1434/*
1435 * Per-filesystem information and stats.
1436 *
1437 * Path: /sys/fs/btrfs/<uuid>/
1438 */
1439static const struct attribute *btrfs_attrs[] = {
1440	BTRFS_ATTR_PTR(, label),
1441	BTRFS_ATTR_PTR(, nodesize),
1442	BTRFS_ATTR_PTR(, sectorsize),
1443	BTRFS_ATTR_PTR(, clone_alignment),
1444	BTRFS_ATTR_PTR(, quota_override),
1445	BTRFS_ATTR_PTR(, metadata_uuid),
1446	BTRFS_ATTR_PTR(, checksum),
1447	BTRFS_ATTR_PTR(, exclusive_operation),
1448	BTRFS_ATTR_PTR(, generation),
1449	BTRFS_ATTR_PTR(, read_policy),
1450	BTRFS_ATTR_PTR(, bg_reclaim_threshold),
1451	BTRFS_ATTR_PTR(, commit_stats),
1452	BTRFS_ATTR_PTR(, temp_fsid),
1453#ifdef CONFIG_BTRFS_EXPERIMENTAL
1454	BTRFS_ATTR_PTR(, offload_csum),
1455#endif
1456	NULL,
1457};
1458
1459static void btrfs_release_fsid_kobj(struct kobject *kobj)
1460{
1461	struct btrfs_fs_devices *fs_devs = to_fs_devs(kobj);
1462
1463	memset(&fs_devs->fsid_kobj, 0, sizeof(struct kobject));
1464	complete(&fs_devs->kobj_unregister);
1465}
1466
1467static const struct kobj_type btrfs_ktype = {
1468	.sysfs_ops	= &kobj_sysfs_ops,
1469	.release	= btrfs_release_fsid_kobj,
1470};
1471
1472static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj)
1473{
1474	if (kobj->ktype != &btrfs_ktype)
1475		return NULL;
1476	return container_of(kobj, struct btrfs_fs_devices, fsid_kobj);
1477}
1478
1479static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj)
1480{
1481	if (kobj->ktype != &btrfs_ktype)
1482		return NULL;
1483	return to_fs_devs(kobj)->fs_info;
1484}
1485
1486static struct kobject *get_btrfs_kobj(struct kobject *kobj)
1487{
1488	while (kobj) {
1489		if (kobj->ktype == &btrfs_ktype)
1490			return kobj;
1491		kobj = kobj->parent;
1492	}
1493	return NULL;
1494}
1495
1496#define NUM_FEATURE_BITS 64
1497#define BTRFS_FEATURE_NAME_MAX 13
1498static char btrfs_unknown_feature_names[FEAT_MAX][NUM_FEATURE_BITS][BTRFS_FEATURE_NAME_MAX];
1499static struct btrfs_feature_attr btrfs_feature_attrs[FEAT_MAX][NUM_FEATURE_BITS];
1500
1501static_assert(ARRAY_SIZE(btrfs_unknown_feature_names) ==
1502	      ARRAY_SIZE(btrfs_feature_attrs));
1503static_assert(ARRAY_SIZE(btrfs_unknown_feature_names[0]) ==
1504	      ARRAY_SIZE(btrfs_feature_attrs[0]));
1505
1506static const u64 supported_feature_masks[FEAT_MAX] = {
1507	[FEAT_COMPAT]    = BTRFS_FEATURE_COMPAT_SUPP,
1508	[FEAT_COMPAT_RO] = BTRFS_FEATURE_COMPAT_RO_SUPP,
1509	[FEAT_INCOMPAT]  = BTRFS_FEATURE_INCOMPAT_SUPP,
1510};
1511
1512static int addrm_unknown_feature_attrs(struct btrfs_fs_info *fs_info, bool add)
1513{
1514	int set;
1515
1516	for (set = 0; set < FEAT_MAX; set++) {
1517		int i;
1518		struct attribute *attrs[2];
1519		struct attribute_group agroup = {
1520			.name = "features",
1521			.attrs = attrs,
1522		};
1523		u64 features = get_features(fs_info, set);
1524		features &= ~supported_feature_masks[set];
1525
1526		if (!features)
1527			continue;
1528
1529		attrs[1] = NULL;
1530		for (i = 0; i < NUM_FEATURE_BITS; i++) {
1531			struct btrfs_feature_attr *fa;
1532
1533			if (!(features & (1ULL << i)))
1534				continue;
1535
1536			fa = &btrfs_feature_attrs[set][i];
1537			attrs[0] = &fa->kobj_attr.attr;
1538			if (add) {
1539				int ret;
1540				ret = sysfs_merge_group(&fs_info->fs_devices->fsid_kobj,
1541							&agroup);
1542				if (ret)
1543					return ret;
1544			} else
1545				sysfs_unmerge_group(&fs_info->fs_devices->fsid_kobj,
1546						    &agroup);
1547		}
1548
1549	}
1550	return 0;
1551}
1552
1553static void __btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs)
1554{
1555	if (fs_devs->devinfo_kobj) {
1556		kobject_del(fs_devs->devinfo_kobj);
1557		kobject_put(fs_devs->devinfo_kobj);
1558		fs_devs->devinfo_kobj = NULL;
1559	}
1560
1561	if (fs_devs->devices_kobj) {
1562		kobject_del(fs_devs->devices_kobj);
1563		kobject_put(fs_devs->devices_kobj);
1564		fs_devs->devices_kobj = NULL;
1565	}
1566
1567	if (fs_devs->fsid_kobj.state_initialized) {
1568		kobject_del(&fs_devs->fsid_kobj);
1569		kobject_put(&fs_devs->fsid_kobj);
1570		wait_for_completion(&fs_devs->kobj_unregister);
1571	}
1572}
1573
1574/* when fs_devs is NULL it will remove all fsid kobject */
1575void btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs)
1576{
1577	struct list_head *fs_uuids = btrfs_get_fs_uuids();
1578
1579	if (fs_devs) {
1580		__btrfs_sysfs_remove_fsid(fs_devs);
1581		return;
1582	}
1583
1584	list_for_each_entry(fs_devs, fs_uuids, fs_list) {
1585		__btrfs_sysfs_remove_fsid(fs_devs);
1586	}
1587}
1588
1589static void btrfs_sysfs_remove_fs_devices(struct btrfs_fs_devices *fs_devices)
1590{
1591	struct btrfs_device *device;
1592	struct btrfs_fs_devices *seed;
1593
1594	list_for_each_entry(device, &fs_devices->devices, dev_list)
1595		btrfs_sysfs_remove_device(device);
1596
1597	list_for_each_entry(seed, &fs_devices->seed_list, seed_list) {
1598		list_for_each_entry(device, &seed->devices, dev_list)
1599			btrfs_sysfs_remove_device(device);
1600	}
1601}
1602
1603void btrfs_sysfs_remove_mounted(struct btrfs_fs_info *fs_info)
1604{
1605	struct kobject *fsid_kobj = &fs_info->fs_devices->fsid_kobj;
1606
1607	sysfs_remove_link(fsid_kobj, "bdi");
1608
1609	if (fs_info->space_info_kobj) {
1610		sysfs_remove_files(fs_info->space_info_kobj, allocation_attrs);
1611		kobject_del(fs_info->space_info_kobj);
1612		kobject_put(fs_info->space_info_kobj);
1613	}
1614	if (fs_info->discard_kobj) {
1615		sysfs_remove_files(fs_info->discard_kobj, discard_attrs);
1616		kobject_del(fs_info->discard_kobj);
1617		kobject_put(fs_info->discard_kobj);
1618	}
1619#ifdef CONFIG_BTRFS_DEBUG
 
 
 
 
 
 
1620	if (fs_info->debug_kobj) {
1621		sysfs_remove_files(fs_info->debug_kobj, btrfs_debug_mount_attrs);
1622		kobject_del(fs_info->debug_kobj);
1623		kobject_put(fs_info->debug_kobj);
1624	}
1625#endif
1626	addrm_unknown_feature_attrs(fs_info, false);
1627	sysfs_remove_group(fsid_kobj, &btrfs_feature_attr_group);
1628	sysfs_remove_files(fsid_kobj, btrfs_attrs);
1629	btrfs_sysfs_remove_fs_devices(fs_info->fs_devices);
1630}
1631
1632static const char * const btrfs_feature_set_names[FEAT_MAX] = {
1633	[FEAT_COMPAT]	 = "compat",
1634	[FEAT_COMPAT_RO] = "compat_ro",
1635	[FEAT_INCOMPAT]	 = "incompat",
1636};
1637
1638const char *btrfs_feature_set_name(enum btrfs_feature_set set)
1639{
1640	return btrfs_feature_set_names[set];
1641}
1642
1643char *btrfs_printable_features(enum btrfs_feature_set set, u64 flags)
1644{
1645	size_t bufsize = 4096; /* safe max, 64 names * 64 bytes */
1646	int len = 0;
1647	int i;
1648	char *str;
1649
1650	str = kmalloc(bufsize, GFP_KERNEL);
1651	if (!str)
1652		return str;
1653
1654	for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
1655		const char *name;
1656
1657		if (!(flags & (1ULL << i)))
1658			continue;
1659
1660		name = btrfs_feature_attrs[set][i].kobj_attr.attr.name;
1661		len += scnprintf(str + len, bufsize - len, "%s%s",
1662				len ? "," : "", name);
1663	}
1664
1665	return str;
1666}
1667
1668static void init_feature_attrs(void)
1669{
1670	struct btrfs_feature_attr *fa;
1671	int set, i;
1672
 
 
 
 
 
1673	memset(btrfs_feature_attrs, 0, sizeof(btrfs_feature_attrs));
1674	memset(btrfs_unknown_feature_names, 0,
1675	       sizeof(btrfs_unknown_feature_names));
1676
1677	for (i = 0; btrfs_supported_feature_attrs[i]; i++) {
1678		struct btrfs_feature_attr *sfa;
1679		struct attribute *a = btrfs_supported_feature_attrs[i];
1680		int bit;
1681		sfa = attr_to_btrfs_feature_attr(a);
1682		bit = ilog2(sfa->feature_bit);
1683		fa = &btrfs_feature_attrs[sfa->feature_set][bit];
1684
1685		fa->kobj_attr.attr.name = sfa->kobj_attr.attr.name;
1686	}
1687
1688	for (set = 0; set < FEAT_MAX; set++) {
1689		for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
1690			char *name = btrfs_unknown_feature_names[set][i];
1691			fa = &btrfs_feature_attrs[set][i];
1692
1693			if (fa->kobj_attr.attr.name)
1694				continue;
1695
1696			snprintf(name, BTRFS_FEATURE_NAME_MAX, "%s:%u",
1697				 btrfs_feature_set_names[set], i);
1698
1699			fa->kobj_attr.attr.name = name;
1700			fa->kobj_attr.attr.mode = S_IRUGO;
1701			fa->feature_set = set;
1702			fa->feature_bit = 1ULL << i;
1703		}
1704	}
1705}
1706
1707/*
1708 * Create a sysfs entry for a given block group type at path
1709 * /sys/fs/btrfs/UUID/allocation/data/TYPE
1710 */
1711void btrfs_sysfs_add_block_group_type(struct btrfs_block_group *cache)
1712{
1713	struct btrfs_fs_info *fs_info = cache->fs_info;
1714	struct btrfs_space_info *space_info = cache->space_info;
1715	struct raid_kobject *rkobj;
1716	const int index = btrfs_bg_flags_to_raid_index(cache->flags);
1717	unsigned int nofs_flag;
1718	int ret;
1719
1720	/*
1721	 * Setup a NOFS context because kobject_add(), deep in its call chain,
1722	 * does GFP_KERNEL allocations, and we are often called in a context
1723	 * where if reclaim is triggered we can deadlock (we are either holding
1724	 * a transaction handle or some lock required for a transaction
1725	 * commit).
1726	 */
1727	nofs_flag = memalloc_nofs_save();
1728
1729	rkobj = kzalloc(sizeof(*rkobj), GFP_NOFS);
1730	if (!rkobj) {
1731		memalloc_nofs_restore(nofs_flag);
1732		btrfs_warn(cache->fs_info,
1733				"couldn't alloc memory for raid level kobject");
1734		return;
1735	}
1736
1737	rkobj->flags = cache->flags;
1738	kobject_init(&rkobj->kobj, &btrfs_raid_ktype);
1739
1740	/*
1741	 * We call this either on mount, or if we've created a block group for a
1742	 * new index type while running (i.e. when restriping).  The running
1743	 * case is tricky because we could race with other threads, so we need
1744	 * to have this check to make sure we didn't already init the kobject.
1745	 *
1746	 * We don't have to protect on the free side because it only happens on
1747	 * unmount.
1748	 */
1749	spin_lock(&space_info->lock);
1750	if (space_info->block_group_kobjs[index]) {
1751		spin_unlock(&space_info->lock);
1752		kobject_put(&rkobj->kobj);
1753		return;
1754	} else {
1755		space_info->block_group_kobjs[index] = &rkobj->kobj;
1756	}
1757	spin_unlock(&space_info->lock);
1758
1759	ret = kobject_add(&rkobj->kobj, &space_info->kobj, "%s",
1760			  btrfs_bg_type_to_raid_name(rkobj->flags));
1761	memalloc_nofs_restore(nofs_flag);
1762	if (ret) {
1763		spin_lock(&space_info->lock);
1764		space_info->block_group_kobjs[index] = NULL;
1765		spin_unlock(&space_info->lock);
1766		kobject_put(&rkobj->kobj);
1767		btrfs_warn(fs_info,
1768			"failed to add kobject for block cache, ignoring");
1769		return;
1770	}
1771}
1772
1773/*
1774 * Remove sysfs directories for all block group types of a given space info and
1775 * the space info as well
1776 */
1777void btrfs_sysfs_remove_space_info(struct btrfs_space_info *space_info)
1778{
1779	int i;
1780
1781	for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) {
1782		struct kobject *kobj;
1783
1784		kobj = space_info->block_group_kobjs[i];
1785		space_info->block_group_kobjs[i] = NULL;
1786		if (kobj) {
1787			kobject_del(kobj);
1788			kobject_put(kobj);
1789		}
1790	}
1791	kobject_del(&space_info->kobj);
1792	kobject_put(&space_info->kobj);
1793}
1794
1795static const char *alloc_name(u64 flags)
1796{
1797	switch (flags) {
1798	case BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA:
1799		return "mixed";
1800	case BTRFS_BLOCK_GROUP_METADATA:
1801		return "metadata";
1802	case BTRFS_BLOCK_GROUP_DATA:
1803		return "data";
1804	case BTRFS_BLOCK_GROUP_SYSTEM:
1805		return "system";
1806	default:
1807		WARN_ON(1);
1808		return "invalid-combination";
1809	}
1810}
1811
1812/*
1813 * Create a sysfs entry for a space info type at path
1814 * /sys/fs/btrfs/UUID/allocation/TYPE
1815 */
1816int btrfs_sysfs_add_space_info_type(struct btrfs_fs_info *fs_info,
1817				    struct btrfs_space_info *space_info)
1818{
1819	int ret;
1820
1821	ret = kobject_init_and_add(&space_info->kobj, &space_info_ktype,
1822				   fs_info->space_info_kobj, "%s",
1823				   alloc_name(space_info->flags));
1824	if (ret) {
1825		kobject_put(&space_info->kobj);
1826		return ret;
1827	}
1828
1829	return 0;
1830}
1831
1832void btrfs_sysfs_remove_device(struct btrfs_device *device)
1833{
1834	struct kobject *devices_kobj;
1835
1836	/*
1837	 * Seed fs_devices devices_kobj aren't used, fetch kobject from the
1838	 * fs_info::fs_devices.
1839	 */
1840	devices_kobj = device->fs_info->fs_devices->devices_kobj;
1841	ASSERT(devices_kobj);
1842
1843	if (device->bdev)
1844		sysfs_remove_link(devices_kobj, bdev_kobj(device->bdev)->name);
1845
1846	if (device->devid_kobj.state_initialized) {
1847		kobject_del(&device->devid_kobj);
1848		kobject_put(&device->devid_kobj);
1849		wait_for_completion(&device->kobj_unregister);
1850	}
1851}
1852
1853static ssize_t btrfs_devinfo_in_fs_metadata_show(struct kobject *kobj,
1854					         struct kobj_attribute *a,
1855					         char *buf)
1856{
1857	int val;
1858	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1859						   devid_kobj);
1860
1861	val = !!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state);
1862
1863	return sysfs_emit(buf, "%d\n", val);
1864}
1865BTRFS_ATTR(devid, in_fs_metadata, btrfs_devinfo_in_fs_metadata_show);
1866
1867static ssize_t btrfs_devinfo_missing_show(struct kobject *kobj,
1868					struct kobj_attribute *a, char *buf)
1869{
1870	int val;
1871	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1872						   devid_kobj);
1873
1874	val = !!test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state);
1875
1876	return sysfs_emit(buf, "%d\n", val);
1877}
1878BTRFS_ATTR(devid, missing, btrfs_devinfo_missing_show);
1879
1880static ssize_t btrfs_devinfo_replace_target_show(struct kobject *kobj,
1881					         struct kobj_attribute *a,
1882					         char *buf)
1883{
1884	int val;
1885	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1886						   devid_kobj);
1887
1888	val = !!test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state);
1889
1890	return sysfs_emit(buf, "%d\n", val);
1891}
1892BTRFS_ATTR(devid, replace_target, btrfs_devinfo_replace_target_show);
1893
1894static ssize_t btrfs_devinfo_scrub_speed_max_show(struct kobject *kobj,
1895					     struct kobj_attribute *a,
1896					     char *buf)
1897{
1898	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1899						   devid_kobj);
1900
1901	return sysfs_emit(buf, "%llu\n", READ_ONCE(device->scrub_speed_max));
 
1902}
1903
1904static ssize_t btrfs_devinfo_scrub_speed_max_store(struct kobject *kobj,
1905					      struct kobj_attribute *a,
1906					      const char *buf, size_t len)
1907{
1908	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1909						   devid_kobj);
1910	char *endptr;
1911	unsigned long long limit;
1912
1913	limit = memparse(buf, &endptr);
1914	/* There could be trailing '\n', also catch any typos after the value. */
1915	endptr = skip_spaces(endptr);
1916	if (*endptr != 0)
1917		return -EINVAL;
1918	WRITE_ONCE(device->scrub_speed_max, limit);
1919	return len;
1920}
1921BTRFS_ATTR_RW(devid, scrub_speed_max, btrfs_devinfo_scrub_speed_max_show,
1922	      btrfs_devinfo_scrub_speed_max_store);
1923
1924static ssize_t btrfs_devinfo_writeable_show(struct kobject *kobj,
1925					    struct kobj_attribute *a, char *buf)
1926{
1927	int val;
1928	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1929						   devid_kobj);
1930
1931	val = !!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state);
1932
1933	return sysfs_emit(buf, "%d\n", val);
1934}
1935BTRFS_ATTR(devid, writeable, btrfs_devinfo_writeable_show);
1936
1937static ssize_t btrfs_devinfo_fsid_show(struct kobject *kobj,
1938				       struct kobj_attribute *a, char *buf)
1939{
1940	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1941						   devid_kobj);
1942
1943	return sysfs_emit(buf, "%pU\n", device->fs_devices->fsid);
1944}
1945BTRFS_ATTR(devid, fsid, btrfs_devinfo_fsid_show);
1946
1947static ssize_t btrfs_devinfo_error_stats_show(struct kobject *kobj,
1948		struct kobj_attribute *a, char *buf)
1949{
1950	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1951						   devid_kobj);
1952
1953	if (!device->dev_stats_valid)
1954		return sysfs_emit(buf, "invalid\n");
1955
1956	/*
1957	 * Print all at once so we get a snapshot of all values from the same
1958	 * time. Keep them in sync and in order of definition of
1959	 * btrfs_dev_stat_values.
1960	 */
1961	return sysfs_emit(buf,
1962		"write_errs %d\n"
1963		"read_errs %d\n"
1964		"flush_errs %d\n"
1965		"corruption_errs %d\n"
1966		"generation_errs %d\n",
1967		btrfs_dev_stat_read(device, BTRFS_DEV_STAT_WRITE_ERRS),
1968		btrfs_dev_stat_read(device, BTRFS_DEV_STAT_READ_ERRS),
1969		btrfs_dev_stat_read(device, BTRFS_DEV_STAT_FLUSH_ERRS),
1970		btrfs_dev_stat_read(device, BTRFS_DEV_STAT_CORRUPTION_ERRS),
1971		btrfs_dev_stat_read(device, BTRFS_DEV_STAT_GENERATION_ERRS));
1972}
1973BTRFS_ATTR(devid, error_stats, btrfs_devinfo_error_stats_show);
1974
1975/*
1976 * Information about one device.
1977 *
1978 * Path: /sys/fs/btrfs/<uuid>/devinfo/<devid>/
1979 */
1980static struct attribute *devid_attrs[] = {
1981	BTRFS_ATTR_PTR(devid, error_stats),
1982	BTRFS_ATTR_PTR(devid, fsid),
1983	BTRFS_ATTR_PTR(devid, in_fs_metadata),
1984	BTRFS_ATTR_PTR(devid, missing),
1985	BTRFS_ATTR_PTR(devid, replace_target),
1986	BTRFS_ATTR_PTR(devid, scrub_speed_max),
1987	BTRFS_ATTR_PTR(devid, writeable),
1988	NULL
1989};
1990ATTRIBUTE_GROUPS(devid);
1991
1992static void btrfs_release_devid_kobj(struct kobject *kobj)
1993{
1994	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1995						   devid_kobj);
1996
1997	memset(&device->devid_kobj, 0, sizeof(struct kobject));
1998	complete(&device->kobj_unregister);
1999}
2000
2001static const struct kobj_type devid_ktype = {
2002	.sysfs_ops	= &kobj_sysfs_ops,
2003	.default_groups = devid_groups,
2004	.release	= btrfs_release_devid_kobj,
2005};
2006
2007int btrfs_sysfs_add_device(struct btrfs_device *device)
2008{
2009	int ret;
2010	unsigned int nofs_flag;
2011	struct kobject *devices_kobj;
2012	struct kobject *devinfo_kobj;
2013
2014	/*
2015	 * Make sure we use the fs_info::fs_devices to fetch the kobjects even
2016	 * for the seed fs_devices
2017	 */
2018	devices_kobj = device->fs_info->fs_devices->devices_kobj;
2019	devinfo_kobj = device->fs_info->fs_devices->devinfo_kobj;
2020	ASSERT(devices_kobj);
2021	ASSERT(devinfo_kobj);
2022
2023	nofs_flag = memalloc_nofs_save();
2024
2025	if (device->bdev) {
2026		struct kobject *disk_kobj = bdev_kobj(device->bdev);
2027
2028		ret = sysfs_create_link(devices_kobj, disk_kobj, disk_kobj->name);
2029		if (ret) {
2030			btrfs_warn(device->fs_info,
2031				"creating sysfs device link for devid %llu failed: %d",
2032				device->devid, ret);
2033			goto out;
2034		}
2035	}
2036
2037	init_completion(&device->kobj_unregister);
2038	ret = kobject_init_and_add(&device->devid_kobj, &devid_ktype,
2039				   devinfo_kobj, "%llu", device->devid);
2040	if (ret) {
2041		kobject_put(&device->devid_kobj);
2042		btrfs_warn(device->fs_info,
2043			   "devinfo init for devid %llu failed: %d",
2044			   device->devid, ret);
2045	}
2046
2047out:
2048	memalloc_nofs_restore(nofs_flag);
2049	return ret;
2050}
2051
2052static int btrfs_sysfs_add_fs_devices(struct btrfs_fs_devices *fs_devices)
2053{
2054	int ret;
2055	struct btrfs_device *device;
2056	struct btrfs_fs_devices *seed;
2057
2058	list_for_each_entry(device, &fs_devices->devices, dev_list) {
2059		ret = btrfs_sysfs_add_device(device);
2060		if (ret)
2061			goto fail;
2062	}
2063
2064	list_for_each_entry(seed, &fs_devices->seed_list, seed_list) {
2065		list_for_each_entry(device, &seed->devices, dev_list) {
2066			ret = btrfs_sysfs_add_device(device);
2067			if (ret)
2068				goto fail;
2069		}
2070	}
2071
2072	return 0;
2073
2074fail:
2075	btrfs_sysfs_remove_fs_devices(fs_devices);
2076	return ret;
2077}
2078
2079void btrfs_kobject_uevent(struct block_device *bdev, enum kobject_action action)
2080{
2081	int ret;
2082
2083	ret = kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, action);
2084	if (ret)
2085		pr_warn("BTRFS: Sending event '%d' to kobject: '%s' (%p): failed\n",
2086			action, kobject_name(&disk_to_dev(bdev->bd_disk)->kobj),
2087			&disk_to_dev(bdev->bd_disk)->kobj);
2088}
2089
2090void btrfs_sysfs_update_sprout_fsid(struct btrfs_fs_devices *fs_devices)
2091
2092{
2093	char fsid_buf[BTRFS_UUID_UNPARSED_SIZE];
2094
2095	/*
2096	 * Sprouting changes fsid of the mounted filesystem, rename the fsid
2097	 * directory
2098	 */
2099	snprintf(fsid_buf, BTRFS_UUID_UNPARSED_SIZE, "%pU", fs_devices->fsid);
2100	if (kobject_rename(&fs_devices->fsid_kobj, fsid_buf))
2101		btrfs_warn(fs_devices->fs_info,
2102				"sysfs: failed to create fsid for sprout");
2103}
2104
2105void btrfs_sysfs_update_devid(struct btrfs_device *device)
2106{
2107	char tmp[24];
2108
2109	snprintf(tmp, sizeof(tmp), "%llu", device->devid);
2110
2111	if (kobject_rename(&device->devid_kobj, tmp))
2112		btrfs_warn(device->fs_devices->fs_info,
2113			   "sysfs: failed to update devid for %llu",
2114			   device->devid);
2115}
2116
2117/* /sys/fs/btrfs/ entry */
2118static struct kset *btrfs_kset;
2119
2120/*
2121 * Creates:
2122 *		/sys/fs/btrfs/UUID
2123 *
2124 * Can be called by the device discovery thread.
2125 */
2126int btrfs_sysfs_add_fsid(struct btrfs_fs_devices *fs_devs)
2127{
2128	int error;
2129
2130	init_completion(&fs_devs->kobj_unregister);
2131	fs_devs->fsid_kobj.kset = btrfs_kset;
2132	error = kobject_init_and_add(&fs_devs->fsid_kobj, &btrfs_ktype, NULL,
2133				     "%pU", fs_devs->fsid);
2134	if (error) {
2135		kobject_put(&fs_devs->fsid_kobj);
2136		return error;
2137	}
2138
2139	fs_devs->devices_kobj = kobject_create_and_add("devices",
2140						       &fs_devs->fsid_kobj);
2141	if (!fs_devs->devices_kobj) {
2142		btrfs_err(fs_devs->fs_info,
2143			  "failed to init sysfs device interface");
2144		btrfs_sysfs_remove_fsid(fs_devs);
2145		return -ENOMEM;
2146	}
2147
2148	fs_devs->devinfo_kobj = kobject_create_and_add("devinfo",
2149						       &fs_devs->fsid_kobj);
2150	if (!fs_devs->devinfo_kobj) {
2151		btrfs_err(fs_devs->fs_info,
2152			  "failed to init sysfs devinfo kobject");
2153		btrfs_sysfs_remove_fsid(fs_devs);
2154		return -ENOMEM;
2155	}
2156
2157	return 0;
2158}
2159
2160int btrfs_sysfs_add_mounted(struct btrfs_fs_info *fs_info)
2161{
2162	int error;
2163	struct btrfs_fs_devices *fs_devs = fs_info->fs_devices;
2164	struct kobject *fsid_kobj = &fs_devs->fsid_kobj;
2165
2166	error = btrfs_sysfs_add_fs_devices(fs_devs);
2167	if (error)
2168		return error;
2169
2170	error = sysfs_create_files(fsid_kobj, btrfs_attrs);
2171	if (error) {
2172		btrfs_sysfs_remove_fs_devices(fs_devs);
2173		return error;
2174	}
2175
2176	error = sysfs_create_group(fsid_kobj,
2177				   &btrfs_feature_attr_group);
2178	if (error)
2179		goto failure;
2180
2181#ifdef CONFIG_BTRFS_DEBUG
2182	fs_info->debug_kobj = kobject_create_and_add("debug", fsid_kobj);
2183	if (!fs_info->debug_kobj) {
2184		error = -ENOMEM;
2185		goto failure;
2186	}
2187
2188	error = sysfs_create_files(fs_info->debug_kobj, btrfs_debug_mount_attrs);
2189	if (error)
2190		goto failure;
2191#endif
2192
2193	/* Discard directory */
2194	fs_info->discard_kobj = kobject_create_and_add("discard", fsid_kobj);
2195	if (!fs_info->discard_kobj) {
 
2196		error = -ENOMEM;
2197		goto failure;
2198	}
2199
2200	error = sysfs_create_files(fs_info->discard_kobj, discard_attrs);
 
2201	if (error)
2202		goto failure;
 
2203
2204	error = addrm_unknown_feature_attrs(fs_info, true);
2205	if (error)
2206		goto failure;
2207
2208	error = sysfs_create_link(fsid_kobj, &fs_info->sb->s_bdi->dev->kobj, "bdi");
2209	if (error)
2210		goto failure;
2211
2212	fs_info->space_info_kobj = kobject_create_and_add("allocation",
2213						  fsid_kobj);
2214	if (!fs_info->space_info_kobj) {
2215		error = -ENOMEM;
2216		goto failure;
2217	}
2218
2219	error = sysfs_create_files(fs_info->space_info_kobj, allocation_attrs);
2220	if (error)
2221		goto failure;
2222
2223	return 0;
2224failure:
2225	btrfs_sysfs_remove_mounted(fs_info);
2226	return error;
2227}
2228
2229static ssize_t qgroup_enabled_show(struct kobject *qgroups_kobj,
2230				   struct kobj_attribute *a,
2231				   char *buf)
2232{
2233	struct btrfs_fs_info *fs_info = to_fs_info(qgroups_kobj->parent);
2234	bool enabled;
2235
2236	spin_lock(&fs_info->qgroup_lock);
2237	enabled = fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_ON;
2238	spin_unlock(&fs_info->qgroup_lock);
2239
2240	return sysfs_emit(buf, "%d\n", enabled);
2241}
2242BTRFS_ATTR(qgroups, enabled, qgroup_enabled_show);
2243
2244static ssize_t qgroup_mode_show(struct kobject *qgroups_kobj,
2245				struct kobj_attribute *a,
2246				char *buf)
2247{
2248	struct btrfs_fs_info *fs_info = to_fs_info(qgroups_kobj->parent);
2249	ssize_t ret = 0;
2250
2251	spin_lock(&fs_info->qgroup_lock);
2252	ASSERT(btrfs_qgroup_enabled(fs_info));
2253	switch (btrfs_qgroup_mode(fs_info)) {
2254	case BTRFS_QGROUP_MODE_FULL:
2255		ret = sysfs_emit(buf, "qgroup\n");
2256		break;
2257	case BTRFS_QGROUP_MODE_SIMPLE:
2258		ret = sysfs_emit(buf, "squota\n");
2259		break;
2260	default:
2261		btrfs_warn(fs_info, "unexpected qgroup mode %d\n",
2262			   btrfs_qgroup_mode(fs_info));
2263		break;
2264	}
2265	spin_unlock(&fs_info->qgroup_lock);
2266
2267	return ret;
2268}
2269BTRFS_ATTR(qgroups, mode, qgroup_mode_show);
2270
2271static ssize_t qgroup_inconsistent_show(struct kobject *qgroups_kobj,
2272					struct kobj_attribute *a,
2273					char *buf)
2274{
2275	struct btrfs_fs_info *fs_info = to_fs_info(qgroups_kobj->parent);
2276	bool inconsistent;
2277
2278	spin_lock(&fs_info->qgroup_lock);
2279	inconsistent = (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT);
2280	spin_unlock(&fs_info->qgroup_lock);
2281
2282	return sysfs_emit(buf, "%d\n", inconsistent);
2283}
2284BTRFS_ATTR(qgroups, inconsistent, qgroup_inconsistent_show);
2285
2286static ssize_t qgroup_drop_subtree_thres_show(struct kobject *qgroups_kobj,
2287					      struct kobj_attribute *a,
2288					      char *buf)
2289{
2290	struct btrfs_fs_info *fs_info = to_fs_info(qgroups_kobj->parent);
2291	u8 result;
2292
2293	spin_lock(&fs_info->qgroup_lock);
2294	result = fs_info->qgroup_drop_subtree_thres;
2295	spin_unlock(&fs_info->qgroup_lock);
2296
2297	return sysfs_emit(buf, "%d\n", result);
2298}
2299
2300static ssize_t qgroup_drop_subtree_thres_store(struct kobject *qgroups_kobj,
2301					       struct kobj_attribute *a,
2302					       const char *buf, size_t len)
2303{
2304	struct btrfs_fs_info *fs_info = to_fs_info(qgroups_kobj->parent);
2305	u8 new_thres;
2306	int ret;
2307
2308	ret = kstrtou8(buf, 10, &new_thres);
2309	if (ret)
2310		return -EINVAL;
2311
2312	if (new_thres > BTRFS_MAX_LEVEL)
2313		return -EINVAL;
2314
2315	spin_lock(&fs_info->qgroup_lock);
2316	fs_info->qgroup_drop_subtree_thres = new_thres;
2317	spin_unlock(&fs_info->qgroup_lock);
2318
2319	return len;
2320}
2321BTRFS_ATTR_RW(qgroups, drop_subtree_threshold, qgroup_drop_subtree_thres_show,
2322	      qgroup_drop_subtree_thres_store);
2323
2324/*
2325 * Qgroups global info
2326 *
2327 * Path: /sys/fs/btrfs/<uuid>/qgroups/
2328 */
2329static struct attribute *qgroups_attrs[] = {
2330	BTRFS_ATTR_PTR(qgroups, enabled),
2331	BTRFS_ATTR_PTR(qgroups, inconsistent),
2332	BTRFS_ATTR_PTR(qgroups, drop_subtree_threshold),
2333	BTRFS_ATTR_PTR(qgroups, mode),
2334	NULL
2335};
2336ATTRIBUTE_GROUPS(qgroups);
2337
2338static void qgroups_release(struct kobject *kobj)
2339{
2340	kfree(kobj);
2341}
2342
2343static const struct kobj_type qgroups_ktype = {
2344	.sysfs_ops = &kobj_sysfs_ops,
2345	.default_groups = qgroups_groups,
2346	.release = qgroups_release,
2347};
2348
2349static inline struct btrfs_fs_info *qgroup_kobj_to_fs_info(struct kobject *kobj)
2350{
2351	return to_fs_info(kobj->parent->parent);
2352}
2353
2354#define QGROUP_ATTR(_member, _show_name)					\
2355static ssize_t btrfs_qgroup_show_##_member(struct kobject *qgroup_kobj,		\
2356					   struct kobj_attribute *a,		\
2357					   char *buf)				\
2358{										\
2359	struct btrfs_fs_info *fs_info = qgroup_kobj_to_fs_info(qgroup_kobj);	\
2360	struct btrfs_qgroup *qgroup = container_of(qgroup_kobj,			\
2361			struct btrfs_qgroup, kobj);				\
2362	return btrfs_show_u64(&qgroup->_member, &fs_info->qgroup_lock, buf);	\
2363}										\
2364BTRFS_ATTR(qgroup, _show_name, btrfs_qgroup_show_##_member)
2365
2366#define QGROUP_RSV_ATTR(_name, _type)						\
2367static ssize_t btrfs_qgroup_rsv_show_##_name(struct kobject *qgroup_kobj,	\
2368					     struct kobj_attribute *a,		\
2369					     char *buf)				\
2370{										\
2371	struct btrfs_fs_info *fs_info = qgroup_kobj_to_fs_info(qgroup_kobj);	\
2372	struct btrfs_qgroup *qgroup = container_of(qgroup_kobj,			\
2373			struct btrfs_qgroup, kobj);				\
2374	return btrfs_show_u64(&qgroup->rsv.values[_type],			\
2375			&fs_info->qgroup_lock, buf);				\
2376}										\
2377BTRFS_ATTR(qgroup, rsv_##_name, btrfs_qgroup_rsv_show_##_name)
2378
2379QGROUP_ATTR(rfer, referenced);
2380QGROUP_ATTR(excl, exclusive);
2381QGROUP_ATTR(max_rfer, max_referenced);
2382QGROUP_ATTR(max_excl, max_exclusive);
2383QGROUP_ATTR(lim_flags, limit_flags);
2384QGROUP_RSV_ATTR(data, BTRFS_QGROUP_RSV_DATA);
2385QGROUP_RSV_ATTR(meta_pertrans, BTRFS_QGROUP_RSV_META_PERTRANS);
2386QGROUP_RSV_ATTR(meta_prealloc, BTRFS_QGROUP_RSV_META_PREALLOC);
2387
2388/*
2389 * Qgroup information.
2390 *
2391 * Path: /sys/fs/btrfs/<uuid>/qgroups/<level>_<qgroupid>/
2392 */
2393static struct attribute *qgroup_attrs[] = {
2394	BTRFS_ATTR_PTR(qgroup, referenced),
2395	BTRFS_ATTR_PTR(qgroup, exclusive),
2396	BTRFS_ATTR_PTR(qgroup, max_referenced),
2397	BTRFS_ATTR_PTR(qgroup, max_exclusive),
2398	BTRFS_ATTR_PTR(qgroup, limit_flags),
2399	BTRFS_ATTR_PTR(qgroup, rsv_data),
2400	BTRFS_ATTR_PTR(qgroup, rsv_meta_pertrans),
2401	BTRFS_ATTR_PTR(qgroup, rsv_meta_prealloc),
2402	NULL
2403};
2404ATTRIBUTE_GROUPS(qgroup);
2405
2406static void qgroup_release(struct kobject *kobj)
2407{
2408	struct btrfs_qgroup *qgroup = container_of(kobj, struct btrfs_qgroup, kobj);
2409
2410	memset(&qgroup->kobj, 0, sizeof(*kobj));
2411}
2412
2413static const struct kobj_type qgroup_ktype = {
2414	.sysfs_ops = &kobj_sysfs_ops,
2415	.release = qgroup_release,
2416	.default_groups = qgroup_groups,
2417};
2418
2419int btrfs_sysfs_add_one_qgroup(struct btrfs_fs_info *fs_info,
2420				struct btrfs_qgroup *qgroup)
2421{
2422	struct kobject *qgroups_kobj = fs_info->qgroups_kobj;
2423	int ret;
2424
2425	if (btrfs_is_testing(fs_info))
2426		return 0;
2427	if (qgroup->kobj.state_initialized)
2428		return 0;
2429	if (!qgroups_kobj)
2430		return -EINVAL;
2431
2432	ret = kobject_init_and_add(&qgroup->kobj, &qgroup_ktype, qgroups_kobj,
2433			"%hu_%llu", btrfs_qgroup_level(qgroup->qgroupid),
2434			btrfs_qgroup_subvolid(qgroup->qgroupid));
2435	if (ret < 0)
2436		kobject_put(&qgroup->kobj);
2437
2438	return ret;
2439}
2440
2441void btrfs_sysfs_del_qgroups(struct btrfs_fs_info *fs_info)
2442{
2443	struct btrfs_qgroup *qgroup;
2444	struct btrfs_qgroup *next;
2445
2446	if (btrfs_is_testing(fs_info))
2447		return;
2448
2449	rbtree_postorder_for_each_entry_safe(qgroup, next,
2450					     &fs_info->qgroup_tree, node)
2451		btrfs_sysfs_del_one_qgroup(fs_info, qgroup);
2452	if (fs_info->qgroups_kobj) {
2453		kobject_del(fs_info->qgroups_kobj);
2454		kobject_put(fs_info->qgroups_kobj);
2455		fs_info->qgroups_kobj = NULL;
2456	}
2457}
2458
2459/* Called when qgroups get initialized, thus there is no need for locking */
2460int btrfs_sysfs_add_qgroups(struct btrfs_fs_info *fs_info)
2461{
2462	struct kobject *fsid_kobj = &fs_info->fs_devices->fsid_kobj;
2463	struct btrfs_qgroup *qgroup;
2464	struct btrfs_qgroup *next;
2465	int ret = 0;
2466
2467	if (btrfs_is_testing(fs_info))
2468		return 0;
2469
2470	ASSERT(fsid_kobj);
2471	if (fs_info->qgroups_kobj)
2472		return 0;
2473
2474	fs_info->qgroups_kobj = kzalloc(sizeof(struct kobject), GFP_KERNEL);
2475	if (!fs_info->qgroups_kobj)
2476		return -ENOMEM;
2477
2478	ret = kobject_init_and_add(fs_info->qgroups_kobj, &qgroups_ktype,
2479				   fsid_kobj, "qgroups");
2480	if (ret < 0)
2481		goto out;
2482
2483	rbtree_postorder_for_each_entry_safe(qgroup, next,
2484					     &fs_info->qgroup_tree, node) {
2485		ret = btrfs_sysfs_add_one_qgroup(fs_info, qgroup);
2486		if (ret < 0)
2487			goto out;
2488	}
2489
2490out:
2491	if (ret < 0)
2492		btrfs_sysfs_del_qgroups(fs_info);
2493	return ret;
2494}
2495
2496void btrfs_sysfs_del_one_qgroup(struct btrfs_fs_info *fs_info,
2497				struct btrfs_qgroup *qgroup)
2498{
2499	if (btrfs_is_testing(fs_info))
2500		return;
2501
2502	if (qgroup->kobj.state_initialized) {
2503		kobject_del(&qgroup->kobj);
2504		kobject_put(&qgroup->kobj);
2505	}
2506}
2507
2508/*
2509 * Change per-fs features in /sys/fs/btrfs/UUID/features to match current
2510 * values in superblock. Call after any changes to incompat/compat_ro flags
2511 */
2512void btrfs_sysfs_feature_update(struct btrfs_fs_info *fs_info)
 
2513{
 
2514	struct kobject *fsid_kobj;
2515	int ret;
 
2516
2517	if (!fs_info)
2518		return;
2519
2520	fsid_kobj = &fs_info->fs_devices->fsid_kobj;
 
 
 
 
 
 
 
 
 
2521	if (!fsid_kobj->state_initialized)
2522		return;
2523
2524	ret = sysfs_update_group(fsid_kobj, &btrfs_feature_attr_group);
2525	if (ret < 0)
2526		btrfs_warn(fs_info,
2527			   "failed to update /sys/fs/btrfs/%pU/features: %d",
2528			   fs_info->fs_devices->fsid, ret);
 
2529}
2530
2531int __init btrfs_init_sysfs(void)
2532{
2533	int ret;
2534
2535	btrfs_kset = kset_create_and_add("btrfs", NULL, fs_kobj);
2536	if (!btrfs_kset)
2537		return -ENOMEM;
2538
2539	init_feature_attrs();
2540	ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
2541	if (ret)
2542		goto out2;
2543	ret = sysfs_merge_group(&btrfs_kset->kobj,
2544				&btrfs_static_feature_attr_group);
2545	if (ret)
2546		goto out_remove_group;
2547
2548#ifdef CONFIG_BTRFS_DEBUG
2549	ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_debug_feature_attr_group);
2550	if (ret) {
2551		sysfs_unmerge_group(&btrfs_kset->kobj,
2552				    &btrfs_static_feature_attr_group);
2553		goto out_remove_group;
2554	}
2555#endif
2556
2557	return 0;
2558
2559out_remove_group:
2560	sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
2561out2:
2562	kset_unregister(btrfs_kset);
2563
2564	return ret;
2565}
2566
2567void __cold btrfs_exit_sysfs(void)
2568{
2569	sysfs_unmerge_group(&btrfs_kset->kobj,
2570			    &btrfs_static_feature_attr_group);
2571	sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
2572#ifdef CONFIG_BTRFS_DEBUG
2573	sysfs_remove_group(&btrfs_kset->kobj, &btrfs_debug_feature_attr_group);
2574#endif
2575	kset_unregister(btrfs_kset);
2576}
v5.14.15
   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Copyright (C) 2007 Oracle.  All rights reserved.
   4 */
   5
   6#include <linux/sched.h>
   7#include <linux/sched/mm.h>
   8#include <linux/slab.h>
   9#include <linux/spinlock.h>
  10#include <linux/completion.h>
  11#include <linux/bug.h>
 
  12#include <crypto/hash.h>
  13
  14#include "ctree.h"
  15#include "discard.h"
  16#include "disk-io.h"
  17#include "send.h"
  18#include "transaction.h"
  19#include "sysfs.h"
  20#include "volumes.h"
  21#include "space-info.h"
  22#include "block-group.h"
  23#include "qgroup.h"
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  24
  25struct btrfs_feature_attr {
  26	struct kobj_attribute kobj_attr;
  27	enum btrfs_feature_set feature_set;
  28	u64 feature_bit;
  29};
  30
  31/* For raid type sysfs entries */
  32struct raid_kobject {
  33	u64 flags;
  34	struct kobject kobj;
  35};
  36
  37#define __INIT_KOBJ_ATTR(_name, _mode, _show, _store)			\
  38{									\
  39	.attr	= { .name = __stringify(_name), .mode = _mode },	\
  40	.show	= _show,						\
  41	.store	= _store,						\
  42}
  43
 
 
 
 
  44#define BTRFS_ATTR_RW(_prefix, _name, _show, _store)			\
  45	static struct kobj_attribute btrfs_attr_##_prefix##_##_name =	\
  46			__INIT_KOBJ_ATTR(_name, 0644, _show, _store)
  47
  48#define BTRFS_ATTR(_prefix, _name, _show)				\
  49	static struct kobj_attribute btrfs_attr_##_prefix##_##_name =	\
  50			__INIT_KOBJ_ATTR(_name, 0444, _show, NULL)
  51
  52#define BTRFS_ATTR_PTR(_prefix, _name)					\
  53	(&btrfs_attr_##_prefix##_##_name.attr)
  54
  55#define BTRFS_FEAT_ATTR(_name, _feature_set, _feature_prefix, _feature_bit)  \
  56static struct btrfs_feature_attr btrfs_attr_features_##_name = {	     \
  57	.kobj_attr = __INIT_KOBJ_ATTR(_name, S_IRUGO,			     \
  58				      btrfs_feature_attr_show,		     \
  59				      btrfs_feature_attr_store),	     \
  60	.feature_set	= _feature_set,					     \
  61	.feature_bit	= _feature_prefix ##_## _feature_bit,		     \
  62}
  63#define BTRFS_FEAT_ATTR_PTR(_name)					     \
  64	(&btrfs_attr_features_##_name.kobj_attr.attr)
  65
  66#define BTRFS_FEAT_ATTR_COMPAT(name, feature) \
  67	BTRFS_FEAT_ATTR(name, FEAT_COMPAT, BTRFS_FEATURE_COMPAT, feature)
  68#define BTRFS_FEAT_ATTR_COMPAT_RO(name, feature) \
  69	BTRFS_FEAT_ATTR(name, FEAT_COMPAT_RO, BTRFS_FEATURE_COMPAT_RO, feature)
  70#define BTRFS_FEAT_ATTR_INCOMPAT(name, feature) \
  71	BTRFS_FEAT_ATTR(name, FEAT_INCOMPAT, BTRFS_FEATURE_INCOMPAT, feature)
  72
  73static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj);
  74static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj);
 
  75
  76static struct btrfs_feature_attr *to_btrfs_feature_attr(struct kobj_attribute *a)
  77{
  78	return container_of(a, struct btrfs_feature_attr, kobj_attr);
  79}
  80
  81static struct kobj_attribute *attr_to_btrfs_attr(struct attribute *attr)
  82{
  83	return container_of(attr, struct kobj_attribute, attr);
  84}
  85
  86static struct btrfs_feature_attr *attr_to_btrfs_feature_attr(
  87		struct attribute *attr)
  88{
  89	return to_btrfs_feature_attr(attr_to_btrfs_attr(attr));
  90}
  91
  92static u64 get_features(struct btrfs_fs_info *fs_info,
  93			enum btrfs_feature_set set)
  94{
  95	struct btrfs_super_block *disk_super = fs_info->super_copy;
  96	if (set == FEAT_COMPAT)
  97		return btrfs_super_compat_flags(disk_super);
  98	else if (set == FEAT_COMPAT_RO)
  99		return btrfs_super_compat_ro_flags(disk_super);
 100	else
 101		return btrfs_super_incompat_flags(disk_super);
 102}
 103
 104static void set_features(struct btrfs_fs_info *fs_info,
 105			 enum btrfs_feature_set set, u64 features)
 106{
 107	struct btrfs_super_block *disk_super = fs_info->super_copy;
 108	if (set == FEAT_COMPAT)
 109		btrfs_set_super_compat_flags(disk_super, features);
 110	else if (set == FEAT_COMPAT_RO)
 111		btrfs_set_super_compat_ro_flags(disk_super, features);
 112	else
 113		btrfs_set_super_incompat_flags(disk_super, features);
 114}
 115
 116static int can_modify_feature(struct btrfs_feature_attr *fa)
 117{
 118	int val = 0;
 119	u64 set, clear;
 120	switch (fa->feature_set) {
 121	case FEAT_COMPAT:
 122		set = BTRFS_FEATURE_COMPAT_SAFE_SET;
 123		clear = BTRFS_FEATURE_COMPAT_SAFE_CLEAR;
 124		break;
 125	case FEAT_COMPAT_RO:
 126		set = BTRFS_FEATURE_COMPAT_RO_SAFE_SET;
 127		clear = BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR;
 128		break;
 129	case FEAT_INCOMPAT:
 130		set = BTRFS_FEATURE_INCOMPAT_SAFE_SET;
 131		clear = BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR;
 132		break;
 133	default:
 134		pr_warn("btrfs: sysfs: unknown feature set %d\n",
 135				fa->feature_set);
 136		return 0;
 137	}
 138
 139	if (set & fa->feature_bit)
 140		val |= 1;
 141	if (clear & fa->feature_bit)
 142		val |= 2;
 143
 144	return val;
 145}
 146
 147static ssize_t btrfs_feature_attr_show(struct kobject *kobj,
 148				       struct kobj_attribute *a, char *buf)
 149{
 150	int val = 0;
 151	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 152	struct btrfs_feature_attr *fa = to_btrfs_feature_attr(a);
 153	if (fs_info) {
 154		u64 features = get_features(fs_info, fa->feature_set);
 155		if (features & fa->feature_bit)
 156			val = 1;
 157	} else
 158		val = can_modify_feature(fa);
 159
 160	return scnprintf(buf, PAGE_SIZE, "%d\n", val);
 161}
 162
 163static ssize_t btrfs_feature_attr_store(struct kobject *kobj,
 164					struct kobj_attribute *a,
 165					const char *buf, size_t count)
 166{
 167	struct btrfs_fs_info *fs_info;
 168	struct btrfs_feature_attr *fa = to_btrfs_feature_attr(a);
 169	u64 features, set, clear;
 170	unsigned long val;
 171	int ret;
 172
 173	fs_info = to_fs_info(kobj);
 174	if (!fs_info)
 175		return -EPERM;
 176
 177	if (sb_rdonly(fs_info->sb))
 178		return -EROFS;
 179
 180	ret = kstrtoul(skip_spaces(buf), 0, &val);
 181	if (ret)
 182		return ret;
 183
 184	if (fa->feature_set == FEAT_COMPAT) {
 185		set = BTRFS_FEATURE_COMPAT_SAFE_SET;
 186		clear = BTRFS_FEATURE_COMPAT_SAFE_CLEAR;
 187	} else if (fa->feature_set == FEAT_COMPAT_RO) {
 188		set = BTRFS_FEATURE_COMPAT_RO_SAFE_SET;
 189		clear = BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR;
 190	} else {
 191		set = BTRFS_FEATURE_INCOMPAT_SAFE_SET;
 192		clear = BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR;
 193	}
 194
 195	features = get_features(fs_info, fa->feature_set);
 196
 197	/* Nothing to do */
 198	if ((val && (features & fa->feature_bit)) ||
 199	    (!val && !(features & fa->feature_bit)))
 200		return count;
 201
 202	if ((val && !(set & fa->feature_bit)) ||
 203	    (!val && !(clear & fa->feature_bit))) {
 204		btrfs_info(fs_info,
 205			"%sabling feature %s on mounted fs is not supported.",
 206			val ? "En" : "Dis", fa->kobj_attr.attr.name);
 207		return -EPERM;
 208	}
 209
 210	btrfs_info(fs_info, "%s %s feature flag",
 211		   val ? "Setting" : "Clearing", fa->kobj_attr.attr.name);
 212
 213	spin_lock(&fs_info->super_lock);
 214	features = get_features(fs_info, fa->feature_set);
 215	if (val)
 216		features |= fa->feature_bit;
 217	else
 218		features &= ~fa->feature_bit;
 219	set_features(fs_info, fa->feature_set, features);
 220	spin_unlock(&fs_info->super_lock);
 221
 222	/*
 223	 * We don't want to do full transaction commit from inside sysfs
 224	 */
 225	btrfs_set_pending(fs_info, COMMIT);
 226	wake_up_process(fs_info->transaction_kthread);
 227
 228	return count;
 229}
 230
 231static umode_t btrfs_feature_visible(struct kobject *kobj,
 232				     struct attribute *attr, int unused)
 233{
 234	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 235	umode_t mode = attr->mode;
 236
 237	if (fs_info) {
 238		struct btrfs_feature_attr *fa;
 239		u64 features;
 240
 241		fa = attr_to_btrfs_feature_attr(attr);
 242		features = get_features(fs_info, fa->feature_set);
 243
 244		if (can_modify_feature(fa))
 245			mode |= S_IWUSR;
 246		else if (!(features & fa->feature_bit))
 247			mode = 0;
 248	}
 249
 250	return mode;
 251}
 252
 253BTRFS_FEAT_ATTR_INCOMPAT(mixed_backref, MIXED_BACKREF);
 254BTRFS_FEAT_ATTR_INCOMPAT(default_subvol, DEFAULT_SUBVOL);
 255BTRFS_FEAT_ATTR_INCOMPAT(mixed_groups, MIXED_GROUPS);
 256BTRFS_FEAT_ATTR_INCOMPAT(compress_lzo, COMPRESS_LZO);
 257BTRFS_FEAT_ATTR_INCOMPAT(compress_zstd, COMPRESS_ZSTD);
 258BTRFS_FEAT_ATTR_INCOMPAT(big_metadata, BIG_METADATA);
 259BTRFS_FEAT_ATTR_INCOMPAT(extended_iref, EXTENDED_IREF);
 260BTRFS_FEAT_ATTR_INCOMPAT(raid56, RAID56);
 261BTRFS_FEAT_ATTR_INCOMPAT(skinny_metadata, SKINNY_METADATA);
 262BTRFS_FEAT_ATTR_INCOMPAT(no_holes, NO_HOLES);
 263BTRFS_FEAT_ATTR_INCOMPAT(metadata_uuid, METADATA_UUID);
 264BTRFS_FEAT_ATTR_COMPAT_RO(free_space_tree, FREE_SPACE_TREE);
 
 265BTRFS_FEAT_ATTR_INCOMPAT(raid1c34, RAID1C34);
 266/* Remove once support for zoned allocation is feature complete */
 267#ifdef CONFIG_BTRFS_DEBUG
 268BTRFS_FEAT_ATTR_INCOMPAT(zoned, ZONED);
 269#endif
 
 
 
 
 
 
 
 
 
 270
 
 
 
 
 
 
 
 271static struct attribute *btrfs_supported_feature_attrs[] = {
 272	BTRFS_FEAT_ATTR_PTR(mixed_backref),
 273	BTRFS_FEAT_ATTR_PTR(default_subvol),
 274	BTRFS_FEAT_ATTR_PTR(mixed_groups),
 275	BTRFS_FEAT_ATTR_PTR(compress_lzo),
 276	BTRFS_FEAT_ATTR_PTR(compress_zstd),
 277	BTRFS_FEAT_ATTR_PTR(big_metadata),
 278	BTRFS_FEAT_ATTR_PTR(extended_iref),
 279	BTRFS_FEAT_ATTR_PTR(raid56),
 280	BTRFS_FEAT_ATTR_PTR(skinny_metadata),
 281	BTRFS_FEAT_ATTR_PTR(no_holes),
 282	BTRFS_FEAT_ATTR_PTR(metadata_uuid),
 283	BTRFS_FEAT_ATTR_PTR(free_space_tree),
 284	BTRFS_FEAT_ATTR_PTR(raid1c34),
 285#ifdef CONFIG_BTRFS_DEBUG
 
 
 286	BTRFS_FEAT_ATTR_PTR(zoned),
 287#endif
 
 
 
 
 
 
 
 288	NULL
 289};
 290
 291/*
 292 * Features which depend on feature bits and may differ between each fs.
 293 *
 294 * /sys/fs/btrfs/features lists all available features of this kernel while
 295 * /sys/fs/btrfs/UUID/features shows features of the fs which are enabled or
 296 * can be changed online.
 297 */
 298static const struct attribute_group btrfs_feature_attr_group = {
 299	.name = "features",
 300	.is_visible = btrfs_feature_visible,
 301	.attrs = btrfs_supported_feature_attrs,
 302};
 303
 304static ssize_t rmdir_subvol_show(struct kobject *kobj,
 305				 struct kobj_attribute *ka, char *buf)
 306{
 307	return scnprintf(buf, PAGE_SIZE, "0\n");
 308}
 309BTRFS_ATTR(static_feature, rmdir_subvol, rmdir_subvol_show);
 310
 311static ssize_t supported_checksums_show(struct kobject *kobj,
 312					struct kobj_attribute *a, char *buf)
 313{
 314	ssize_t ret = 0;
 315	int i;
 316
 317	for (i = 0; i < btrfs_get_num_csums(); i++) {
 318		/*
 319		 * This "trick" only works as long as 'enum btrfs_csum_type' has
 320		 * no holes in it
 321		 */
 322		ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%s",
 323				(i == 0 ? "" : " "), btrfs_super_csum_name(i));
 324
 325	}
 326
 327	ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
 328	return ret;
 329}
 330BTRFS_ATTR(static_feature, supported_checksums, supported_checksums_show);
 331
 332static ssize_t send_stream_version_show(struct kobject *kobj,
 333					struct kobj_attribute *ka, char *buf)
 334{
 335	return snprintf(buf, PAGE_SIZE, "%d\n", BTRFS_SEND_STREAM_VERSION);
 336}
 337BTRFS_ATTR(static_feature, send_stream_version, send_stream_version_show);
 338
 339static const char *rescue_opts[] = {
 340	"usebackuproot",
 341	"nologreplay",
 342	"ignorebadroots",
 343	"ignoredatacsums",
 
 
 344	"all",
 345};
 346
 347static ssize_t supported_rescue_options_show(struct kobject *kobj,
 348					     struct kobj_attribute *a,
 349					     char *buf)
 350{
 351	ssize_t ret = 0;
 352	int i;
 353
 354	for (i = 0; i < ARRAY_SIZE(rescue_opts); i++)
 355		ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%s",
 356				 (i ? " " : ""), rescue_opts[i]);
 357	ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
 358	return ret;
 359}
 360BTRFS_ATTR(static_feature, supported_rescue_options,
 361	   supported_rescue_options_show);
 362
 363static ssize_t supported_sectorsizes_show(struct kobject *kobj,
 364					  struct kobj_attribute *a,
 365					  char *buf)
 366{
 367	ssize_t ret = 0;
 368
 369	/* Only sectorsize == PAGE_SIZE is now supported */
 370	ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%lu\n", PAGE_SIZE);
 
 
 371
 372	return ret;
 373}
 374BTRFS_ATTR(static_feature, supported_sectorsizes,
 375	   supported_sectorsizes_show);
 376
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 377static struct attribute *btrfs_supported_static_feature_attrs[] = {
 
 378	BTRFS_ATTR_PTR(static_feature, rmdir_subvol),
 379	BTRFS_ATTR_PTR(static_feature, supported_checksums),
 380	BTRFS_ATTR_PTR(static_feature, send_stream_version),
 381	BTRFS_ATTR_PTR(static_feature, supported_rescue_options),
 382	BTRFS_ATTR_PTR(static_feature, supported_sectorsizes),
 
 383	NULL
 384};
 385
 386/*
 387 * Features which only depend on kernel version.
 388 *
 389 * These are listed in /sys/fs/btrfs/features along with
 390 * btrfs_feature_attr_group
 391 */
 392static const struct attribute_group btrfs_static_feature_attr_group = {
 393	.name = "features",
 394	.attrs = btrfs_supported_static_feature_attrs,
 395};
 396
 397#ifdef CONFIG_BTRFS_DEBUG
 398
 399/*
 400 * Discard statistics and tunables
 401 */
 402#define discard_to_fs_info(_kobj)	to_fs_info((_kobj)->parent->parent)
 403
 404static ssize_t btrfs_discardable_bytes_show(struct kobject *kobj,
 405					    struct kobj_attribute *a,
 406					    char *buf)
 407{
 408	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 409
 410	return scnprintf(buf, PAGE_SIZE, "%lld\n",
 411			atomic64_read(&fs_info->discard_ctl.discardable_bytes));
 412}
 413BTRFS_ATTR(discard, discardable_bytes, btrfs_discardable_bytes_show);
 414
 415static ssize_t btrfs_discardable_extents_show(struct kobject *kobj,
 416					      struct kobj_attribute *a,
 417					      char *buf)
 418{
 419	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 420
 421	return scnprintf(buf, PAGE_SIZE, "%d\n",
 422			atomic_read(&fs_info->discard_ctl.discardable_extents));
 423}
 424BTRFS_ATTR(discard, discardable_extents, btrfs_discardable_extents_show);
 425
 426static ssize_t btrfs_discard_bitmap_bytes_show(struct kobject *kobj,
 427					       struct kobj_attribute *a,
 428					       char *buf)
 429{
 430	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 431
 432	return scnprintf(buf, PAGE_SIZE, "%llu\n",
 433			fs_info->discard_ctl.discard_bitmap_bytes);
 434}
 435BTRFS_ATTR(discard, discard_bitmap_bytes, btrfs_discard_bitmap_bytes_show);
 436
 437static ssize_t btrfs_discard_bytes_saved_show(struct kobject *kobj,
 438					      struct kobj_attribute *a,
 439					      char *buf)
 440{
 441	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 442
 443	return scnprintf(buf, PAGE_SIZE, "%lld\n",
 444		atomic64_read(&fs_info->discard_ctl.discard_bytes_saved));
 445}
 446BTRFS_ATTR(discard, discard_bytes_saved, btrfs_discard_bytes_saved_show);
 447
 448static ssize_t btrfs_discard_extent_bytes_show(struct kobject *kobj,
 449					       struct kobj_attribute *a,
 450					       char *buf)
 451{
 452	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 453
 454	return scnprintf(buf, PAGE_SIZE, "%llu\n",
 455			fs_info->discard_ctl.discard_extent_bytes);
 456}
 457BTRFS_ATTR(discard, discard_extent_bytes, btrfs_discard_extent_bytes_show);
 458
 459static ssize_t btrfs_discard_iops_limit_show(struct kobject *kobj,
 460					     struct kobj_attribute *a,
 461					     char *buf)
 462{
 463	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 464
 465	return scnprintf(buf, PAGE_SIZE, "%u\n",
 466			READ_ONCE(fs_info->discard_ctl.iops_limit));
 467}
 468
 469static ssize_t btrfs_discard_iops_limit_store(struct kobject *kobj,
 470					      struct kobj_attribute *a,
 471					      const char *buf, size_t len)
 472{
 473	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 474	struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
 475	u32 iops_limit;
 476	int ret;
 477
 478	ret = kstrtou32(buf, 10, &iops_limit);
 479	if (ret)
 480		return -EINVAL;
 481
 482	WRITE_ONCE(discard_ctl->iops_limit, iops_limit);
 483	btrfs_discard_calc_delay(discard_ctl);
 484	btrfs_discard_schedule_work(discard_ctl, true);
 485	return len;
 486}
 487BTRFS_ATTR_RW(discard, iops_limit, btrfs_discard_iops_limit_show,
 488	      btrfs_discard_iops_limit_store);
 489
 490static ssize_t btrfs_discard_kbps_limit_show(struct kobject *kobj,
 491					     struct kobj_attribute *a,
 492					     char *buf)
 493{
 494	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 495
 496	return scnprintf(buf, PAGE_SIZE, "%u\n",
 497			READ_ONCE(fs_info->discard_ctl.kbps_limit));
 498}
 499
 500static ssize_t btrfs_discard_kbps_limit_store(struct kobject *kobj,
 501					      struct kobj_attribute *a,
 502					      const char *buf, size_t len)
 503{
 504	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 505	struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
 506	u32 kbps_limit;
 507	int ret;
 508
 509	ret = kstrtou32(buf, 10, &kbps_limit);
 510	if (ret)
 511		return -EINVAL;
 512
 513	WRITE_ONCE(discard_ctl->kbps_limit, kbps_limit);
 514	btrfs_discard_schedule_work(discard_ctl, true);
 515	return len;
 516}
 517BTRFS_ATTR_RW(discard, kbps_limit, btrfs_discard_kbps_limit_show,
 518	      btrfs_discard_kbps_limit_store);
 519
 520static ssize_t btrfs_discard_max_discard_size_show(struct kobject *kobj,
 521						   struct kobj_attribute *a,
 522						   char *buf)
 523{
 524	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 525
 526	return scnprintf(buf, PAGE_SIZE, "%llu\n",
 527			READ_ONCE(fs_info->discard_ctl.max_discard_size));
 528}
 529
 530static ssize_t btrfs_discard_max_discard_size_store(struct kobject *kobj,
 531						    struct kobj_attribute *a,
 532						    const char *buf, size_t len)
 533{
 534	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
 535	struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
 536	u64 max_discard_size;
 537	int ret;
 538
 539	ret = kstrtou64(buf, 10, &max_discard_size);
 540	if (ret)
 541		return -EINVAL;
 542
 543	WRITE_ONCE(discard_ctl->max_discard_size, max_discard_size);
 544
 545	return len;
 546}
 547BTRFS_ATTR_RW(discard, max_discard_size, btrfs_discard_max_discard_size_show,
 548	      btrfs_discard_max_discard_size_store);
 549
 550static const struct attribute *discard_debug_attrs[] = {
 
 
 
 
 
 551	BTRFS_ATTR_PTR(discard, discardable_bytes),
 552	BTRFS_ATTR_PTR(discard, discardable_extents),
 553	BTRFS_ATTR_PTR(discard, discard_bitmap_bytes),
 554	BTRFS_ATTR_PTR(discard, discard_bytes_saved),
 555	BTRFS_ATTR_PTR(discard, discard_extent_bytes),
 556	BTRFS_ATTR_PTR(discard, iops_limit),
 557	BTRFS_ATTR_PTR(discard, kbps_limit),
 558	BTRFS_ATTR_PTR(discard, max_discard_size),
 559	NULL,
 560};
 561
 
 
 562/*
 563 * Runtime debugging exported via sysfs
 564 *
 565 * /sys/fs/btrfs/debug - applies to module or all filesystems
 566 * /sys/fs/btrfs/UUID  - applies only to the given filesystem
 567 */
 568static const struct attribute *btrfs_debug_mount_attrs[] = {
 569	NULL,
 570};
 571
 
 
 
 
 
 572static struct attribute *btrfs_debug_feature_attrs[] = {
 573	NULL
 574};
 575
 576static const struct attribute_group btrfs_debug_feature_attr_group = {
 577	.name = "debug",
 578	.attrs = btrfs_debug_feature_attrs,
 579};
 580
 581#endif
 582
 583static ssize_t btrfs_show_u64(u64 *value_ptr, spinlock_t *lock, char *buf)
 584{
 585	u64 val;
 586	if (lock)
 587		spin_lock(lock);
 588	val = *value_ptr;
 589	if (lock)
 590		spin_unlock(lock);
 591	return scnprintf(buf, PAGE_SIZE, "%llu\n", val);
 592}
 593
 594static ssize_t global_rsv_size_show(struct kobject *kobj,
 595				    struct kobj_attribute *ka, char *buf)
 596{
 597	struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent);
 598	struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
 599	return btrfs_show_u64(&block_rsv->size, &block_rsv->lock, buf);
 600}
 601BTRFS_ATTR(allocation, global_rsv_size, global_rsv_size_show);
 602
 603static ssize_t global_rsv_reserved_show(struct kobject *kobj,
 604					struct kobj_attribute *a, char *buf)
 605{
 606	struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent);
 607	struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
 608	return btrfs_show_u64(&block_rsv->reserved, &block_rsv->lock, buf);
 609}
 610BTRFS_ATTR(allocation, global_rsv_reserved, global_rsv_reserved_show);
 611
 612#define to_space_info(_kobj) container_of(_kobj, struct btrfs_space_info, kobj)
 613#define to_raid_kobj(_kobj) container_of(_kobj, struct raid_kobject, kobj)
 614
 615static ssize_t raid_bytes_show(struct kobject *kobj,
 616			       struct kobj_attribute *attr, char *buf);
 617BTRFS_ATTR(raid, total_bytes, raid_bytes_show);
 618BTRFS_ATTR(raid, used_bytes, raid_bytes_show);
 619
 620static ssize_t raid_bytes_show(struct kobject *kobj,
 621			       struct kobj_attribute *attr, char *buf)
 622
 623{
 624	struct btrfs_space_info *sinfo = to_space_info(kobj->parent);
 625	struct btrfs_block_group *block_group;
 626	int index = btrfs_bg_flags_to_raid_index(to_raid_kobj(kobj)->flags);
 627	u64 val = 0;
 628
 629	down_read(&sinfo->groups_sem);
 630	list_for_each_entry(block_group, &sinfo->block_groups[index], list) {
 631		if (&attr->attr == BTRFS_ATTR_PTR(raid, total_bytes))
 632			val += block_group->length;
 633		else
 634			val += block_group->used;
 635	}
 636	up_read(&sinfo->groups_sem);
 637	return scnprintf(buf, PAGE_SIZE, "%llu\n", val);
 638}
 639
 
 
 
 
 
 640static struct attribute *raid_attrs[] = {
 641	BTRFS_ATTR_PTR(raid, total_bytes),
 642	BTRFS_ATTR_PTR(raid, used_bytes),
 643	NULL
 644};
 645ATTRIBUTE_GROUPS(raid);
 646
 647static void release_raid_kobj(struct kobject *kobj)
 648{
 649	kfree(to_raid_kobj(kobj));
 650}
 651
 652static struct kobj_type btrfs_raid_ktype = {
 653	.sysfs_ops = &kobj_sysfs_ops,
 654	.release = release_raid_kobj,
 655	.default_groups = raid_groups,
 656};
 657
 658#define SPACE_INFO_ATTR(field)						\
 659static ssize_t btrfs_space_info_show_##field(struct kobject *kobj,	\
 660					     struct kobj_attribute *a,	\
 661					     char *buf)			\
 662{									\
 663	struct btrfs_space_info *sinfo = to_space_info(kobj);		\
 664	return btrfs_show_u64(&sinfo->field, &sinfo->lock, buf);	\
 665}									\
 666BTRFS_ATTR(space_info, field, btrfs_space_info_show_##field)
 667
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 668SPACE_INFO_ATTR(flags);
 669SPACE_INFO_ATTR(total_bytes);
 670SPACE_INFO_ATTR(bytes_used);
 671SPACE_INFO_ATTR(bytes_pinned);
 672SPACE_INFO_ATTR(bytes_reserved);
 673SPACE_INFO_ATTR(bytes_may_use);
 674SPACE_INFO_ATTR(bytes_readonly);
 675SPACE_INFO_ATTR(bytes_zone_unusable);
 676SPACE_INFO_ATTR(disk_used);
 677SPACE_INFO_ATTR(disk_total);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 678
 
 
 
 
 
 679static struct attribute *space_info_attrs[] = {
 680	BTRFS_ATTR_PTR(space_info, flags),
 681	BTRFS_ATTR_PTR(space_info, total_bytes),
 682	BTRFS_ATTR_PTR(space_info, bytes_used),
 683	BTRFS_ATTR_PTR(space_info, bytes_pinned),
 684	BTRFS_ATTR_PTR(space_info, bytes_reserved),
 685	BTRFS_ATTR_PTR(space_info, bytes_may_use),
 686	BTRFS_ATTR_PTR(space_info, bytes_readonly),
 687	BTRFS_ATTR_PTR(space_info, bytes_zone_unusable),
 688	BTRFS_ATTR_PTR(space_info, disk_used),
 689	BTRFS_ATTR_PTR(space_info, disk_total),
 
 
 
 
 
 
 
 
 
 
 
 690	NULL,
 691};
 692ATTRIBUTE_GROUPS(space_info);
 693
 694static void space_info_release(struct kobject *kobj)
 695{
 696	struct btrfs_space_info *sinfo = to_space_info(kobj);
 697	kfree(sinfo);
 698}
 699
 700static struct kobj_type space_info_ktype = {
 701	.sysfs_ops = &kobj_sysfs_ops,
 702	.release = space_info_release,
 703	.default_groups = space_info_groups,
 704};
 705
 
 
 
 
 
 706static const struct attribute *allocation_attrs[] = {
 707	BTRFS_ATTR_PTR(allocation, global_rsv_reserved),
 708	BTRFS_ATTR_PTR(allocation, global_rsv_size),
 709	NULL,
 710};
 711
 712static ssize_t btrfs_label_show(struct kobject *kobj,
 713				struct kobj_attribute *a, char *buf)
 714{
 715	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 716	char *label = fs_info->super_copy->label;
 717	ssize_t ret;
 718
 719	spin_lock(&fs_info->super_lock);
 720	ret = scnprintf(buf, PAGE_SIZE, label[0] ? "%s\n" : "%s", label);
 721	spin_unlock(&fs_info->super_lock);
 722
 723	return ret;
 724}
 725
 726static ssize_t btrfs_label_store(struct kobject *kobj,
 727				 struct kobj_attribute *a,
 728				 const char *buf, size_t len)
 729{
 730	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 731	size_t p_len;
 732
 733	if (!fs_info)
 734		return -EPERM;
 735
 736	if (sb_rdonly(fs_info->sb))
 737		return -EROFS;
 738
 739	/*
 740	 * p_len is the len until the first occurrence of either
 741	 * '\n' or '\0'
 742	 */
 743	p_len = strcspn(buf, "\n");
 744
 745	if (p_len >= BTRFS_LABEL_SIZE)
 746		return -EINVAL;
 747
 748	spin_lock(&fs_info->super_lock);
 749	memset(fs_info->super_copy->label, 0, BTRFS_LABEL_SIZE);
 750	memcpy(fs_info->super_copy->label, buf, p_len);
 751	spin_unlock(&fs_info->super_lock);
 752
 753	/*
 754	 * We don't want to do full transaction commit from inside sysfs
 755	 */
 756	btrfs_set_pending(fs_info, COMMIT);
 757	wake_up_process(fs_info->transaction_kthread);
 758
 759	return len;
 760}
 761BTRFS_ATTR_RW(, label, btrfs_label_show, btrfs_label_store);
 762
 763static ssize_t btrfs_nodesize_show(struct kobject *kobj,
 764				struct kobj_attribute *a, char *buf)
 765{
 766	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 767
 768	return scnprintf(buf, PAGE_SIZE, "%u\n", fs_info->super_copy->nodesize);
 769}
 770
 771BTRFS_ATTR(, nodesize, btrfs_nodesize_show);
 772
 773static ssize_t btrfs_sectorsize_show(struct kobject *kobj,
 774				struct kobj_attribute *a, char *buf)
 775{
 776	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 777
 778	return scnprintf(buf, PAGE_SIZE, "%u\n",
 779			 fs_info->super_copy->sectorsize);
 780}
 781
 782BTRFS_ATTR(, sectorsize, btrfs_sectorsize_show);
 783
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 784static ssize_t btrfs_clone_alignment_show(struct kobject *kobj,
 785				struct kobj_attribute *a, char *buf)
 786{
 787	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 788
 789	return scnprintf(buf, PAGE_SIZE, "%u\n", fs_info->super_copy->sectorsize);
 790}
 791
 792BTRFS_ATTR(, clone_alignment, btrfs_clone_alignment_show);
 793
 794static ssize_t quota_override_show(struct kobject *kobj,
 795				   struct kobj_attribute *a, char *buf)
 796{
 797	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 798	int quota_override;
 799
 800	quota_override = test_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
 801	return scnprintf(buf, PAGE_SIZE, "%d\n", quota_override);
 802}
 803
 804static ssize_t quota_override_store(struct kobject *kobj,
 805				    struct kobj_attribute *a,
 806				    const char *buf, size_t len)
 807{
 808	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 809	unsigned long knob;
 810	int err;
 811
 812	if (!fs_info)
 813		return -EPERM;
 814
 815	if (!capable(CAP_SYS_RESOURCE))
 816		return -EPERM;
 817
 818	err = kstrtoul(buf, 10, &knob);
 819	if (err)
 820		return err;
 821	if (knob > 1)
 822		return -EINVAL;
 823
 824	if (knob)
 825		set_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
 826	else
 827		clear_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
 828
 829	return len;
 830}
 831
 832BTRFS_ATTR_RW(, quota_override, quota_override_show, quota_override_store);
 833
 834static ssize_t btrfs_metadata_uuid_show(struct kobject *kobj,
 835				struct kobj_attribute *a, char *buf)
 836{
 837	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 838
 839	return scnprintf(buf, PAGE_SIZE, "%pU\n",
 840			fs_info->fs_devices->metadata_uuid);
 841}
 842
 843BTRFS_ATTR(, metadata_uuid, btrfs_metadata_uuid_show);
 844
 845static ssize_t btrfs_checksum_show(struct kobject *kobj,
 846				   struct kobj_attribute *a, char *buf)
 847{
 848	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 849	u16 csum_type = btrfs_super_csum_type(fs_info->super_copy);
 850
 851	return scnprintf(buf, PAGE_SIZE, "%s (%s)\n",
 852			btrfs_super_csum_name(csum_type),
 853			crypto_shash_driver_name(fs_info->csum_shash));
 854}
 855
 856BTRFS_ATTR(, checksum, btrfs_checksum_show);
 857
 858static ssize_t btrfs_exclusive_operation_show(struct kobject *kobj,
 859		struct kobj_attribute *a, char *buf)
 860{
 861	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 862	const char *str;
 863
 864	switch (READ_ONCE(fs_info->exclusive_operation)) {
 865		case  BTRFS_EXCLOP_NONE:
 866			str = "none\n";
 867			break;
 868		case BTRFS_EXCLOP_BALANCE:
 869			str = "balance\n";
 870			break;
 
 
 
 871		case BTRFS_EXCLOP_DEV_ADD:
 872			str = "device add\n";
 873			break;
 874		case BTRFS_EXCLOP_DEV_REMOVE:
 875			str = "device remove\n";
 876			break;
 877		case BTRFS_EXCLOP_DEV_REPLACE:
 878			str = "device replace\n";
 879			break;
 880		case BTRFS_EXCLOP_RESIZE:
 881			str = "resize\n";
 882			break;
 883		case BTRFS_EXCLOP_SWAP_ACTIVATE:
 884			str = "swap activate\n";
 885			break;
 886		default:
 887			str = "UNKNOWN\n";
 888			break;
 889	}
 890	return scnprintf(buf, PAGE_SIZE, "%s", str);
 891}
 892BTRFS_ATTR(, exclusive_operation, btrfs_exclusive_operation_show);
 893
 894static ssize_t btrfs_generation_show(struct kobject *kobj,
 895				     struct kobj_attribute *a, char *buf)
 896{
 897	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 898
 899	return scnprintf(buf, PAGE_SIZE, "%llu\n", fs_info->generation);
 900}
 901BTRFS_ATTR(, generation, btrfs_generation_show);
 902
 903/*
 904 * Look for an exact string @string in @buffer with possible leading or
 905 * trailing whitespace
 906 */
 907static bool strmatch(const char *buffer, const char *string)
 908{
 909	const size_t len = strlen(string);
 910
 911	/* Skip leading whitespace */
 912	buffer = skip_spaces(buffer);
 913
 914	/* Match entire string, check if the rest is whitespace or empty */
 915	if (strncmp(string, buffer, len) == 0 &&
 916	    strlen(skip_spaces(buffer + len)) == 0)
 917		return true;
 918
 919	return false;
 920}
 
 921
 922static const char * const btrfs_read_policy_name[] = { "pid" };
 923
 924static ssize_t btrfs_read_policy_show(struct kobject *kobj,
 925				      struct kobj_attribute *a, char *buf)
 926{
 927	struct btrfs_fs_devices *fs_devices = to_fs_devs(kobj);
 
 928	ssize_t ret = 0;
 929	int i;
 930
 931	for (i = 0; i < BTRFS_NR_READ_POLICY; i++) {
 932		if (fs_devices->read_policy == i)
 933			ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s[%s]",
 934					 (ret == 0 ? "" : " "),
 935					 btrfs_read_policy_name[i]);
 936		else
 937			ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%s",
 938					 (ret == 0 ? "" : " "),
 939					 btrfs_read_policy_name[i]);
 940	}
 941
 942	ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
 943
 944	return ret;
 945}
 946
 947static ssize_t btrfs_read_policy_store(struct kobject *kobj,
 948				       struct kobj_attribute *a,
 949				       const char *buf, size_t len)
 950{
 951	struct btrfs_fs_devices *fs_devices = to_fs_devs(kobj);
 952	int i;
 953
 954	for (i = 0; i < BTRFS_NR_READ_POLICY; i++) {
 955		if (strmatch(buf, btrfs_read_policy_name[i])) {
 956			if (i != fs_devices->read_policy) {
 957				fs_devices->read_policy = i;
 958				btrfs_info(fs_devices->fs_info,
 959					   "read policy set to '%s'",
 960					   btrfs_read_policy_name[i]);
 961			}
 962			return len;
 963		}
 964	}
 965
 966	return -EINVAL;
 967}
 968BTRFS_ATTR_RW(, read_policy, btrfs_read_policy_show, btrfs_read_policy_store);
 969
 970static ssize_t btrfs_bg_reclaim_threshold_show(struct kobject *kobj,
 971					       struct kobj_attribute *a,
 972					       char *buf)
 973{
 974	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 975	ssize_t ret;
 976
 977	ret = scnprintf(buf, PAGE_SIZE, "%d\n", fs_info->bg_reclaim_threshold);
 978
 979	return ret;
 980}
 981
 982static ssize_t btrfs_bg_reclaim_threshold_store(struct kobject *kobj,
 983						struct kobj_attribute *a,
 984						const char *buf, size_t len)
 985{
 986	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 987	int thresh;
 988	int ret;
 989
 990	ret = kstrtoint(buf, 10, &thresh);
 991	if (ret)
 992		return ret;
 993
 994	if (thresh <= 50 || thresh > 100)
 
 995		return -EINVAL;
 
 
 
 
 996
 997	fs_info->bg_reclaim_threshold = thresh;
 998
 999	return len;
1000}
1001BTRFS_ATTR_RW(, bg_reclaim_threshold, btrfs_bg_reclaim_threshold_show,
1002	      btrfs_bg_reclaim_threshold_store);
1003
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1004static const struct attribute *btrfs_attrs[] = {
1005	BTRFS_ATTR_PTR(, label),
1006	BTRFS_ATTR_PTR(, nodesize),
1007	BTRFS_ATTR_PTR(, sectorsize),
1008	BTRFS_ATTR_PTR(, clone_alignment),
1009	BTRFS_ATTR_PTR(, quota_override),
1010	BTRFS_ATTR_PTR(, metadata_uuid),
1011	BTRFS_ATTR_PTR(, checksum),
1012	BTRFS_ATTR_PTR(, exclusive_operation),
1013	BTRFS_ATTR_PTR(, generation),
1014	BTRFS_ATTR_PTR(, read_policy),
1015	BTRFS_ATTR_PTR(, bg_reclaim_threshold),
 
 
 
 
 
1016	NULL,
1017};
1018
1019static void btrfs_release_fsid_kobj(struct kobject *kobj)
1020{
1021	struct btrfs_fs_devices *fs_devs = to_fs_devs(kobj);
1022
1023	memset(&fs_devs->fsid_kobj, 0, sizeof(struct kobject));
1024	complete(&fs_devs->kobj_unregister);
1025}
1026
1027static struct kobj_type btrfs_ktype = {
1028	.sysfs_ops	= &kobj_sysfs_ops,
1029	.release	= btrfs_release_fsid_kobj,
1030};
1031
1032static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj)
1033{
1034	if (kobj->ktype != &btrfs_ktype)
1035		return NULL;
1036	return container_of(kobj, struct btrfs_fs_devices, fsid_kobj);
1037}
1038
1039static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj)
1040{
1041	if (kobj->ktype != &btrfs_ktype)
1042		return NULL;
1043	return to_fs_devs(kobj)->fs_info;
1044}
1045
 
 
 
 
 
 
 
 
 
 
1046#define NUM_FEATURE_BITS 64
1047#define BTRFS_FEATURE_NAME_MAX 13
1048static char btrfs_unknown_feature_names[FEAT_MAX][NUM_FEATURE_BITS][BTRFS_FEATURE_NAME_MAX];
1049static struct btrfs_feature_attr btrfs_feature_attrs[FEAT_MAX][NUM_FEATURE_BITS];
1050
 
 
 
 
 
1051static const u64 supported_feature_masks[FEAT_MAX] = {
1052	[FEAT_COMPAT]    = BTRFS_FEATURE_COMPAT_SUPP,
1053	[FEAT_COMPAT_RO] = BTRFS_FEATURE_COMPAT_RO_SUPP,
1054	[FEAT_INCOMPAT]  = BTRFS_FEATURE_INCOMPAT_SUPP,
1055};
1056
1057static int addrm_unknown_feature_attrs(struct btrfs_fs_info *fs_info, bool add)
1058{
1059	int set;
1060
1061	for (set = 0; set < FEAT_MAX; set++) {
1062		int i;
1063		struct attribute *attrs[2];
1064		struct attribute_group agroup = {
1065			.name = "features",
1066			.attrs = attrs,
1067		};
1068		u64 features = get_features(fs_info, set);
1069		features &= ~supported_feature_masks[set];
1070
1071		if (!features)
1072			continue;
1073
1074		attrs[1] = NULL;
1075		for (i = 0; i < NUM_FEATURE_BITS; i++) {
1076			struct btrfs_feature_attr *fa;
1077
1078			if (!(features & (1ULL << i)))
1079				continue;
1080
1081			fa = &btrfs_feature_attrs[set][i];
1082			attrs[0] = &fa->kobj_attr.attr;
1083			if (add) {
1084				int ret;
1085				ret = sysfs_merge_group(&fs_info->fs_devices->fsid_kobj,
1086							&agroup);
1087				if (ret)
1088					return ret;
1089			} else
1090				sysfs_unmerge_group(&fs_info->fs_devices->fsid_kobj,
1091						    &agroup);
1092		}
1093
1094	}
1095	return 0;
1096}
1097
1098static void __btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs)
1099{
1100	if (fs_devs->devinfo_kobj) {
1101		kobject_del(fs_devs->devinfo_kobj);
1102		kobject_put(fs_devs->devinfo_kobj);
1103		fs_devs->devinfo_kobj = NULL;
1104	}
1105
1106	if (fs_devs->devices_kobj) {
1107		kobject_del(fs_devs->devices_kobj);
1108		kobject_put(fs_devs->devices_kobj);
1109		fs_devs->devices_kobj = NULL;
1110	}
1111
1112	if (fs_devs->fsid_kobj.state_initialized) {
1113		kobject_del(&fs_devs->fsid_kobj);
1114		kobject_put(&fs_devs->fsid_kobj);
1115		wait_for_completion(&fs_devs->kobj_unregister);
1116	}
1117}
1118
1119/* when fs_devs is NULL it will remove all fsid kobject */
1120void btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs)
1121{
1122	struct list_head *fs_uuids = btrfs_get_fs_uuids();
1123
1124	if (fs_devs) {
1125		__btrfs_sysfs_remove_fsid(fs_devs);
1126		return;
1127	}
1128
1129	list_for_each_entry(fs_devs, fs_uuids, fs_list) {
1130		__btrfs_sysfs_remove_fsid(fs_devs);
1131	}
1132}
1133
1134static void btrfs_sysfs_remove_fs_devices(struct btrfs_fs_devices *fs_devices)
1135{
1136	struct btrfs_device *device;
1137	struct btrfs_fs_devices *seed;
1138
1139	list_for_each_entry(device, &fs_devices->devices, dev_list)
1140		btrfs_sysfs_remove_device(device);
1141
1142	list_for_each_entry(seed, &fs_devices->seed_list, seed_list) {
1143		list_for_each_entry(device, &seed->devices, dev_list)
1144			btrfs_sysfs_remove_device(device);
1145	}
1146}
1147
1148void btrfs_sysfs_remove_mounted(struct btrfs_fs_info *fs_info)
1149{
1150	struct kobject *fsid_kobj = &fs_info->fs_devices->fsid_kobj;
1151
1152	sysfs_remove_link(fsid_kobj, "bdi");
1153
1154	if (fs_info->space_info_kobj) {
1155		sysfs_remove_files(fs_info->space_info_kobj, allocation_attrs);
1156		kobject_del(fs_info->space_info_kobj);
1157		kobject_put(fs_info->space_info_kobj);
1158	}
 
 
 
 
 
1159#ifdef CONFIG_BTRFS_DEBUG
1160	if (fs_info->discard_debug_kobj) {
1161		sysfs_remove_files(fs_info->discard_debug_kobj,
1162				   discard_debug_attrs);
1163		kobject_del(fs_info->discard_debug_kobj);
1164		kobject_put(fs_info->discard_debug_kobj);
1165	}
1166	if (fs_info->debug_kobj) {
1167		sysfs_remove_files(fs_info->debug_kobj, btrfs_debug_mount_attrs);
1168		kobject_del(fs_info->debug_kobj);
1169		kobject_put(fs_info->debug_kobj);
1170	}
1171#endif
1172	addrm_unknown_feature_attrs(fs_info, false);
1173	sysfs_remove_group(fsid_kobj, &btrfs_feature_attr_group);
1174	sysfs_remove_files(fsid_kobj, btrfs_attrs);
1175	btrfs_sysfs_remove_fs_devices(fs_info->fs_devices);
1176}
1177
1178static const char * const btrfs_feature_set_names[FEAT_MAX] = {
1179	[FEAT_COMPAT]	 = "compat",
1180	[FEAT_COMPAT_RO] = "compat_ro",
1181	[FEAT_INCOMPAT]	 = "incompat",
1182};
1183
1184const char *btrfs_feature_set_name(enum btrfs_feature_set set)
1185{
1186	return btrfs_feature_set_names[set];
1187}
1188
1189char *btrfs_printable_features(enum btrfs_feature_set set, u64 flags)
1190{
1191	size_t bufsize = 4096; /* safe max, 64 names * 64 bytes */
1192	int len = 0;
1193	int i;
1194	char *str;
1195
1196	str = kmalloc(bufsize, GFP_KERNEL);
1197	if (!str)
1198		return str;
1199
1200	for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
1201		const char *name;
1202
1203		if (!(flags & (1ULL << i)))
1204			continue;
1205
1206		name = btrfs_feature_attrs[set][i].kobj_attr.attr.name;
1207		len += scnprintf(str + len, bufsize - len, "%s%s",
1208				len ? "," : "", name);
1209	}
1210
1211	return str;
1212}
1213
1214static void init_feature_attrs(void)
1215{
1216	struct btrfs_feature_attr *fa;
1217	int set, i;
1218
1219	BUILD_BUG_ON(ARRAY_SIZE(btrfs_unknown_feature_names) !=
1220		     ARRAY_SIZE(btrfs_feature_attrs));
1221	BUILD_BUG_ON(ARRAY_SIZE(btrfs_unknown_feature_names[0]) !=
1222		     ARRAY_SIZE(btrfs_feature_attrs[0]));
1223
1224	memset(btrfs_feature_attrs, 0, sizeof(btrfs_feature_attrs));
1225	memset(btrfs_unknown_feature_names, 0,
1226	       sizeof(btrfs_unknown_feature_names));
1227
1228	for (i = 0; btrfs_supported_feature_attrs[i]; i++) {
1229		struct btrfs_feature_attr *sfa;
1230		struct attribute *a = btrfs_supported_feature_attrs[i];
1231		int bit;
1232		sfa = attr_to_btrfs_feature_attr(a);
1233		bit = ilog2(sfa->feature_bit);
1234		fa = &btrfs_feature_attrs[sfa->feature_set][bit];
1235
1236		fa->kobj_attr.attr.name = sfa->kobj_attr.attr.name;
1237	}
1238
1239	for (set = 0; set < FEAT_MAX; set++) {
1240		for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
1241			char *name = btrfs_unknown_feature_names[set][i];
1242			fa = &btrfs_feature_attrs[set][i];
1243
1244			if (fa->kobj_attr.attr.name)
1245				continue;
1246
1247			snprintf(name, BTRFS_FEATURE_NAME_MAX, "%s:%u",
1248				 btrfs_feature_set_names[set], i);
1249
1250			fa->kobj_attr.attr.name = name;
1251			fa->kobj_attr.attr.mode = S_IRUGO;
1252			fa->feature_set = set;
1253			fa->feature_bit = 1ULL << i;
1254		}
1255	}
1256}
1257
1258/*
1259 * Create a sysfs entry for a given block group type at path
1260 * /sys/fs/btrfs/UUID/allocation/data/TYPE
1261 */
1262void btrfs_sysfs_add_block_group_type(struct btrfs_block_group *cache)
1263{
1264	struct btrfs_fs_info *fs_info = cache->fs_info;
1265	struct btrfs_space_info *space_info = cache->space_info;
1266	struct raid_kobject *rkobj;
1267	const int index = btrfs_bg_flags_to_raid_index(cache->flags);
1268	unsigned int nofs_flag;
1269	int ret;
1270
1271	/*
1272	 * Setup a NOFS context because kobject_add(), deep in its call chain,
1273	 * does GFP_KERNEL allocations, and we are often called in a context
1274	 * where if reclaim is triggered we can deadlock (we are either holding
1275	 * a transaction handle or some lock required for a transaction
1276	 * commit).
1277	 */
1278	nofs_flag = memalloc_nofs_save();
1279
1280	rkobj = kzalloc(sizeof(*rkobj), GFP_NOFS);
1281	if (!rkobj) {
1282		memalloc_nofs_restore(nofs_flag);
1283		btrfs_warn(cache->fs_info,
1284				"couldn't alloc memory for raid level kobject");
1285		return;
1286	}
1287
1288	rkobj->flags = cache->flags;
1289	kobject_init(&rkobj->kobj, &btrfs_raid_ktype);
1290
1291	/*
1292	 * We call this either on mount, or if we've created a block group for a
1293	 * new index type while running (i.e. when restriping).  The running
1294	 * case is tricky because we could race with other threads, so we need
1295	 * to have this check to make sure we didn't already init the kobject.
1296	 *
1297	 * We don't have to protect on the free side because it only happens on
1298	 * unmount.
1299	 */
1300	spin_lock(&space_info->lock);
1301	if (space_info->block_group_kobjs[index]) {
1302		spin_unlock(&space_info->lock);
1303		kobject_put(&rkobj->kobj);
1304		return;
1305	} else {
1306		space_info->block_group_kobjs[index] = &rkobj->kobj;
1307	}
1308	spin_unlock(&space_info->lock);
1309
1310	ret = kobject_add(&rkobj->kobj, &space_info->kobj, "%s",
1311			  btrfs_bg_type_to_raid_name(rkobj->flags));
1312	memalloc_nofs_restore(nofs_flag);
1313	if (ret) {
1314		spin_lock(&space_info->lock);
1315		space_info->block_group_kobjs[index] = NULL;
1316		spin_unlock(&space_info->lock);
1317		kobject_put(&rkobj->kobj);
1318		btrfs_warn(fs_info,
1319			"failed to add kobject for block cache, ignoring");
1320		return;
1321	}
1322}
1323
1324/*
1325 * Remove sysfs directories for all block group types of a given space info and
1326 * the space info as well
1327 */
1328void btrfs_sysfs_remove_space_info(struct btrfs_space_info *space_info)
1329{
1330	int i;
1331
1332	for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) {
1333		struct kobject *kobj;
1334
1335		kobj = space_info->block_group_kobjs[i];
1336		space_info->block_group_kobjs[i] = NULL;
1337		if (kobj) {
1338			kobject_del(kobj);
1339			kobject_put(kobj);
1340		}
1341	}
1342	kobject_del(&space_info->kobj);
1343	kobject_put(&space_info->kobj);
1344}
1345
1346static const char *alloc_name(u64 flags)
1347{
1348	switch (flags) {
1349	case BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA:
1350		return "mixed";
1351	case BTRFS_BLOCK_GROUP_METADATA:
1352		return "metadata";
1353	case BTRFS_BLOCK_GROUP_DATA:
1354		return "data";
1355	case BTRFS_BLOCK_GROUP_SYSTEM:
1356		return "system";
1357	default:
1358		WARN_ON(1);
1359		return "invalid-combination";
1360	}
1361}
1362
1363/*
1364 * Create a sysfs entry for a space info type at path
1365 * /sys/fs/btrfs/UUID/allocation/TYPE
1366 */
1367int btrfs_sysfs_add_space_info_type(struct btrfs_fs_info *fs_info,
1368				    struct btrfs_space_info *space_info)
1369{
1370	int ret;
1371
1372	ret = kobject_init_and_add(&space_info->kobj, &space_info_ktype,
1373				   fs_info->space_info_kobj, "%s",
1374				   alloc_name(space_info->flags));
1375	if (ret) {
1376		kobject_put(&space_info->kobj);
1377		return ret;
1378	}
1379
1380	return 0;
1381}
1382
1383void btrfs_sysfs_remove_device(struct btrfs_device *device)
1384{
1385	struct kobject *devices_kobj;
1386
1387	/*
1388	 * Seed fs_devices devices_kobj aren't used, fetch kobject from the
1389	 * fs_info::fs_devices.
1390	 */
1391	devices_kobj = device->fs_info->fs_devices->devices_kobj;
1392	ASSERT(devices_kobj);
1393
1394	if (device->bdev)
1395		sysfs_remove_link(devices_kobj, bdev_kobj(device->bdev)->name);
1396
1397	if (device->devid_kobj.state_initialized) {
1398		kobject_del(&device->devid_kobj);
1399		kobject_put(&device->devid_kobj);
1400		wait_for_completion(&device->kobj_unregister);
1401	}
1402}
1403
1404static ssize_t btrfs_devinfo_in_fs_metadata_show(struct kobject *kobj,
1405					         struct kobj_attribute *a,
1406					         char *buf)
1407{
1408	int val;
1409	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1410						   devid_kobj);
1411
1412	val = !!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state);
1413
1414	return scnprintf(buf, PAGE_SIZE, "%d\n", val);
1415}
1416BTRFS_ATTR(devid, in_fs_metadata, btrfs_devinfo_in_fs_metadata_show);
1417
1418static ssize_t btrfs_devinfo_missing_show(struct kobject *kobj,
1419					struct kobj_attribute *a, char *buf)
1420{
1421	int val;
1422	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1423						   devid_kobj);
1424
1425	val = !!test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state);
1426
1427	return scnprintf(buf, PAGE_SIZE, "%d\n", val);
1428}
1429BTRFS_ATTR(devid, missing, btrfs_devinfo_missing_show);
1430
1431static ssize_t btrfs_devinfo_replace_target_show(struct kobject *kobj,
1432					         struct kobj_attribute *a,
1433					         char *buf)
1434{
1435	int val;
1436	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1437						   devid_kobj);
1438
1439	val = !!test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state);
1440
1441	return scnprintf(buf, PAGE_SIZE, "%d\n", val);
1442}
1443BTRFS_ATTR(devid, replace_target, btrfs_devinfo_replace_target_show);
1444
1445static ssize_t btrfs_devinfo_scrub_speed_max_show(struct kobject *kobj,
1446					     struct kobj_attribute *a,
1447					     char *buf)
1448{
1449	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1450						   devid_kobj);
1451
1452	return scnprintf(buf, PAGE_SIZE, "%llu\n",
1453			 READ_ONCE(device->scrub_speed_max));
1454}
1455
1456static ssize_t btrfs_devinfo_scrub_speed_max_store(struct kobject *kobj,
1457					      struct kobj_attribute *a,
1458					      const char *buf, size_t len)
1459{
1460	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1461						   devid_kobj);
1462	char *endptr;
1463	unsigned long long limit;
1464
1465	limit = memparse(buf, &endptr);
 
 
 
 
1466	WRITE_ONCE(device->scrub_speed_max, limit);
1467	return len;
1468}
1469BTRFS_ATTR_RW(devid, scrub_speed_max, btrfs_devinfo_scrub_speed_max_show,
1470	      btrfs_devinfo_scrub_speed_max_store);
1471
1472static ssize_t btrfs_devinfo_writeable_show(struct kobject *kobj,
1473					    struct kobj_attribute *a, char *buf)
1474{
1475	int val;
1476	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1477						   devid_kobj);
1478
1479	val = !!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state);
1480
1481	return scnprintf(buf, PAGE_SIZE, "%d\n", val);
1482}
1483BTRFS_ATTR(devid, writeable, btrfs_devinfo_writeable_show);
1484
 
 
 
 
 
 
 
 
 
 
1485static ssize_t btrfs_devinfo_error_stats_show(struct kobject *kobj,
1486		struct kobj_attribute *a, char *buf)
1487{
1488	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1489						   devid_kobj);
1490
1491	if (!device->dev_stats_valid)
1492		return scnprintf(buf, PAGE_SIZE, "invalid\n");
1493
1494	/*
1495	 * Print all at once so we get a snapshot of all values from the same
1496	 * time. Keep them in sync and in order of definition of
1497	 * btrfs_dev_stat_values.
1498	 */
1499	return scnprintf(buf, PAGE_SIZE,
1500		"write_errs %d\n"
1501		"read_errs %d\n"
1502		"flush_errs %d\n"
1503		"corruption_errs %d\n"
1504		"generation_errs %d\n",
1505		btrfs_dev_stat_read(device, BTRFS_DEV_STAT_WRITE_ERRS),
1506		btrfs_dev_stat_read(device, BTRFS_DEV_STAT_READ_ERRS),
1507		btrfs_dev_stat_read(device, BTRFS_DEV_STAT_FLUSH_ERRS),
1508		btrfs_dev_stat_read(device, BTRFS_DEV_STAT_CORRUPTION_ERRS),
1509		btrfs_dev_stat_read(device, BTRFS_DEV_STAT_GENERATION_ERRS));
1510}
1511BTRFS_ATTR(devid, error_stats, btrfs_devinfo_error_stats_show);
1512
 
 
 
 
 
1513static struct attribute *devid_attrs[] = {
1514	BTRFS_ATTR_PTR(devid, error_stats),
 
1515	BTRFS_ATTR_PTR(devid, in_fs_metadata),
1516	BTRFS_ATTR_PTR(devid, missing),
1517	BTRFS_ATTR_PTR(devid, replace_target),
1518	BTRFS_ATTR_PTR(devid, scrub_speed_max),
1519	BTRFS_ATTR_PTR(devid, writeable),
1520	NULL
1521};
1522ATTRIBUTE_GROUPS(devid);
1523
1524static void btrfs_release_devid_kobj(struct kobject *kobj)
1525{
1526	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1527						   devid_kobj);
1528
1529	memset(&device->devid_kobj, 0, sizeof(struct kobject));
1530	complete(&device->kobj_unregister);
1531}
1532
1533static struct kobj_type devid_ktype = {
1534	.sysfs_ops	= &kobj_sysfs_ops,
1535	.default_groups = devid_groups,
1536	.release	= btrfs_release_devid_kobj,
1537};
1538
1539int btrfs_sysfs_add_device(struct btrfs_device *device)
1540{
1541	int ret;
1542	unsigned int nofs_flag;
1543	struct kobject *devices_kobj;
1544	struct kobject *devinfo_kobj;
1545
1546	/*
1547	 * Make sure we use the fs_info::fs_devices to fetch the kobjects even
1548	 * for the seed fs_devices
1549	 */
1550	devices_kobj = device->fs_info->fs_devices->devices_kobj;
1551	devinfo_kobj = device->fs_info->fs_devices->devinfo_kobj;
1552	ASSERT(devices_kobj);
1553	ASSERT(devinfo_kobj);
1554
1555	nofs_flag = memalloc_nofs_save();
1556
1557	if (device->bdev) {
1558		struct kobject *disk_kobj = bdev_kobj(device->bdev);
1559
1560		ret = sysfs_create_link(devices_kobj, disk_kobj, disk_kobj->name);
1561		if (ret) {
1562			btrfs_warn(device->fs_info,
1563				"creating sysfs device link for devid %llu failed: %d",
1564				device->devid, ret);
1565			goto out;
1566		}
1567	}
1568
1569	init_completion(&device->kobj_unregister);
1570	ret = kobject_init_and_add(&device->devid_kobj, &devid_ktype,
1571				   devinfo_kobj, "%llu", device->devid);
1572	if (ret) {
1573		kobject_put(&device->devid_kobj);
1574		btrfs_warn(device->fs_info,
1575			   "devinfo init for devid %llu failed: %d",
1576			   device->devid, ret);
1577	}
1578
1579out:
1580	memalloc_nofs_restore(nofs_flag);
1581	return ret;
1582}
1583
1584static int btrfs_sysfs_add_fs_devices(struct btrfs_fs_devices *fs_devices)
1585{
1586	int ret;
1587	struct btrfs_device *device;
1588	struct btrfs_fs_devices *seed;
1589
1590	list_for_each_entry(device, &fs_devices->devices, dev_list) {
1591		ret = btrfs_sysfs_add_device(device);
1592		if (ret)
1593			goto fail;
1594	}
1595
1596	list_for_each_entry(seed, &fs_devices->seed_list, seed_list) {
1597		list_for_each_entry(device, &seed->devices, dev_list) {
1598			ret = btrfs_sysfs_add_device(device);
1599			if (ret)
1600				goto fail;
1601		}
1602	}
1603
1604	return 0;
1605
1606fail:
1607	btrfs_sysfs_remove_fs_devices(fs_devices);
1608	return ret;
1609}
1610
1611void btrfs_kobject_uevent(struct block_device *bdev, enum kobject_action action)
1612{
1613	int ret;
1614
1615	ret = kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, action);
1616	if (ret)
1617		pr_warn("BTRFS: Sending event '%d' to kobject: '%s' (%p): failed\n",
1618			action, kobject_name(&disk_to_dev(bdev->bd_disk)->kobj),
1619			&disk_to_dev(bdev->bd_disk)->kobj);
1620}
1621
1622void btrfs_sysfs_update_sprout_fsid(struct btrfs_fs_devices *fs_devices)
1623
1624{
1625	char fsid_buf[BTRFS_UUID_UNPARSED_SIZE];
1626
1627	/*
1628	 * Sprouting changes fsid of the mounted filesystem, rename the fsid
1629	 * directory
1630	 */
1631	snprintf(fsid_buf, BTRFS_UUID_UNPARSED_SIZE, "%pU", fs_devices->fsid);
1632	if (kobject_rename(&fs_devices->fsid_kobj, fsid_buf))
1633		btrfs_warn(fs_devices->fs_info,
1634				"sysfs: failed to create fsid for sprout");
1635}
1636
1637void btrfs_sysfs_update_devid(struct btrfs_device *device)
1638{
1639	char tmp[24];
1640
1641	snprintf(tmp, sizeof(tmp), "%llu", device->devid);
1642
1643	if (kobject_rename(&device->devid_kobj, tmp))
1644		btrfs_warn(device->fs_devices->fs_info,
1645			   "sysfs: failed to update devid for %llu",
1646			   device->devid);
1647}
1648
1649/* /sys/fs/btrfs/ entry */
1650static struct kset *btrfs_kset;
1651
1652/*
1653 * Creates:
1654 *		/sys/fs/btrfs/UUID
1655 *
1656 * Can be called by the device discovery thread.
1657 */
1658int btrfs_sysfs_add_fsid(struct btrfs_fs_devices *fs_devs)
1659{
1660	int error;
1661
1662	init_completion(&fs_devs->kobj_unregister);
1663	fs_devs->fsid_kobj.kset = btrfs_kset;
1664	error = kobject_init_and_add(&fs_devs->fsid_kobj, &btrfs_ktype, NULL,
1665				     "%pU", fs_devs->fsid);
1666	if (error) {
1667		kobject_put(&fs_devs->fsid_kobj);
1668		return error;
1669	}
1670
1671	fs_devs->devices_kobj = kobject_create_and_add("devices",
1672						       &fs_devs->fsid_kobj);
1673	if (!fs_devs->devices_kobj) {
1674		btrfs_err(fs_devs->fs_info,
1675			  "failed to init sysfs device interface");
1676		btrfs_sysfs_remove_fsid(fs_devs);
1677		return -ENOMEM;
1678	}
1679
1680	fs_devs->devinfo_kobj = kobject_create_and_add("devinfo",
1681						       &fs_devs->fsid_kobj);
1682	if (!fs_devs->devinfo_kobj) {
1683		btrfs_err(fs_devs->fs_info,
1684			  "failed to init sysfs devinfo kobject");
1685		btrfs_sysfs_remove_fsid(fs_devs);
1686		return -ENOMEM;
1687	}
1688
1689	return 0;
1690}
1691
1692int btrfs_sysfs_add_mounted(struct btrfs_fs_info *fs_info)
1693{
1694	int error;
1695	struct btrfs_fs_devices *fs_devs = fs_info->fs_devices;
1696	struct kobject *fsid_kobj = &fs_devs->fsid_kobj;
1697
1698	error = btrfs_sysfs_add_fs_devices(fs_devs);
1699	if (error)
1700		return error;
1701
1702	error = sysfs_create_files(fsid_kobj, btrfs_attrs);
1703	if (error) {
1704		btrfs_sysfs_remove_fs_devices(fs_devs);
1705		return error;
1706	}
1707
1708	error = sysfs_create_group(fsid_kobj,
1709				   &btrfs_feature_attr_group);
1710	if (error)
1711		goto failure;
1712
1713#ifdef CONFIG_BTRFS_DEBUG
1714	fs_info->debug_kobj = kobject_create_and_add("debug", fsid_kobj);
1715	if (!fs_info->debug_kobj) {
1716		error = -ENOMEM;
1717		goto failure;
1718	}
1719
1720	error = sysfs_create_files(fs_info->debug_kobj, btrfs_debug_mount_attrs);
1721	if (error)
1722		goto failure;
 
1723
1724	/* Discard directory */
1725	fs_info->discard_debug_kobj = kobject_create_and_add("discard",
1726						     fs_info->debug_kobj);
1727	if (!fs_info->discard_debug_kobj) {
1728		error = -ENOMEM;
1729		goto failure;
1730	}
1731
1732	error = sysfs_create_files(fs_info->discard_debug_kobj,
1733				   discard_debug_attrs);
1734	if (error)
1735		goto failure;
1736#endif
1737
1738	error = addrm_unknown_feature_attrs(fs_info, true);
1739	if (error)
1740		goto failure;
1741
1742	error = sysfs_create_link(fsid_kobj, &fs_info->sb->s_bdi->dev->kobj, "bdi");
1743	if (error)
1744		goto failure;
1745
1746	fs_info->space_info_kobj = kobject_create_and_add("allocation",
1747						  fsid_kobj);
1748	if (!fs_info->space_info_kobj) {
1749		error = -ENOMEM;
1750		goto failure;
1751	}
1752
1753	error = sysfs_create_files(fs_info->space_info_kobj, allocation_attrs);
1754	if (error)
1755		goto failure;
1756
1757	return 0;
1758failure:
1759	btrfs_sysfs_remove_mounted(fs_info);
1760	return error;
1761}
1762
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1763static inline struct btrfs_fs_info *qgroup_kobj_to_fs_info(struct kobject *kobj)
1764{
1765	return to_fs_info(kobj->parent->parent);
1766}
1767
1768#define QGROUP_ATTR(_member, _show_name)					\
1769static ssize_t btrfs_qgroup_show_##_member(struct kobject *qgroup_kobj,		\
1770					   struct kobj_attribute *a,		\
1771					   char *buf)				\
1772{										\
1773	struct btrfs_fs_info *fs_info = qgroup_kobj_to_fs_info(qgroup_kobj);	\
1774	struct btrfs_qgroup *qgroup = container_of(qgroup_kobj,			\
1775			struct btrfs_qgroup, kobj);				\
1776	return btrfs_show_u64(&qgroup->_member, &fs_info->qgroup_lock, buf);	\
1777}										\
1778BTRFS_ATTR(qgroup, _show_name, btrfs_qgroup_show_##_member)
1779
1780#define QGROUP_RSV_ATTR(_name, _type)						\
1781static ssize_t btrfs_qgroup_rsv_show_##_name(struct kobject *qgroup_kobj,	\
1782					     struct kobj_attribute *a,		\
1783					     char *buf)				\
1784{										\
1785	struct btrfs_fs_info *fs_info = qgroup_kobj_to_fs_info(qgroup_kobj);	\
1786	struct btrfs_qgroup *qgroup = container_of(qgroup_kobj,			\
1787			struct btrfs_qgroup, kobj);				\
1788	return btrfs_show_u64(&qgroup->rsv.values[_type],			\
1789			&fs_info->qgroup_lock, buf);				\
1790}										\
1791BTRFS_ATTR(qgroup, rsv_##_name, btrfs_qgroup_rsv_show_##_name)
1792
1793QGROUP_ATTR(rfer, referenced);
1794QGROUP_ATTR(excl, exclusive);
1795QGROUP_ATTR(max_rfer, max_referenced);
1796QGROUP_ATTR(max_excl, max_exclusive);
1797QGROUP_ATTR(lim_flags, limit_flags);
1798QGROUP_RSV_ATTR(data, BTRFS_QGROUP_RSV_DATA);
1799QGROUP_RSV_ATTR(meta_pertrans, BTRFS_QGROUP_RSV_META_PERTRANS);
1800QGROUP_RSV_ATTR(meta_prealloc, BTRFS_QGROUP_RSV_META_PREALLOC);
1801
 
 
 
 
 
1802static struct attribute *qgroup_attrs[] = {
1803	BTRFS_ATTR_PTR(qgroup, referenced),
1804	BTRFS_ATTR_PTR(qgroup, exclusive),
1805	BTRFS_ATTR_PTR(qgroup, max_referenced),
1806	BTRFS_ATTR_PTR(qgroup, max_exclusive),
1807	BTRFS_ATTR_PTR(qgroup, limit_flags),
1808	BTRFS_ATTR_PTR(qgroup, rsv_data),
1809	BTRFS_ATTR_PTR(qgroup, rsv_meta_pertrans),
1810	BTRFS_ATTR_PTR(qgroup, rsv_meta_prealloc),
1811	NULL
1812};
1813ATTRIBUTE_GROUPS(qgroup);
1814
1815static void qgroup_release(struct kobject *kobj)
1816{
1817	struct btrfs_qgroup *qgroup = container_of(kobj, struct btrfs_qgroup, kobj);
1818
1819	memset(&qgroup->kobj, 0, sizeof(*kobj));
1820}
1821
1822static struct kobj_type qgroup_ktype = {
1823	.sysfs_ops = &kobj_sysfs_ops,
1824	.release = qgroup_release,
1825	.default_groups = qgroup_groups,
1826};
1827
1828int btrfs_sysfs_add_one_qgroup(struct btrfs_fs_info *fs_info,
1829				struct btrfs_qgroup *qgroup)
1830{
1831	struct kobject *qgroups_kobj = fs_info->qgroups_kobj;
1832	int ret;
1833
1834	if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
1835		return 0;
1836	if (qgroup->kobj.state_initialized)
1837		return 0;
1838	if (!qgroups_kobj)
1839		return -EINVAL;
1840
1841	ret = kobject_init_and_add(&qgroup->kobj, &qgroup_ktype, qgroups_kobj,
1842			"%hu_%llu", btrfs_qgroup_level(qgroup->qgroupid),
1843			btrfs_qgroup_subvolid(qgroup->qgroupid));
1844	if (ret < 0)
1845		kobject_put(&qgroup->kobj);
1846
1847	return ret;
1848}
1849
1850void btrfs_sysfs_del_qgroups(struct btrfs_fs_info *fs_info)
1851{
1852	struct btrfs_qgroup *qgroup;
1853	struct btrfs_qgroup *next;
1854
1855	if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
1856		return;
1857
1858	rbtree_postorder_for_each_entry_safe(qgroup, next,
1859					     &fs_info->qgroup_tree, node)
1860		btrfs_sysfs_del_one_qgroup(fs_info, qgroup);
1861	if (fs_info->qgroups_kobj) {
1862		kobject_del(fs_info->qgroups_kobj);
1863		kobject_put(fs_info->qgroups_kobj);
1864		fs_info->qgroups_kobj = NULL;
1865	}
1866}
1867
1868/* Called when qgroups get initialized, thus there is no need for locking */
1869int btrfs_sysfs_add_qgroups(struct btrfs_fs_info *fs_info)
1870{
1871	struct kobject *fsid_kobj = &fs_info->fs_devices->fsid_kobj;
1872	struct btrfs_qgroup *qgroup;
1873	struct btrfs_qgroup *next;
1874	int ret = 0;
1875
1876	if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
1877		return 0;
1878
1879	ASSERT(fsid_kobj);
1880	if (fs_info->qgroups_kobj)
1881		return 0;
1882
1883	fs_info->qgroups_kobj = kobject_create_and_add("qgroups", fsid_kobj);
1884	if (!fs_info->qgroups_kobj) {
1885		ret = -ENOMEM;
 
 
 
 
1886		goto out;
1887	}
1888	rbtree_postorder_for_each_entry_safe(qgroup, next,
1889					     &fs_info->qgroup_tree, node) {
1890		ret = btrfs_sysfs_add_one_qgroup(fs_info, qgroup);
1891		if (ret < 0)
1892			goto out;
1893	}
1894
1895out:
1896	if (ret < 0)
1897		btrfs_sysfs_del_qgroups(fs_info);
1898	return ret;
1899}
1900
1901void btrfs_sysfs_del_one_qgroup(struct btrfs_fs_info *fs_info,
1902				struct btrfs_qgroup *qgroup)
1903{
1904	if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
1905		return;
1906
1907	if (qgroup->kobj.state_initialized) {
1908		kobject_del(&qgroup->kobj);
1909		kobject_put(&qgroup->kobj);
1910	}
1911}
1912
1913/*
1914 * Change per-fs features in /sys/fs/btrfs/UUID/features to match current
1915 * values in superblock. Call after any changes to incompat/compat_ro flags
1916 */
1917void btrfs_sysfs_feature_update(struct btrfs_fs_info *fs_info,
1918		u64 bit, enum btrfs_feature_set set)
1919{
1920	struct btrfs_fs_devices *fs_devs;
1921	struct kobject *fsid_kobj;
1922	u64 __maybe_unused features;
1923	int __maybe_unused ret;
1924
1925	if (!fs_info)
1926		return;
1927
1928	/*
1929	 * See 14e46e04958df74 and e410e34fad913dd, feature bit updates are not
1930	 * safe when called from some contexts (eg. balance)
1931	 */
1932	features = get_features(fs_info, set);
1933	ASSERT(bit & supported_feature_masks[set]);
1934
1935	fs_devs = fs_info->fs_devices;
1936	fsid_kobj = &fs_devs->fsid_kobj;
1937
1938	if (!fsid_kobj->state_initialized)
1939		return;
1940
1941	/*
1942	 * FIXME: this is too heavy to update just one value, ideally we'd like
1943	 * to use sysfs_update_group but some refactoring is needed first.
1944	 */
1945	sysfs_remove_group(fsid_kobj, &btrfs_feature_attr_group);
1946	ret = sysfs_create_group(fsid_kobj, &btrfs_feature_attr_group);
1947}
1948
1949int __init btrfs_init_sysfs(void)
1950{
1951	int ret;
1952
1953	btrfs_kset = kset_create_and_add("btrfs", NULL, fs_kobj);
1954	if (!btrfs_kset)
1955		return -ENOMEM;
1956
1957	init_feature_attrs();
1958	ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
1959	if (ret)
1960		goto out2;
1961	ret = sysfs_merge_group(&btrfs_kset->kobj,
1962				&btrfs_static_feature_attr_group);
1963	if (ret)
1964		goto out_remove_group;
1965
1966#ifdef CONFIG_BTRFS_DEBUG
1967	ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_debug_feature_attr_group);
1968	if (ret)
1969		goto out2;
 
 
 
1970#endif
1971
1972	return 0;
1973
1974out_remove_group:
1975	sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
1976out2:
1977	kset_unregister(btrfs_kset);
1978
1979	return ret;
1980}
1981
1982void __cold btrfs_exit_sysfs(void)
1983{
1984	sysfs_unmerge_group(&btrfs_kset->kobj,
1985			    &btrfs_static_feature_attr_group);
1986	sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
1987#ifdef CONFIG_BTRFS_DEBUG
1988	sysfs_remove_group(&btrfs_kset->kobj, &btrfs_debug_feature_attr_group);
1989#endif
1990	kset_unregister(btrfs_kset);
1991}
1992